ref: bf4f158707ebfeacb15826ad4283ff247d7d81ae
dir: /sys/src/cmd/gs/jpeg/wrrle.c/
/*
* wrrle.c
*
* Copyright (C) 1991-1996, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains routines to write output images in RLE format.
* The Utah Raster Toolkit library is required (version 3.1 or later).
*
* These routines may need modification for non-Unix environments or
* specialized applications. As they stand, they assume output to
* an ordinary stdio stream.
*
* Based on code contributed by Mike Lijewski,
* with updates from Robert Hutchinson.
*/
#include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
#ifdef RLE_SUPPORTED
/* rle.h is provided by the Utah Raster Toolkit. */
#include <rle.h>
/*
* We assume that JSAMPLE has the same representation as rle_pixel,
* to wit, "unsigned char". Hence we can't cope with 12- or 16-bit samples.
*/
#if BITS_IN_JSAMPLE != 8
Sorry, this code only copes with 8-bit JSAMPLEs. /* deliberate syntax err */
#endif
/*
* Since RLE stores scanlines bottom-to-top, we have to invert the image
* from JPEG's top-to-bottom order. To do this, we save the outgoing data
* in a virtual array during put_pixel_row calls, then actually emit the
* RLE file during finish_output.
*/
/*
* For now, if we emit an RLE color map then it is always 256 entries long,
* though not all of the entries need be used.
*/
#define CMAPBITS 8
#define CMAPLENGTH (1<<(CMAPBITS))
typedef struct {
struct djpeg_dest_struct pub; /* public fields */
jvirt_sarray_ptr image; /* virtual array to store the output image */
rle_map *colormap; /* RLE-style color map, or NULL if none */
rle_pixel **rle_row; /* To pass rows to rle_putrow() */
} rle_dest_struct;
typedef rle_dest_struct * rle_dest_ptr;
/* Forward declarations */
METHODDEF(void) rle_put_pixel_rows
JPP((j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
JDIMENSION rows_supplied));
/*
* Write the file header.
*
* In this module it's easier to wait till finish_output to write anything.
*/
METHODDEF(void)
start_output_rle (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
{
rle_dest_ptr dest = (rle_dest_ptr) dinfo;
size_t cmapsize;
int i, ci;
#ifdef PROGRESS_REPORT
cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
#endif
/*
* Make sure the image can be stored in RLE format.
*
* - RLE stores image dimensions as *signed* 16 bit integers. JPEG
* uses unsigned, so we have to check the width.
*
* - Colorspace is expected to be grayscale or RGB.
*
* - The number of channels (components) is expected to be 1 (grayscale/
* pseudocolor) or 3 (truecolor/directcolor).
* (could be 2 or 4 if using an alpha channel, but we aren't)
*/
if (cinfo->output_width > 32767 || cinfo->output_height > 32767)
ERREXIT2(cinfo, JERR_RLE_DIMENSIONS, cinfo->output_width,
cinfo->output_height);
if (cinfo->out_color_space != JCS_GRAYSCALE &&
cinfo->out_color_space != JCS_RGB)
ERREXIT(cinfo, JERR_RLE_COLORSPACE);
if (cinfo->output_components != 1 && cinfo->output_components != 3)
ERREXIT1(cinfo, JERR_RLE_TOOMANYCHANNELS, cinfo->num_components);
/* Convert colormap, if any, to RLE format. */
dest->colormap = NULL;
if (cinfo->quantize_colors) {
/* Allocate storage for RLE-style cmap, zero any extra entries */
cmapsize = cinfo->out_color_components * CMAPLENGTH * SIZEOF(rle_map);
dest->colormap = (rle_map *) (*cinfo->mem->alloc_small)
((j_common_ptr) cinfo, JPOOL_IMAGE, cmapsize);
MEMZERO(dest->colormap, cmapsize);
/* Save away data in RLE format --- note 8-bit left shift! */
/* Shifting would need adjustment for JSAMPLEs wider than 8 bits. */
for (ci = 0; ci < cinfo->out_color_components; ci++) {
for (i = 0; i < cinfo->actual_number_of_colors; i++) {
dest->colormap[ci * CMAPLENGTH + i] =
GETJSAMPLE(cinfo->colormap[ci][i]) << 8;
}
}
}
/* Set the output buffer to the first row */
dest->pub.buffer = (*cinfo->mem->access_virt_sarray)
((j_common_ptr) cinfo, dest->image, (JDIMENSION) 0, (JDIMENSION) 1, TRUE);
dest->pub.buffer_height = 1;
dest->pub.put_pixel_rows = rle_put_pixel_rows;
#ifdef PROGRESS_REPORT
if (progress != NULL) {
progress->total_extra_passes++; /* count file writing as separate pass */
}
#endif
}
/*
* Write some pixel data.
*
* This routine just saves the data away in a virtual array.
