The Independent JPEG Group's JPEG software v5
diff --git a/rdrle.c b/rdrle.c
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+/*
+ * rdrle.c
+ *
+ * Copyright (C) 1991-1994, 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 */
+ 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,
+ (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->pub.buffer = (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, source->image, cinfo->next_scanline, 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];
+ src_row = * (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, source->image, cinfo->next_scanline, FALSE);
+
+ for (col = cinfo->image_width; col > 0; col--) {
+ val = GETJSAMPLE(*src_row++);
+ *dest_row++ = colormap[val ] >> 8;
+ *dest_row++ = colormap[val + 256] >> 8;
+ *dest_row++ = 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;
+ row = cinfo->image_height;
+
+ /* 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:
+ while (row--) {
+ rle_row = (rle_pixel **) (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, source->image, row, 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:
+ while (row--) {
+ scanline = * (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, source->image, row, 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:
+ while (row--) {
+ scanline = * (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, source->image, row, 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;
+ }
+
+ /* 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 */