The Independent JPEG Group's JPEG software v5a
diff --git a/rdppm.c b/rdppm.c
index 6aa8e6f..2641e6d 100644
--- a/rdppm.c
+++ b/rdppm.c
@@ -6,6 +6,7 @@
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains routines to read input images in PPM/PGM format.
+ * The extended 2-byte-per-sample raw PPM/PGM formats are supported.
* The PBMPLUS library is NOT required to compile this software
* (but it is highly useful as a set of PPM image manipulation programs).
*
@@ -72,7 +73,7 @@
U_CHAR *iobuffer; /* non-FAR pointer to I/O buffer */
JSAMPROW pixrow; /* FAR pointer to same */
- JDIMENSION buffer_width; /* width of one row */
+ size_t buffer_width; /* width of I/O buffer */
JSAMPLE *rescale; /* => maxval-remapping array, or NULL */
} ppm_source_struct;
@@ -85,7 +86,7 @@
/* A comment/newline sequence is returned as a newline */
{
register int ch;
-
+
ch = getc(infile);
if (ch == '#') {
do {
@@ -105,17 +106,17 @@
{
register int ch;
register unsigned int val;
-
+
/* Skip any leading whitespace */
do {
ch = pbm_getc(infile);
if (ch == EOF)
ERREXIT(cinfo, JERR_INPUT_EOF);
} while (ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r');
-
+
if (ch < '0' || ch > '9')
ERREXIT(cinfo, JERR_PPM_NONNUMERIC);
-
+
val = ch - '0';
while ((ch = pbm_getc(infile)) >= '0' && ch <= '9') {
val *= 10;
@@ -131,8 +132,8 @@
* We provide several different versions depending on input file format.
* In all cases, input is scaled to the size of JSAMPLE.
*
- * Note that a really fast path is provided for reading raw files with
- * maxval = MAXJSAMPLE, which is the normal case (at least for 8-bit JSAMPLEs).
+ * A really fast path is provided for reading byte/sample raw files with
+ * maxval = MAXJSAMPLE, which is the normal case for 8-bit data.
*/
@@ -145,7 +146,7 @@
register JSAMPROW ptr;
register JSAMPLE *rescale = source->rescale;
JDIMENSION col;
-
+
ptr = source->pub.buffer[0];
for (col = cinfo->image_width; col > 0; col--) {
*ptr++ = rescale[read_pbm_integer(cinfo, infile)];
@@ -163,7 +164,7 @@
register JSAMPROW ptr;
register JSAMPLE *rescale = source->rescale;
JDIMENSION col;
-
+
ptr = source->pub.buffer[0];
for (col = cinfo->image_width; col > 0; col--) {
*ptr++ = rescale[read_pbm_integer(cinfo, infile)];
@@ -176,7 +177,7 @@
METHODDEF JDIMENSION
get_scaled_gray_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
-/* This version is for reading raw-format PGM files with any maxval */
+/* This version is for reading raw-byte-format PGM files with any maxval */
{
ppm_source_ptr source = (ppm_source_ptr) sinfo;
register JSAMPROW ptr;
@@ -197,7 +198,7 @@
METHODDEF JDIMENSION
get_scaled_rgb_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
-/* This version is for reading raw-format PPM files with any maxval */
+/* This version is for reading raw-byte-format PPM files with any maxval */
{
ppm_source_ptr source = (ppm_source_ptr) sinfo;
register JSAMPROW ptr;
@@ -220,9 +221,10 @@
METHODDEF JDIMENSION
get_raw_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
-/* This version is for reading raw-format files with maxval = MAXJSAMPLE. */
-/* In this case we just read right into the JSAMPLE buffer! */
-/* Note that same code works for PPM and PGM files. */
+/* This version is for reading raw-byte-format files with maxval = MAXJSAMPLE.
+ * In this case we just read right into the JSAMPLE buffer!
+ * Note that same code works for PPM and PGM files.
+ */
{
ppm_source_ptr source = (ppm_source_ptr) sinfo;
@@ -232,6 +234,60 @@
}
+METHODDEF JDIMENSION
+get_word_gray_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
+/* This version is for reading raw-word-format PGM files with any maxval */
+{
+ ppm_source_ptr source = (ppm_source_ptr) sinfo;
+ register JSAMPROW ptr;
+ register U_CHAR * bufferptr;
+ register JSAMPLE *rescale = source->rescale;
+ JDIMENSION col;
+
+ if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
+ ERREXIT(cinfo, JERR_INPUT_EOF);
+ ptr = source->pub.buffer[0];
+ bufferptr = source->iobuffer;
+ for (col = cinfo->image_width; col > 0; col--) {
+ register int temp;
+ temp = UCH(*bufferptr++);
+ temp |= UCH(*bufferptr++) << 8;
+ *ptr++ = rescale[temp];
+ }
+ return 1;
+}
+
+
+METHODDEF JDIMENSION
+get_word_rgb_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
+/* This version is for reading raw-word-format PPM files with any maxval */
+{
+ ppm_source_ptr source = (ppm_source_ptr) sinfo;
+ register JSAMPROW ptr;
+ register U_CHAR * bufferptr;
+ register JSAMPLE *rescale = source->rescale;
+ JDIMENSION col;
+
+ if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
+ ERREXIT(cinfo, JERR_INPUT_EOF);
+ ptr = source->pub.buffer[0];
+ bufferptr = source->iobuffer;
+ for (col = cinfo->image_width; col > 0; col--) {
+ register int temp;
+ temp = UCH(*bufferptr++);
+ temp |= UCH(*bufferptr++) << 8;
+ *ptr++ = rescale[temp];
+ temp = UCH(*bufferptr++);
+ temp |= UCH(*bufferptr++) << 8;
+ *ptr++ = rescale[temp];
+ temp = UCH(*bufferptr++);
+ temp |= UCH(*bufferptr++) << 8;
+ *ptr++ = rescale[temp];
+ }
+ return 1;
+}
+
+
/*
* Read the file header; return image size and component count.
