kc3-lang/SDL

diff --git a/include/SDL_audio.h b/include/SDL_audio.h
index 5634e09..305c01a 100644
--- a/include/SDL_audio.h
+++ b/include/SDL_audio.h
@@ -420,23 +420,56 @@ extern DECLSPEC void SDLCALL SDL_PauseAudioDevice(SDL_AudioDeviceID dev,
 /* @} *//* Pause audio functions */
 
 /**
- *  This function loads a WAVE from the data source, automatically freeing
- *  that source if \c freesrc is non-zero.  For example, to load a WAVE file,
- *  you could do:
+ *  \brief Load the audio data of a WAVE file into memory
+ *
+ *  Loading a WAVE file requires \c src, \c spec, \c audio_buf and \c audio_len
+ *  to be valid pointers. The entire data portion of the file is then loaded
+ *  into memory and decoded if necessary.
+ *
+ *  If \c freesrc is non-zero, the data source gets automatically closed and
+ *  freed before the function returns.
+ *
+ *  Supported are RIFF WAVE files with the formats PCM (8, 16, 24, and 32 bits),
+ *  IEEE Float (32 bits), Microsoft ADPCM and IMA ADPCM (4 bits), and A-law and
+ *  µ-law (8 bits). Other formats are currently unsupported and cause an error.
+ *
+ *  If this function succeeds, the pointer returned by it is equal to \c spec
+ *  and the pointer to the audio data allocated by the function is written to
+ *  \c audio_buf and its length in bytes to \c audio_len. The \ref SDL_AudioSpec
+ *  members \c freq, \c channels, and \c format are set to the values of the
+ *  audio data in the buffer. The \c samples member is set to a sane default and
+ *  all others are set to zero.
+ *
+ *  It's necessary to use SDL_FreeWAV() to free the audio data returned in
+ *  \c audio_buf when it is no longer used.
+ *
+ *  Because of the underspecification of the Waveform format, there are many
+ *  problematic files in the wild that cause issues with strict decoders. To
+ *  provide compatibility with these files, this decoder is lenient in regards
+ *  to the truncation of the file, the fact chunk, and the size of the RIFF
+ *  chunk. The hints SDL_HINT_WAVE_RIFF_CHUNK_SIZE, SDL_HINT_WAVE_TRUNCATION,
+ *  and SDL_HINT_WAVE_FACT_CHUNK can be used to tune the behavior of the
+ *  loading process.
+ *
+ *  Any file that is invalid (due to truncation, corruption, or wrong values in
+ *  the headers), too big, or unsupported causes an error. Additionally, any
+ *  critical I/O error from the data source will terminate the loading process
+ *  with an error. The function returns NULL on error and in all cases (with the
+ *  exception of \c src being NULL), an appropriate error message will be set.
+ *
+ *  It is required that the data source supports seeking.
+ *
+ *  Example:
  *  \code
  *      SDL_LoadWAV_RW(SDL_RWFromFile("sample.wav", "rb"), 1, ...);
  *  \endcode
  *
- *  If this function succeeds, it returns the given SDL_AudioSpec,
- *  filled with the audio data format of the wave data, and sets
- *  \c *audio_buf to a malloc()'d buffer containing the audio data,
- *  and sets \c *audio_len to the length of that audio buffer, in bytes.
- *  You need to free the audio buffer with SDL_FreeWAV() when you are
- *  done with it.
- *
- *  This function returns NULL and sets the SDL error message if the
- *  wave file cannot be opened, uses an unknown data format, or is
- *  corrupt.  Currently raw and MS-ADPCM WAVE files are supported.
+ *  \param src The data source with the WAVE data
+ *  \param freesrc A integer value that makes the function close the data source if non-zero
+ *  \param spec A pointer filled with the audio format of the audio data
+ *  \param audio_buf A pointer filled with the audio data allocated by the function
+ *  \param audio_len A pointer filled with the length of the audio data buffer in bytes
+ *  \return NULL on error, or non-NULL on success.
  */
 extern DECLSPEC SDL_AudioSpec *SDLCALL SDL_LoadWAV_RW(SDL_RWops * src,
                                                       int freesrc,
diff --git a/include/SDL_hints.h b/include/SDL_hints.h
index e2bd691..4c83dd3 100644
--- a/include/SDL_hints.h
+++ b/include/SDL_hints.h
@@ -1122,6 +1122,70 @@ extern "C" {
 
 
 /**
+ *  \brief  Controls how the size of the RIFF chunk affects the loading of a WAVE file.
+ *
+ *  The size of the RIFF chunk (which includes all the sub-chunks of the WAVE
+ *  file) is not always reliable. In case the size is wrong, it's possible to
+ *  just ignore it and step through the chunks until a fixed limit is reached.
+ *
+ *  Note that files that have trailing data unrelated to the WAVE file or
+ *  corrupt files may slow down the loading process without a reliable boundary.
+ *  By default, SDL stops after 10000 chunks to prevent wasting time. Use the
+ *  environment variable SDL_WAVE_CHUNK_LIMIT to adjust this value.
+ *
+ *  This variable can be set to the following values:
+ *
+ *    "chunksearch"  - Use the RIFF chunk size as a boundary for the chunk search
+ *    "ignorezero"   - Like "chunksearch", but a zero size searches up to 4 GiB (default)
+ *    "ignore"       - Ignore the RIFF chunk size and always search up to 4 GiB
+ *    "maximum"      - Search for chunks until the end of file (not recommended)
+ */
+#define SDL_HINT_WAVE_RIFF_CHUNK_SIZE   "SDL_WAVE_RIFF_CHUNK_SIZE"
+
+/**
+ *  \brief  Controls how a truncated WAVE file is handled.
+ *
+ *  A WAVE file is considered truncated if any of the chunks are incomplete or
+ *  the data chunk size is not a multiple of the block size. By default, SDL
+ *  decodes until the first incomplete block, as most applications seem to do.
+ *
+ *  This variable can be set to the following values:
+ *
+ *    "verystrict" - Raise an error if the file is truncated
+ *    "strict"     - Like "verystrict", but the size of the RIFF chunk is ignored
+ *    "dropframe"  - Decode until the first incomplete sample frame
+ *    "dropblock"  - Decode until the first incomplete block (default)
+ */
+#define SDL_HINT_WAVE_TRUNCATION   "SDL_WAVE_TRUNCATION"
+
+/**
+ *  \brief  Controls how the fact chunk affects the loading of a WAVE file.
+ *
+ *  The fact chunk stores information about the number of samples of a WAVE
+ *  file. The Standards Update from Microsoft notes that this value can be used
+ *  to 'determine the length of the data in seconds'. This is especially useful
+ *  for compressed formats (for which this is a mandatory chunk) if they produce
+ *  multiple sample frames per block and truncating the block is not allowed.
+ *  The fact chunk can exactly specify how many sample frames there should be
+ *  in this case.
+ *
+ *  Unfortunately, most application seem to ignore the fact chunk and so SDL
+ *  ignores it by default as well.
+ *
+ *  This variable can be set to the following values:
+ *
+ *    "truncate"    - Use the number of samples to truncate the wave data if
+ *                    the fact chunk is present and valid
+ *    "strict"      - Like "truncate", but raise an error if the fact chunk
+ *                    is invalid, not present for non-PCM formats, or if the
+ *                    data chunk doesn't have that many samples
+ *    "ignorezero"  - Like "truncate", but ignore fact chunk if the number of
+ *                    samples is zero
+ *    "ignore"      - Ignore fact chunk entirely (default)
+ */
+#define SDL_HINT_WAVE_FACT_CHUNK   "SDL_WAVE_FACT_CHUNK"
+
+/**
  *  \brief  An enumeration of hint priorities
  */
 typedef enum
diff --git a/src/audio/SDL_wave.c b/src/audio/SDL_wave.c
index 170a9c9..5c3b964 100644
--- a/src/audio/SDL_wave.c
+++ b/src/audio/SDL_wave.c
@@ -20,680 +20,2112 @@
 */
 #include "../SDL_internal.h"
 
+#ifdef HAVE_LIMITS_H
+#include <limits.h>
+#else
+#ifndef SIZE_MAX
+#define SIZE_MAX ((size_t)-1)
+#endif
+#ifndef INT_MAX
+/* Make a lucky guess. */
+#define INT_MAX (SDL_MAX_SINT32)
+#endif
+#endif
+
 /* Microsoft WAVE file loading routines */
 
+#include "SDL_log.h"
+#include "SDL_hints.h"
 #include "SDL_audio.h"
 #include "SDL_wave.h"
 
