DLLEXPORT int tjDecompressToYUVPlanes(tjhandle handle,
                                      const unsigned char *jpegBuf,
                                      unsigned long jpegSize,
                                      unsigned char **dstPlanes, int width,
                                      int *strides, int height, int flags)
{
  int i, sfi, row, retval = 0;
  int jpegwidth, jpegheight, jpegSubsamp, scaledw, scaledh;
  int pw[MAX_COMPONENTS], ph[MAX_COMPONENTS], iw[MAX_COMPONENTS],
    tmpbufsize = 0, usetmpbuf = 0, th[MAX_COMPONENTS];
  JSAMPLE *_tmpbuf = NULL, *ptr;
  JSAMPROW *outbuf[MAX_COMPONENTS], *tmpbuf[MAX_COMPONENTS];
  int dctsize;

  getdinstance(handle);
  this->jerr.stopOnWarning = (flags & TJFLAG_STOPONWARNING) ? TRUE : FALSE;

  for (i = 0; i < MAX_COMPONENTS; i++) {
    tmpbuf[i] = NULL;  outbuf[i] = NULL;
  }

  if ((this->init & DECOMPRESS) == 0)
    _throw("tjDecompressToYUVPlanes(): Instance has not been initialized for decompression");

  if (jpegBuf == NULL || jpegSize <= 0 || !dstPlanes || !dstPlanes[0] ||
      width < 0 || height < 0)
    _throw("tjDecompressToYUVPlanes(): Invalid argument");

#ifndef NO_PUTENV
  if (flags & TJFLAG_FORCEMMX) putenv("JSIMD_FORCEMMX=1");
  else if (flags & TJFLAG_FORCESSE) putenv("JSIMD_FORCESSE=1");
  else if (flags & TJFLAG_FORCESSE2) putenv("JSIMD_FORCESSE2=1");
#endif

  if (setjmp(this->jerr.setjmp_buffer)) {
    /* If we get here, the JPEG code has signaled an error. */
    retval = -1;  goto bailout;
  }

  if (!this->headerRead) {
    jpeg_mem_src_tj(dinfo, jpegBuf, jpegSize);
    jpeg_read_header(dinfo, TRUE);
  }
  this->headerRead = 0;
  jpegSubsamp = getSubsamp(dinfo);
  if (jpegSubsamp < 0)
    _throw("tjDecompressToYUVPlanes(): Could not determine subsampling type for JPEG image");

  if (jpegSubsamp != TJSAMP_GRAY && (!dstPlanes[1] || !dstPlanes[2]))
    _throw("tjDecompressToYUVPlanes(): Invalid argument");

  jpegwidth = dinfo->image_width;  jpegheight = dinfo->image_height;
  if (width == 0) width = jpegwidth;
  if (height == 0) height = jpegheight;
  for (i = 0; i < NUMSF; i++) {
    scaledw = TJSCALED(jpegwidth, sf[i]);
    scaledh = TJSCALED(jpegheight, sf[i]);
    if (scaledw <= width && scaledh <= height)
      break;
  }
  if (i >= NUMSF)
    _throw("tjDecompressToYUVPlanes(): Could not scale down to desired image dimensions");
  if (dinfo->num_components > 3)
    _throw("tjDecompressToYUVPlanes(): JPEG image must have 3 or fewer components");

  width = scaledw;  height = scaledh;
  dinfo->scale_num = sf[i].num;
  dinfo->scale_denom = sf[i].denom;
  sfi = i;
  jpeg_calc_output_dimensions(dinfo);

  dctsize = DCTSIZE * sf[sfi].num / sf[sfi].denom;

  for (i = 0; i < dinfo->num_components; i++) {
    jpeg_component_info *compptr = &dinfo->comp_info[i];
    int ih;

