kc3-lang/libjpeg-turbo/src/jdmerge.h

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• Hash : e69dd40c
  Author :
  Date : 2024-01-23T13:26:41
  

  Reorganize source to make things easier to find
  
  - Move all libjpeg documentation, except for README.ijg, into the doc/
    subdirectory.
  
  - Move the TurboJPEG C API documentation from doc/html/ into
    doc/turbojpeg/.
  
  - Move all C source code and headers into a src/ subdirectory.
  
  - Move turbojpeg-jni.c into the java/ subdirectory.
  
  Referring to #226, there is no ideal solution to this problem.  A
  semantically ideal solution would have involved placing all source code,
  including the SIMD and Java source code, under src/ (or perhaps placing
  C library source code under lib/ and C test program source code under
  test/), all header files under include/, and all documentation under
  doc/.  However:
  
  - To me it makes more sense to have separate top-level directories for
    each language, since the SIMD extensions and the Java API are
    technically optional features.  src/ now contains only the code that
    is relevant to the core C API libraries and associated programs.
  - I didn't want to bury the java/ and simd/ directories or add a level
    of depth to them, since both directories already contain source code
    that is 3-4 levels deep.
  - I would prefer not to separate the header files from the C source
    code, because:
    1. It would be disruptive.  libjpeg and libjpeg-turbo have
       historically placed C source code and headers in the same
       directory, and people who are familiar with both projects (self
       included) are used to looking for the headers in the same directory
       as the C source code.
    2. In terms of how the headers are used internally in libjpeg-turbo,
       the distinction between public and private headers is a bit fuzzy.
  - It didn't make sense to separate the test source code from the library
    source code, since there is not a clear distinction in some cases.
    (For instance, the IJG image I/O functions are used by cjpeg and djpeg
    as well as by the TurboJPEG API.)
  
  This solution is minimally disruptive, since it keeps all C source code
  and headers together and keeps java/ and simd/ as top-level directories.
  It is a bit awkward, because java/ and simd/ technically contain source
  code, even though they are not under src/.  However, other solutions
  would have been more awkward for different reasons.
  
  Closes #226
  

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• src/jdmerge.h

• /*
   * jdmerge.h
   *
   * This file was part of the Independent JPEG Group's software:
   * Copyright (C) 1994-1996, Thomas G. Lane.
   * libjpeg-turbo Modifications:
   * Copyright (C) 2020, 2022, D. R. Commander.
   * For conditions of distribution and use, see the accompanying README.ijg
   * file.
   */
  
  #define JPEG_INTERNALS
  #include "jpeglib.h"
  #include "jsamplecomp.h"
  
  #ifdef UPSAMPLE_MERGING_SUPPORTED
  
  
  /* Private subobject */
  
  typedef struct {
    struct jpeg_upsampler pub;    /* public fields */
  
    /* Pointer to routine to do actual upsampling/conversion of one row group */
    void (*upmethod) (j_decompress_ptr cinfo, _JSAMPIMAGE input_buf,
                      JDIMENSION in_row_group_ctr, _JSAMPARRAY output_buf);
  
    /* Private state for YCC->RGB conversion */
    int *Cr_r_tab;                /* => table for Cr to R conversion */
    int *Cb_b_tab;                /* => table for Cb to B conversion */
    JLONG *Cr_g_tab;              /* => table for Cr to G conversion */
    JLONG *Cb_g_tab;              /* => table for Cb to G conversion */
  
    /* For 2:1 vertical sampling, we produce two output rows at a time.
     * We need a "spare" row buffer to hold the second output row if the
     * application provides just a one-row buffer; we also use the spare
     * to discard the dummy last row if the image height is odd.
     */
    _JSAMPROW spare_row;
    boolean spare_full;           /* T if spare buffer is occupied */
  
    JDIMENSION out_row_width;     /* samples per output row */
    JDIMENSION rows_to_go;        /* counts rows remaining in image */
  } my_merged_upsampler;
  
  typedef my_merged_upsampler *my_merged_upsample_ptr;
  
  #endif /* UPSAMPLE_MERGING_SUPPORTED */
  

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