*/
@@ -242,14 +298,14 @@
ppm_source_ptr source = (ppm_source_ptr) sinfo;
int c;
unsigned int w, h, maxval;
- boolean can_use_raw;
+ boolean need_iobuffer, use_raw_buffer, need_rescale;
if (getc(source->pub.input_file) != 'P')
ERREXIT(cinfo, JERR_PPM_NOT);
c = getc(source->pub.input_file); /* save format discriminator for a sec */
- /* while we fetch the remaining header info */
+ /* fetch the remaining header info */
w = read_pbm_integer(cinfo, source->pub.input_file);
h = read_pbm_integer(cinfo, source->pub.input_file);
maxval = read_pbm_integer(cinfo, source->pub.input_file);
@@ -261,8 +317,10 @@
cinfo->image_width = (JDIMENSION) w;
cinfo->image_height = (JDIMENSION) h;
- /* Raw PPM/PGM matches JSAMPLE representation iff: */
- can_use_raw = (maxval == MAXJSAMPLE && SIZEOF(JSAMPLE) == SIZEOF(U_CHAR));
+ /* initialize flags to most common settings */
+ need_iobuffer = TRUE; /* do we need an I/O buffer? */
+ use_raw_buffer = FALSE; /* do we map input buffer onto I/O buffer? */
+ need_rescale = TRUE; /* do we need a rescale array? */
switch (c) {
case '2': /* it's a text-format PGM file */
@@ -270,7 +328,7 @@
cinfo->in_color_space = JCS_GRAYSCALE;
TRACEMS2(cinfo, 1, JTRC_PGM_TEXT, w, h);
source->pub.get_pixel_rows = get_text_gray_row;
- can_use_raw = FALSE; /* force a rescale array to be made */
+ need_iobuffer = FALSE;
break;
case '3': /* it's a text-format PPM file */
@@ -278,35 +336,37 @@
cinfo->in_color_space = JCS_RGB;
TRACEMS2(cinfo, 1, JTRC_PPM_TEXT, w, h);
source->pub.get_pixel_rows = get_text_rgb_row;
- can_use_raw = FALSE; /* force a rescale array to be made */
+ need_iobuffer = FALSE;
break;
case '5': /* it's a raw-format PGM file */
cinfo->input_components = 1;
cinfo->in_color_space = JCS_GRAYSCALE;
TRACEMS2(cinfo, 1, JTRC_PGM, w, h);
- if (can_use_raw)
+ if (maxval > 255) {
+ source->pub.get_pixel_rows = get_word_gray_row;
+ } else if (maxval == MAXJSAMPLE && SIZEOF(JSAMPLE) == SIZEOF(U_CHAR)) {
source->pub.get_pixel_rows = get_raw_row;
- else
+ use_raw_buffer = TRUE;
+ need_rescale = FALSE;
+ } else {
source->pub.get_pixel_rows = get_scaled_gray_row;
- /* allocate space for I/O buffer: 1 byte/pixel */
- source->iobuffer = (U_CHAR *)
- (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- (size_t) (SIZEOF(U_CHAR) * (size_t) w));
+ }
break;
case '6': /* it's a raw-format PPM file */
cinfo->input_components = 3;
cinfo->in_color_space = JCS_RGB;
TRACEMS2(cinfo, 1, JTRC_PPM, w, h);
- if (can_use_raw)
+ if (maxval > 255) {
+ source->pub.get_pixel_rows = get_word_rgb_row;
+ } else if (maxval == MAXJSAMPLE && SIZEOF(JSAMPLE) == SIZEOF(U_CHAR)) {
source->pub.get_pixel_rows = get_raw_row;
- else
+ use_raw_buffer = TRUE;
+ need_rescale = FALSE;
+ } else {
source->pub.get_pixel_rows = get_scaled_rgb_row;
- /* allocate space for I/O buffer: 3 bytes/pixel */
- source->iobuffer = (U_CHAR *)
- (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- (size_t) (3 * SIZEOF(U_CHAR) * (size_t) w));
+ }
break;
default:
@@ -314,9 +374,17 @@
break;
}
+ /* Allocate space for I/O buffer: 1 or 3 bytes or words/pixel. */
+ if (need_iobuffer) {
+ source->buffer_width = (size_t) w * cinfo->input_components *
+ ((maxval<=255) ? SIZEOF(U_CHAR) : (2*SIZEOF(U_CHAR)));
+ source->iobuffer = (U_CHAR *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ source->buffer_width);
+ }
+
/* Create compressor input buffer. */
- source->buffer_width = (JDIMENSION) w * cinfo->input_components;
- if (can_use_raw) {
+ if (use_raw_buffer) {
/* For unscaled raw-input case, we can just map it onto the I/O buffer. */
/* Synthesize a JSAMPARRAY pointer structure */
/* Cast here implies near->far pointer conversion on PCs */
@@ -327,14 +395,12 @@
/* Need to translate anyway, so make a separate sample buffer. */
source->pub.buffer = (*cinfo->mem->alloc_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE,
- source->buffer_width, (JDIMENSION) 1);
+ (JDIMENSION) w * cinfo->input_components, (JDIMENSION) 1);
source->pub.buffer_height = 1;
}
- /* Compute the rescaling array if required (we use it for all but raw) */
- if (can_use_raw) {
- source->rescale = NULL; /* no rescaling required */
- } else {
+ /* Compute the rescaling array if required. */
+ if (need_rescale) {
INT32 val, half_maxval;
/* On 16-bit-int machines we have to be careful of maxval = 65535 */
