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* Copyright (C) 1991-1996, Thomas G. Lane.
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* This file is part of the Independent JPEG Group's software.
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* For conditions of distribution and use, see the accompanying README file.
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* This file contains routines to write output images in RLE format.
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* The Utah Raster Toolkit library is required (version 3.1 or later).
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* These routines may need modification for non-Unix environments or
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* specialized applications. As they stand, they assume output to
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* an ordinary stdio stream.
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* Based on code contributed by Mike Lijewski,
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* with updates from Robert Hutchinson.
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#include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
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/* rle.h is provided by the Utah Raster Toolkit. */
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* We assume that JSAMPLE has the same representation as rle_pixel,
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* to wit, "unsigned char". Hence we can't cope with 12- or 16-bit samples.
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#if BITS_IN_JSAMPLE != 8
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Sorry, this code only copes with 8-bit JSAMPLEs. /* deliberate syntax err */
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* Since RLE stores scanlines bottom-to-top, we have to invert the image
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* from JPEG's top-to-bottom order. To do this, we save the outgoing data
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* in a virtual array during put_pixel_row calls, then actually emit the
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* RLE file during finish_output.
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* For now, if we emit an RLE color map then it is always 256 entries long,
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* though not all of the entries need be used.
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#define CMAPLENGTH (1<<(CMAPBITS))
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struct djpeg_dest_struct pub; /* public fields */
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jvirt_sarray_ptr image; /* virtual array to store the output image */
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rle_map *colormap; /* RLE-style color map, or NULL if none */
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rle_pixel **rle_row; /* To pass rows to rle_putrow() */
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typedef rle_dest_struct * rle_dest_ptr;
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/* Forward declarations */
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METHODDEF(void) rle_put_pixel_rows
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JPP((j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
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JDIMENSION rows_supplied));
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* Write the file header.
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* In this module it's easier to wait till finish_output to write anything.
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start_output_rle (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
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rle_dest_ptr dest = (rle_dest_ptr) dinfo;
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#ifdef PROGRESS_REPORT
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cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
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* Make sure the image can be stored in RLE format.
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* - RLE stores image dimensions as *signed* 16 bit integers. JPEG
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* uses unsigned, so we have to check the width.
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* - Colorspace is expected to be grayscale or RGB.
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* - The number of channels (components) is expected to be 1 (grayscale/
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* pseudocolor) or 3 (truecolor/directcolor).
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* (could be 2 or 4 if using an alpha channel, but we aren't)
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if (cinfo->output_width > 32767 || cinfo->output_height > 32767)
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ERREXIT2(cinfo, JERR_RLE_DIMENSIONS, cinfo->output_width,
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cinfo->output_height);
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if (cinfo->out_color_space != JCS_GRAYSCALE &&
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cinfo->out_color_space != JCS_RGB)
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ERREXIT(cinfo, JERR_RLE_COLORSPACE);
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if (cinfo->output_components != 1 && cinfo->output_components != 3)
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ERREXIT1(cinfo, JERR_RLE_TOOMANYCHANNELS, cinfo->num_components);
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/* Convert colormap, if any, to RLE format. */
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dest->colormap = NULL;
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if (cinfo->quantize_colors) {
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/* Allocate storage for RLE-style cmap, zero any extra entries */
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cmapsize = cinfo->out_color_components * CMAPLENGTH * SIZEOF(rle_map);
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dest->colormap = (rle_map *) (*cinfo->mem->alloc_small)
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((j_common_ptr) cinfo, JPOOL_IMAGE, cmapsize);
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MEMZERO(dest->colormap, cmapsize);
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/* Save away data in RLE format --- note 8-bit left shift! */
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/* Shifting would need adjustment for JSAMPLEs wider than 8 bits. */
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for (ci = 0; ci < cinfo->out_color_components; ci++) {
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for (i = 0; i < cinfo->actual_number_of_colors; i++) {
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dest->colormap[ci * CMAPLENGTH + i] =
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GETJSAMPLE(cinfo->colormap[ci][i]) << 8;
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/* Set the output buffer to the first row */
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dest->pub.buffer = (*cinfo->mem->access_virt_sarray)
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((j_common_ptr) cinfo, dest->image, (JDIMENSION) 0, (JDIMENSION) 1, TRUE);
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dest->pub.buffer_height = 1;
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dest->pub.put_pixel_rows = rle_put_pixel_rows;
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#ifdef PROGRESS_REPORT
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if (progress != NULL) {
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progress->total_extra_passes++; /* count file writing as separate pass */
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* Write some pixel data.
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* This routine just saves the data away in a virtual array.