+/* Reads the value stored at the location of the f1 pointer, multiplies it
+ * with the second argument, and then stores it back to f1 again.
+ * Returns SDL_TRUE if the multiplication overflows, f1 does not get modified.
+ */
+static SDL_bool
+MultiplySize(size_t *f1, size_t f2)
+{
+    if (*f1 > 0 && SIZE_MAX / *f1 <= f2) {
+        return SDL_TRUE;
+    }
+    *f1 *= f2;
+    return SDL_FALSE;
+}
+
+typedef struct ADPCM_DecoderState
+{
+    Uint32 channels;        /* Number of channels. */
+    size_t blocksize;       /* Size of an ADPCM block in bytes. */
+    size_t blockheadersize; /* Size of an ADPCM block header in bytes. */
+    size_t samplesperblock; /* Number of samples per channel in an ADPCM block. */
+    size_t framesize;       /* Size of a sample frame (16-bit PCM) in bytes. */
+    Sint64 framestotal;     /* Total number of sample frames. */
+    Sint64 framesleft;      /* Number of sample frames still to be decoded. */
+    void *ddata;            /* Decoder data from initialization. */
+    void *cstate;           /* Decoding state for each channel. */
+
+    /* ADPCM data. */
+    struct {
+        Uint8 *data;
+        size_t size;
+        size_t pos;
+    } input;
+
+    /* Current ADPCM block in the ADPCM data above. */
+    struct {
+        Uint8 *data;
+        size_t size;
+        size_t pos;
+    } block;
+
+    /* Decoded 16-bit PCM data. */
+    struct {
+        Sint16 *data;
+        size_t size;
+        size_t pos;
+    } output;
+} ADPCM_DecoderState;
+
+typedef struct MS_ADPCM_CoeffData
+{
+    Uint16 coeffcount;
+    Sint16 *coeff;
+    Sint16 aligndummy; /* Has to be last member. */
+} MS_ADPCM_CoeffData;
+
+typedef struct MS_ADPCM_ChannelState
+{
+    Uint16 delta;
+    Sint16 coeff1;
+    Sint16 coeff2;
+} MS_ADPCM_ChannelState;
+
+#ifdef SDL_WAVE_DEBUG_LOG_FORMAT
+static void
+WaveDebugLogFormat(WaveFile *file)
+{
+    WaveFormat *format = &file->format;
+    const char *fmtstr = "WAVE file: %s, %u Hz, %s, %u bits, %u %s/s";
+    const char *waveformat, *wavechannel, *wavebpsunit = "B";
+    Uint32 wavebps = format->byterate;
+    char channelstr[64] = {0};
+
+    switch (format->encoding) {
+    case PCM_CODE:
+        waveformat = "PCM";
+        break;
+    case IEEE_FLOAT_CODE:
+        waveformat = "IEEE Float";
+        break;
+    case ALAW_CODE:
+        waveformat = "A-law";
+        break;
+    case MULAW_CODE:
+        waveformat = "\xc2\xb5-law";
+        break;
+    case MS_ADPCM_CODE:
+        waveformat = "MS ADPCM";
+        break;
+    case IMA_ADPCM_CODE:
+        waveformat = "IMA ADPCM";
+        break;
+    default:
+        waveformat = "Unknown";
+        break;
+    }
+
+#define SDL_WAVE_DEBUG_CHANNELCFG(STR, CODE) case CODE: wavechannel = STR; break;
+#define SDL_WAVE_DEBUG_CHANNELSTR(STR, CODE) if (format->channelmask & CODE) { \
+    SDL_strlcat(channelstr, channelstr[0] ? "-" STR : STR, sizeof(channelstr));}
+
+    if (format->formattag == EXTENSIBLE_CODE && format->channelmask > 0) {
+        switch (format->channelmask) {
+            SDL_WAVE_DEBUG_CHANNELCFG("1.0 Mono",         0x4)
+            SDL_WAVE_DEBUG_CHANNELCFG("1.1 Mono",         0xc)
+            SDL_WAVE_DEBUG_CHANNELCFG("2.0 Stereo",       0x3)
+            SDL_WAVE_DEBUG_CHANNELCFG("2.1 Stereo",       0xb)
+            SDL_WAVE_DEBUG_CHANNELCFG("3.0 Stereo",       0x7)
+            SDL_WAVE_DEBUG_CHANNELCFG("3.1 Stereo",       0xf)
+            SDL_WAVE_DEBUG_CHANNELCFG("3.0 Surround",     0x103)
+            SDL_WAVE_DEBUG_CHANNELCFG("3.1 Surround",     0x10b)
+            SDL_WAVE_DEBUG_CHANNELCFG("4.0 Quad",         0x33)
+            SDL_WAVE_DEBUG_CHANNELCFG("4.1 Quad",         0x3b)
+            SDL_WAVE_DEBUG_CHANNELCFG("4.0 Surround",     0x107)
+            SDL_WAVE_DEBUG_CHANNELCFG("4.1 Surround",     0x10f)
+            SDL_WAVE_DEBUG_CHANNELCFG("5.0",              0x37)
+            SDL_WAVE_DEBUG_CHANNELCFG("5.1",              0x3f)
+            SDL_WAVE_DEBUG_CHANNELCFG("5.0 Side",         0x607)
+            SDL_WAVE_DEBUG_CHANNELCFG("5.1 Side",         0x60f)
+            SDL_WAVE_DEBUG_CHANNELCFG("6.0",              0x137)
+            SDL_WAVE_DEBUG_CHANNELCFG("6.1",              0x13f)
+            SDL_WAVE_DEBUG_CHANNELCFG("6.0 Side",         0x707)
+            SDL_WAVE_DEBUG_CHANNELCFG("6.1 Side",         0x70f)
+            SDL_WAVE_DEBUG_CHANNELCFG("7.0",              0xf7)
+            SDL_WAVE_DEBUG_CHANNELCFG("7.1",              0xff)
+            SDL_WAVE_DEBUG_CHANNELCFG("7.0 Side",         0x6c7)
+            SDL_WAVE_DEBUG_CHANNELCFG("7.1 Side",         0x6cf)
+            SDL_WAVE_DEBUG_CHANNELCFG("7.0 Surround",     0x637)
+            SDL_WAVE_DEBUG_CHANNELCFG("7.1 Surround",     0x63f)
+            SDL_WAVE_DEBUG_CHANNELCFG("9.0 Surround",     0x5637)
+            SDL_WAVE_DEBUG_CHANNELCFG("9.1 Surround",     0x563f)
+            SDL_WAVE_DEBUG_CHANNELCFG("11.0 Surround",    0x56f7)
+            SDL_WAVE_DEBUG_CHANNELCFG("11.1 Surround",    0x56ff)
+        default:
+            SDL_WAVE_DEBUG_CHANNELSTR("FL",  0x1)
+            SDL_WAVE_DEBUG_CHANNELSTR("FR",  0x2)
+            SDL_WAVE_DEBUG_CHANNELSTR("FC",  0x4)
+            SDL_WAVE_DEBUG_CHANNELSTR("LF",  0x8)
+            SDL_WAVE_DEBUG_CHANNELSTR("BL",  0x10)
+            SDL_WAVE_DEBUG_CHANNELSTR("BR",  0x20)
+            SDL_WAVE_DEBUG_CHANNELSTR("FLC", 0x40)
+            SDL_WAVE_DEBUG_CHANNELSTR("FRC", 0x80)
+            SDL_WAVE_DEBUG_CHANNELSTR("BC",  0x100)
+            SDL_WAVE_DEBUG_CHANNELSTR("SL",  0x200)
+            SDL_WAVE_DEBUG_CHANNELSTR("SR",  0x400)
+            SDL_WAVE_DEBUG_CHANNELSTR("TC",  0x800)
+            SDL_WAVE_DEBUG_CHANNELSTR("TFL", 0x1000)
+            SDL_WAVE_DEBUG_CHANNELSTR("TFC", 0x2000)
+            SDL_WAVE_DEBUG_CHANNELSTR("TFR", 0x4000)
+            SDL_WAVE_DEBUG_CHANNELSTR("TBL", 0x8000)
+            SDL_WAVE_DEBUG_CHANNELSTR("TBC", 0x10000)
+            SDL_WAVE_DEBUG_CHANNELSTR("TBR", 0x20000)
+            break;
+        }
+    } else {
+        switch (format->channels) {
+        default:
+            if (SDL_snprintf(channelstr, sizeof(channelstr), "%u channels", format->channels) >= 0) {
+                wavechannel = channelstr;
+                break;
+            }
+        case 0:
+            wavechannel = "Unknown";
+            break;
+        case 1:
+            wavechannel = "Mono";
+            break;
+        case 2:
+            wavechannel = "Setero";
+            break;
+        }
+    }
+
+#undef SDL_WAVE_DEBUG_CHANNELCFG
+#undef SDL_WAVE_DEBUG_CHANNELSTR
+
+    if (wavebps >= 1024) {
+        wavebpsunit = "KiB";
+        wavebps = wavebps / 1024 + (wavebps & 0x3ff ? 1 : 0);
+    }
+
+    SDL_LogDebug(SDL_LOG_CATEGORY_AUDIO, fmtstr, waveformat, format->frequency, wavechannel, format->bitspersample, wavebps, wavebpsunit);
+}
+#endif
+
+#ifdef SDL_WAVE_DEBUG_DUMP_FORMAT
+static void
+WaveDebugDumpFormat(WaveFile *file, Uint32 rifflen, Uint32 fmtlen, Uint32 datalen)
+{
+    WaveFormat *format = &file->format;
+    const char *fmtstr1 = "WAVE chunk dump:\n"
+        "-------------------------------------------\n"
+        "RIFF                            %11u\n"
+        "-------------------------------------------\n"
+        "    fmt                         %11u\n"
+        "        wFormatTag                   0x%04x\n"
+        "        nChannels               %11u\n"
+        "        nSamplesPerSec          %11u\n"
+        "        nAvgBytesPerSec         %11u\n"
+        "        nBlockAlign             %11u\n";
+    const char *fmtstr2 = "        wBitsPerSample          %11u\n";
+    const char *fmtstr3 = "        cbSize                  %11u\n";
+    const char *fmtstr4a = "        wValidBitsPerSample     %11u\n";
+    const char *fmtstr4b = "        wSamplesPerBlock        %11u\n";
+    const char *fmtstr5 = "        dwChannelMask            0x%08x\n"
+        "        SubFormat\n"
+        "        %08x-%04x-%04x-%02x%02x%02x%02x%02x%02x%02x%02x\n";
+    const char *fmtstr6 = "-------------------------------------------\n"
+        " fact\n"
+        "  dwSampleLength                %11u\n";
+    const char *fmtstr7 = "-------------------------------------------\n"
+        " data                           %11u\n"
+        "-------------------------------------------\n";
+    char *dumpstr;
+    size_t dumppos = 0;
+    const size_t bufsize = 1024;
+    int res;
+
+    dumpstr = SDL_malloc(bufsize);
+    if (dumpstr == NULL) {
+        return;
+    }
+    dumpstr[0] = 0;
+
+    res = SDL_snprintf(dumpstr, bufsize, fmtstr1, rifflen, fmtlen, format->formattag, format->channels, format->frequency, format->byterate, format->blockalign);
+    dumppos += res > 0 ? res : 0;
+    if (fmtlen >= 16) {
+        res = SDL_snprintf(dumpstr + dumppos, bufsize - dumppos, fmtstr2, format->bitspersample);
+        dumppos += res > 0 ? res : 0;
+    }
+    if (fmtlen >= 18) {
+        res = SDL_snprintf(dumpstr + dumppos, bufsize - dumppos, fmtstr3, format->extsize);
+        dumppos += res > 0 ? res : 0;
+    }
+    if (format->formattag == EXTENSIBLE_CODE && fmtlen >= 40 && format->extsize >= 22) {
+        const Uint8 *g = format->subformat;
+        const Uint32 g1 = g[0] | ((Uint32)g[1] << 8) | ((Uint32)g[2] << 16) | ((Uint32)g[3] << 24);
+        const Uint32 g2 = g[4] | ((Uint32)g[5] << 8);
+        const Uint32 g3 = g[6] | ((Uint32)g[7] << 8);
+
+        switch (format->encoding) {
+        default:
+            res = SDL_snprintf(dumpstr + dumppos, bufsize - dumppos, fmtstr4a, format->validsamplebits);
+            dumppos += res > 0 ? res : 0;
+            break;
+        case MS_ADPCM_CODE:
+        case IMA_ADPCM_CODE:
+            res = SDL_snprintf(dumpstr + dumppos, bufsize - dumppos, fmtstr4b, format->samplesperblock);
+            dumppos += res > 0 ? res : 0;
+            break;
+        }
+        res = SDL_snprintf(dumpstr + dumppos, bufsize - dumppos, fmtstr5, format->channelmask, g1, g2, g3, g[8], g[9], g[10], g[11], g[12], g[13], g[14], g[15]);
+        dumppos += res > 0 ? res : 0;
+    } else {
+        switch (format->encoding) {
+        case MS_ADPCM_CODE:
+        case IMA_ADPCM_CODE:
+            if (fmtlen >= 20 && format->extsize >= 2) {
+                res = SDL_snprintf(dumpstr + dumppos, bufsize - dumppos, fmtstr4b, format->samplesperblock);
+                dumppos += res > 0 ? res : 0;
+            }
+            break;
+        }
+    }
+    if (file->fact.status >= 1) {
+        res = SDL_snprintf(dumpstr + dumppos, bufsize - dumppos, fmtstr6, file->fact.samplelength);
+        dumppos += res > 0 ? res : 0;
+    }
+    res = SDL_snprintf(dumpstr + dumppos, bufsize - dumppos, fmtstr7, datalen);
+    dumppos += res > 0 ? res : 0;
+
+    SDL_LogDebug(SDL_LOG_CATEGORY_AUDIO, "%s", dumpstr);
+
+    free(dumpstr);
+}
+#endif
+
+static Sint64
+WaveAdjustToFactValue(WaveFile *file, Sint64 sampleframes)
+{
+    if (file->fact.status == 2) {
+        if (file->facthint == FactStrict && sampleframes < file->fact.samplelength) {
+            return SDL_SetError("Invalid number of sample frames in WAVE fact chunk (too many)");
+        } else if (sampleframes > file->fact.samplelength) {
+            return file->fact.samplelength;
+        }
+    }
+
+    return sampleframes;
+}
+
+static int
+MS_ADPCM_CalculateSampleFrames(WaveFile *file, size_t datalength)
+{
+    WaveFormat *format = &file->format;
+    const size_t blockheadersize = file->format.channels * 7;
+    const size_t availableblocks = datalength / file->format.blockalign;
+    const size_t blockframebitsize = file->format.bitspersample * file->format.channels;
+    const size_t trailingdata = datalength % file->format.blockalign;
+
+    if (file->trunchint == TruncVeryStrict || file->trunchint == TruncStrict) {
+        /* The size of the data chunk must be a multiple of the block size. */
+        if (datalength < blockheadersize || trailingdata > 0) {
+            return SDL_SetError("Truncated MS ADPCM block");
+        }
+    }
+
+    /* Calculate number of sample frames that will be decoded. */
+    file->sampleframes = (Sint64)availableblocks * format->samplesperblock;
+    if (trailingdata > 0) {
+        /* The last block is truncated. Check if we can get any samples out of it. */
+        if (file->trunchint == TruncDropFrame) {
+            /* Drop incomplete sample frame. */
+            if (trailingdata >= blockheadersize) {
+                size_t trailingsamples = 2 + (trailingdata - blockheadersize) * 8 / blockframebitsize;
+                if (trailingsamples > format->samplesperblock) {
+                    trailingsamples = format->samplesperblock;
+                }
+                file->sampleframes += trailingsamples;
+            }
+        }
+    }
+
+    file->sampleframes = WaveAdjustToFactValue(file, file->sampleframes);
+    if (file->sampleframes < 0) {
+        return -1;
+    }
+
+    return 0;
+}
+
+static int
+MS_ADPCM_Init(WaveFile *file, size_t datalength)
+{
+    WaveFormat *format = &file->format;
+    WaveChunk *chunk = &file->chunk;
+    const size_t blockheadersize = format->channels * 7;
+    const size_t blockdatasize = (size_t)format->blockalign - blockheadersize;
+    const size_t blockframebitsize = format->bitspersample * format->channels;
+    const size_t blockdatasamples = (blockdatasize * 8) / blockframebitsize;
+    const Sint16 presetcoeffs[14] = {256, 0, 512, -256, 0, 0, 192, 64, 240, 0, 460, -208, 392, -232};
+    size_t i, coeffcount;
+    MS_ADPCM_CoeffData *coeffdata;
+
+    /* Sanity checks. */
+
+    /* While it's clear how IMA ADPCM handles more than two channels, the nibble
+     * order of MS ADPCM makes it awkward. The Standards Update does not talk
+     * about supporting more than stereo anyway.
+     */
+    if (format->channels > 2) {
+        return SDL_SetError("Invalid number of channels");
+    }
+
+    if (format->bitspersample != 4) {
+        return SDL_SetError("Invalid MS ADPCM bits per sample of %d", (int)format->bitspersample);
+    }
+
+    /* The block size must be big enough to contain the block header. */
+    if (format->blockalign < blockheadersize) {
+        return SDL_SetError("Invalid MS ADPCM block size (nBlockAlign)");
+    }
+
+    if (format->formattag == EXTENSIBLE_CODE) {
+        /* Does have a GUID (like all format tags), but there's no specification
+         * for how the data is packed into the extensible header. Making
+         * assumptions here could lead to new formats nobody wants to support.
+         */
+        return SDL_SetError("MS ADPCM with the extensible header is not supported");
+    }
+
+    /* There are wSamplesPerBlock, wNumCoef, and at least 7 coefficient pairs in
+     * the extended part of the header.
+     */
+    if (chunk->size < 22) {
+        return SDL_SetError("Could not read MS ADPCM format header");
+    }
+
+    format->samplesperblock = chunk->data[18] | ((Uint16)chunk->data[19] << 8);
+    /* Number of coefficient pairs. A pair has two 16-bit integers. */
+    coeffcount = chunk->data[20] | ((size_t)chunk->data[21] << 8);
+    /* bPredictor, the integer offset into the coefficients array, is only
+     * 8 bits. It can only address the first 256 coefficients. Let's limit
+     * the count number here.
+     */
+    if (coeffcount > 256) {
+        coeffcount = 256;
+    }
+
+    if (chunk->size < 22 + coeffcount * 4) {
+        return SDL_SetError("Could not read custom coefficients in MS ADPCM format header");
+    } else if (format->extsize < 4 + coeffcount * 4) {
+        return SDL_SetError("Invalid MS ADPCM format header (too small)");
+    } else if (coeffcount < 7) {
+        return SDL_SetError("Missing required coefficients in MS ADPCM format header");
+    }
+
+    coeffdata = (MS_ADPCM_CoeffData *)SDL_malloc(sizeof(MS_ADPCM_CoeffData) + coeffcount * 4);
+    file->decoderdata = coeffdata; /* Freed in cleanup. */
+    if (coeffdata == NULL) {
+        return SDL_OutOfMemory();
+    }
+    coeffdata->coeff = &coeffdata->aligndummy;
+    coeffdata->coeffcount = (Uint16)coeffcount;
+
+    /* Copy the 16-bit pairs. */
+    for (i = 0; i < coeffcount * 2; i++) {
+        Sint32 c = chunk->data[22 + i * 2] | ((Sint32)chunk->data[23 + i * 2] << 8);
+        if (c >= 0x8000) {
+            c -= 0x10000;
+        }
+        if (i < 14 && c != presetcoeffs[i]) {
+            return SDL_SetError("Wrong preset coefficients in MS ADPCM format header");
+        }
+        coeffdata->coeff[i] = (Sint16)c;
+    }
+
+    /* Technically, wSamplesPerBlock is required, but we have all the
+     * information in the other fields to calculate it, if it's zero.
+     */
+    if (format->samplesperblock == 0) {
+        /* Let's be nice to the encoders that didn't know how to fill this.
+         * The Standards Update calculates it this way:
+         *
+         *   x = Block size (in bits) minus header size (in bits)
+         *   y = Bit depth multiplied by channel count
+         *   z = Number of samples per channel in block header
+         *   wSamplesPerBlock = x / y + z
+         */
+        format->samplesperblock = (Uint32)blockdatasamples + 2;
+    }
+
+    /* nBlockAlign can be in conflict with wSamplesPerBlock. For example, if
+     * the number of samples doesn't fit into the block. The Standards Update
+     * also describes wSamplesPerBlock with a formula that makes it necessary to
+     * always fill the block with the maximum amount of samples, but this is not
