DrKLO/Telegram · error

opus_repacketizer_cat() failed: %s\n

Error message

opus_repacketizer_cat() failed: %s\n

What it means

opus_repacketizer_cat() returned a status other than OPUS_OK when adding a packet to the repacketizer context. This library function validates the packet before merging it: it checks that the packet is a valid Opus packet and that its configuration (sample rate, frame size, mode, bandwidth) is compatible with packets already in the buffer. The specific error code is translated to a human-readable string by opus_strerror(). After the error, the loop breaks but the tool does not exit immediately — it proceeds to output whatever packets were successfully buffered.

Source

Thrown at TMessagesProj/jni/opus/src/repacketizer_demo.c:149

                fprintf(stderr, "Invalid payload length\n");
                fclose(fin);
                fclose(fout);
                return EXIT_FAILURE;
             }
             break;
         }
         err = fread(ch, 1, 4, fin);
         rng[i] = char_to_int(ch);
         err = fread(packets[i], 1, len[i], fin);
         if (feof(fin))
         {
            eof = 1;
            break;
         }
         err = opus_repacketizer_cat(rp, packets[i], len[i]);
         if (err!=OPUS_OK)
         {
            fprintf(stderr, "opus_repacketizer_cat() failed: %s\n", opus_strerror(err));
            break;
         }
      }
      nb_packets = i;

      if (eof)
         break;

      if (!split)
      {
         err = opus_repacketizer_out(rp, output_packet, MAX_PACKETOUT);
         if (err>0) {
            unsigned char int_field[4];
            int_to_char(err, int_field);
            if(fwrite(int_field, 1, 4, fout)!=4){
               fprintf(stderr, "Error writing.\n");
               return EXIT_FAILURE;
            }

View on GitHub (pinned to 45ab8f4308)

Solutions

1. Ensure all packets being merged come from the same encoder session with identical configuration (same sample rate, channels, application, frame size).
2. Log the opus_strerror output to identify the specific failure (OPUS_INVALID_PACKET vs OPUS_BAD_ARG).
3. Validate each packet with opus_packet_parse before feeding it to the repacketizer.
4. Reduce the merge count to isolate which packet triggers the error.

Example fix

// before
err = opus_repacketizer_cat(rp, packets[i], len[i]);
if (err != OPUS_OK) {
    fprintf(stderr, "opus_repacketizer_cat() failed: %s\n", opus_strerror(err));
    break;
}
// after: validate packet compatibility before cat
int toc = packets[i][0];
int frame_size_check = opus_packet_get_nb_samples(packets[i], len[i], 48000);
if (frame_size_check <= 0) {
    fprintf(stderr, "Skipping invalid packet at index %d\n", i);
    continue;
}
err = opus_repacketizer_cat(rp, packets[i], len[i]);
if (err != OPUS_OK) {
    fprintf(stderr, "opus_repacketizer_cat() failed: %s\n", opus_strerror(err));
    break;
}

// Validate packet before calling opus_repacketizer_cat
int safe_cat(OpusRepacketizer *rp, const unsigned char *data, int len) {
    // Check packet looks valid
    if (len < 1 || data[0] == 0) return OPUS_INVALID_PACKET;
    int ret = opus_repacketizer_cat(rp, data, len);
    if (ret != OPUS_OK) {
        fprintf(stderr, "cat failed: %s (len=%d, toc=0x%02x)\n",
                opus_strerror(ret), len, data[0]);
    }
    return ret;
}

if ((err = opus_repacketizer_cat(rp, data, len)) != OPUS_OK) {
    fprintf(stderr, "cat failed: %s\n", opus_strerror(err));
    // optionally: skip this packet and continue, or abort
    break;
}

When it happens

Trigger: Merging packets from different encoder instances with different configurations; merging packets with different frame sizes (e.g., 20ms and 40ms); merging a CELT-mode packet with a SILK-mode packet; passing a malformed or truncated packet payload; exceeding the maximum merged packet size. The most common error code is OPUS_INVALID_PACKET.

Common situations: Concatenating packets from different audio streams; a bug in the packet-generation step producing malformed packets; mixing narrowband and wideband packets; version mismatch between encoder and the repacketizer API.

Related errors

• opus_repacketizer_out() failed: %s\n
• usage: %s [options] input_file output_file\n
• -merge parameter must be at least 1.\n
• -merge parameter must be less than 48.\n
• Unknown option: %s\n

AI-assisted analysis of DrKLO/Telegram@45ab8f4308 (2026-08-14). Data as JSON: /api/errors/7e9bd8cfe7a4eddc. Report an issue: GitHub.