ref: 5c1feb0ef0b795e5de71e956f9ccddcd5c4b7f21
dir: /sys/src/cmd/gs/jpeg/rdswitch.c/
/*
* rdswitch.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 process some of cjpeg's more complicated
* command-line switches. Switches processed here are:
* -qtables file Read quantization tables from text file
* -scans file Read scan script from text file
* -qslots N[,N,...] Set component quantization table selectors
* -sample HxV[,HxV,...] Set component sampling factors
*/
#include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
#include <ctype.h> /* to declare isdigit(), isspace() */
LOCAL(int)
text_getc (FILE * file)
/* Read next char, skipping over any comments (# to end of line) */
/* A comment/newline sequence is returned as a newline */
{
register int ch;
ch = getc(file);
if (ch == '#') {
do {
ch = getc(file);
} while (ch != '\n' && ch != EOF);
}
return ch;
}
LOCAL(boolean)
read_text_integer (FILE * file, long * result, int * termchar)
/* Read an unsigned decimal integer from a file, store it in result */
/* Reads one trailing character after the integer; returns it in termchar */
{
register int ch;
register long val;
/* Skip any leading whitespace, detect EOF */
do {
ch = text_getc(file);
if (ch == EOF) {
*termchar = ch;
return FALSE;
}
} while (isspace(ch));
if (! isdigit(ch)) {
*termchar = ch;
return FALSE;
}
val = ch - '0';
while ((ch = text_getc(file)) != EOF) {
if (! isdigit(ch))
break;
val *= 10;
val += ch - '0';
}
*result = val;
*termchar = ch;
return TRUE;
}
GLOBAL(boolean)
read_quant_tables (j_compress_ptr cinfo, char * filename,
int scale_factor, boolean force_baseline)
/* Read a set of quantization tables from the specified file.
* The file is plain ASCII text: decimal numbers with whitespace between.
* Comments preceded by '#' may be included in the file.
* There may be one to NUM_QUANT_TBLS tables in the file, each of 64 values.
* The tables are implicitly numbered 0,1,etc.
* NOTE: does not affect the qslots mapping, which will default to selecting
* table 0 for luminance (or primary) components, 1 for chrominance components.
* You must use -qslots if you want a different component->table mapping.
*/
{
FILE * fp;
int tblno, i, termchar;
long val;
unsigned int table[DCTSIZE2];
if ((fp = fopen(filename, "r")) == NULL) {
fprintf(stderr, "Can't open table file %s\n", filename);
return FALSE;
}
tblno = 0;
while (read_text_integer(fp, &val, &termchar)) { /* read 1st element of table */
if (tblno >= NUM_QUANT_TBLS) {
fprintf(stderr, "Too many tables in file %s\n", filename);
fclose(fp);
return FALSE;
}
table[0] = (unsigned int) val;
for (i = 1; i < DCTSIZE2; i++) {
if (! read_text_integer(fp, &val, &termchar)) {
fprintf(stderr, "Invalid table data in file %s\n", filename);
fclose(fp);
return FALSE;
}
table[i] = (unsigned int) val;
}
jpeg_add_quant_table(cinfo, tblno, table, scale_factor, force_baseline);
tblno++;
}
if (termchar != EOF) {
fprintf(stderr, "Non-numeric data in file %s\n", filename);
fclose(fp);
return FALSE;
}
fclose(fp);
return TRUE;
}
#ifdef C_MULTISCAN_FILES_SUPPORTED
LOCAL(boolean)
read_scan_integer (FILE * file, long * result, int * termchar)
/* Variant of read_text_integer that always looks for a non-space termchar;
* this simplifies parsing of punctuation in scan scripts.
*/
{
register int ch;
if (! read_text_integer(file, result, termchar))
return FALSE;
ch = *termchar;
while (ch != EOF && isspace(ch))
ch = text_getc(file);
if (isdigit(ch)) { /* oops, put it back */
if (ungetc(ch, file) == EOF)
return FALSE;
ch = ' ';
} else {
/* Any separators other than ';' and ':' are ignored;
* this allows user to insert commas, etc, if desired.
*/
if (ch != EOF && ch != ';' && ch != ':')
ch = ' ';
}
*termchar = ch;
return TRUE;
}
GLOBAL(boolean)
read_scan_script (j_compress_ptr cinfo, char * filename)
/* Read a scan script from the specified text file.
* Each entry in the file defines one scan to be emitted.
* Entries are separated by semicolons ';'.
* An entry contains one to four component indexes,
* optionally followed by a colon ':' and four progressive-JPEG parameters.
* The component indexes denote which component(s) are to be transmitted
* in the current scan. The first component has index 0.
* Sequential JPEG is used if the progressive-JPEG parameters are omitted.
* The file is free format text: any whitespace may appear between numbers
* and the ':' and ';' punctuation marks. Also, other punctuation (such
* as commas or dashes) can be placed between numbers if desired.
* Comments preceded by '#' may be included in the file.
* Note: we do very little validity checking here;
* jcmaster.c will validate the script parameters.