+     * enforced here as there are no compatibility issues.
+     * A truncated block header with just one sample is not supported.
+     */
+    if (format->samplesperblock == 1 || blockdatasamples < format->samplesperblock - 2) {
+        return SDL_SetError("Invalid number of samples per MS ADPCM block (wSamplesPerBlock)");
+    }
+
+    if (MS_ADPCM_CalculateSampleFrames(file, datalength) < 0) {
+        return -1;
+    }
+
+    return 0;
+}
+
+static Sint16
+MS_ADPCM_ProcessNibble(MS_ADPCM_ChannelState *cstate, Sint32 sample1, Sint32 sample2, Uint8 nybble)
+{
+    const Sint32 max_audioval = 32767;
+    const Sint32 min_audioval = -32768;
+    const Uint16 max_deltaval = 65535;
+    const Uint16 adaptive[] = {
+        230, 230, 230, 230, 307, 409, 512, 614,
+        768, 614, 512, 409, 307, 230, 230, 230
+    };
+    Sint32 new_sample;
+    Sint32 errordelta;
+    Uint32 delta = cstate->delta;
+
+    new_sample = (sample1 * cstate->coeff1 + sample2 * cstate->coeff2) / 256;
+    /* The nibble is a signed 4-bit error delta. */
+    errordelta = (Sint32)nybble - (nybble >= 0x08 ? 0x10 : 0);
+    new_sample += (Sint32)delta * errordelta;
+    if (new_sample < min_audioval) {
+        new_sample = min_audioval;
+    } else if (new_sample > max_audioval) {
+        new_sample = max_audioval;
+    }
+    delta = (delta * adaptive[nybble]) / 256;
+    if (delta < 16) {
+        delta = 16;
+    } else if (delta > max_deltaval) {
+        /* This issue is not described in the Standards Update and therefore
+         * undefined. It seems sensible to prevent overflows with a limit.
+         */
+        delta = max_deltaval;
+    }
+
+    cstate->delta = (Uint16)delta;
+    return (Sint16)new_sample;
+}
+
+static int
+MS_ADPCM_DecodeBlockHeader(ADPCM_DecoderState *state)
+{
+    Uint8 coeffindex;
+    const Uint32 channels = state->channels;
+    Sint32 sample;
+    Uint32 c;
+    MS_ADPCM_ChannelState *cstate = (MS_ADPCM_ChannelState *)state->cstate;
+    MS_ADPCM_CoeffData *ddata = (MS_ADPCM_CoeffData *)state->ddata;
+
+    for (c = 0; c < channels; c++) {
+        size_t o = c;
+
+        /* Load the coefficient pair into the channel state. */
+        coeffindex = state->block.data[o];
+        if (coeffindex > ddata->coeffcount) {
+            return SDL_SetError("Invalid MS ADPCM coefficient index in block header");
+        }
+        cstate[c].coeff1 = ddata->coeff[coeffindex * 2];
+        cstate[c].coeff2 = ddata->coeff[coeffindex * 2 + 1];
+
+        /* Initial delta value. */
+        o = channels + c * 2;
+        cstate[c].delta = state->block.data[o] | ((Uint16)state->block.data[o + 1] << 8);
+
+        /* Load the samples from the header. Interestingly, the sample later in
+         * the output stream comes first.
+         */
+        o = channels * 3 + c * 2;
+        sample = state->block.data[o] | ((Sint32)state->block.data[o + 1] << 8);
+        if (sample >= 0x8000) {
+            sample -= 0x10000;
+        }
+        state->output.data[state->output.pos + channels] = (Sint16)sample;
+
+        o = channels * 5 + c * 2;
+        sample = state->block.data[o] | ((Sint32)state->block.data[o + 1] << 8);
+        if (sample >= 0x8000) {
+            sample -= 0x10000;
+        }
+        state->output.data[state->output.pos] = (Sint16)sample;
+
+        state->output.pos++;
+    }
+
+    state->block.pos += state->blockheadersize;
+
+    /* Skip second sample frame that came from the header. */
+    state->output.pos += state->channels;
+
+    /* Header provided two sample frames. */
+    state->framesleft -= 2;
+
+    return 0;
+}
+
+/* Decodes the data of the MS ADPCM block. Decoding will stop if a block is too
+ * short, returning with none or partially decoded data. The partial data
+ * will always contain full sample frames (same sample count for each channel).
+ * Incomplete sample frames are discarded.
+ */
+static int
+MS_ADPCM_DecodeBlockData(ADPCM_DecoderState *state)
+{
+    Uint16 nybble = 0;
+    Sint16 sample1, sample2;
+    const Uint32 channels = state->channels;
+    Uint32 c;
+    MS_ADPCM_ChannelState *cstate = (MS_ADPCM_ChannelState *)state->cstate;
+
+    size_t blockpos = state->block.pos;
+    size_t blocksize = state->block.size;
+
+    size_t outpos = state->output.pos;
+
+    Sint64 blockframesleft = state->samplesperblock - 2;
+    if (blockframesleft > state->framesleft) {
+        blockframesleft = state->framesleft;
+    }
+
+    while (blockframesleft > 0) {
+        for (c = 0; c < channels; c++) {
+            if (nybble & 0x8000) {
+                nybble <<= 4;
+            } else if (blockpos < blocksize) {
+                nybble = state->block.data[blockpos++] | 0x8000;
+            } else {
+                /* Out of input data. Drop the incomplete frame and return. */
+                state->output.pos = outpos - c;
+                return -1;
+            }
+
+            /* Load previous samples which may come from the block header. */
+            sample1 = state->output.data[outpos - channels];
+            sample2 = state->output.data[outpos - channels * 2];
+
+            sample1 = MS_ADPCM_ProcessNibble(cstate + c, sample1, sample2, (nybble >> 4) & 0x0f);
+            state->output.data[outpos++] = sample1;
+        }
+
+        state->framesleft--;
+        blockframesleft--;
+    }
+
+    state->output.pos = outpos;
+
+    return 0;
+}
+
+static int
+MS_ADPCM_Decode(WaveFile *file, Uint8 **audio_buf, Uint32 *audio_len)
+{
+    int result;
+    size_t bytesleft, outputsize;
+    WaveChunk *chunk = &file->chunk;
+    ADPCM_DecoderState state = {0};
+    MS_ADPCM_ChannelState cstate[2] = {0};
+
+    if (chunk->size != chunk->length) {
+        /* Could not read everything. Recalculate number of sample frames. */
+        if (MS_ADPCM_CalculateSampleFrames(file, chunk->size) < 0) {
+            return -1;
+        }
+    }
+
+    /* Nothing to decode, nothing to return. */
+    if (file->sampleframes == 0) {
+        *audio_buf = NULL;
+        *audio_len = 0;
+        return 0;
+    }
+
+    state.blocksize = file->format.blockalign;
+    state.channels = file->format.channels;
+    state.blockheadersize = state.channels * 7;
+    state.samplesperblock = file->format.samplesperblock;
+    state.framesize = state.channels * sizeof(Sint16);
+    state.ddata = file->decoderdata;
+    state.framestotal = file->sampleframes;
+    state.framesleft = state.framestotal;
+
+    state.input.data = chunk->data;
+    state.input.size = chunk->size;
+    state.input.pos = 0;
+
+    /* The output size in bytes. May get modified if data is truncated. */
+    outputsize = (size_t)state.framestotal;
+    if (MultiplySize(&outputsize, state.framesize)) {
+        return SDL_OutOfMemory();
+    } else if (outputsize > SDL_MAX_UINT32 || state.framestotal > SIZE_MAX) {
+        return SDL_SetError("WAVE file too big");
+    }
+
+    state.output.pos = 0;
+    state.output.size = outputsize / sizeof(Sint16);
+    state.output.data = (Sint16 *)SDL_malloc(outputsize);
+    if (state.output.data == NULL) {
+        return SDL_OutOfMemory();
+    }
+
+    state.cstate = &cstate;
+
+    /* Decode block by block. A truncated block will stop the decoding. */
+    bytesleft = state.input.size - state.input.pos;
+    while (state.framesleft > 0 && bytesleft >= state.blockheadersize) {
+        state.block.data = state.input.data + state.input.pos;
+        state.block.size = bytesleft < state.blocksize ? bytesleft : state.blocksize;
+        state.block.pos = 0;
+
+        if (state.output.size - state.output.pos < (Uint64)state.framesleft * state.channels) {
+            /* Somehow didn't allocate enough space for the output. */
+            SDL_free(state.output.data);
+            return SDL_SetError("Unexpected overflow in MS ADPCM decoder");
+        }
+
+        /* Initialize decoder with the values from the block header. */
+        result = MS_ADPCM_DecodeBlockHeader(&state);
+        if (result == -1) {
+            SDL_free(state.output.data);
+            return -1;
+        }
+
+        /* Decode the block data. It stores the samples directly in the output. */
+        result = MS_ADPCM_DecodeBlockData(&state);
+        if (result == -1) {
+            /* Unexpected end. Stop decoding and return partial data if necessary. */
+            if (file->trunchint == TruncVeryStrict || file->trunchint == TruncVeryStrict) {
+                SDL_free(state.output.data);
+                return SDL_SetError("Truncated data chunk");
+            } else if (file->trunchint != TruncDropFrame) {
+                state.output.pos -= state.output.pos % (state.samplesperblock * state.channels);
+            }
+            outputsize = state.output.pos * sizeof(Sint16); /* Can't overflow, is always smaller. */
+            break;
+        }
+
+        state.input.pos += state.block.size;
+        bytesleft = state.input.size - state.input.pos;
+    }
+
+    *audio_buf = (Uint8 *)state.output.data;
+    *audio_len = (Uint32)outputsize;
+
+    return 0;
+}
+
+static int
+IMA_ADPCM_CalculateSampleFrames(WaveFile *file, size_t datalength)
+{
+    WaveFormat *format = &file->format;
+    const size_t blockheadersize = format->channels * 4;
+    const size_t subblockframesize = format->channels * 4;
+    const size_t availableblocks = datalength / format->blockalign;
+    const size_t trailingdata = datalength % format->blockalign;
+
+    if (file->trunchint == TruncVeryStrict || file->trunchint == TruncStrict) {
+        /* The size of the data chunk must be a multiple of the block size. */
+        if (datalength < blockheadersize || trailingdata > 0) {
+            return SDL_SetError("Truncated IMA ADPCM block");
+        }
+    }
+
+    /* Calculate number of sample frames that will be decoded. */
+    file->sampleframes = (Uint64)availableblocks * format->samplesperblock;
+    if (trailingdata > 0) {
+        /* The last block is truncated. Check if we can get any samples out of it. */
+        if (file->trunchint == TruncDropFrame && trailingdata > blockheadersize - 2) {
+            /* The sample frame in the header of the truncated block is present.
+             * Drop incomplete sample frames.
+             */
+            size_t trailingsamples = 1;
+
+            if (trailingdata > blockheadersize) {
+                /* More data following after the header. */
+                const size_t trailingblockdata = trailingdata - blockheadersize;
+                const size_t trailingsubblockdata = trailingblockdata % subblockframesize;
+                trailingsamples += (trailingblockdata / subblockframesize) * 8;
+                /* Due to the interleaved sub-blocks, the last 4 bytes determine
+                 * how many samples of the truncated sub-block are lost.
+                 */
+                if (trailingsubblockdata > subblockframesize - 4) {
+                    trailingsamples += (trailingsubblockdata % 4) * 2;
+                }
+            }
+
+            if (trailingsamples > format->samplesperblock) {
+                trailingsamples = format->samplesperblock;
+            }
+            file->sampleframes += trailingsamples;
+        }
+    }
+
+    file->sampleframes = WaveAdjustToFactValue(file, file->sampleframes);
+    if (file->sampleframes < 0) {
+        return -1;
+    }
+
+    return 0;
+}
+
+static int
+IMA_ADPCM_Init(WaveFile *file, size_t datalength)
+{
+    WaveFormat *format = &file->format;
+    WaveChunk *chunk = &file->chunk;
+    const size_t blockheadersize = format->channels * 4;
+    const size_t blockdatasize = (size_t)format->blockalign - blockheadersize;
+    const size_t blockframebitsize = format->bitspersample * format->channels;
+    const size_t blockdatasamples = (blockdatasize * 8) / blockframebitsize;
+
+    /* Sanity checks. */
+
+    /* IMA ADPCAM can also have 3-bit samples, but it's not supported by SDL at this time. */
+    if (format->bitspersample == 3) {
+        return SDL_SetError("3-bit IMA ADPCM currently not supported");
+    } else if (format->bitspersample != 4) {
+        return SDL_SetError("Invalid IMA ADPCM bits per sample of %d", (int)format->bitspersample);
+    }
+
+    /* The block size is required to be a multiple of 4 and it must be able to
+     * hold a block header.
+     */
+    if (format->blockalign < blockheadersize || format->blockalign % 4) {
+        return SDL_SetError("Invalid IMA ADPCM block size (nBlockAlign)");
+    }
+
+    if (format->formattag == EXTENSIBLE_CODE) {
+        /* There's no specification for this, but it's basically the same
+         * format because the extensible header has wSampePerBlocks too.
+         */
+    } else  {
+        /* The Standards Update says there 'should' be 2 bytes for wSamplesPerBlock. */
+        if (chunk->size >= 20 && format->extsize >= 2) {
+            format->samplesperblock = chunk->data[18] | ((Uint16)chunk->data[19] << 8);
+        }
+    }
+
+    if (format->samplesperblock == 0) {
+        /* Field zero? No problem. We just assume the encoder packed the block.
+         * The specification calculates it this way:
+         *
+         *   x = Block size (in bits) minus header size (in bits)
+         *   y = Bit depth multiplied by channel count
+         *   z = Number of samples per channel in header
+         *   wSamplesPerBlock = x / y + z
+         */
+        format->samplesperblock = (Uint32)blockdatasamples + 1;
+    }
+
+    /* nBlockAlign can be in conflict with wSamplesPerBlock. For example, if
+     * the number of samples doesn't fit into the block. The Standards Update
+     * also describes wSamplesPerBlock with a formula that makes it necessary
+     * to always fill the block with the maximum amount of samples, but this is
+     * not enforced here as there are no compatibility issues.
+     */
+    if (blockdatasamples < format->samplesperblock - 1) {
+        return SDL_SetError("Invalid number of samples per IMA ADPCM block (wSamplesPerBlock)");
+    }
+
+    if (IMA_ADPCM_CalculateSampleFrames(file, datalength) < 0) {
+        return -1;
+    }
+
+    return 0;
+}
+
+static Sint16
+IMA_ADPCM_ProcessNibble(Sint8 *cindex, Sint16 lastsample, Uint8 nybble)
+{
+    const Sint32 max_audioval = 32767;
+    const Sint32 min_audioval = -32768;
+    const Sint8 index_table_4b[16] = {
+        -1, -1, -1, -1,
+        2, 4, 6, 8,
+        -1, -1, -1, -1,
+        2, 4, 6, 8
+    };
+    const Uint16 step_table[89] = {
+        7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 19, 21, 23, 25, 28, 31,
+        34, 37, 41, 45, 50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130,
+        143, 157, 173, 190, 209, 230, 253, 279, 307, 337, 371, 408,
+        449, 494, 544, 598, 658, 724, 796, 876, 963, 1060, 1166, 1282,
+        1411, 1552, 1707, 1878, 2066, 2272, 2499, 2749, 3024, 3327,
+        3660, 4026, 4428, 4871, 5358, 5894, 6484, 7132, 7845, 8630,
+        9493, 10442, 11487, 12635, 13899, 15289, 16818, 18500, 20350,
+        22385, 24623, 27086, 29794, 32767
+    };
+    Uint32 step;
+    Sint32 sample, delta;
+    Sint8 index = *cindex;
+
+    /* Clamp index into valid range. */
+    if (index > 88) {
+        index = 88;
+    } else if (index < 0) {
+        index = 0;
+    }
+
+    /* explicit cast to avoid gcc warning about using 'char' as array index */
+    step = step_table[(size_t)index];
+
+    /* Update index value */
+    *cindex = index + index_table_4b[nybble];
+
+    /* This calculation uses shifts and additions because multiplications were
+     * much slower back then. Sadly, this can't just be replaced with an actual
+     * multiplication now as the old algorithm drops some bits. The closest
+     * approximation I could find is something like this:
+     * (nybble & 0x8 ? -1 : 1) * ((nybble & 0x7) * step / 4 + step / 8)
+     */
+    delta = step >> 3;
+    if (nybble & 0x04)
+        delta += step;
+    if (nybble & 0x02)
+        delta += step >> 1;
+    if (nybble & 0x01)
+        delta += step >> 2;
+    if (nybble & 0x08)
+        delta = -delta;
+
+    sample = lastsample + delta;
+
+    /* Clamp output sample */
+    if (sample > max_audioval) {
+        sample = max_audioval;
+    } else if (sample < min_audioval) {
+        sample = min_audioval;
+    }
+
+    return (Sint16)sample;
+}
+
+static int
+IMA_ADPCM_DecodeBlockHeader(ADPCM_DecoderState *state)
+{
+    Sint16 step;
+    Uint32 c;
+    Uint8 *cstate = state->cstate;
+
+    for (c = 0; c < state->channels; c++) {
+        size_t o = state->block.pos + c * 4;
+
+        /* Extract the sample from the header. */
+        Sint32 sample = state->block.data[o] | ((Sint32)state->block.data[o + 1] << 8);
+        if (sample >= 0x8000) {
+            sample -= 0x10000;
+        }
+        state->output.data[state->output.pos++] = (Sint16)sample;
+
+        /* Channel step index. */
+        step = (Sint16)state->block.data[o + 2];
+        cstate[c] = (Sint8)(step > 0x80 ? step - 0x100 : step);
+
+        /* Reserved byte in block header, should be 0. */
+        if (state->block.data[o + 3] != 0) {
+            /* Uh oh, corrupt data?  Buggy code? */ ;
+        }
+    }
+
+    state->block.pos += state->blockheadersize;
+
+    /* Header provided one sample frame. */
+    state->framesleft--;
+
+    return 0;
+}
+
+/* Decodes the data of the IMA ADPCM block. Decoding will stop if a block is too
+ * short, returning with none or partially decoded data. The partial data always
