DrKLO/Telegram · error

Could not open input file %s\n

Error message

Could not open input file %s\n

What it means

fopen(inFile, "rb") returned NULL — the input PCM (.sw) file cannot be opened for reading. inFile is argv[argc-2], the second-to-last argument. The demo exits with return 1.

Source

Thrown at TMessagesProj/jni/opus/celt/opus_custom_demo.c:92

   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;
   }

   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;

View on GitHub (pinned to 45ab8f4308)

Solutions

1. Verify the input file exists and is readable: check argv[argc-2], run stat/access on it.
2. Use an absolute path to avoid working-directory confusion.
3. Confirm argument order: input is the second-to-last arg, output is the last.
4. Ensure the file is raw PCM16 .sw, not a .wav with a header (which would misalign samples).

Example fix

// before
./test_opus_custom 48000 1 960 40 wrong_input_filename.sw output.sw

// after
./test_opus_custom 48000 1 960 40 /abs/path/input.sw output.sw

// Verify the input file exists and is readable before fopen.
if (access(inFile, R_OK) != 0) {
    fprintf(stderr, "Input file not readable: %s\n", inFile);
    return 1;
}

When it happens

Trigger: The input path does not exist, is not readable, or points to a directory. The file is expected to be raw little-endian 16-bit PCM (no header) of frame_size*channels samples per frame.

Common situations: Typo in the input filename; wrong working directory so the relative path misses; the file is on a path that needs a permission not granted; passing an output-first argument order.

Related errors

• Could not open output file %s\n
• Error opening '%s'.\n
• Usage: test_opus_custom <rate> <channels> <frame size> <byt
• Error reading yuv file\n
• Usage: %s [-s] [-r rate2] <file1.sw> <file2.sw>\n

AI-assisted analysis of DrKLO/Telegram@45ab8f4308 (2026-08-14). Data as JSON: /api/errors/a150f6e583424911. Report an issue: GitHub.