C++ (Cpp) JpegSetSrcManager Examples

Example #1

File: jpeg.c Project: andryblack/ketlaer

int
DecompressJpegRect(int x, int y, int w, int h)
{
  struct jpeg_decompress_struct cinfo;
  struct jpeg_error_mgr jerr;
  int compressedLen;
  CARD8 *compressedData;
  CARD16 *pixelPtr;
  JSAMPROW rowPointer[1];
  int dx, dy;

  compressedLen = (int)ReadCompactLen();
  if (compressedLen <= 0) {
    fprintf(stderr, "Incorrect data received from the server.\n");
    return 0;
  }

  compressedData = malloc(compressedLen);
  if (compressedData == NULL) {
    fprintf(stderr, "Memory allocation error.\n");
    return 0;
  }

  if (!read_from_rfb_server(sock, (char*)compressedData, compressedLen)) {
    free(compressedData);
    return 0;
  }

  cinfo.err = jpeg_std_error(&jerr);
  jpeg_create_decompress(&cinfo);

  JpegSetSrcManager(&cinfo, compressedData, compressedLen);

  jpeg_read_header(&cinfo, TRUE);
  cinfo.out_color_space = JCS_RGB;

  jpeg_start_decompress(&cinfo);
  if (cinfo.output_width != w || cinfo.output_height != h ||
      cinfo.output_components != 3) { 
    fprintf(stderr, "Tight Encoding: Wrong JPEG data received.\n");
    jpeg_destroy_decompress(&cinfo);
    free(compressedData);
    return 0;
  }

  rowPointer[0] = (JSAMPROW)buffer;
  dy = 0;
  while (cinfo.output_scanline < cinfo.output_height) {
    jpeg_read_scanlines(&cinfo, rowPointer, 1);
    if (jpegError) {
      break;
    }
    /* FIXME 16 bpp hardcoded */
    /* Fill the second half of our global buffer with the uncompressed data */
    pixelPtr = (CARD16 *)&buffer[BUFFER_SIZE / 2];
    for (dx = 0; dx < w; dx++) {
       *pixelPtr++ =
 	RGB24_TO_PIXEL(16, buffer[dx*3], buffer[dx*3+1], buffer[dx*3+2]);
     }
    
    /* write scanline to screen */
    dfb_write_data_to_screen(x, y + dy, w, 1, &buffer[BUFFER_SIZE/2]);
    dy++;
  }

  if (!jpegError)
    jpeg_finish_decompress(&cinfo);

  jpeg_destroy_decompress(&cinfo);
  free(compressedData);

  return !jpegError;
}

Example #2

void 
	ClientConnection::DecompressJpegRect(BYTE *src, int srclen, BYTE *dst, int dst_size,int w, int h,rfbPixelFormat m_remoteformat)
{
  struct jpeg_decompress_struct cinfo;
  struct jpeg_error_mgr jerr;
  int pixelsize;
  BYTE *dstBuf=NULL;
  bool dstBufIsTemp = false;

 // Set up JPEG decompression
  cinfo.err = jpeg_std_error(&jerr);
  jpeg_create_decompress(&cinfo);
  JpegSetSrcManager(&cinfo, (char*)src, srclen);
  jpeg_read_header(&cinfo, TRUE);
  cinfo.out_color_space = JCS_RGB;
  pixelsize = 3;


#ifdef JCS_EXTENSIONS
  // Try to have libjpeg output directly to our native format
  if(m_remoteformat.bitsPerPixel==32) {
    int redShift, greenShift, blueShift;

    if(m_remoteformat.bigEndian) {
      redShift = 24 - m_remoteformat.redShift;
      greenShift = 24 - m_remoteformat.greenShift;
      blueShift = 24 - m_remoteformat.blueShift;
    } else {
      redShift = m_remoteformat.redShift;
      greenShift = m_remoteformat.greenShift;
      blueShift = m_remoteformat.blueShift;
    }

    // libjpeg can only handle some "standard" formats
    if(redShift == 0 && greenShift == 8 && blueShift == 16)
      cinfo.out_color_space = JCS_EXT_RGBX;
    if(redShift == 16 && greenShift == 8 && blueShift == 0)
      cinfo.out_color_space = JCS_EXT_BGRX;
    if(redShift == 24 && greenShift == 16 && blueShift == 8)
      cinfo.out_color_space = JCS_EXT_XBGR;
    if(redShift == 8 && greenShift == 16 && blueShift == 24)
      cinfo.out_color_space = JCS_EXT_XRGB;

    if (cinfo.out_color_space != JCS_RGB) {
      dstBuf = dst;
      pixelsize = 4;
    }
  }
#endif

  if (cinfo.out_color_space == JCS_RGB) {
    dstBuf = new BYTE[w * h * pixelsize];
    dstBufIsTemp = true;
  }

  JSAMPROW *rowPointer = new JSAMPROW[h];
  for (int dy = 0; dy < h; dy++)
    rowPointer[dy] = (JSAMPROW)(&dstBuf[dy * w * pixelsize]);

  jpeg_start_decompress(&cinfo);
  if (cinfo.output_width != (unsigned)w || cinfo.output_height != (unsigned)h ||
      cinfo.output_components != pixelsize) {
      jpeg_destroy_decompress(&cinfo);
      return;
  }

  while (cinfo.output_scanline < cinfo.output_height) {
    jpeg_read_scanlines(&cinfo, &rowPointer[cinfo.output_scanline],
			cinfo.output_height - cinfo.output_scanline);
    if (jpegError) {
      break;
    }
  }

  delete [] rowPointer;

  if (!jpegError) {
    jpeg_finish_decompress(&cinfo);
  }

  jpeg_destroy_decompress(&cinfo);
  if (dstBufIsTemp) delete [] dstBuf;
  return ;
}