+ * contains full sample frames (same sample count for each channel).
+ * Incomplete sample frames are discarded.
+ */
+static int
+IMA_ADPCM_DecodeBlockData(ADPCM_DecoderState *state)
+{
+    size_t i;
+    int retval = 0;
+    const Uint32 channels = state->channels;
+    const size_t subblockframesize = channels * 4;
+    Uint64 bytesrequired;
+    Uint32 c;
+
+    size_t blockpos = state->block.pos;
+    size_t blocksize = state->block.size;
+    size_t blockleft = blocksize - blockpos;
+
+    size_t outpos = state->output.pos;
+
+    Sint64 blockframesleft = state->samplesperblock - 1;
+    if (blockframesleft > state->framesleft) {
+        blockframesleft = state->framesleft;
+    }
+
+    bytesrequired = (blockframesleft + 7) / 8 * subblockframesize;
+    if (blockleft < bytesrequired) {
+        /* Data truncated. Calculate how many samples we can get out if it. */
+        const size_t guaranteedframes = blockleft / subblockframesize;
+        const size_t remainingbytes = blockleft % subblockframesize;
+        blockframesleft = guaranteedframes;
+        if (remainingbytes > subblockframesize - 4) {
+            blockframesleft += (remainingbytes % 4) * 2;
+        }
+        /* Signal the truncation. */
+        retval = -1;
+    }
+
+    /* Each channel has their nibbles packed into 32-bit blocks. These blocks
+     * are interleaved and make up the data part of the ADPCM block. This loop
+     * decodes the samples as they come from the input data and puts them at
+     * the appropriate places in the output data.
+     */
+    while (blockframesleft > 0) {
+        const size_t subblocksamples = blockframesleft < 8 ? (size_t)blockframesleft : 8;
+
+        for (c = 0; c < channels; c++) {
+            Uint8 nybble = 0;
+            /* Load previous sample which may come from the block header. */
+            Sint16 sample = state->output.data[outpos + c - channels];
+
+            for (i = 0; i < subblocksamples; i++) {
+                if (i & 1) {
+                    nybble >>= 4;
+                } else {
+                    nybble = state->block.data[blockpos++];
+                }
+
+                sample = IMA_ADPCM_ProcessNibble((Sint8 *)state->cstate + c, sample, nybble & 0x0f);
+                state->output.data[outpos + c + i * channels] = sample;
+            }
+        }
+
+        outpos += channels * subblocksamples;
+        state->framesleft -= subblocksamples;
+        blockframesleft -= subblocksamples;
+    }
+
+    state->block.pos = blockpos;
+    state->output.pos = outpos;
+
+    return retval;
+}
+
+static int
+IMA_ADPCM_Decode(WaveFile *file, Uint8 **audio_buf, Uint32 *audio_len)
+{
+    int result;
+    size_t bytesleft, outputsize;
+    WaveChunk *chunk = &file->chunk;
+    ADPCM_DecoderState state = {0};
+    Sint8 *cstate;
+
+    if (chunk->size != chunk->length) {
+        /* Could not read everything. Recalculate number of sample frames. */
+        if (IMA_ADPCM_CalculateSampleFrames(file, chunk->size) < 0) {
+            return -1;
+        }
+    }
+
+    /* Nothing to decode, nothing to return. */
+    if (file->sampleframes == 0) {
+        *audio_buf = NULL;
+        *audio_len = 0;
+        return 0;
+    }
+
+    state.channels = file->format.channels;
+    state.blocksize = file->format.blockalign;
+    state.blockheadersize = state.channels * 4;
+    state.samplesperblock = file->format.samplesperblock;
+    state.framesize = state.channels * sizeof(Sint16);
+    state.framestotal = file->sampleframes;
+    state.framesleft = state.framestotal;
+
+    state.input.data = chunk->data;
+    state.input.size = chunk->size;
+    state.input.pos = 0;
+
+    /* The output size in bytes. May get modified if data is truncated. */
+    outputsize = (size_t)state.framestotal;
+    if (MultiplySize(&outputsize, state.framesize)) {
+        return SDL_OutOfMemory();
+    } else if (outputsize > SDL_MAX_UINT32 || state.framestotal > SIZE_MAX) {
+        return SDL_SetError("WAVE file too big");
+    }
+
+    state.output.pos = 0;
+    state.output.size = outputsize / sizeof(Sint16);
+    state.output.data = (Sint16 *)SDL_malloc(outputsize);
+    if (state.output.data == NULL) {
+        return SDL_OutOfMemory();
+    }
+
+    cstate = (Sint8 *)SDL_calloc(state.channels, sizeof(Sint8));
+    if (cstate == NULL) {
+        SDL_free(state.output.data);
+        return SDL_OutOfMemory();
+    }
+    state.cstate = cstate;
+
+    /* Decode block by block. A truncated block will stop the decoding. */
+    bytesleft = state.input.size - state.input.pos;
+    while (state.framesleft > 0 && bytesleft >= state.blockheadersize) {
+        state.block.data = state.input.data + state.input.pos;
+        state.block.size = bytesleft < state.blocksize ? bytesleft : state.blocksize;
+        state.block.pos = 0;
+
+        if (state.output.size - state.output.pos < (Uint64)state.framesleft * state.channels) {
+            /* Somehow didn't allocate enough space for the output. */
+            SDL_free(state.output.data);
+            SDL_free(cstate);
+            return SDL_SetError("Unexpected overflow in IMA ADPCM decoder");
+        }
+
+        /* Initialize decoder with the values from the block header. */
+        result = IMA_ADPCM_DecodeBlockHeader(&state);
+
+        /* Decode the block data. It stores the samples directly in the output. */
+        result = IMA_ADPCM_DecodeBlockData(&state);
+        if (result == -1) {
+            /* Unexpected end. Stop decoding and return partial data if necessary. */
+            if (file->trunchint == TruncVeryStrict || file->trunchint == TruncVeryStrict) {
+                SDL_free(state.output.data);
+                SDL_free(cstate);
+                return SDL_SetError("Truncated data chunk");
+            } else if (file->trunchint != TruncDropFrame) {
+                state.output.pos -= state.output.pos % (state.samplesperblock * state.channels);
+            }
+            outputsize = state.output.pos * sizeof(Sint16); /* Can't overflow, is always smaller. */
+            break;
+        }
+
+        state.input.pos += state.block.size;
+        bytesleft = state.input.size - state.input.pos;
+    }
+
+    *audio_buf = (Uint8 *)state.output.data;
+    *audio_len = (Uint32)outputsize;
+
+    SDL_free(cstate);
+
+    return 0;
+}
+
+static int
+LAW_Init(WaveFile *file, size_t datalength)
+{
+    WaveFormat *format = &file->format;
+
+    /* Standards Update requires this to be 8. */
+    if (format->bitspersample != 8) {
+        return SDL_SetError("Invalid companded bits per sample of %d", (int)format->bitspersample);
+    }
+
+    /* Not going to bother with weird padding. */
+    if (format->blockalign != format->channels) {
+        return SDL_SetError("Unsupported block alignment");
+    }
+
+    if ((file->trunchint == TruncVeryStrict || file->trunchint == TruncStrict)) {
+        if (format->blockalign > 1 && datalength % format->blockalign) {
+            return SDL_SetError("Truncated data chunk in WAVE file");
+        }
+    }
+
+    file->sampleframes = WaveAdjustToFactValue(file, datalength / format->blockalign);
+    if (file->sampleframes < 0) {
+        return -1;
+    }
+
+    return 0;
+}
+
+static int
+LAW_Decode(WaveFile *file, Uint8 **audio_buf, Uint32 *audio_len)
+{
+#ifdef SDL_WAVE_LAW_LUT
+    const Sint16 alaw_lut[256] = {
+        -5504, -5248, -6016, -5760, -4480, -4224, -4992, -4736, -7552, -7296, -8064, -7808, -6528, -6272, -7040, -6784, -2752,
+        -2624, -3008, -2880, -2240, -2112, -2496, -2368, -3776, -3648, -4032, -3904, -3264, -3136, -3520, -3392, -22016,
+        -20992, -24064, -23040, -17920, -16896, -19968, -18944, -30208, -29184, -32256, -31232, -26112, -25088, -28160, -27136, -11008,
+        -10496, -12032, -11520, -8960, -8448, -9984, -9472, -15104, -14592, -16128, -15616, -13056, -12544, -14080, -13568, -344,
+        -328, -376, -360, -280, -264, -312, -296, -472, -456, -504, -488, -408, -392, -440, -424, -88,
+        -72, -120, -104, -24, -8, -56, -40, -216, -200, -248, -232, -152, -136, -184, -168, -1376,
+        -1312, -1504, -1440, -1120, -1056, -1248, -1184, -1888, -1824, -2016, -1952, -1632, -1568, -1760, -1696, -688,
+        -656, -752, -720, -560, -528, -624, -592, -944, -912, -1008, -976, -816, -784, -880, -848, 5504,
+        5248, 6016, 5760, 4480, 4224, 4992, 4736, 7552, 7296, 8064, 7808, 6528, 6272, 7040, 6784, 2752,
+        2624, 3008, 2880, 2240, 2112, 2496, 2368, 3776, 3648, 4032, 3904, 3264, 3136, 3520, 3392, 22016,
+        20992, 24064, 23040, 17920, 16896, 19968, 18944, 30208, 29184, 32256, 31232, 26112, 25088, 28160, 27136, 11008,
+        10496, 12032, 11520, 8960, 8448, 9984, 9472, 15104, 14592, 16128, 15616, 13056, 12544, 14080, 13568, 344,
+        328, 376, 360, 280, 264, 312, 296, 472, 456, 504, 488, 408, 392, 440, 424, 88,
+        72, 120, 104, 24, 8, 56, 40, 216, 200, 248, 232, 152, 136, 184, 168, 1376,
+        1312, 1504, 1440, 1120, 1056, 1248, 1184, 1888, 1824, 2016, 1952, 1632, 1568, 1760, 1696, 688,
+        656, 752, 720, 560, 528, 624, 592, 944, 912, 1008, 976, 816, 784, 880, 848
+    };
+    const Sint16 mulaw_lut[256] = {
+        -32124, -31100, -30076, -29052, -28028, -27004, -25980, -24956, -23932, -22908, -21884, -20860, -19836, -18812, -17788, -16764, -15996,
+        -15484, -14972, -14460, -13948, -13436, -12924, -12412, -11900, -11388, -10876, -10364, -9852, -9340, -8828, -8316, -7932,
+        -7676, -7420, -7164, -6908, -6652, -6396, -6140, -5884, -5628, -5372, -5116, -4860, -4604, -4348, -4092, -3900,
+        -3772, -3644, -3516, -3388, -3260, -3132, -3004, -2876, -2748, -2620, -2492, -2364, -2236, -2108, -1980, -1884,
+        -1820, -1756, -1692, -1628, -1564, -1500, -1436, -1372, -1308, -1244, -1180, -1116, -1052, -988, -924, -876,
+        -844, -812, -780, -748, -716, -684, -652, -620, -588, -556, -524, -492, -460, -428, -396, -372,
+        -356, -340, -324, -308, -292, -276, -260, -244, -228, -212, -196, -180, -164, -148, -132, -120,
+        -112, -104, -96, -88, -80, -72, -64, -56, -48, -40, -32, -24, -16, -8, 0, 32124,
+        31100, 30076, 29052, 28028, 27004, 25980, 24956, 23932, 22908, 21884, 20860, 19836, 18812, 17788, 16764, 15996,
+        15484, 14972, 14460, 13948, 13436, 12924, 12412, 11900, 11388, 10876, 10364, 9852, 9340, 8828, 8316, 7932,
+        7676, 7420, 7164, 6908, 6652, 6396, 6140, 5884, 5628, 5372, 5116, 4860, 4604, 4348, 4092, 3900,
+        3772, 3644, 3516, 3388, 3260, 3132, 3004, 2876, 2748, 2620, 2492, 2364, 2236, 2108, 1980, 1884,
+        1820, 1756, 1692, 1628, 1564, 1500, 1436, 1372, 1308, 1244, 1180, 1116, 1052, 988, 924, 876,
+        844, 812, 780, 748, 716, 684, 652, 620, 588, 556, 524, 492, 460, 428, 396, 372,
+        356, 340, 324, 308, 292, 276, 260, 244, 228, 212, 196, 180, 164, 148, 132, 120,
+        112, 104, 96, 88, 80, 72, 64, 56, 48, 40, 32, 24, 16, 8, 0
+    };
+#endif
+
+    WaveFormat *format = &file->format;
+    WaveChunk *chunk = &file->chunk;
+    size_t i, sample_count, expanded_len;
+    Uint8 *src;
+    Sint16 *dst;
+
+    if (chunk->length != chunk->size) {
+        file->sampleframes = WaveAdjustToFactValue(file, chunk->size / format->blockalign);
+        if (file->sampleframes < 0) {
+            return -1;
+        }
+    }
+
+    /* Nothing to decode, nothing to return. */
+    if (file->sampleframes == 0) {
+        *audio_buf = NULL;
+        *audio_len = 0;
+        return 0;
+    }
+
+    sample_count = (size_t)file->sampleframes;
+    if (MultiplySize(&sample_count, format->channels)) {
+        return SDL_OutOfMemory();
+    }
+
+    expanded_len = sample_count;
+    if (MultiplySize(&expanded_len, sizeof(Sint16))) {
+        return SDL_OutOfMemory();
+    } else if (expanded_len > SDL_MAX_UINT32 || file->sampleframes > SIZE_MAX) {
+        return SDL_SetError("WAVE file too big");
+    }
+
+    src = (Uint8 *)SDL_realloc(chunk->data, expanded_len);
+    if (src == NULL) {
+        return SDL_OutOfMemory();
+    }
+    chunk->data = NULL;
+    chunk->size = 0;
+
+    dst = (Sint16 *)src;
+
+    /* Work backwards, since we're expanding in-place. SDL_AudioSpec.format will
+     * inform the caller about the byte order.
+     */
+    i = sample_count;
+    switch (file->format.encoding) {
+#ifdef SDL_WAVE_LAW_LUT
+    case ALAW_CODE:
+        while (i--) {
+            dst[i] = alaw_lut[src[i]];
+        }
+        break;
+    case MULAW_CODE:
+        while (i--) {
+            dst[i] = mulaw_lut[src[i]];
+        }
+        break;
+#else
+    case ALAW_CODE:
+        while (i--) {
+            Uint8 nibble = src[i];
+            Uint8 exponent = (nibble & 0x7f) ^ 0x55;
+            Sint16 mantissa = exponent & 0xf;
+
+            exponent >>= 4;
+            if (exponent > 0) {
+                mantissa |= 0x10;
+            }
+            mantissa = mantissa << 4 | 0x8;
+            if (exponent > 1) {
+                mantissa <<= exponent - 1;
+            }
+
+            dst[i] = nibble & 0x80 ? mantissa : -mantissa;
+        }
+        break;
+    case MULAW_CODE:
+        while (i--) {
+            Uint8 nibble = ~src[i];
+            Sint16 mantissa = nibble & 0xf;
+            Uint8 exponent = nibble >> 4 & 0x7;
+            Sint16 step = 4 << (exponent + 1);
+
+            mantissa = (0x80 << exponent) + step * mantissa + step / 2 - 132;
+
+            dst[i] = nibble & 0x80 ? -mantissa : mantissa;
+        }
+        break;
+#endif
+    default:
+        SDL_free(src);
+        return SDL_SetError("Unknown companded encoding");
+    }
+
+    *audio_buf = src;
+    *audio_len = (Uint32)expanded_len;
+
+    return 0;
+}
+
+static int
+PCM_Init(WaveFile *file, size_t datalength)
+{
+    WaveFormat *format = &file->format;
+
+    if (format->encoding == PCM_CODE) {
+        switch (format->bitspersample) {
+        case 8:
+        case 16:
+        case 24:
+        case 32:
+            /* These are supported. */
+            break;
+        default:
+            return SDL_SetError("%d-bit PCM format not supported", (int)format->bitspersample);
+        }
+    } else if (format->encoding == IEEE_FLOAT_CODE) {
+        if (format->bitspersample != 32) {
+            return SDL_SetError("%d-bit IEEE floating-point format not supported", (int)format->bitspersample);
+        }
+    }
+
+    /* It wouldn't be that hard to support more exotic block sizes, but
+     * the most common formats should do for now.
+     */
+    if (format->blockalign * 8 != format->channels * format->bitspersample) {
+        return SDL_SetError("Unsupported block alignment");
+    }
+
+    if ((file->trunchint == TruncVeryStrict || file->trunchint == TruncStrict)) {
+        if (format->blockalign > 1 && datalength % format->blockalign) {
+            return SDL_SetError("Truncated data chunk in WAVE file");
+        }
+    }
+
+    file->sampleframes = WaveAdjustToFactValue(file, datalength / format->blockalign);
+    if (file->sampleframes < 0) {
+        return -1;
+    }
+
+    return 0;
+}
+
+static int
+PCM_ConvertSint24ToSint32(WaveFile *file, Uint8 **audio_buf, Uint32 *audio_len)
+{
+    WaveFormat *format = &file->format;
+    WaveChunk *chunk = &file->chunk;
+    size_t i, expanded_len, sample_count;
+    Uint8 *ptr;
+
+    sample_count = (size_t)file->sampleframes;
+    if (MultiplySize(&sample_count, format->channels)) {
+        return SDL_OutOfMemory();
+    }
+
+    expanded_len = sample_count;
+    if (MultiplySize(&expanded_len, sizeof(Sint32))) {
+        return SDL_OutOfMemory();
+    } else if (expanded_len > SDL_MAX_UINT32 || file->sampleframes > SIZE_MAX) {
+        return SDL_SetError("WAVE file too big");
+    }
+
+    ptr = (Uint8 *)SDL_realloc(chunk->data, expanded_len);
+    if (ptr == NULL) {
+        return SDL_OutOfMemory();
+    }
+
+    /* This pointer is now invalid. */
+    chunk->data = NULL;
+    chunk->size = 0;
+
+    *audio_buf = ptr;
+    *audio_len = (Uint32)expanded_len;
+
+    /* work from end to start, since we're expanding in-place. */
+    for (i = sample_count; i > 0; i--) {
+        const size_t o = i - 1;
+        uint8_t b[4];
+
+        b[0] = 0;
+        b[1] = ptr[o * 3];
+        b[2] = ptr[o * 3 + 1];
+        b[3] = ptr[o * 3 + 2];
+
+        ptr[o * 4 + 0] = b[0];
+        ptr[o * 4 + 1] = b[1];
+        ptr[o * 4 + 2] = b[2];
+        ptr[o * 4 + 3] = b[3];
+    }
+
+    return 0;
+}
+
+static int
+PCM_Decode(WaveFile *file, Uint8 **audio_buf, Uint32 *audio_len)
+{
+    WaveFormat *format = &file->format;
+    WaveChunk *chunk = &file->chunk;
+    size_t outputsize;
+
+    if (chunk->length != chunk->size) {
+        file->sampleframes = WaveAdjustToFactValue(file, chunk->size / format->blockalign);
+        if (file->sampleframes < 0) {
+            return -1;
+        }
+    }
+
+    /* Nothing to decode, nothing to return. */
+    if (file->sampleframes == 0) {
+        *audio_buf = NULL;
+        *audio_len = 0;
+        return 0;
+    }
+
+    /* 24-bit samples get shifted to 32 bits. */
+    if (format->encoding == PCM_CODE && format->bitspersample == 24) {
+        return PCM_ConvertSint24ToSint32(file, audio_buf, audio_len);
+    }
+
+    outputsize = (size_t)file->sampleframes;
+    if (MultiplySize(&outputsize, format->blockalign)) {
+        return SDL_OutOfMemory();
+    } else if (outputsize > SDL_MAX_UINT32 || file->sampleframes > SIZE_MAX) {
+        return SDL_SetError("WAVE file too big");
+    }
+
+    *audio_buf = chunk->data;
+    *audio_len = (Uint32)outputsize;
 
