DrKLO/Telegram · error

Error opening '%s'.\n

Error message

Error opening '%s'.\n

What it means

fopen(_argv[1], "rb") for the first input file (fin1) returned NULL. opus_compare cannot open the first .sw file for reading and exits before touching the second file.

Source

Thrown at TMessagesProj/jni/opus/src/opus_compare.c:221

    rate=atoi(_argv[2]);
    if(rate!=8000&&rate!=12000&&rate!=16000&&rate!=24000&&rate!=48000){
      fprintf(stderr,
       "Sampling rate must be 8000, 12000, 16000, 24000, or 48000\n");
      return EXIT_FAILURE;
    }
    downsample=48000/rate;
    switch(rate){
      case  8000:ybands=13;break;
      case 12000:ybands=15;break;
      case 16000:ybands=17;break;
      case 24000:ybands=19;break;
    }
    yfreqs=NFREQS/downsample;
    _argv+=2;
  }
  fin1=fopen(_argv[1],"rb");
  if(fin1==NULL){
    fprintf(stderr,"Error opening '%s'.\n",_argv[1]);
    return EXIT_FAILURE;
  }
  fin2=fopen(_argv[2],"rb");
  if(fin2==NULL){
    fprintf(stderr,"Error opening '%s'.\n",_argv[2]);
    fclose(fin1);
    return EXIT_FAILURE;
  }
  /*Read in the data and allocate scratch space.*/
  xlength=read_pcm16(&x,fin1,2);
  if(nchannels==1){
    for(xi=0;xi<xlength;xi++)x[xi]=.5*(x[2*xi]+x[2*xi+1]);
  }
  fclose(fin1);
  ylength=read_pcm16(&y,fin2,nchannels);
  fclose(fin2);
  if(xlength!=ylength*downsample){
    fprintf(stderr,"Sample counts do not match (%lu!=%lu).\n",

View on GitHub (pinned to 45ab8f4308)

Solutions

1. Verify the first file path exists and is readable (access/stat).
2. Use an absolute path.
3. Make sure flags (-s, -r rate) come before the two file paths so _argv[1] lands on the actual file.

Example fix

// before
./opus_compare -r 48000 missing1.sw file2.sw

// after
./opus_compare -r 48000 /abs/path/file1.sw file2.sw

// Check the first file is readable before fopen.
if (access(_argv[1], R_OK) != 0) {
    fprintf(stderr, "Error opening '%s'.\n", _argv[1]);
    return EXIT_FAILURE;
}

When it happens

Trigger: The first file path does not exist, is unreadable, or is a directory. After optional -s/-r parsing, _argv[1] is the first non-option argument (the first .sw file).

Common situations: Typo in filename; wrong working directory; file needs a permission not granted; the -s/-r flags consumed the real filename because of misordered arguments.

Related errors

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

AI-assisted analysis of DrKLO/Telegram@45ab8f4308 (2026-08-14). Data as JSON: /api/errors/09bccb6d7d10f172. Report an issue: GitHub.