*/
METHODDEF(void)
rle_put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
JDIMENSION rows_supplied)
{
rle_dest_ptr dest = (rle_dest_ptr) dinfo;
if (cinfo->output_scanline < cinfo->output_height) {
dest->pub.buffer = (*cinfo->mem->access_virt_sarray)
((j_common_ptr) cinfo, dest->image,
cinfo->output_scanline, (JDIMENSION) 1, TRUE);
}
}
/*
* Finish up at the end of the file.
*
* Here is where we really output the RLE file.
*/
METHODDEF(void)
finish_output_rle (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
{
rle_dest_ptr dest = (rle_dest_ptr) dinfo;
rle_hdr header; /* Output file information */
rle_pixel **rle_row, *red, *green, *blue;
JSAMPROW output_row;
char cmapcomment[80];
int row, col;
int ci;
#ifdef PROGRESS_REPORT
cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
#endif
/* Initialize the header info */
header = *rle_hdr_init(NULL);
header.rle_file = dest->pub.output_file;
header.xmin = 0;
header.xmax = cinfo->output_width - 1;
header.ymin = 0;
header.ymax = cinfo->output_height - 1;
header.alpha = 0;
header.ncolors = cinfo->output_components;
for (ci = 0; ci < cinfo->output_components; ci++) {
RLE_SET_BIT(header, ci);
}
if (cinfo->quantize_colors) {
header.ncmap = cinfo->out_color_components;
header.cmaplen = CMAPBITS;
header.cmap = dest->colormap;
/* Add a comment to the output image with the true colormap length. */
sprintf(cmapcomment, "color_map_length=%d", cinfo->actual_number_of_colors);
rle_putcom(cmapcomment, &header);
}
/* Emit the RLE header and color map (if any) */
rle_put_setup(&header);
/* Now output the RLE data from our virtual array.
* We assume here that (a) rle_pixel is represented the same as JSAMPLE,
* and (b) we are not on a machine where FAR pointers differ from regular.
*/
#ifdef PROGRESS_REPORT
if (progress != NULL) {
progress->pub.pass_limit = cinfo->output_height;
progress->pub.pass_counter = 0;
(*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
}
#endif
if (cinfo->output_components == 1) {
for (row = cinfo->output_height-1; row >= 0; row--) {
rle_row = (rle_pixel **) (*cinfo->mem->access_virt_sarray)
((j_common_ptr) cinfo, dest->image,
(JDIMENSION) row, (JDIMENSION) 1, FALSE);
rle_putrow(rle_row, (int) cinfo->output_width, &header);
#ifdef PROGRESS_REPORT
if (progress != NULL) {
progress->pub.pass_counter++;
(*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
}
#endif
}
} else {
for (row = cinfo->output_height-1; row >= 0; row--) {
rle_row = (rle_pixel **) dest->rle_row;
output_row = * (*cinfo->mem->access_virt_sarray)
((j_common_ptr) cinfo, dest->image,
(JDIMENSION) row, (JDIMENSION) 1, FALSE);
red = rle_row[0];
green = rle_row[1];
blue = rle_row[2];
for (col = cinfo->output_width; col > 0; col--) {
*red++ = GETJSAMPLE(*output_row++);
*green++ = GETJSAMPLE(*output_row++);
*blue++ = GETJSAMPLE(*output_row++);
}
rle_putrow(rle_row, (int) cinfo->output_width, &header);
#ifdef PROGRESS_REPORT
if (progress != NULL) {
progress->pub.pass_counter++;
(*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
}
#endif
}
}
#ifdef PROGRESS_REPORT
if (progress != NULL)
progress->completed_extra_passes++;
#endif
/* Emit file trailer */
rle_puteof(&header);
fflush(dest->pub.output_file);
if (ferror(dest->pub.output_file))
ERREXIT(cinfo, JERR_FILE_WRITE);
}
/*
* The module selection routine for RLE format output.
*/
GLOBAL(djpeg_dest_ptr)
jinit_write_rle (j_decompress_ptr cinfo)
{
rle_dest_ptr dest;
/* Create module interface object, fill in method pointers */
dest = (rle_dest_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(rle_dest_struct));
dest->pub.start_output = start_output_rle;
dest->pub.finish_output = finish_output_rle;
/* Calculate output image dimensions so we can allocate space */
jpeg_calc_output_dimensions(cinfo);
/* Allocate a work array for output to the RLE library. */
dest->rle_row = (*cinfo->mem->alloc_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE,
cinfo->output_width, (JDIMENSION) cinfo->output_components);
/* Allocate a virtual array to hold the image. */
dest->image = (*cinfo->mem->request_virt_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
(JDIMENSION) (cinfo->output_width * cinfo->output_components),
cinfo->output_height, (JDIMENSION) 1);
return (djpeg_dest_ptr) dest;
}
#endif /* RLE_SUPPORTED */