-static int ReadChunk(SDL_RWops * src, Chunk * chunk);
+    /* This pointer is going to be returned to the caller. Prevent free in cleanup. */
+    chunk->data = NULL;
+    chunk->size = 0;
 
-struct MS_ADPCM_decodestate
-{
-    Uint8 hPredictor;
-    Uint16 iDelta;
-    Sint16 iSamp1;
-    Sint16 iSamp2;
-};
-static struct MS_ADPCM_decoder
-{
-    WaveFMT wavefmt;
-    Uint16 wSamplesPerBlock;
-    Uint16 wNumCoef;
-    Sint16 aCoeff[7][2];
-    /* * * */
-    struct MS_ADPCM_decodestate state[2];
-} MS_ADPCM_state;
+    return 0;
+}
 
-static int
-InitMS_ADPCM(WaveFMT * format)
-{
-    Uint8 *rogue_feel;
-    int i;
-
-    /* Set the rogue pointer to the MS_ADPCM specific data */
-    MS_ADPCM_state.wavefmt.encoding = SDL_SwapLE16(format->encoding);
-    MS_ADPCM_state.wavefmt.channels = SDL_SwapLE16(format->channels);
-    MS_ADPCM_state.wavefmt.frequency = SDL_SwapLE32(format->frequency);
-    MS_ADPCM_state.wavefmt.byterate = SDL_SwapLE32(format->byterate);
-    MS_ADPCM_state.wavefmt.blockalign = SDL_SwapLE16(format->blockalign);
-    MS_ADPCM_state.wavefmt.bitspersample =
-        SDL_SwapLE16(format->bitspersample);
-    rogue_feel = (Uint8 *) format + sizeof(*format);
-    if (sizeof(*format) == 16) {
-        /* const Uint16 extra_info = ((rogue_feel[1] << 8) | rogue_feel[0]); */
-        rogue_feel += sizeof(Uint16);
-    }
-    MS_ADPCM_state.wSamplesPerBlock = ((rogue_feel[1] << 8) | rogue_feel[0]);
-    rogue_feel += sizeof(Uint16);
-    MS_ADPCM_state.wNumCoef = ((rogue_feel[1] << 8) | rogue_feel[0]);
-    rogue_feel += sizeof(Uint16);
-    if (MS_ADPCM_state.wNumCoef != 7) {
-        SDL_SetError("Unknown set of MS_ADPCM coefficients");
-        return (-1);
-    }
-    for (i = 0; i < MS_ADPCM_state.wNumCoef; ++i) {
-        MS_ADPCM_state.aCoeff[i][0] = ((rogue_feel[1] << 8) | rogue_feel[0]);
-        rogue_feel += sizeof(Uint16);
-        MS_ADPCM_state.aCoeff[i][1] = ((rogue_feel[1] << 8) | rogue_feel[0]);
-        rogue_feel += sizeof(Uint16);
-    }
-    return (0);
-}
-
-static Sint32
-MS_ADPCM_nibble(struct MS_ADPCM_decodestate *state,
-                Uint8 nybble, Sint16 * coeff)
-{
-    const Sint32 max_audioval = ((1 << (16 - 1)) - 1);
-    const Sint32 min_audioval = -(1 << (16 - 1));
-    const Sint32 adaptive[] = {
-        230, 230, 230, 230, 307, 409, 512, 614,
-        768, 614, 512, 409, 307, 230, 230, 230
-    };
-    Sint32 new_sample, delta;
+static WaveRiffSizeHint
+WaveGetRiffSizeHint()
+{
+    const char *hint = SDL_GetHint(SDL_HINT_WAVE_RIFF_CHUNK_SIZE);
 
-    new_sample = ((state->iSamp1 * coeff[0]) +
-                  (state->iSamp2 * coeff[1])) / 256;
-    if (nybble & 0x08) {
-        new_sample += state->iDelta * (nybble - 0x10);
-    } else {
-        new_sample += state->iDelta * nybble;
-    }
-    if (new_sample < min_audioval) {
-        new_sample = min_audioval;
-    } else if (new_sample > max_audioval) {
-        new_sample = max_audioval;
-    }
-    delta = ((Sint32) state->iDelta * adaptive[nybble]) / 256;
-    if (delta < 16) {
-        delta = 16;
+    if (hint != NULL) {
+        if (SDL_strcmp(hint, "chunksearch") == 0) {
+            return RiffSizeChunkSearch;
+        } else if (SDL_strcmp(hint, "ignore") == 0) {
+            return RiffSizeIgnore;
+        } else if (SDL_strcmp(hint, "ignorezero") == 0) {
+            return RiffSizeIgnoreZero;
+        } else if (SDL_strcmp(hint, "maximum") == 0) {
+            return RiffSizeMaximum;
+        }
     }
-    state->iDelta = (Uint16) delta;
-    state->iSamp2 = state->iSamp1;
-    state->iSamp1 = (Sint16) new_sample;
-    return (new_sample);
+
+    return RiffSizeNoHint;
 }
 
-static int
-MS_ADPCM_decode(Uint8 ** audio_buf, Uint32 * audio_len)
-{
-    struct MS_ADPCM_decodestate *state[2];
-    Uint8 *freeable, *encoded, *decoded;
-    Sint32 encoded_len, samplesleft;
-    Sint8 nybble;
-    Uint8 stereo;
-    Sint16 *coeff[2];
-    Sint32 new_sample;
+static WaveTruncationHint
+WaveGetTruncationHint()
+{
+    const char *hint = SDL_GetHint(SDL_HINT_WAVE_TRUNCATION);
 
-    /* Allocate the proper sized output buffer */
-    encoded_len = *audio_len;
-    encoded = *audio_buf;
-    freeable = *audio_buf;
-    *audio_len = (encoded_len / MS_ADPCM_state.wavefmt.blockalign) *
-        MS_ADPCM_state.wSamplesPerBlock *
-        MS_ADPCM_state.wavefmt.channels * sizeof(Sint16);
-    *audio_buf = (Uint8 *) SDL_malloc(*audio_len);
-    if (*audio_buf == NULL) {
-        return SDL_OutOfMemory();
+    if (hint != NULL) {
+        if (SDL_strcmp(hint, "verystrict") == 0) {
+            return TruncVeryStrict;
+        } else if (SDL_strcmp(hint, "strict") == 0) {
+            return TruncStrict;
+        } else if (SDL_strcmp(hint, "dropframe") == 0) {
+            return TruncDropFrame;
+        } else if (SDL_strcmp(hint, "dropblock") == 0) {
+            return TruncDropBlock;
+        }
     }
-    decoded = *audio_buf;
-
-    /* Get ready... Go! */
-    stereo = (MS_ADPCM_state.wavefmt.channels == 2);
-    state[0] = &MS_ADPCM_state.state[0];
-    state[1] = &MS_ADPCM_state.state[stereo];
-    while (encoded_len >= MS_ADPCM_state.wavefmt.blockalign) {
-        /* Grab the initial information for this block */
-        state[0]->hPredictor = *encoded++;
-        if (stereo) {
-            state[1]->hPredictor = *encoded++;
-        }
-        state[0]->iDelta = ((encoded[1] << 8) | encoded[0]);
-        encoded += sizeof(Sint16);
-        if (stereo) {
-            state[1]->iDelta = ((encoded[1] << 8) | encoded[0]);
-            encoded += sizeof(Sint16);
-        }
-        state[0]->iSamp1 = ((encoded[1] << 8) | encoded[0]);
-        encoded += sizeof(Sint16);
-        if (stereo) {
-            state[1]->iSamp1 = ((encoded[1] << 8) | encoded[0]);
-            encoded += sizeof(Sint16);
-        }
-        state[0]->iSamp2 = ((encoded[1] << 8) | encoded[0]);
-        encoded += sizeof(Sint16);
-        if (stereo) {
-            state[1]->iSamp2 = ((encoded[1] << 8) | encoded[0]);
-            encoded += sizeof(Sint16);
-        }
-        coeff[0] = MS_ADPCM_state.aCoeff[state[0]->hPredictor];
-        coeff[1] = MS_ADPCM_state.aCoeff[state[1]->hPredictor];
-
-        /* Store the two initial samples we start with */
-        decoded[0] = state[0]->iSamp2 & 0xFF;
-        decoded[1] = state[0]->iSamp2 >> 8;
-        decoded += 2;
-        if (stereo) {
-            decoded[0] = state[1]->iSamp2 & 0xFF;
-            decoded[1] = state[1]->iSamp2 >> 8;
-            decoded += 2;
-        }
-        decoded[0] = state[0]->iSamp1 & 0xFF;
-        decoded[1] = state[0]->iSamp1 >> 8;
-        decoded += 2;
-        if (stereo) {
-            decoded[0] = state[1]->iSamp1 & 0xFF;
-            decoded[1] = state[1]->iSamp1 >> 8;
-            decoded += 2;
-        }
-
-        /* Decode and store the other samples in this block */
-        samplesleft = (MS_ADPCM_state.wSamplesPerBlock - 2) *
-            MS_ADPCM_state.wavefmt.channels;
-        while (samplesleft > 0) {
-            nybble = (*encoded) >> 4;
-            new_sample = MS_ADPCM_nibble(state[0], nybble, coeff[0]);
-            decoded[0] = new_sample & 0xFF;
-            new_sample >>= 8;
-            decoded[1] = new_sample & 0xFF;
-            decoded += 2;
-
-            nybble = (*encoded) & 0x0F;
-            new_sample = MS_ADPCM_nibble(state[1], nybble, coeff[1]);
-            decoded[0] = new_sample & 0xFF;
-            new_sample >>= 8;
-            decoded[1] = new_sample & 0xFF;
-            decoded += 2;
-
-            ++encoded;
-            samplesleft -= 2;
-        }
-        encoded_len -= MS_ADPCM_state.wavefmt.blockalign;
-    }
-    SDL_free(freeable);
-    return (0);
-}
-
-struct IMA_ADPCM_decodestate
-{
-    Sint32 sample;
-    Sint8 index;
-};
-static struct IMA_ADPCM_decoder
-{
-    WaveFMT wavefmt;
-    Uint16 wSamplesPerBlock;
-    /* * * */
-    struct IMA_ADPCM_decodestate state[2];
-} IMA_ADPCM_state;
 
