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plt-scheme  4.2.1
Defines | Functions
rdswitch.c File Reference
#include "cdjpeg.h"
#include <ctype.h>

Go to the source code of this file.

Defines

#define MAX_SCANS   100 /* quite arbitrary limit */

Functions

 text_getc (FILE *file)
 read_text_integer (FILE *file, long *result, int *termchar)
 read_quant_tables (j_compress_ptr cinfo, char *filename, int scale_factor, boolean force_baseline)
 read_scan_integer (FILE *file, long *result, int *termchar)
 read_scan_script (j_compress_ptr cinfo, char *filename)
 set_quant_slots (j_compress_ptr cinfo, char *arg)
 set_sample_factors (j_compress_ptr cinfo, char *arg)

Define Documentation

#define MAX_SCANS   100 /* quite arbitrary limit */

Function Documentation

read_quant_tables ( j_compress_ptr  cinfo,
char *  filename,
int  scale_factor,
boolean  force_baseline 
)

Definition at line 73 of file rdswitch.c.

{
  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;
}

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read_scan_integer ( FILE *  file,
long *  result,
int termchar 
)

Definition at line 129 of file rdswitch.c.

{
  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;
}

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read_scan_script ( j_compress_ptr  cinfo,
char *  filename 
)

Definition at line 158 of file rdswitch.c.

{
  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;
}

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read_text_integer ( FILE *  file,
long *  result,
int termchar 
)

Definition at line 38 of file rdswitch.c.

{
  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;
}

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set_quant_slots ( j_compress_ptr  cinfo,
char *  arg 
)

Definition at line 266 of file rdswitch.c.

{
  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;
}

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set_sample_factors ( j_compress_ptr  cinfo,
char *  arg 
)

Definition at line 301 of file rdswitch.c.

{
  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;
}

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text_getc ( FILE *  file)

Definition at line 21 of file rdswitch.c.

{
  register int ch;
  
  ch = getc(file);
  if (ch == '#') {
    do {
      ch = getc(file);
    } while (ch != '\n' && ch != EOF);
  }
  return ch;
}

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