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rle_put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
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JDIMENSION rows_supplied)
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rle_dest_ptr dest = (rle_dest_ptr) dinfo;
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if (cinfo->output_scanline < cinfo->output_height) {
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dest->pub.buffer = (*cinfo->mem->access_virt_sarray)
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((j_common_ptr) cinfo, dest->image,
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cinfo->output_scanline, (JDIMENSION) 1, TRUE);
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* Finish up at the end of the file.
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* Here is where we really output the RLE file.
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finish_output_rle (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
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rle_dest_ptr dest = (rle_dest_ptr) dinfo;
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rle_hdr header; /* Output file information */
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rle_pixel **rle_row, *red, *green, *blue;
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char cmapcomment[80];
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#ifdef PROGRESS_REPORT
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cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
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/* Initialize the header info */
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header = *rle_hdr_init(NULL);
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header.rle_file = dest->pub.output_file;
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header.xmax = cinfo->output_width - 1;
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header.ymax = cinfo->output_height - 1;
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header.ncolors = cinfo->output_components;
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for (ci = 0; ci < cinfo->output_components; ci++) {
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RLE_SET_BIT(header, ci);
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if (cinfo->quantize_colors) {
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header.ncmap = cinfo->out_color_components;
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header.cmaplen = CMAPBITS;
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header.cmap = dest->colormap;
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/* Add a comment to the output image with the true colormap length. */
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sprintf(cmapcomment, "color_map_length=%d", cinfo->actual_number_of_colors);
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rle_putcom(cmapcomment, &header);
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/* Emit the RLE header and color map (if any) */
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rle_put_setup(&header);
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/* Now output the RLE data from our virtual array.
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* We assume here that (a) rle_pixel is represented the same as JSAMPLE,
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* and (b) we are not on a machine where FAR pointers differ from regular.
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#ifdef PROGRESS_REPORT
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if (progress != NULL) {
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progress->pub.pass_limit = cinfo->output_height;
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progress->pub.pass_counter = 0;
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(*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
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if (cinfo->output_components == 1) {
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for (row = cinfo->output_height-1; row >= 0; row--) {
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rle_row = (rle_pixel **) (*cinfo->mem->access_virt_sarray)
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((j_common_ptr) cinfo, dest->image,
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(JDIMENSION) row, (JDIMENSION) 1, FALSE);
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rle_putrow(rle_row, (int) cinfo->output_width, &header);
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#ifdef PROGRESS_REPORT
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if (progress != NULL) {
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progress->pub.pass_counter++;
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(*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
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for (row = cinfo->output_height-1; row >= 0; row--) {
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rle_row = (rle_pixel **) dest->rle_row;
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output_row = * (*cinfo->mem->access_virt_sarray)
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((j_common_ptr) cinfo, dest->image,
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(JDIMENSION) row, (JDIMENSION) 1, FALSE);
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for (col = cinfo->output_width; col > 0; col--) {
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*red++ = GETJSAMPLE(*output_row++);
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*green++ = GETJSAMPLE(*output_row++);
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*blue++ = GETJSAMPLE(*output_row++);
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rle_putrow(rle_row, (int) cinfo->output_width, &header);
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#ifdef PROGRESS_REPORT
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if (progress != NULL) {
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progress->pub.pass_counter++;
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(*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
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#ifdef PROGRESS_REPORT
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if (progress != NULL)
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progress->completed_extra_passes++;
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/* Emit file trailer */
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fflush(dest->pub.output_file);
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if (ferror(dest->pub.output_file))
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ERREXIT(cinfo, JERR_FILE_WRITE);
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* The module selection routine for RLE format output.
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GLOBAL(djpeg_dest_ptr)
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jinit_write_rle (j_decompress_ptr cinfo)
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/* Create module interface object, fill in method pointers */
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dest = (rle_dest_ptr)
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(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
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SIZEOF(rle_dest_struct));
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dest->pub.start_output = start_output_rle;
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dest->pub.finish_output = finish_output_rle;
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/* Calculate output image dimensions so we can allocate space */
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jpeg_calc_output_dimensions(cinfo);
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/* Allocate a work array for output to the RLE library. */
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dest->rle_row = (*cinfo->mem->alloc_sarray)
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((j_common_ptr) cinfo, JPOOL_IMAGE,
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cinfo->output_width, (JDIMENSION) cinfo->output_components);
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/* Allocate a virtual array to hold the image. */
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dest->image = (*cinfo->mem->request_virt_sarray)
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((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
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(JDIMENSION) (cinfo->output_width * cinfo->output_components),
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cinfo->output_height, (JDIMENSION) 1);
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return (djpeg_dest_ptr) dest;
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#endif /* RLE_SUPPORTED */