-static int
-InitIMA_ADPCM(WaveFMT * format, int length)
-{
-    Uint8 *rogue_feel, *rogue_feel_end;
-
-    /* Set the rogue pointer to the IMA_ADPCM specific data */
-    if (length < sizeof(*format)) goto too_short;
-    IMA_ADPCM_state.wavefmt.encoding = SDL_SwapLE16(format->encoding);
-    IMA_ADPCM_state.wavefmt.channels = SDL_SwapLE16(format->channels);
-    IMA_ADPCM_state.wavefmt.frequency = SDL_SwapLE32(format->frequency);
-    IMA_ADPCM_state.wavefmt.byterate = SDL_SwapLE32(format->byterate);
-    IMA_ADPCM_state.wavefmt.blockalign = SDL_SwapLE16(format->blockalign);
-    IMA_ADPCM_state.wavefmt.bitspersample = SDL_SwapLE16(format->bitspersample);
-    rogue_feel = (Uint8 *) format + sizeof(*format);
-    rogue_feel_end = (Uint8 *) format + length;
-    if (sizeof(*format) == 16) {
-        /* const Uint16 extra_info = ((rogue_feel[1] << 8) | rogue_feel[0]); */
-        rogue_feel += sizeof(Uint16);
-    }
-    if (rogue_feel + 2 > rogue_feel_end) goto too_short;
-    IMA_ADPCM_state.wSamplesPerBlock = ((rogue_feel[1] << 8) | rogue_feel[0]);
-    return (0);
-too_short:
-    SDL_SetError("Unexpected length of a chunk with an IMA ADPCM format");
-    return (-1);
-}
-
-static Sint32
-IMA_ADPCM_nibble(struct IMA_ADPCM_decodestate *state, Uint8 nybble)
-{
-    const Sint32 max_audioval = ((1 << (16 - 1)) - 1);
-    const Sint32 min_audioval = -(1 << (16 - 1));
-    const int index_table[16] = {
-        -1, -1, -1, -1,
-        2, 4, 6, 8,
-        -1, -1, -1, -1,
-        2, 4, 6, 8
-    };
-    const Sint32 step_table[89] = {
-        7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 19, 21, 23, 25, 28, 31,
-        34, 37, 41, 45, 50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130,
-        143, 157, 173, 190, 209, 230, 253, 279, 307, 337, 371, 408,
-        449, 494, 544, 598, 658, 724, 796, 876, 963, 1060, 1166, 1282,
-        1411, 1552, 1707, 1878, 2066, 2272, 2499, 2749, 3024, 3327,
-        3660, 4026, 4428, 4871, 5358, 5894, 6484, 7132, 7845, 8630,
-        9493, 10442, 11487, 12635, 13899, 15289, 16818, 18500, 20350,
-        22385, 24623, 27086, 29794, 32767
-    };
-    Sint32 delta, step;
+    return TruncNoHint;
+}
+
+static WaveFactChunkHint
+WaveGetFactChunkHint()
+{
+    const char *hint = SDL_GetHint(SDL_HINT_WAVE_FACT_CHUNK);
 
-    /* Compute difference and new sample value */
-    if (state->index > 88) {
-        state->index = 88;
-    } else if (state->index < 0) {
-        state->index = 0;
+    if (hint != NULL) {
+        if (SDL_strcmp(hint, "truncate") == 0) {
+            return FactTruncate;
+        } else if (SDL_strcmp(hint, "strict") == 0) {
+            return FactStrict;
+        } else if (SDL_strcmp(hint, "ignorezero") == 0) {
+            return FactIgnoreZero;
+        } else if (SDL_strcmp(hint, "ignore") == 0) {
+            return FactIgnore;
+        }
     }
-    /* explicit cast to avoid gcc warning about using 'char' as array index */
-    step = step_table[(int)state->index];
-    delta = step >> 3;
-    if (nybble & 0x04)
-        delta += step;
-    if (nybble & 0x02)
-        delta += (step >> 1);
-    if (nybble & 0x01)
-        delta += (step >> 2);
-    if (nybble & 0x08)
-        delta = -delta;
-    state->sample += delta;
 
-    /* Update index value */
-    state->index += index_table[nybble];
+    return FactNoHint;
+}
 
-    /* Clamp output sample */
-    if (state->sample > max_audioval) {
-        state->sample = max_audioval;
-    } else if (state->sample < min_audioval) {
-        state->sample = min_audioval;
+static void
+WaveFreeChunkData(WaveChunk *chunk)
+{
+    if (chunk->data != NULL) {
+        SDL_free(chunk->data);
+        chunk->data = NULL;
     }
-    return (state->sample);
+    chunk->size = 0;
 }
 
-/* Fill the decode buffer with a channel block of data (8 samples) */
-static void
-Fill_IMA_ADPCM_block(Uint8 * decoded, Uint8 * encoded,
-                     int channel, int numchannels,
-                     struct IMA_ADPCM_decodestate *state)
+static int
+WaveNextChunk(SDL_RWops *src, WaveChunk *chunk)
 {
-    int i;
-    Sint8 nybble;
-    Sint32 new_sample;
+    Uint32 chunkheader[2];
+    Sint64 nextposition = chunk->position + chunk->length;
 
-    decoded += (channel * 2);
-    for (i = 0; i < 4; ++i) {
-        nybble = (*encoded) & 0x0F;
-        new_sample = IMA_ADPCM_nibble(state, nybble);
-        decoded[0] = new_sample & 0xFF;
-        new_sample >>= 8;
-        decoded[1] = new_sample & 0xFF;
-        decoded += 2 * numchannels;
+    /* Data is no longer valid after this function returns. */
+    WaveFreeChunkData(chunk);
 
-        nybble = (*encoded) >> 4;
-        new_sample = IMA_ADPCM_nibble(state, nybble);
-        decoded[0] = new_sample & 0xFF;
-        new_sample >>= 8;
-        decoded[1] = new_sample & 0xFF;
-        decoded += 2 * numchannels;
+    /* RIFF chunks have a 2-byte alignment. Skip padding byte. */
+    if (chunk->length & 1) {
+        nextposition++;
+    }
 
-        ++encoded;
+    if (SDL_RWseek(src, nextposition, RW_SEEK_SET) != nextposition) {
+        /* Not sure how we ended up here. Just abort. */
+        return -2;
+    } else if (SDL_RWread(src, chunkheader, 4, 2) != 2) {
+        return -1;
     }
+
+    chunk->fourcc = SDL_SwapLE32(chunkheader[0]);
+    chunk->length = SDL_SwapLE32(chunkheader[1]);
+    chunk->position = nextposition + 8;
+
+    return 0;
 }
 
 static int
-IMA_ADPCM_decode(Uint8 ** audio_buf, Uint32 * audio_len)
-{
-    struct IMA_ADPCM_decodestate *state;
-    Uint8 *freeable, *encoded, *decoded;
-    Sint32 encoded_len, samplesleft;
-    unsigned int c, channels;
-
-    /* Check to make sure we have enough variables in the state array */
-    channels = IMA_ADPCM_state.wavefmt.channels;
-    if (channels > SDL_arraysize(IMA_ADPCM_state.state)) {
-        SDL_SetError("IMA ADPCM decoder can only handle %u channels",
-                     (unsigned int)SDL_arraysize(IMA_ADPCM_state.state));
-        return (-1);
-    }
-    state = IMA_ADPCM_state.state;
-
-    /* Allocate the proper sized output buffer */
-    encoded_len = *audio_len;
-    encoded = *audio_buf;
-    freeable = *audio_buf;
-    *audio_len = (encoded_len / IMA_ADPCM_state.wavefmt.blockalign) *
-        IMA_ADPCM_state.wSamplesPerBlock *
-        IMA_ADPCM_state.wavefmt.channels * sizeof(Sint16);
-    *audio_buf = (Uint8 *) SDL_malloc(*audio_len);
-    if (*audio_buf == NULL) {
-        return SDL_OutOfMemory();
+WaveReadPartialChunkData(SDL_RWops *src, WaveChunk *chunk, size_t length)
+{
+    WaveFreeChunkData(chunk);
+
+    if (length > chunk->length) {
+        length = chunk->length;
     }
-    decoded = *audio_buf;
-
-    /* Get ready... Go! */
-    while (encoded_len >= IMA_ADPCM_state.wavefmt.blockalign) {
-        /* Grab the initial information for this block */
-        for (c = 0; c < channels; ++c) {
-            /* Fill the state information for this block */
-            state[c].sample = ((encoded[1] << 8) | encoded[0]);
-            encoded += 2;
-            if (state[c].sample & 0x8000) {
-                state[c].sample -= 0x10000;
-            }
-            state[c].index = *encoded++;
-            /* Reserved byte in buffer header, should be 0 */
-            if (*encoded++ != 0) {
-                /* Uh oh, corrupt data?  Buggy code? */ ;
-            }
 
-            /* Store the initial sample we start with */
-            decoded[0] = (Uint8) (state[c].sample & 0xFF);
-            decoded[1] = (Uint8) (state[c].sample >> 8);
-            decoded += 2;
+    if (length > 0) {
+        chunk->data = SDL_malloc(length);
+        if (chunk->data == NULL) {
+            return SDL_OutOfMemory();
         }
 
-        /* Decode and store the other samples in this block */
-        samplesleft = (IMA_ADPCM_state.wSamplesPerBlock - 1) * channels;
-        while (samplesleft > 0) {
-            for (c = 0; c < channels; ++c) {
-                Fill_IMA_ADPCM_block(decoded, encoded,
-                                     c, channels, &state[c]);
-                encoded += 4;
-                samplesleft -= 8;
-            }
-            decoded += (channels * 8 * 2);
+        if (SDL_RWseek(src, chunk->position, RW_SEEK_SET) != chunk->position) {
+            /* Not sure how we ended up here. Just abort. */
+            return -2;
+        }
+
+        chunk->size = SDL_RWread(src, chunk->data, 1, length);
+        if (chunk->size != length) {
+            /* Expected to be handled by the caller. */
         }
-        encoded_len -= IMA_ADPCM_state.wavefmt.blockalign;
     }
-    SDL_free(freeable);
-    return (0);
+
+    return 0;
+}
+
+static int
+WaveReadChunkData(SDL_RWops *src, WaveChunk *chunk)
+{
+    return WaveReadPartialChunkData(src, chunk, chunk->length);
 }
 
+typedef struct WaveExtensibleGUID {
+    Uint16 encoding;
+    Uint8 guid[16];
+} WaveExtensibleGUID;
+
+/* Some of the GUIDs that are used by WAVEFORMATEXTENSIBLE. */
+#define WAVE_FORMATTAG_GUID(tag) {(tag) & 0xff, (tag) >> 8, 0, 0, 0, 0, 16, 0, 128, 0, 0, 170, 0, 56, 155, 113}
+static WaveExtensibleGUID extensible_guids[] = {
+    {PCM_CODE,        WAVE_FORMATTAG_GUID(PCM_CODE)},
+    {MS_ADPCM_CODE,   WAVE_FORMATTAG_GUID(MS_ADPCM_CODE)},
+    {IEEE_FLOAT_CODE, WAVE_FORMATTAG_GUID(IEEE_FLOAT_CODE)},
+    {ALAW_CODE,       WAVE_FORMATTAG_GUID(ALAW_CODE)},
+    {MULAW_CODE,      WAVE_FORMATTAG_GUID(MULAW_CODE)},
+    {IMA_ADPCM_CODE,  WAVE_FORMATTAG_GUID(IMA_ADPCM_CODE)}
+};
+
+static Uint16
+WaveGetFormatGUIDEncoding(WaveFormat *format)
+{
+    size_t i;
+    for (i = 0; i < SDL_arraysize(extensible_guids); i++) {
+        if (SDL_memcmp(format->subformat, extensible_guids[i].guid, 16) == 0) {
+            return extensible_guids[i].encoding;
+        }
+    }
+    return UNKNOWN_CODE;
+}
 
 static int
-ConvertSint24ToSint32(Uint8 ** audio_buf, Uint32 * audio_len)
-{
-    const double DIVBY8388608 = 0.00000011920928955078125;
-    const Uint32 original_len = *audio_len;
-    const Uint32 samples = original_len / 3;
-    const Uint32 expanded_len = samples * sizeof (Uint32);
-    Uint8 *ptr = (Uint8 *) SDL_realloc(*audio_buf, expanded_len);
-    const Uint8 *src;
-    Uint32 *dst;
-    Uint32 i;
-
-    if (!ptr) {
+WaveReadFormat(WaveFile *file)
+{
+    WaveChunk *chunk = &file->chunk;
+    WaveFormat *format = &file->format;
+    SDL_RWops *fmtsrc;
+    size_t fmtlen = chunk->size;
+
+    if (fmtlen > SDL_MAX_SINT32) {
+        /* Limit given by SDL_RWFromConstMem. */
+        return SDL_SetError("Data of WAVE fmt chunk too big");
+    }
+    fmtsrc = SDL_RWFromConstMem(chunk->data, (int)chunk->size);
+    if (fmtsrc == NULL) {
         return SDL_OutOfMemory();
     }
 
-    *audio_buf = ptr;
-    *audio_len = expanded_len;
+    format->formattag = SDL_ReadLE16(fmtsrc);
+    format->encoding = format->formattag;
+    format->channels = SDL_ReadLE16(fmtsrc);
+    format->frequency = SDL_ReadLE32(fmtsrc);
+    format->byterate = SDL_ReadLE32(fmtsrc);
+    format->blockalign = SDL_ReadLE16(fmtsrc);
 
-    /* work from end to start, since we're expanding in-place. */
-    src = (ptr + original_len) - 3;
-    dst = ((Uint32 *) (ptr + expanded_len)) - 1;
-    for (i = 0; i < samples; i++) {
-        /* There's probably a faster way to do all this. */
-        const Sint32 converted = ((Sint32) ( (((Uint32) src[2]) << 24) |
-                                             (((Uint32) src[1]) << 16) |
-                                             (((Uint32) src[0]) << 8) )) >> 8;
-        const double scaled = (((double) converted) * DIVBY8388608);
-        src -= 3;
-        *(dst--) = (Sint32) (scaled * 2147483647.0);
+    /* This is PCM specific in the first version of the specification. */
+    if (fmtlen >= 16) {
+        format->bitspersample = SDL_ReadLE16(fmtsrc);
+    } else if (format->encoding == PCM_CODE) {
+        SDL_RWclose(fmtsrc);
+        return SDL_SetError("Missing wBitsPerSample field in WAVE fmt chunk");
+    }
+
+    /* The earlier versions also don't have this field. */
+    if (fmtlen >= 18) {
+        format->extsize = SDL_ReadLE16(fmtsrc);
+    }
+
+    if (format->formattag == EXTENSIBLE_CODE) {
+        /* note that this ignores channel masks, smaller valid bit counts
+         * inside a larger container, and most subtypes. This is just enough
+         * to get things that didn't really _need_ WAVE_FORMAT_EXTENSIBLE
+         * to be useful working when they use this format flag.
+         */
+
+        /* Extensible header must be at least 22 bytes. */
+        if (fmtlen < 40 || format->extsize < 22) {
+            SDL_RWclose(fmtsrc);
+            return SDL_SetError("Extensible WAVE header too small");
+        }
+
+        format->validsamplebits = SDL_ReadLE16(fmtsrc);
+        format->samplesperblock = format->validsamplebits;
+        format->channelmask = SDL_ReadLE32(fmtsrc);
+        SDL_RWread(fmtsrc, format->subformat, 1, 16);
+        format->encoding = WaveGetFormatGUIDEncoding(format);
     }
 
+    SDL_RWclose(fmtsrc);
+
     return 0;
 }
 
+static int
+WaveCheckFormat(WaveFile *file, size_t datalength)
+{
+    WaveFormat *format = &file->format;
+
+    /* Check for some obvious issues. */
 
-/* GUIDs that are used by WAVE_FORMAT_EXTENSIBLE */
-static const Uint8 extensible_pcm_guid[16] = { 1, 0, 0, 0, 0, 0, 16, 0, 128, 0, 0, 170, 0, 56, 155, 113 };
-static const Uint8 extensible_ieee_guid[16] = { 3, 0, 0, 0, 0, 0, 16, 0, 128, 0, 0, 170, 0, 56, 155, 113 };
+    if (format->channels == 0) {
+        return SDL_SetError("Invalid number of channels");
+    } else if (format->channels > 255) {
+        /* Limit given by SDL_AudioSpec.channels. */
+        return SDL_SetError("Number of channels exceeds limit of 255");
+    }
 