*/
{
FILE * fp;
int scanno, ncomps, termchar;
long val;
jpeg_scan_info * scanptr;
#define MAX_SCANS 100 /* quite arbitrary limit */
jpeg_scan_info scans[MAX_SCANS];
if ((fp = fopen(filename, "r")) == NULL) {
fprintf(stderr, "Can't open scan definition file %s\n", filename);
return FALSE;
}
scanptr = scans;
scanno = 0;
while (read_scan_integer(fp, &val, &termchar)) {
if (scanno >= MAX_SCANS) {
fprintf(stderr, "Too many scans defined in file %s\n", filename);
fclose(fp);
return FALSE;
}
scanptr->component_index[0] = (int) val;
ncomps = 1;
while (termchar == ' ') {
if (ncomps >= MAX_COMPS_IN_SCAN) {
fprintf(stderr, "Too many components in one scan in file %s\n",
filename);
fclose(fp);
return FALSE;
}
if (! read_scan_integer(fp, &val, &termchar))
goto bogus;
scanptr->component_index[ncomps] = (int) val;
ncomps++;
}
scanptr->comps_in_scan = ncomps;
if (termchar == ':') {
if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')
goto bogus;
scanptr->Ss = (int) val;
if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')
goto bogus;
scanptr->Se = (int) val;
if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')
goto bogus;
scanptr->Ah = (int) val;
if (! read_scan_integer(fp, &val, &termchar))
goto bogus;
scanptr->Al = (int) val;
} else {
/* set non-progressive parameters */
scanptr->Ss = 0;
scanptr->Se = DCTSIZE2-1;
scanptr->Ah = 0;
scanptr->Al = 0;
}
if (termchar != ';' && termchar != EOF) {
bogus:
fprintf(stderr, "Invalid scan entry format in file %s\n", filename);
fclose(fp);
return FALSE;
}
scanptr++, scanno++;
}
if (termchar != EOF) {
fprintf(stderr, "Non-numeric data in file %s\n", filename);
fclose(fp);
return FALSE;
}
if (scanno > 0) {
/* Stash completed scan list in cinfo structure.
* NOTE: for cjpeg's use, JPOOL_IMAGE is the right lifetime for this data,
* but if you want to compress multiple images you'd want JPOOL_PERMANENT.
*/
scanptr = (jpeg_scan_info *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
scanno * SIZEOF(jpeg_scan_info));
MEMCOPY(scanptr, scans, scanno * SIZEOF(jpeg_scan_info));
cinfo->scan_info = scanptr;
cinfo->num_scans = scanno;
}
fclose(fp);
return TRUE;
}
#endif /* C_MULTISCAN_FILES_SUPPORTED */
GLOBAL(boolean)
set_quant_slots (j_compress_ptr cinfo, char *arg)
/* Process a quantization-table-selectors parameter string, of the form
* N[,N,...]
* If there are more components than parameters, the last value is replicated.
*/
{
int val = 0; /* default table # */
int ci;
char ch;
for (ci = 0; ci < MAX_COMPONENTS; ci++) {
if (*arg) {
ch = ','; /* if not set by sscanf, will be ',' */
if (sscanf(arg, "%d%c", &val, &ch) < 1)
return FALSE;
if (ch != ',') /* syntax check */
return FALSE;
if (val < 0 || val >= NUM_QUANT_TBLS) {
fprintf(stderr, "JPEG quantization tables are numbered 0..%d\n",
NUM_QUANT_TBLS-1);
return FALSE;
}
cinfo->comp_info[ci].quant_tbl_no = val;
while (*arg && *arg++ != ',') /* advance to next segment of arg string */
;
} else {
/* reached end of parameter, set remaining components to last table */
cinfo->comp_info[ci].quant_tbl_no = val;
}
}
return TRUE;
}
GLOBAL(boolean)
set_sample_factors (j_compress_ptr cinfo, char *arg)
/* Process a sample-factors parameter string, of the form
* HxV[,HxV,...]
* If there are more components than parameters, "1x1" is assumed for the rest.
*/
{
int ci, val1, val2;
char ch1, ch2;
for (ci = 0; ci < MAX_COMPONENTS; ci++) {
if (*arg) {
ch2 = ','; /* if not set by sscanf, will be ',' */
if (sscanf(arg, "%d%c%d%c", &val1, &ch1, &val2, &ch2) < 3)
return FALSE;
if ((ch1 != 'x' && ch1 != 'X') || ch2 != ',') /* syntax check */
return FALSE;
if (val1 <= 0 || val1 > 4 || val2 <= 0 || val2 > 4) {
fprintf(stderr, "JPEG sampling factors must be 1..4\n");
return FALSE;
}
cinfo->comp_info[ci].h_samp_factor = val1;
cinfo->comp_info[ci].v_samp_factor = val2;
while (*arg && *arg++ != ',') /* advance to next segment of arg string */
;
} else {
/* reached end of parameter, set remaining components to 1x1 sampling */
cinfo->comp_info[ci].h_samp_factor = 1;
cinfo->comp_info[ci].v_samp_factor = 1;
}
}
return TRUE;
}