ref: dab539cd14726de15932b0310532212f8da29bf7
dir: /sys/src/cmd/gs/jpeg/rdrle.c/
/*
* rdrle.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 read input images in Utah 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 input from
* an ordinary stdio stream. They further assume that reading begins
* at the start of the file; start_input may need work if the
* user interface has already read some data (e.g., to determine that
* the file is indeed RLE format).
*
* 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
/*
* We support the following types of RLE files:
*
* GRAYSCALE - 8 bits, no colormap
* MAPPEDGRAY - 8 bits, 1 channel colomap
* PSEUDOCOLOR - 8 bits, 3 channel colormap
* TRUECOLOR - 24 bits, 3 channel colormap
* DIRECTCOLOR - 24 bits, no colormap
*
* For now, we ignore any alpha channel in the image.
*/
typedef enum
{ GRAYSCALE, MAPPEDGRAY, PSEUDOCOLOR, TRUECOLOR, DIRECTCOLOR } rle_kind;
/*
* Since RLE stores scanlines bottom-to-top, we have to invert the image
* to conform to JPEG's top-to-bottom order. To do this, we read the
* incoming image into a virtual array on the first get_pixel_rows call,
* then fetch the required row from the virtual array on subsequent calls.
*/
typedef struct _rle_source_struct * rle_source_ptr;
typedef struct _rle_source_struct {
struct cjpeg_source_struct pub; /* public fields */
rle_kind visual; /* actual type of input file */
jvirt_sarray_ptr image; /* virtual array to hold the image */
JDIMENSION row; /* current row # in the virtual array */
rle_hdr header; /* Input file information */
rle_pixel** rle_row; /* holds a row returned by rle_getrow() */
} rle_source_struct;
/*
* Read the file header; return image size and component count.
*/
METHODDEF(void)
start_input_rle (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
rle_source_ptr source = (rle_source_ptr) sinfo;
JDIMENSION width, height;
#ifdef PROGRESS_REPORT
cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
#endif
/* Use RLE library routine to get the header info */
source->header = *rle_hdr_init(NULL);
source->header.rle_file = source->pub.input_file;
switch (rle_get_setup(&(source->header))) {
case RLE_SUCCESS:
/* A-OK */
break;
case RLE_NOT_RLE:
ERREXIT(cinfo, JERR_RLE_NOT);
break;
case RLE_NO_SPACE:
ERREXIT(cinfo, JERR_RLE_MEM);
break;
case RLE_EMPTY:
ERREXIT(cinfo, JERR_RLE_EMPTY);
break;
case RLE_EOF:
ERREXIT(cinfo, JERR_RLE_EOF);
break;
default:
ERREXIT(cinfo, JERR_RLE_BADERROR);
break;
}
/* Figure out what we have, set private vars and return values accordingly */
width = source->header.xmax - source->header.xmin + 1;
height = source->header.ymax - source->header.ymin + 1;
source->header.xmin = 0; /* realign horizontally */
source->header.xmax = width-1;
cinfo->image_width = width;
cinfo->image_height = height;
cinfo->data_precision = 8; /* we can only handle 8 bit data */
if (source->header.ncolors == 1 && source->header.ncmap == 0) {
source->visual = GRAYSCALE;
TRACEMS2(cinfo, 1, JTRC_RLE_GRAY, width, height);
} else if (source->header.ncolors == 1 && source->header.ncmap == 1) {
source->visual = MAPPEDGRAY;
TRACEMS3(cinfo, 1, JTRC_RLE_MAPGRAY, width, height,
1 << source->header.cmaplen);
} else if (source->header.ncolors == 1 && source->header.ncmap == 3) {
source->visual = PSEUDOCOLOR;
TRACEMS3(cinfo, 1, JTRC_RLE_MAPPED, width, height,
1 << source->header.cmaplen);
} else if (source->header.ncolors == 3 && source->header.ncmap == 3) {
source->visual = TRUECOLOR;
TRACEMS3(cinfo, 1, JTRC_RLE_FULLMAP, width, height,
1 << source->header.cmaplen);
} else if (source->header.ncolors == 3 && source->header.ncmap == 0) {
source->visual = DIRECTCOLOR;
TRACEMS2(cinfo, 1, JTRC_RLE, width, height);
} else
ERREXIT(cinfo, JERR_RLE_UNSUPPORTED);
if (source->visual == GRAYSCALE || source->visual == MAPPEDGRAY) {
cinfo->in_color_space = JCS_GRAYSCALE;
cinfo->input_components = 1;
} else {
cinfo->in_color_space = JCS_RGB;
cinfo->input_components = 3;
}
/*
* A place to hold each scanline while it's converted.
* (GRAYSCALE scanlines don't need converting)
*/
if (source->visual != GRAYSCALE) {
source->rle_row = (rle_pixel**) (*cinfo->mem->alloc_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE,
(JDIMENSION) width, (JDIMENSION) cinfo->input_components);
}
/* request a virtual array to hold the image */
source->image = (*cinfo->mem->request_virt_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
(JDIMENSION) (width * source->header.ncolors),
(JDIMENSION) height, (JDIMENSION) 1);
#ifdef PROGRESS_REPORT
if (progress != NULL) {
/* count file input as separate pass */
progress->total_extra_passes++;
}
#endif
source->pub.buffer_height = 1;
}
/*
* Read one row of pixels.
* Called only after load_image has read the image into the virtual array.
* Used for GRAYSCALE, MAPPEDGRAY, TRUECOLOR, and DIRECTCOLOR images.
