DrKLO/Telegram · warning

bytes per packet must be between 0 and %d\n

Error message

bytes per packet must be between 0 and %d\n

What it means

The bytes-per-packet value (argv[4], parsed with atoi) is outside [0, MAX_PACKET]. Opus custom encoder output packets must fit in the MAX_PACKET-byte scratch buffer; this guard prevents buffer overflow when encoding into the fixed-size data[] array.

Source

Thrown at TMessagesProj/jni/opus/celt/opus_custom_demo.c:83

               " <bytes per packet> [<complexity> [packet loss rate]] "
               "<input> <output>\n");
      return 1;
   }

   rate = (opus_int32)atol(argv[1]);
   channels = atoi(argv[2]);
   frame_size = atoi(argv[3]);
   mode = opus_custom_mode_create(rate, frame_size, NULL);
   if (mode == NULL)
   {
      fprintf(stderr, "failed to create a mode\n");
      return 1;
   }

   bytes_per_packet = atoi(argv[4]);
   if (bytes_per_packet < 0 || bytes_per_packet > MAX_PACKET)
   {
      fprintf (stderr, "bytes per packet must be between 0 and %d\n",
                        MAX_PACKET);
      return 1;
   }

   inFile = argv[argc-2];
   fin = fopen(inFile, "rb");
   if (!fin)
   {
      fprintf (stderr, "Could not open input file %s\n", argv[argc-2]);
      return 1;
   }
   outFile = argv[argc-1];
   fout = fopen(outFile, "wb+");
   if (!fout)
   {
      fprintf (stderr, "Could not open output file %s\n", argv[argc-1]);
      fclose(fin);
      return 1;

View on GitHub (pinned to 45ab8f4308)

Solutions

1. Supply a bytes-per-packet in [0, MAX_PACKET]; check MAX_PACKET in opus_defines.h for the build's exact cap.
2. Confirm argv[4] is the 4th positional arg (rate channels frame_size BYTES input output).
3. Guard atoi with explicit digit-validation to reject garbage input.

Example fix

// before
./test_opus_custom 48000 1 960 4096 input.sw output.sw

// after
./test_opus_custom 48000 1 960 100 input.sw output.sw

// Range-check bytes_per_packet against MAX_PACKET before encoding.
if (bytes_per_packet < 0 || bytes_per_packet > MAX_PACKET) {
    fprintf(stderr, "bytes per packet must be between 0 and %d\n", MAX_PACKET);
    return 1;
}

When it happens

Trigger: bytes_per_packet < 0 or bytes_per_packet > MAX_PACKET. MAX_PACKET is the size of the local unsigned char data[MAX_PACKET] buffer used for encoded output. A negative value comes from atoi parsing a '-' prefix; an oversized value would overflow data[].

Common situations: Typing a bytes-per-packet larger than MAX_PACKET (commonly 127 or 1024 depending on build); passing a non-numeric string that atoi silently turns into 0; misreading the parameter order and supplying the frame size or rate in this slot.

Related errors

• Sampling rate must be 8000, 12000, 16000, 24000, or 48000\n
• Sample counts do not match (%lu!=%lu).\n
• Usage: test_opus_custom <rate> <channels> <frame size> <byt
• failed to create a mode\n
• Could not open input file %s\n

AI-assisted analysis of DrKLO/Telegram@45ab8f4308 (2026-08-14). Data as JSON: /api/errors/510379a46be339a3. Report an issue: GitHub.