compress_output	(	j_compress_ptr	cinfo,
		JSAMPIMAGE	input_buf
	)
Definition at line 272 of file jctrans.c.
Referenced by start_pass_coef(), and transencode_coef_controller().
{
  my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
  JDIMENSION MCU_col_num;   /* index of current MCU within row */
  JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
  int blkn, ci, xindex, yindex, yoffset, blockcnt;
  JDIMENSION start_col;
  JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
  JBLOCKROW MCU_buffer[C_MAX_BLOCKS_IN_MCU];
  JBLOCKROW buffer_ptr;
  jpeg_component_info *compptr;

  /* Align the virtual buffers for the components used in this scan. */
  for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
    compptr = cinfo->cur_comp_info[ci];
    buffer[ci] = (*cinfo->mem->access_virt_barray)
      ((j_common_ptr) cinfo, coef->whole_image[compptr->component_index],
       coef->iMCU_row_num * compptr->v_samp_factor,
       (JDIMENSION) compptr->v_samp_factor, FALSE);
  }

  /* Loop to process one whole iMCU row */
  for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
       yoffset++) {
    for (MCU_col_num = coef->mcu_ctr; MCU_col_num < cinfo->MCUs_per_row;
     MCU_col_num++) {
      /* Construct list of pointers to DCT blocks belonging to this MCU */
      blkn = 0;         /* index of current DCT block within MCU */
      for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
    compptr = cinfo->cur_comp_info[ci];
    start_col = MCU_col_num * compptr->MCU_width;
    blockcnt = (MCU_col_num < last_MCU_col) ? compptr->MCU_width
                        : compptr->last_col_width;
    for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
      if (coef->iMCU_row_num < last_iMCU_row ||
          yindex+yoffset < compptr->last_row_height) {
        /* Fill in pointers to real blocks in this row */
        buffer_ptr = buffer[ci][yindex+yoffset] + start_col;
        for (xindex = 0; xindex < blockcnt; xindex++)
          MCU_buffer[blkn++] = buffer_ptr++;
      } else {
        /* At bottom of image, need a whole row of dummy blocks */
        xindex = 0;
      }
      /* Fill in any dummy blocks needed in this row.
       * Dummy blocks are filled in the same way as in jccoefct.c:
       * all zeroes in the AC entries, DC entries equal to previous
       * block's DC value.  The init routine has already zeroed the
       * AC entries, so we need only set the DC entries correctly.
       */
      for (; xindex < compptr->MCU_width; xindex++) {
        MCU_buffer[blkn] = coef->dummy_buffer[blkn];
        MCU_buffer[blkn][0][0] = MCU_buffer[blkn-1][0][0];
        blkn++;
      }
    }
      }
      /* Try to write the MCU. */
      if (! (*cinfo->entropy->encode_mcu) (cinfo, MCU_buffer)) {
    /* Suspension forced; update state counters and exit */
    coef->MCU_vert_offset = yoffset;
    coef->mcu_ctr = MCU_col_num;
    return FALSE;
      }
    }
    /* Completed an MCU row, but perhaps not an iMCU row */
    coef->mcu_ctr = 0;
  }
  /* Completed the iMCU row, advance counters for next one */
  coef->iMCU_row_num++;
  start_iMCU_row(cinfo);
  return TRUE;
}
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