*/
METHODDEF(JDIMENSION)
get_rle_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
rle_source_ptr source = (rle_source_ptr) sinfo;
source->row--;
source->pub.buffer = (*cinfo->mem->access_virt_sarray)
((j_common_ptr) cinfo, source->image, source->row, (JDIMENSION) 1, FALSE);
return 1;
}
/*
* Read one row of pixels.
* Called only after load_image has read the image into the virtual array.
* Used for PSEUDOCOLOR images.
*/
METHODDEF(JDIMENSION)
get_pseudocolor_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
rle_source_ptr source = (rle_source_ptr) sinfo;
JSAMPROW src_row, dest_row;
JDIMENSION col;
rle_map *colormap;
int val;
colormap = source->header.cmap;
dest_row = source->pub.buffer[0];
source->row--;
src_row = * (*cinfo->mem->access_virt_sarray)
((j_common_ptr) cinfo, source->image, source->row, (JDIMENSION) 1, FALSE);
for (col = cinfo->image_width; col > 0; col--) {
val = GETJSAMPLE(*src_row++);
*dest_row++ = (JSAMPLE) (colormap[val ] >> 8);
*dest_row++ = (JSAMPLE) (colormap[val + 256] >> 8);
*dest_row++ = (JSAMPLE) (colormap[val + 512] >> 8);
}
return 1;
}
/*
* Load the image into a virtual array. We have to do this because RLE
* files start at the lower left while the JPEG standard has them starting
* in the upper left. This is called the first time we want to get a row
* of input. What we do is load the RLE data into the array and then call
* the appropriate routine to read one row from the array. Before returning,
* we set source->pub.get_pixel_rows so that subsequent calls go straight to
* the appropriate row-reading routine.
*/
METHODDEF(JDIMENSION)
load_image (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
rle_source_ptr source = (rle_source_ptr) sinfo;
JDIMENSION row, col;
JSAMPROW scanline, red_ptr, green_ptr, blue_ptr;
rle_pixel **rle_row;
rle_map *colormap;
char channel;
#ifdef PROGRESS_REPORT
cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
#endif
colormap = source->header.cmap;
rle_row = source->rle_row;
/* Read the RLE data into 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.
*/
RLE_CLR_BIT(source->header, RLE_ALPHA); /* don't read the alpha channel */
#ifdef PROGRESS_REPORT
if (progress != NULL) {
progress->pub.pass_limit = cinfo->image_height;
progress->pub.pass_counter = 0;
(*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
}
#endif
switch (source->visual) {
case GRAYSCALE:
case PSEUDOCOLOR:
for (row = 0; row < cinfo->image_height; row++) {
rle_row = (rle_pixel **) (*cinfo->mem->access_virt_sarray)
((j_common_ptr) cinfo, source->image, row, (JDIMENSION) 1, TRUE);
rle_getrow(&source->header, rle_row);
#ifdef PROGRESS_REPORT
if (progress != NULL) {
progress->pub.pass_counter++;
(*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
}
#endif
}
break;
case MAPPEDGRAY:
case TRUECOLOR:
for (row = 0; row < cinfo->image_height; row++) {
scanline = * (*cinfo->mem->access_virt_sarray)
((j_common_ptr) cinfo, source->image, row, (JDIMENSION) 1, TRUE);
rle_row = source->rle_row;
rle_getrow(&source->header, rle_row);
for (col = 0; col < cinfo->image_width; col++) {
for (channel = 0; channel < source->header.ncolors; channel++) {
*scanline++ = (JSAMPLE)
(colormap[GETJSAMPLE(rle_row[channel][col]) + 256 * channel] >> 8);
}
}
#ifdef PROGRESS_REPORT
if (progress != NULL) {
progress->pub.pass_counter++;
(*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
}
#endif
}
break;
case DIRECTCOLOR:
for (row = 0; row < cinfo->image_height; row++) {
scanline = * (*cinfo->mem->access_virt_sarray)
((j_common_ptr) cinfo, source->image, row, (JDIMENSION) 1, TRUE);
rle_getrow(&source->header, rle_row);
red_ptr = rle_row[0];
green_ptr = rle_row[1];
blue_ptr = rle_row[2];
for (col = cinfo->image_width; col > 0; col--) {
*scanline++ = *red_ptr++;
*scanline++ = *green_ptr++;
*scanline++ = *blue_ptr++;
}
#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
/* Set up to call proper row-extraction routine in future */
if (source->visual == PSEUDOCOLOR) {
source->pub.buffer = source->rle_row;
source->pub.get_pixel_rows = get_pseudocolor_row;
} else {
source->pub.get_pixel_rows = get_rle_row;
}
source->row = cinfo->image_height;
/* And fetch the topmost (bottommost) row */
return (*source->pub.get_pixel_rows) (cinfo, sinfo);
}
/*
* Finish up at the end of the file.
*/
METHODDEF(void)
finish_input_rle (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
{
/* no work */
}
/*
* The module selection routine for RLE format input.
*/
GLOBAL(cjpeg_source_ptr)
jinit_read_rle (j_compress_ptr cinfo)
{
rle_source_ptr source;
/* Create module interface object */
source = (rle_source_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(rle_source_struct));
/* Fill in method ptrs */
source->pub.start_input = start_input_rle;
source->pub.finish_input = finish_input_rle;
source->pub.get_pixel_rows = load_image;
return (cjpeg_source_ptr) source;
}
#endif /* RLE_SUPPORTED */