ref: b0a059537147237e868b4a8f07922ae8a349e55c
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; }