-SDL_AudioSpec *
-SDL_LoadWAV_RW(SDL_RWops * src, int freesrc,
-               SDL_AudioSpec * spec, Uint8 ** audio_buf, Uint32 * audio_len)
-{
-    int was_error;
-    Chunk chunk;
-    int lenread;
-    int IEEE_float_encoded, MS_ADPCM_encoded, IMA_ADPCM_encoded;
-    int samplesize;
+    if (format->frequency == 0) {
+        return SDL_SetError("Invalid sample rate");
+    } else if (format->frequency > INT_MAX) {
+        /* Limit given by SDL_AudioSpec.freq. */
+        return SDL_SetError("Sample rate exceeds limit of %d", INT_MAX);
+    }
 
-    /* WAV magic header */
-    Uint32 RIFFchunk;
-    Uint32 wavelen = 0;
-    Uint32 WAVEmagic;
-    Uint32 headerDiff = 0;
+    /* Reject invalid fact chunks in strict mode. */
+    if (file->facthint == FactStrict && file->fact.status == -1) {
+        return SDL_SetError("Invalid fact chunk in WAVE file");
+    }
 
-    /* FMT chunk */
-    WaveFMT *format = NULL;
-    WaveExtensibleFMT *ext = NULL;
+    /* Check the issues common to all encodings. Some unsupported formats set
+     * the bits per sample to zero. These fall through to the 'unsupported
+     * format' error.
+     */
+    switch (format->encoding) {
+    case IEEE_FLOAT_CODE:
+    case ALAW_CODE:
+    case MULAW_CODE:
+    case MS_ADPCM_CODE:
+    case IMA_ADPCM_CODE:
+        /* These formats require a fact chunk. */
+        if (file->facthint == FactStrict && file->fact.status <= 0) {
+            return SDL_SetError("Missing fact chunk in WAVE file");
+        }
+        /* fallthrough */
+    case PCM_CODE:
+        /* All supported formats require a non-zero bit depth. */
+        if (file->chunk.size < 16) {
+            return SDL_SetError("Missing wBitsPerSample field in WAVE fmt chunk");
+        } else if (format->bitspersample == 0) {
+            return SDL_SetError("Invalid bits per sample");
+        }
 
-    SDL_zero(chunk);
+        /* All supported formats must have a proper block size. */
+        if (format->blockalign == 0) {
+            return SDL_SetError("Invalid block alignment");
+        }
 
-    /* Make sure we are passed a valid data source */
-    was_error = 0;
-    if (src == NULL) {
-        was_error = 1;
-        goto done;
+        /* If the fact chunk is valid and the appropriate hint is set, the
+         * decoders will use the number of sample frames from the fact chunk.
+         */
+        if (file->fact.status == 1) {
+            WaveFactChunkHint hint = file->facthint;
+            Uint32 samples = file->fact.samplelength;
+            if (hint == FactTruncate || hint == FactStrict || (hint == FactIgnoreZero && samples > 0)) {
+                file->fact.status = 2;
+            }
+        }
     }
 
-    /* Check the magic header */
-    RIFFchunk = SDL_ReadLE32(src);
-    wavelen = SDL_ReadLE32(src);
-    if (wavelen == WAVE) {      /* The RIFFchunk has already been read */
-        WAVEmagic = wavelen;
-        wavelen = RIFFchunk;
-        RIFFchunk = RIFF;
-    } else {
-        WAVEmagic = SDL_ReadLE32(src);
-    }
-    if ((RIFFchunk != RIFF) || (WAVEmagic != WAVE)) {
-        SDL_SetError("Unrecognized file type (not WAVE)");
-        was_error = 1;
-        goto done;
-    }
-    headerDiff += sizeof(Uint32);       /* for WAVE */
-
-    /* Read the audio data format chunk */
-    chunk.data = NULL;
-    do {
-        SDL_free(chunk.data);
-        chunk.data = NULL;
-        lenread = ReadChunk(src, &chunk);
-        if (lenread < 0) {
-            was_error = 1;
-            goto done;
-        }
-        /* 2 Uint32's for chunk header+len, plus the lenread */
-        headerDiff += lenread + 2 * sizeof(Uint32);
-    } while ((chunk.magic == FACT) || (chunk.magic == LIST) || (chunk.magic == BEXT) || (chunk.magic == JUNK));
-
-    /* Decode the audio data format */
-    format = (WaveFMT *) chunk.data;
-    if (chunk.magic != FMT) {
-        SDL_SetError("Complex WAVE files not supported");
-        was_error = 1;
-        goto done;
-    }
-    IEEE_float_encoded = MS_ADPCM_encoded = IMA_ADPCM_encoded = 0;
-    switch (SDL_SwapLE16(format->encoding)) {
+    /* Check the format for encoding specific issues and initialize decoders. */
+    switch (format->encoding) {
     case PCM_CODE:
-        /* We can understand this */
-        break;
     case IEEE_FLOAT_CODE:
-        IEEE_float_encoded = 1;
-        /* We can understand this */
+        if (PCM_Init(file, datalength) < 0) {
+            return -1;
+        }
+        break;
+    case ALAW_CODE:
+    case MULAW_CODE:
+        if (LAW_Init(file, datalength) < 0) {
+            return -1;
+        }
         break;
     case MS_ADPCM_CODE:
-        /* Try to understand this */
-        if (InitMS_ADPCM(format) < 0) {
-            was_error = 1;
-            goto done;
+        if (MS_ADPCM_Init(file, datalength) < 0) {
+            return -1;
         }
-        MS_ADPCM_encoded = 1;
         break;
     case IMA_ADPCM_CODE:
-        /* Try to understand this */
-        if (InitIMA_ADPCM(format, lenread) < 0) {
-            was_error = 1;
-            goto done;
+        if (IMA_ADPCM_Init(file, datalength) < 0) {
+            return -1;
         }
-        IMA_ADPCM_encoded = 1;
         break;
-    case EXTENSIBLE_CODE:
-        /* note that this ignores channel masks, smaller valid bit counts
-           inside a larger container, and most subtypes. This is just enough
-           to get things that didn't really _need_ WAVE_FORMAT_EXTENSIBLE
-           to be useful working when they use this format flag. */
-        ext = (WaveExtensibleFMT *) format;
-        if (SDL_SwapLE16(ext->size) < 22) {
-            SDL_SetError("bogus extended .wav header");
-            was_error = 1;
-            goto done;
-        }
-        if (SDL_memcmp(ext->subformat, extensible_pcm_guid, 16) == 0) {
-            break;  /* cool. */
-        } else if (SDL_memcmp(ext->subformat, extensible_ieee_guid, 16) == 0) {
-            IEEE_float_encoded = 1;
-            break;
+    case MPEG_CODE:
+    case MPEGLAYER3_CODE:
+        return SDL_SetError("MPEG formats not supported");
+    default:
+        if (format->formattag == EXTENSIBLE_CODE) {
+            const char *errstr = "Unknown WAVE format GUID: %08x-%04x-%04x-%02x%02x%02x%02x%02x%02x%02x%02x";
+            const Uint8 *g = format->subformat;
+            const Uint32 g1 = g[0] | ((Uint32)g[1] << 8) | ((Uint32)g[2] << 16) | ((Uint32)g[3] << 24);
+            const Uint32 g2 = g[4] | ((Uint32)g[5] << 8);
+            const Uint32 g3 = g[6] | ((Uint32)g[7] << 8);
+            return SDL_SetError(errstr, g1, g2, g3, g[8], g[9], g[10], g[11], g[12], g[13], g[14], g[15]);
+        }
+        return SDL_SetError("Unknown WAVE format tag: 0x%04x", (int)format->encoding);
+    }
+
+    return 0;
+}
+
+static int
+WaveLoad(SDL_RWops *src, WaveFile *file, SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len)
+{
+    int result;
+    Uint32 chunkcount = 0;
+    Uint32 chunkcountlimit = 10000;
+    char *envchunkcountlimit;
+    Sint64 RIFFstart, RIFFend, lastchunkpos;
+    SDL_bool RIFFlengthknown = SDL_FALSE;
+    WaveFormat *format = &file->format;
+    WaveChunk *chunk = &file->chunk;
+    WaveChunk RIFFchunk = {0};
+    WaveChunk fmtchunk = {0};
+    WaveChunk datachunk = {0};
+
+    envchunkcountlimit = SDL_getenv("SDL_WAVE_CHUNK_LIMIT");
+    if (envchunkcountlimit != NULL) {
+        unsigned int count;
+        if (SDL_sscanf(envchunkcountlimit, "%u", &count) == 1) {
+            chunkcountlimit = count <= SDL_MAX_UINT32 ? count : SDL_MAX_UINT32;
+        }
+    }
+
+    RIFFstart = SDL_RWtell(src);
+    if (RIFFstart < 0) {
+        return SDL_SetError("Could not seek in file");
+    }
+
+    RIFFchunk.position = RIFFstart;
+    if (WaveNextChunk(src, &RIFFchunk) < 0) {
+        return SDL_SetError("Could not read RIFF header");
+    }
+
+    /* Check main WAVE file identifiers. */
+    if (RIFFchunk.fourcc == RIFF) {
+        Uint32 formtype;
+        /* Read the form type. "WAVE" expected. */
+        if (SDL_RWread(src, &formtype, sizeof(Uint32), 1) != 1) {
+            return SDL_SetError("Could not read RIFF form type");
+        } else if (SDL_SwapLE32(formtype) != WAVE) {
+            return SDL_SetError("RIFF form type is not WAVE (not a Waveform file)");
         }
+    } else if (RIFFchunk.fourcc == WAVE) {
+        /* RIFF chunk missing or skipped. Length unknown. */
+        RIFFchunk.position = 0;
+        RIFFchunk.length = 0;
+    } else {
+        return SDL_SetError("Could not find RIFF or WAVE identifiers (not a Waveform file)");
+    }
+
+    /* The 4-byte form type is immediately followed by the first chunk.*/
+    chunk->position = RIFFchunk.position + 4;
+
+    /* Use the RIFF chunk size to limit the search for the chunks. This is not
+     * always reliable and the hint can be used to tune the behavior. By
+     * default, it will never search past 4 GiB.
+     */
+    switch (file->riffhint) {
+    case RiffSizeIgnore:
+        RIFFend = RIFFchunk.position + SDL_MAX_UINT32;
         break;
-    case MP3_CODE:
-        SDL_SetError("MPEG Layer 3 data not supported");
-        was_error = 1;
-        goto done;
     default:
-        SDL_SetError("Unknown WAVE data format: 0x%.4x",
-                     SDL_SwapLE16(format->encoding));
-        was_error = 1;
-        goto done;
+    case RiffSizeIgnoreZero:
+        if (RIFFchunk.length == 0) {
+            RIFFend = RIFFchunk.position + SDL_MAX_UINT32;
+            break;
+        }
+        /* fallthrough */
+    case RiffSizeChunkSearch:
+        RIFFend = RIFFchunk.position + RIFFchunk.length;
+        RIFFlengthknown = SDL_TRUE;
+        break;
+    case RiffSizeMaximum:
+        RIFFend = SDL_MAX_SINT64;
+        break;
     }
-    SDL_zerop(spec);
-    spec->freq = SDL_SwapLE32(format->frequency);
 
-    if (IEEE_float_encoded) {
-        if ((SDL_SwapLE16(format->bitspersample)) != 32) {
-            was_error = 1;
-        } else {
-            spec->format = AUDIO_F32;
+    /* Step through all chunks and save information on the fmt, data, and fact
+     * chunks. Ignore the chunks we don't know as per specification. This
+     * currently also ignores cue, list, and slnt chunks.
+     */
+    while (RIFFend > chunk->position + chunk->length + (chunk->length & 1)) {
+        /* Abort after too many chunks or else corrupt files may waste time. */
+        if (chunkcount++ >= chunkcountlimit) {
+            return SDL_SetError("Chunk count in WAVE file exceeds limit of %u", chunkcountlimit);
         }
-    } else {
-        switch (SDL_SwapLE16(format->bitspersample)) {
-        case 4:
-            if (MS_ADPCM_encoded || IMA_ADPCM_encoded) {
-                spec->format = AUDIO_S16;
-            } else {
-                was_error = 1;
+
+        result = WaveNextChunk(src, chunk);
+        if (result == -1) {
+            /* Unexpected EOF. Corrupt file or I/O issues. */
+            if (file->trunchint == TruncVeryStrict) {
+                return SDL_SetError("Unexpected end of WAVE file");
             }
+            /* Let the checks after this loop sort this issue out. */
             break;
+        } else if (result == -2) {
+            return SDL_SetError("Could not seek to WAVE chunk header");
+        }
+
+        if (chunk->fourcc == FMT) {
+            if (fmtchunk.fourcc == FMT) {
+                /* Multiple fmt chunks. Ignore or error? */
+            } else {
+                /* The fmt chunk must occur before the data chunk. */
+                if (datachunk.fourcc == DATA) {
+                    return SDL_SetError("fmt chunk after data chunk in WAVE file");
+                }
+                fmtchunk = *chunk;
+            }
+        } else if (chunk->fourcc == DATA) {
+            /* Only use the first data chunk. Handling the wavl list madness
+             * may require a different approach.
+             */
+            if (datachunk.fourcc != DATA) {
+                datachunk = *chunk;
+            }
+        } else if (chunk->fourcc == FACT) {
+            /* The fact chunk data must be at least 4 bytes for the
+             * dwSampleLength field. Ignore all fact chunks after the first one.
+             */
+            if (file->fact.status == 0) {
+                if (chunk->length < 4) {
+                    file->fact.status = -1;
+                } else {
+                    /* Let's use src directly, it's just too convenient. */
+                    Sint64 position = SDL_RWseek(src, chunk->position, RW_SEEK_SET);
+                    Uint32 samplelength;
+                    if (position == chunk->position && SDL_RWread(src, &samplelength, sizeof(Uint32), 1) == 1) {
+                        file->fact.status = 1;
+                        file->fact.samplelength = SDL_SwapLE32(samplelength);
+                    } else {
+                        file->fact.status = -1;
+                    }
+                }
+            }
+        }
+
+        /* Go through all chunks in verystrict mode or stop the search early if
+         * all required chunks were found.
+         */
+        if (file->trunchint == TruncVeryStrict) {
+            if (RIFFend < chunk->position + chunk->length) {
+                return SDL_SetError("RIFF size truncates chunk");
+            }
+        } else if (fmtchunk.fourcc == FMT && datachunk.fourcc == DATA) {
+            if (file->fact.status == 1 || file->facthint == FactIgnore || file->facthint == FactNoHint) {
+                break;
+            }
+        }
+    }
+
+    /* Save the position after the last chunk. This position will be used if the
+     * RIFF length is unknown.
+     */
+    lastchunkpos = chunk->position + chunk->length;
+
+    /* The fmt chunk is mandatory. */
+    if (fmtchunk.fourcc != FMT) {
+        return SDL_SetError("Missing fmt chunk in WAVE file");
+    }
+    /* A data chunk must be present. */
+    if (datachunk.fourcc != DATA) {
+        return SDL_SetError("Missing data chunk in WAVE file");
+    }
+    /* Check if the last chunk has all of its data in verystrict mode. */
+    if (file->trunchint == TruncVeryStrict) {
+        /* data chunk is handled later. */
+        if (chunk->fourcc != DATA && chunk->length > 0) {
+            Uint8 tmp;
+            Sint64 position = chunk->position + chunk->length - 1;
+            if (SDL_RWseek(src, position, RW_SEEK_SET) != position) {
+                return SDL_SetError("Could not seek to WAVE chunk data");
+            } else if (SDL_RWread(src, &tmp, 1, 1) != 1) {
+                return SDL_SetError("RIFF size truncates chunk");
+            }
+        }
+    }
+
+    /* Process fmt chunk. */
+    *chunk = fmtchunk;
+
+    /* No need to read more than 1046 bytes of the fmt chunk data with the
+     * formats that are currently supported. (1046 because of MS ADPCM coefficients)
+     */
+    if (WaveReadPartialChunkData(src, chunk, 1046) < 0) {
+        return SDL_SetError("Could not read data of WAVE fmt chunk");
+    }
+
+    /* The fmt chunk data must be at least 14 bytes to include all common fields.
+     * It usually is 16 and larger depending on the header and encoding.
+     */
+    if (chunk->length < 14) {
+        return SDL_SetError("Invalid WAVE fmt chunk length (too small)");
+    } else if (chunk->size < 14) {
+        return SDL_SetError("Could not read data of WAVE fmt chunk");
+    } else if (WaveReadFormat(file) < 0) {
+        return -1;
+    } else if (WaveCheckFormat(file, (size_t)datachunk.length) < 0) {
+        return -1;
+    }
+
+#ifdef SDL_WAVE_DEBUG_LOG_FORMAT
+    WaveDebugLogFormat(file);
+#endif
+#ifdef SDL_WAVE_DEBUG_DUMP_FORMAT
+    WaveDebugDumpFormat(file, RIFFchunk.length, fmtchunk.length, datachunk.length);
+#endif
+
+    WaveFreeChunkData(chunk);
+
+    /* Process data chunk. */
+    *chunk = datachunk;
+
+    if (chunk->length > 0) {
+        result = WaveReadChunkData(src, chunk);
+        if (result == -1) {
+            return -1;
+        } else if (result == -2) {
+            return SDL_SetError("Could not seek data of WAVE data chunk");
+        }
+    }
+
+    if (chunk->length != chunk->size) {
+        /* I/O issues or corrupt file. */
+        if (file->trunchint == TruncVeryStrict || file->trunchint == TruncStrict) {
+            return SDL_SetError("Could not read data of WAVE data chunk");
+        }
+        /* The decoders handle this truncation. */
+    }
+
+    /* Decode or convert the data if necessary. */
+    switch (format->encoding) {
+    case PCM_CODE:
+    case IEEE_FLOAT_CODE:
+        if (PCM_Decode(file, audio_buf, audio_len) < 0) {
+            return -1;
+        }
+        break;
+    case ALAW_CODE:
+    case MULAW_CODE:
+        if (LAW_Decode(file, audio_buf, audio_len) < 0) {
+            return -1;
+        }
+        break;
+    case MS_ADPCM_CODE:
+        if (MS_ADPCM_Decode(file, audio_buf, audio_len) < 0) {
+            return -1;
+        }
+        break;
+    case IMA_ADPCM_CODE:
+        if (IMA_ADPCM_Decode(file, audio_buf, audio_len) < 0) {
+            return -1;
+        }
+        break;
+    }
+
+    /* Setting up the SDL_AudioSpec. All unsupported formats were filtered out
+     * by checks earlier in this function.
+     */
+    SDL_zerop(spec);
+    spec->freq = format->frequency;
+    spec->channels = (Uint8)format->channels;
+    spec->samples = 4096;       /* Good default buffer size */
+
+    switch (format->encoding) {
+    case MS_ADPCM_CODE:
+    case IMA_ADPCM_CODE:
+    case ALAW_CODE:
+    case MULAW_CODE:
+        /* These can be easily stored in the byte order of the system. */
+        spec->format = AUDIO_S16SYS;
+        break;
+    case IEEE_FLOAT_CODE:
+        spec->format = AUDIO_F32LSB;
+        break;
+    case PCM_CODE:
+        switch (format->bitspersample) {
         case 8:
             spec->format = AUDIO_U8;
             break;
         case 16:
-            spec->format = AUDIO_S16;
-            break;
-        case 24:  /* convert this. */
-            spec->format = AUDIO_S32;
+            spec->format = AUDIO_S16LSB;
             break;
+        case 24: /* Has been shifted to 32 bits. */
         case 32:
-            spec->format = AUDIO_S32;
+            spec->format = AUDIO_S32LSB;
             break;
         default:
-            was_error = 1;
-            break;
+            /* Just in case something unexpected happened in the checks. */
+            return SDL_SetError("Unexpected %d-bit PCM data format", format->bitspersample);
         }
+        break;
     }
 
