What causes "Invalid table data in file %s " in DrKLO/Telegram?

Ensure each table contains exactly 64 whitespace-separated decimal integers.

Invalid table data in file %s

Error message

Invalid table data in file %s

What it means

While reading a quantization table, read_quant_tables expects exactly 64 integer values per table. After reading the first value successfully, if any subsequent read_text_integer call fails (returns 0), it means the file ended prematurely or contains non-numeric data mid-table. The function reports invalid table data, closes the file, and returns FALSE.

Source

Thrown at TMessagesProj/jni/mozjpeg/rdswitch.c:112

  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;
    }
#if JPEG_LIB_VERSION >= 70
    jpeg_add_quant_table(cinfo, tblno, table, cinfo->q_scale_factor[tblno],
                         force_baseline);
#else
    jpeg_add_quant_table(cinfo, tblno, table, q_scale_factor[tblno],
                         force_baseline);
#endif
    tblno++;
  }

  if (termchar != EOF) {
    fprintf(stderr, "Non-numeric data in file %s\n", filename);
    fclose(fp);

View on GitHub (pinned to 45ab8f4308)

Solutions

Ensure each table contains exactly 64 whitespace-separated decimal integers.
Validate the file format programmatically: count tokens per table block before passing it to cjpeg.
Regenerate the table file using a script that guarantees 64 values per table.

Example fix

# before (table file with 63 values in one block)
# after (ensure exactly 64 values per table block)
python3 -c "print(' '.join(['%d' % (i+1) for i in range(64)]))" > table.qtl

Defensive patterns

Strategy: validation

Validate before calling

// Pre-validate: ensure each table block has exactly 64 integers
#include <stdio.h>
static boolean validate_quant_file(const char *filename) {
  FILE *fp = fopen(filename, "r");
  if (!fp) return FALSE;
  long val; int termchar, vals = 0;
  while (read_text_integer(fp, &val, &termchar)) {
    vals++;
  }
  fclose(fp);
  return (vals % DCTSIZE2 == 0);
}

Prevention

Generate quantization table files programmatically to guarantee 64 values per table.
Count tokens per table block using awk or a script before passing to cjpeg.
Avoid hand-editing table files; use templates and sed for controlled modifications.

When it happens

Trigger: A quantization table file where a table has fewer than 64 values; a non-numeric token appears within a 64-value table block; the file is truncated in the middle of a table definition.

Common situations: Hand-edited table files with missing values; files generated by a script with an off-by-one error in the loop; copy-paste errors that dropped values; encoding issues (BOM, non-ASCII digits).

Related errors

AI-assisted analysis of DrKLO/Telegram@45ab8f4308 (2026-08-14). Data as JSON: /api/errors/fc13efcba68e0b16. Report an issue: GitHub.