    iw[i] = compptr->width_in_blocks * dctsize;
    ih = compptr->height_in_blocks * dctsize;
    pw[i] = PAD(dinfo->output_width, dinfo->max_h_samp_factor) *
            compptr->h_samp_factor / dinfo->max_h_samp_factor;
    ph[i] = PAD(dinfo->output_height, dinfo->max_v_samp_factor) *
            compptr->v_samp_factor / dinfo->max_v_samp_factor;
    if (iw[i] != pw[i] || ih != ph[i]) usetmpbuf = 1;
    th[i] = compptr->v_samp_factor * dctsize;
    tmpbufsize += iw[i] * th[i];
    if ((outbuf[i] = (JSAMPROW *)malloc(sizeof(JSAMPROW) * ph[i])) == NULL)
      _throw("tjDecompressToYUVPlanes(): Memory allocation failure");
    ptr = dstPlanes[i];
    for (row = 0; row < ph[i]; row++) {
      outbuf[i][row] = ptr;
      ptr += (strides && strides[i] != 0) ? strides[i] : pw[i];
    }
  }
  if (usetmpbuf) {
    if ((_tmpbuf = (JSAMPLE *)malloc(sizeof(JSAMPLE) * tmpbufsize)) == NULL)
      _throw("tjDecompressToYUVPlanes(): Memory allocation failure");
    ptr = _tmpbuf;
    for (i = 0; i < dinfo->num_components; i++) {
      if ((tmpbuf[i] = (JSAMPROW *)malloc(sizeof(JSAMPROW) * th[i])) == NULL)
        _throw("tjDecompressToYUVPlanes(): Memory allocation failure");
      for (row = 0; row < th[i]; row++) {
        tmpbuf[i][row] = ptr;
        ptr += iw[i];
      }
    }
  }

  if (setjmp(this->jerr.setjmp_buffer)) {
    /* If we get here, the JPEG code has signaled an error. */
    retval = -1;  goto bailout;
  }

  if (flags & TJFLAG_FASTUPSAMPLE) dinfo->do_fancy_upsampling = FALSE;
  if (flags & TJFLAG_FASTDCT) dinfo->dct_method = JDCT_FASTEST;
  dinfo->raw_data_out = TRUE;

  jpeg_start_decompress(dinfo);
  for (row = 0; row < (int)dinfo->output_height;
       row += dinfo->max_v_samp_factor * dinfo->_min_DCT_scaled_size) {
    JSAMPARRAY yuvptr[MAX_COMPONENTS];
    int crow[MAX_COMPONENTS];

    for (i = 0; i < dinfo->num_components; i++) {
      jpeg_component_info *compptr = &dinfo->comp_info[i];

      if (jpegSubsamp == TJ_420) {
        /* When 4:2:0 subsampling is used with IDCT scaling, libjpeg will try
           to be clever and use the IDCT to perform upsampling on the U and V
           planes.  For instance, if the output image is to be scaled by 1/2
           relative to the JPEG image, then the scaling factor and upsampling
           effectively cancel each other, so a normal 8x8 IDCT can be used.
           However, this is not desirable when using the decompress-to-YUV
           functionality in TurboJPEG, since we want to output the U and V
           planes in their subsampled form.  Thus, we have to override some
           internal libjpeg parameters to force it to use the "scaled" IDCT
           functions on the U and V planes. */
        compptr->_DCT_scaled_size = dctsize;
        compptr->MCU_sample_width = tjMCUWidth[jpegSubsamp] *
          sf[sfi].num / sf[sfi].denom *
          compptr->v_samp_factor / dinfo->max_v_samp_factor;
        dinfo->idct->inverse_DCT[i] = dinfo->idct->inverse_DCT[0];
      }
      crow[i] = row * compptr->v_samp_factor / dinfo->max_v_samp_factor;
      if (usetmpbuf) yuvptr[i] = tmpbuf[i];
      else yuvptr[i] = &outbuf[i][crow[i]];
    }
    jpeg_read_raw_data(dinfo, yuvptr,
                       dinfo->max_v_samp_factor * dinfo->_min_DCT_scaled_size);
    if (usetmpbuf) {
      int j;

      for (i = 0; i < dinfo->num_components; i++) {
        for (j = 0; j < MIN(th[i], ph[i] - crow[i]); j++) {
          memcpy(outbuf[i][crow[i] + j], tmpbuf[i][j], pw[i]);
        }
      }
    }
  }
  jpeg_finish_decompress(dinfo);

bailout:
  if (dinfo->global_state > DSTATE_START) jpeg_abort_decompress(dinfo);
  for (i = 0; i < MAX_COMPONENTS; i++) {
    if (tmpbuf[i]) free(tmpbuf[i]);
    if (outbuf[i]) free(outbuf[i]);
  }
  if (_tmpbuf) free(_tmpbuf);
  if (this->jerr.warning) retval = -1;
  this->jerr.stopOnWarning = FALSE;
  return retval;
}
Unknown