-    if (was_error) {
-        SDL_SetError("Unknown %d-bit PCM data format",
-                     SDL_SwapLE16(format->bitspersample));
-        goto done;
+    /* Report the end position back to the cleanup code. */
+    if (RIFFlengthknown) {
+        chunk->position = RIFFend;
+    } else {
+        chunk->position = lastchunkpos;
     }
-    spec->channels = (Uint8) SDL_SwapLE16(format->channels);
-    spec->samples = 4096;       /* Good default buffer size */
 
-    /* Read the audio data chunk */
-    *audio_buf = NULL;
-    do {
-        SDL_free(*audio_buf);
-        *audio_buf = NULL;
-        lenread = ReadChunk(src, &chunk);
-        if (lenread < 0) {
-            was_error = 1;
-            goto done;
-        }
-        *audio_len = lenread;
-        *audio_buf = chunk.data;
-        if (chunk.magic != DATA)
-            headerDiff += lenread + 2 * sizeof(Uint32);
-    } while (chunk.magic != DATA);
-    headerDiff += 2 * sizeof(Uint32);   /* for the data chunk and len */
+    return 0;
+}
 
-    if (MS_ADPCM_encoded) {
-        if (MS_ADPCM_decode(audio_buf, audio_len) < 0) {
-            was_error = 1;
-            goto done;
-        }
-    }
-    if (IMA_ADPCM_encoded) {
-        if (IMA_ADPCM_decode(audio_buf, audio_len) < 0) {
-            was_error = 1;
-            goto done;
-        }
-    }
+SDL_AudioSpec *
+SDL_LoadWAV_RW(SDL_RWops *src, int freesrc, SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len)
+{
+    int result;
+    WaveFile file = {0};
 
-    if (SDL_SwapLE16(format->bitspersample) == 24) {
-        if (ConvertSint24ToSint32(audio_buf, audio_len) < 0) {
-            was_error = 1;
-            goto done;
-        }
+    /* Make sure we are passed a valid data source */
+    if (src == NULL) {
+        /* Error may come from RWops. */
+        return NULL;
+    } else if (spec == NULL) {
+        SDL_InvalidParamError("spec");
+        return NULL;
+    } else if (audio_buf == NULL) {
+        SDL_InvalidParamError("audio_buf");
+        return NULL;
+    } else if (audio_len == NULL) {
+        SDL_InvalidParamError("audio_len");
+        return NULL;
     }
 
-    /* Don't return a buffer that isn't a multiple of samplesize */
-    samplesize = ((SDL_AUDIO_BITSIZE(spec->format)) / 8) * spec->channels;
-    *audio_len &= ~(samplesize - 1);
+    *audio_buf = NULL;
+    *audio_len = 0;
 
-  done:
-    SDL_free(format);
-    if (src) {
-        if (freesrc) {
-            SDL_RWclose(src);
-        } else {
-            /* seek to the end of the file (given by the RIFF chunk) */
-            SDL_RWseek(src, wavelen - chunk.length - headerDiff, RW_SEEK_CUR);
-        }
-    }
-    if (was_error) {
+    file.riffhint = WaveGetRiffSizeHint();
+    file.trunchint = WaveGetTruncationHint();
+    file.facthint = WaveGetFactChunkHint();
+
+    result = WaveLoad(src, &file, spec, audio_buf, audio_len);
+    if (result < 0) {
+        SDL_free(*audio_buf);
         spec = NULL;
+        audio_buf = NULL;
+        audio_len = 0;
+    }
+
+    /* Cleanup */
+    if (freesrc) {
+        SDL_RWclose(src);
+    } else {
+        SDL_RWseek(src, file.chunk.position, RW_SEEK_SET);
     }
-    return (spec);
+    WaveFreeChunkData(&file.chunk);
+    SDL_free(file.decoderdata);
+
+    return spec;
 }
 
 /* Since the WAV memory is allocated in the shared library, it must also
    be freed here.  (Necessary under Win32, VC++)
  */
 void
-SDL_FreeWAV(Uint8 * audio_buf)
+SDL_FreeWAV(Uint8 *audio_buf)
 {
     SDL_free(audio_buf);
 }
 
-static int
-ReadChunk(SDL_RWops * src, Chunk * chunk)
-{
-    chunk->magic = SDL_ReadLE32(src);
-    chunk->length = SDL_ReadLE32(src);
-    chunk->data = (Uint8 *) SDL_malloc(chunk->length);
-    if (chunk->data == NULL) {
-        return SDL_OutOfMemory();
-    }
-    if (SDL_RWread(src, chunk->data, chunk->length, 1) != 1) {
-        SDL_free(chunk->data);
-        chunk->data = NULL;
-        return SDL_Error(SDL_EFREAD);
-    }
-    return (chunk->length);
-}
-
 /* vi: set ts=4 sw=4 expandtab: */
diff --git a/src/audio/SDL_wave.h b/src/audio/SDL_wave.h
index c739c4b..3d0ae55 100644
--- a/src/audio/SDL_wave.h
+++ b/src/audio/SDL_wave.h
@@ -20,11 +20,12 @@
 */
 #include "../SDL_internal.h"
 
-/* WAVE files are little-endian */
+/* RIFF WAVE files are little-endian */
 
 /*******************************************/
 /* Define values for Microsoft WAVE format */
 /*******************************************/
+/* FOURCC */
 #define RIFF            0x46464952      /* "RIFF" */
 #define WAVE            0x45564157      /* "WAVE" */
 #define FACT            0x74636166      /* "fact" */
@@ -33,45 +34,116 @@
 #define JUNK            0x4B4E554A      /* "JUNK" */
 #define FMT             0x20746D66      /* "fmt " */
 #define DATA            0x61746164      /* "data" */
+/* Format tags */
+#define UNKNOWN_CODE    0x0000
 #define PCM_CODE        0x0001
 #define MS_ADPCM_CODE   0x0002
 #define IEEE_FLOAT_CODE 0x0003
+#define ALAW_CODE       0x0006
+#define MULAW_CODE      0x0007
 #define IMA_ADPCM_CODE  0x0011
-#define MP3_CODE        0x0055
+#define MPEG_CODE       0x0050
+#define MPEGLAYER3_CODE 0x0055
 #define EXTENSIBLE_CODE 0xFFFE
-#define WAVE_MONO       1
-#define WAVE_STEREO     2
 
-/* Normally, these three chunks come consecutively in a WAVE file */
-typedef struct WaveFMT
+/* Stores the WAVE format information. */
+typedef struct WaveFormat
 {
-/* Not saved in the chunk we read:
-    Uint32  FMTchunk;
-    Uint32  fmtlen;
-*/
-    Uint16 encoding;
-    Uint16 channels;            /* 1 = mono, 2 = stereo */
-    Uint32 frequency;           /* One of 11025, 22050, or 44100 Hz */
-    Uint32 byterate;            /* Average bytes per second */
-    Uint16 blockalign;          /* Bytes per sample block */
-    Uint16 bitspersample;       /* One of 8, 12, 16, or 4 for ADPCM */
-} WaveFMT;
-
-/* The general chunk found in the WAVE file */
-typedef struct Chunk
+    Uint16 formattag;       /* Raw value of the first field in the fmt chunk data. */
+    Uint16 encoding;        /* Actual encoding, possibly from the extensible header. */
+    Uint16 channels;        /* Number of channels. */
+    Uint32 frequency;       /* Sampling rate in Hz. */
+    Uint32 byterate;        /* Average bytes per second. */
+    Uint16 blockalign;      /* Bytes per block. */
+    Uint16 bitspersample;   /* Currently supported are 8, 16, 24, 32, and 4 for ADPCM. */
+
+    /* Extra information size. Number of extra bytes starting at byte 18 in the
+     * fmt chunk data. This is at least 22 for the extensible header.
+     */
+    Uint16 extsize;
+
+    /* Extensible WAVE header fields */
+    Uint16 validsamplebits;
+    Uint32 samplesperblock; /* For compressed formats. Can be zero. Actually 16 bits in the header. */
+    Uint32 channelmask;
+    Uint8 subformat[16];    /* A format GUID. */
+} WaveFormat;
+
+/* Stores information on the fact chunk. */
+typedef struct WaveFact {
+    /* Represents the state of the fact chunk in the WAVE file.
+     * Set to -1 if the fact chunk is invalid.
+     * Set to 0 if the fact chunk is not present
+     * Set to 1 if the fact chunk is present and valid.
+     * Set to 2 if samplelength is going to be used as the number of sample frames.
+     */
+    Sint32 status;
+
+    /* Version 1 of the RIFF specification calls the field in the fact chunk
+     * dwFileSize. The Standards Update then calls it dwSampleLength and specifies
+     * that it is 'the length of the data in samples'. WAVE files from Windows
+     * with this chunk have it set to the samples per channel (sample frames).
+     * This is useful to truncate compressed audio to a specific sample count
+     * because a compressed block is usually decoded to a fixed number of
+     * sample frames.
+     */
+    Uint32 samplelength; /* Raw sample length value from the fact chunk. */
+} WaveFact;
+
+/* Generic struct for the chunks in the WAVE file. */
+typedef struct WaveChunk
 {
-    Uint32 magic;
-    Uint32 length;
-    Uint8 *data;
-} Chunk;
+    Uint32 fourcc;   /* FOURCC of the chunk. */
+    Uint32 length;   /* Size of the chunk data. */
+    Sint64 position; /* Position of the data in the stream. */
+    Uint8 *data;     /* When allocated, this points to the chunk data. length is used for the malloc size. */
+    size_t size;     /* Number of bytes in data that could be read from the stream. Can be smaller than length. */
+} WaveChunk;
 
-typedef struct WaveExtensibleFMT
+/* Controls how the size of the RIFF chunk affects the loading of a WAVE file. */
+typedef enum WaveRiffSizeHint {
+    RiffSizeNoHint,
+    RiffSizeChunkSearch,
+    RiffSizeIgnoreZero,
+    RiffSizeIgnore,
+    RiffSizeMaximum,
+} WaveRiffSizeHint;
+
+/* Controls how a truncated WAVE file is handled. */
+typedef enum WaveTruncationHint {
+    TruncNoHint,
+    TruncVeryStrict,
+    TruncStrict,
+    TruncDropFrame,
+    TruncDropBlock,
+} WaveTruncationHint;
+
+/* Controls how the fact chunk affects the loading of a WAVE file. */
+typedef enum WaveFactChunkHint {
+    FactNoHint,
+    FactTruncate,
+    FactStrict,
+    FactIgnoreZero,
+    FactIgnore,
+} WaveFactChunkHint;
+
+typedef struct WaveFile
 {
-    WaveFMT format;
-    Uint16 size;
-    Uint16 validbits;
-    Uint32 channelmask;
-    Uint8 subformat[16];  /* a GUID. */
-} WaveExtensibleFMT;
+    WaveChunk chunk;
+    WaveFormat format;
+    WaveFact fact;
+
+    /* Number of sample frames that will be decoded. Calculated either with the
+     * size of the data chunk or, if the appropriate hint is enabled, with the
+     * sample length value from the fact chunk.
+     */
+    Sint64 sampleframes;
+
+    void *decoderdata;   /* Some decoders require extra data for a state. */
+
+    WaveRiffSizeHint riffhint;
+    WaveTruncationHint trunchint;
+    WaveFactChunkHint facthint;
+} WaveFile;
 
 /* vi: set ts=4 sw=4 expandtab: */