Delphi: Быстрое (де)кодирование JPEG с помощью libjpeg-turbo

{ Known color spaces. }
 J_COLOR_SPACE = (
   JCS_UNKNOWN, { error/unspecified }
  JCS_GRAYSCALE,  //* monochrome */
  JCS_RGB,  //* red/green/blue as specified by the RGB_RED, RGB_GREEN,
      //RGB_BLUE, and RGB_PIXELSIZE macros */
  JCS_YCbCr,  //* Y/Cb/Cr (also known as YUV) */
  JCS_CMYK,  //* C/M/Y/K */
  JCS_YCCK,  //* Y/Cb/Cr/K */
  JCS_EXT_RGB,  //* red/green/blue */
  JCS_EXT_RGBX,  //* red/green/blue/x */
  JCS_EXT_BGR,  //* blue/green/red */
  JCS_EXT_BGRX,  //* blue/green/red/x */
  JCS_EXT_XBGR,  //* x/blue/green/red */
  JCS_EXT_XRGB,  //* x/red/green/blue */
//  When out_color_space it set to JCS_EXT_RGBX, JCS_EXT_BGRX,
//    JCS_EXT_XBGR, or JCS_EXT_XRGB during decompression, the X byte is
//    undefined, and in order to ensure the best performance,
//    libjpeg-turbo can set that byte to whatever value it wishes.  Use
//    the following colorspace constants to ensure that the X byte is set
//    to 0xFF, so that it can be interpreted as an opaque alpha
//    channel.
  JCS_EXT_RGBA,  ///* red/green/blue/alpha */
  JCS_EXT_BGRA,  //* blue/green/red/alpha */
  JCS_EXT_ABGR,  //* alpha/blue/green/red */
  JCS_EXT_ARGB  //* alpha/red/green/blue */
   );
 
...
 
 { Standard data source and destination managers: stdio streams. }
 { Caller is responsible for opening the file before and closing after. }
 // jpeg_stdio_dest: procedure(cinfo: j_compress_ptr; FILE * outfile); cdecl;
 // jpeg_stdio_src: procedure(cinfo: j_decompress_ptr; FILE * infile); cdecl;
 
 jpeg_mem_src: procedure(cinfo: j_decompress_ptr; inbuffer: Pointer; insize: LongWord); cdecl;
 jpeg_mem_dest: procedure(cinfo: j_decompress_ptr; outbuffer: Pointer; outsize: PLongWord); cdecl;
 
...
Function init_libJPEG(): boolean;
...
     @jpeg_mem_src := GetProcAddress(libJPEG_Handle, 'jpeg_mem_src');
     @jpeg_mem_dest := GetProcAddress(libJPEG_Handle, 'jpeg_mem_dest');
 
...
 {$DEFINE JPEG_LIB_VERSION = 62} //Version 6b
type
 J_MESSAGE_CODE = (
   JMSG_NOMESSAGE,
   {$IF Declared(JPEG_LIB_VERSION) and (JPEG_LIB_VERSION < 70)}
   JERR_ARITH_NOTIMPL,
   {$IFEND}
   JERR_BAD_ALIGN_TYPE,
   JERR_BAD_ALLOC_CHUNK,
   JERR_BAD_BUFFER_MODE,
   JERR_BAD_COMPONENT_ID,
   {$IF Declared(JPEG_LIB_VERSION) and (JPEG_LIB_VERSION >= 70)}
   JERR_BAD_CROP_SPEC,
   {$IFEND}
   JERR_BAD_DCT_COEF,
   JERR_BAD_DCTSIZE,
   {$IF Declared(JPEG_LIB_VERSION) and (JPEG_LIB_VERSION >= 70)}
   JERR_BAD_DROP_SAMPLING,
   {$IFEND}
   JERR_BAD_HUFF_TABLE,
   JERR_BAD_IN_COLORSPACE,
   JERR_BAD_J_COLORSPACE,
   JERR_BAD_LENGTH,
   JERR_BAD_LIB_VERSION,
   JERR_BAD_MCU_SIZE,
   JERR_BAD_POOL_ID,
   JERR_BAD_PRECISION,
   JERR_BAD_PROGRESSION,
   JERR_BAD_PROG_SCRIPT,
   JERR_BAD_SAMPLING,
   JERR_BAD_SCAN_SCRIPT,
   JERR_BAD_STATE,
   JERR_BAD_STRUCT_SIZE,
   JERR_BAD_VIRTUAL_ACCESS,
   JERR_BUFFER_SIZE,
   JERR_CANT_SUSPEND,
   JERR_CCIR601_NOTIMPL,
   JERR_COMPONENT_COUNT,
   JERR_CONVERSION_NOTIMPL,
   JERR_DAC_INDEX,
   JERR_DAC_VALUE,
   JERR_DHT_INDEX,
   JERR_DQT_INDEX,
   JERR_EMPTY_IMAGE,
   JERR_EMS_READ,
   JERR_EMS_WRITE,
   JERR_EOI_EXPECTED,
   JERR_FILE_READ,
   JERR_FILE_WRITE,
   JERR_FRACT_SAMPLE_NOTIMPL,
   JERR_HUFF_CLEN_OVERFLOW,
   JERR_HUFF_MISSING_CODE,
   JERR_IMAGE_TOO_BIG,
   JERR_INPUT_EMPTY,
   JERR_INPUT_EOF,
   JERR_MISMATCHED_QUANT_TABLE,
   JERR_MISSING_DATA,
   JERR_MODE_CHANGE,
   JERR_NOTIMPL,
   JERR_NOT_COMPILED,
   {$IF Declared(JPEG_LIB_VERSION) and (JPEG_LIB_VERSION >= 70)}
   JERR_NO_ARITH_TABLE,
   {$IFEND}
   JERR_NO_BACKING_STORE,
   JERR_NO_HUFF_TABLE,
   JERR_NO_IMAGE,
   JERR_NO_QUANT_TABLE,
   JERR_NO_SOI,
   JERR_OUT_OF_MEMORY,
   JERR_QUANT_COMPONENTS,
   JERR_QUANT_FEW_COLORS,
   JERR_QUANT_MANY_COLORS,
   JERR_SOF_DUPLICATE,
   JERR_SOF_NO_SOS,
   JERR_SOF_UNSUPPORTED,
   JERR_SOI_DUPLICATE,
   JERR_SOS_NO_SOF,
   JERR_TFILE_CREATE,
   JERR_TFILE_READ,
   JERR_TFILE_SEEK,
   JERR_TFILE_WRITE,
   JERR_TOO_LITTLE_DATA,
   JERR_UNKNOWN_MARKER,
   JERR_VIRTUAL_BUG,
   JERR_WIDTH_OVERFLOW,
   JERR_XMS_READ,
   JERR_XMS_WRITE
 );
 
procedure ERREXIT(cinfo: j_common_ptr; code: J_MESSAGE_CODE);
procedure ERREXIT1(cinfo: j_common_ptr; code: J_MESSAGE_CODE; p1: Integer);
 
...
 
//Макрос из jerror.h
//Fatal errors (print message and exit)
procedure ERREXIT(cinfo: j_common_ptr; code: J_MESSAGE_CODE);
begin
 cinfo^.err^.msg_code := Ord(code);
 cinfo^.err^.error_exit(j_common_ptr(cinfo));
end;
 
procedure ERREXIT1(cinfo: j_common_ptr; code: J_MESSAGE_CODE; p1: Integer);
begin
 cinfo^.err^.msg_code := Ord(code);
 cinfo^.err^.msg_parm.i[0] := p1;
 cinfo^.err^.error_exit(j_common_ptr(cinfo));
end;

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