DrKLO/Telegram · error

Failed to create the decoder: %s\n

Error message

Failed to create the decoder: %s\n

What it means

opus_custom_decoder_create(mode, channels, &err) set err non-zero — the decoder object could not be created. The encoder was created successfully and is implicitly leaked here (no opus_custom_encoder_destroy on this error path). Both file handles are closed.

Source

Thrown at TMessagesProj/jni/opus/celt/opus_custom_demo.c:115

   if (!fout)
   {
      fprintf (stderr, "Could not open output file %s\n", argv[argc-1]);
      fclose(fin);
      return 1;
   }

   enc = opus_custom_encoder_create(mode, channels, &err);
   if (err != 0)
   {
      fprintf(stderr, "Failed to create the encoder: %s\n", opus_strerror(err));
      fclose(fin);
      fclose(fout);
      return 1;
   }
   dec = opus_custom_decoder_create(mode, channels, &err);
   if (err != 0)
   {
      fprintf(stderr, "Failed to create the decoder: %s\n", opus_strerror(err));
      fclose(fin);
      fclose(fout);
      return 1;
   }
   opus_custom_decoder_ctl(dec, OPUS_GET_LOOKAHEAD(&skip));

   if (argc>7)
   {
      complexity=atoi(argv[5]);
      opus_custom_encoder_ctl(enc,OPUS_SET_COMPLEXITY(complexity));
   }

   in = (opus_int16*)malloc(frame_size*channels*sizeof(opus_int16));
   out = (opus_int16*)malloc(frame_size*channels*sizeof(opus_int16));

   while (!feof(fin))
   {
      int ret;

View on GitHub (pinned to 45ab8f4308)

Solutions

1. Validate channels is 1 or 2 and matches what was used for the encoder.
2. Inspect opus_strerror(err) for the concrete cause.
3. Destroy the encoder (opus_custom_encoder_destroy(enc)) on this path to avoid a leak.
4. Ensure adequate free memory for the decoder allocation.

Example fix

// before
dec = opus_custom_decoder_create(mode, channels, &err);
if (err != 0) { fprintf(stderr, "Failed to create the decoder: %s\n", opus_strerror(err)); fclose(fin); fclose(fout); return 1; }

// after: also free the encoder
dec = opus_custom_decoder_create(mode, channels, &err);
if (err != 0) { fprintf(stderr, "Failed to create the decoder: %s\n", opus_strerror(err)); opus_custom_encoder_destroy(enc); fclose(fin); fclose(fout); return 1; }

// Validate channels and destroy the encoder on failure.
if (channels != 1 && channels != 2) { fprintf(stderr, "channels must be 1 or 2\n"); return 1; }
dec = opus_custom_decoder_create(mode, channels, &err);
if (err != 0) { opus_custom_encoder_destroy(enc); fprintf(stderr, "Failed to create the decoder: %s\n", opus_strerror(err)); fclose(fin); fclose(fout); return 1; }

When it happens

Trigger: err != OPUS_OK. Same shape as the encoder error: OPUS_BAD_ARG for invalid channels, or allocation failure. channels must match the encoder's channel count for the round-trip demo to be valid.

Common situations: channels mismatch with the mode; channels value 0 or >2 from a bad CLI arg; memory pressure; the mode parameters being incompatible with decoder construction.

Related errors

• Failed to create the encoder: %s\n
• opus_custom_decode() failed: %s\n
• Opus decoder does not support secure decode
• Invalid initialization data size
• Invalid pre-skip or seek pre-roll

AI-assisted analysis of DrKLO/Telegram@45ab8f4308 (2026-08-14). Data as JSON: /api/errors/62e471b577557d9a. Report an issue: GitHub.