kc3-lang/libjpeg-turbo/src/jstdhuff.c

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• Hash : 6da05150
  Author :
  Date : 2024-10-24T13:25:10
  

  Allow disabling prog/opt/lossless if prev. enabled
  
  - Due to an oversight, a113506d175d03ae0e40965c3d3d21a5d561e119
    (libjpeg-turbo 1.4 beta1) effectively made the call to
    std_huff_tables() in jpeg_set_defaults() a no-op if the Huffman tables
    were previously defined, which made it impossible to disable Huffman
    table optimization or progressive mode if they were previously enabled
    in the same API instance.  std_huff_tables() retains its previous
    behavior for decompression instances, but it now force-enables the
    standard (baseline) Huffman tables for compression instances.
  
  - Due to another oversight, there was no way to disable lossless mode
    if it was previously enabled in a particular API instance.
    jpeg_set_defaults() now accomplishes this, which makes
    TJ*PARAM_LOSSLESS behave as intended/documented.
  
  - Due to yet another oversight, setCompDefaults() in the TurboJPEG API
    library permanently modified the value of TJ*PARAM_SUBSAMP when
    generating a lossless JPEG image, which affected subsequent lossy
    compression operations.  This issue was hidden by the issue above and
    thus does not need to be publicly documented.
  
  Fixes #792
  

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• src/jstdhuff.c

• /*
   * jstdhuff.c
   *
   * This file was part of the Independent JPEG Group's software:
   * Copyright (C) 1991-1998, Thomas G. Lane.
   * libjpeg-turbo Modifications:
   * Copyright (C) 2013, 2022, 2024, D. R. Commander.
   * For conditions of distribution and use, see the accompanying README.ijg
   * file.
   *
   * This file contains routines to set the default Huffman tables, if they are
   * not already set.
   */
  
  /*
   * Huffman table setup routines
   */
  
  LOCAL(void)
  add_huff_table(j_common_ptr cinfo, JHUFF_TBL **htblptr, const UINT8 *bits,
                 const UINT8 *val)
  /* Define a Huffman table */
  {
    int nsymbols, len;
  
    if (*htblptr == NULL)
      *htblptr = jpeg_alloc_huff_table(cinfo);
    else if (cinfo->is_decompressor)
      return;
  
    /* Copy the number-of-symbols-of-each-code-length counts */
    memcpy((*htblptr)->bits, bits, sizeof((*htblptr)->bits));
  
    /* Validate the counts.  We do this here mainly so we can copy the right
     * number of symbols from the val[] array, without risking marching off
     * the end of memory.  jchuff.c will do a more thorough test later.
     */
    nsymbols = 0;
    for (len = 1; len <= 16; len++)
      nsymbols += bits[len];
    if (nsymbols < 1 || nsymbols > 256)
      ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
  
    memcpy((*htblptr)->huffval, val, nsymbols * sizeof(UINT8));
    memset(&((*htblptr)->huffval[nsymbols]), 0,
           (256 - nsymbols) * sizeof(UINT8));
  
    /* Initialize sent_table FALSE so table will be written to JPEG file. */
    (*htblptr)->sent_table = FALSE;
  }
  
  
  LOCAL(void)
  std_huff_tables(j_common_ptr cinfo)
  /* Set up the standard Huffman tables (cf. JPEG standard section K.3) */
  /* IMPORTANT: these are only valid for 8-bit data precision! */
  {
    JHUFF_TBL **dc_huff_tbl_ptrs, **ac_huff_tbl_ptrs;
  
    static const UINT8 bits_dc_luminance[17] = {
      /* 0-base */ 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0
    };
    static const UINT8 val_dc_luminance[] = {
      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
    };
  
    static const UINT8 bits_dc_chrominance[17] = {
      /* 0-base */ 0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0
    };
    static const UINT8 val_dc_chrominance[] = {
      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
    };
  
    static const UINT8 bits_ac_luminance[17] = {
      /* 0-base */ 0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d
    };
    static const UINT8 val_ac_luminance[] = {
      0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
      0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
      0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
      0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,
      0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
      0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
      0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
      0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
      0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
      0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
      0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
      0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
      0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
      0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
      0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
      0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
      0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
      0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
      0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
      0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
      0xf9, 0xfa
    };
  
    static const UINT8 bits_ac_chrominance[17] = {
      /* 0-base */ 0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77
    };
    static const UINT8 val_ac_chrominance[] = {
      0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
      0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
      0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
      0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,
      0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,
      0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,
      0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,
      0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
      0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
      0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
      0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
      0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
      0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96,
      0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,
      0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,
      0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,
      0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,
      0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,
      0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
      0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
      0xf9, 0xfa
    };
  
    if (cinfo->is_decompressor) {
      dc_huff_tbl_ptrs = ((j_decompress_ptr)cinfo)->dc_huff_tbl_ptrs;
      ac_huff_tbl_ptrs = ((j_decompress_ptr)cinfo)->ac_huff_tbl_ptrs;
    } else {
      dc_huff_tbl_ptrs = ((j_compress_ptr)cinfo)->dc_huff_tbl_ptrs;
      ac_huff_tbl_ptrs = ((j_compress_ptr)cinfo)->ac_huff_tbl_ptrs;
    }
  
    add_huff_table(cinfo, &dc_huff_tbl_ptrs[0], bits_dc_luminance,
                   val_dc_luminance);
    add_huff_table(cinfo, &ac_huff_tbl_ptrs[0], bits_ac_luminance,
                   val_ac_luminance);
    add_huff_table(cinfo, &dc_huff_tbl_ptrs[1], bits_dc_chrominance,
                   val_dc_chrominance);
    add_huff_table(cinfo, &ac_huff_tbl_ptrs[1], bits_ac_chrominance,
                   val_ac_chrominance);
  }
  

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