[Vorbis] ov_open_callbacks takes so much time to open 210 MB OGG file

[Pavel Nikitenko]

Here is my compiled EXE file of the little modified vorbisfile_example.c 
code.
http://dl.dropbox.com/u/3532445/win/vorbisdec_static.zip

It takes 23.3 minutes for ov_open_callbacks to open the file, no joke.

Here is my VS2010 project file with all the source codes included 
including libvorbis-1.3.3, libogg 1.3.0 and my vorbisfile_example.c code.
http://dl.dropbox.com/u/3532445/win/vorbis_example_ov_open_callbacks_test.zip

I use vorbis_static.sln VS2010 solution file in the 
libvorbis-1.3.3\win32\VS2010 to compile vorbisfile_example.c code and 
the vorbisdec_static.exe is generated in:
libvorbis-1.3.3\win32\VS2010\Win32\Release\vorbisdec_static.exe

Pavel

On 16.12.2012 20:26, xiphmont at xiph.org wrote:
> On Sun, Dec 16, 2012 at 12:12 PM, Pavel Nikitenko <pavnsw at gmail.com> wrote:
>> Hi Monty,
>>
>> Did you have a chance to look on the observed issue with ov_open_callbacks,
>> please?
> Yes; the file opens properly here using the last few vorbis releases
> [630ms in my test--- higher than I'd like, but meh... 52 links].  You
> are using the 1.3.3 "Omnipresent" release for both encode and decode?
> I also checked using your lightly modified vorbisfile_example.c just in case.
>
>>> It looks something is wrong. Either something with ov_open_callbacks if it
>>> is not optimized or the OGG is not generated as it should.
> There are some problems in the generated Ogg, but like I said, they
> would not cause a problem of this magnitude.  A stock build here
> successfully opens, parses and decodes the file.
>
>>> I do not
>>> understand much terminology of the OGG file format. The OGG file is
>>> generated by appending of new OGG file at the end of previously generated
>>> OGG file. If there would be better way, I would use it for sure.
> That is the correct way to put two Ogg files together.  However, the
> files that are being appended in your Ogg are unfinished fragments;
> the streams are not being flushed and closed out before beginning the
> next.  In addition, it looks like there is some unencapsulated data
> being placed between section (perhaps caused by the same bug).
>
> Eg, the normal way to do this in encoding is to call
> vorbis_analysis_wrote with a write length of zero indicating the end
> of data.  At that point, the vorbis encoder will flush internal
> pending data and a construct a final Ogg end-of-stream page.
>
> Also... are these streams intended to be encoded as quadraphonic?  Two
> of the channels in your file are completely unused.
>
> Again, all of this is likely completely unrelated to the lengthy open time.
>
> Monty

-------------- next part --------------
/********************************************************************
 *                                                                  *
 * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *
 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
 *                                                                  *
 * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2007             *
 * by the Xiph.Org Foundation http://www.xiph.org/                  *
 *                                                                  *
 ********************************************************************

 function: simple example decoder using vorbisfile
 last mod: $Id: vorbisfile_example.c 16328 2009-07-24 01:51:10Z xiphmont $

 ********************************************************************/

/* Takes a vorbis bitstream from stdin and writes raw stereo PCM to
   stdout using vorbisfile. Using vorbisfile is much simpler than
   dealing with libvorbis. */

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <vorbis/codec.h>
#include <vorbis/vorbisfile.h>
#include <ctime>

#ifdef _WIN32 /* We need the following two to set stdin/stdout to binary */
#include <io.h>
#include <fcntl.h>
#endif

char pcmout[4096]; /* take 4k out of the data segment, not the stack */

int main(){
  OggVorbis_File vf;
  int eof=0;
  int current_section;

#ifdef _WIN32 /* We need to set stdin/stdout to binary mode. Damn windows. */
  /* Beware the evil ifdef. We avoid these where we can, but this one we 
     cannot. Don't add any more, you'll probably go to hell if you do. */
  _setmode( _fileno( stdin ), _O_BINARY );
  _setmode( _fileno( stdout ), _O_BINARY );
#endif

  fprintf(stderr,"Starting to measure time of ov_open_callbacks.");
  clock_t start,end;
  start=clock();
  fprintf(stderr,"\nclock start:=%d\n",start);

  if(ov_open_callbacks(stdin, &vf, NULL, 0, OV_CALLBACKS_NOCLOSE) < 0) {
      fprintf(stderr,"Input does not appear to be an Ogg bitstream.\n");
      exit(1);
  }

  end=clock();
  fprintf(stderr,"clock end:=%d\n",end);
  fprintf(stderr,"time=%f\n",((double)(end-start))/CLK_TCK);

  /* Throw the comments plus a few lines about the bitstream we're
     decoding */
  {
    char **ptr=ov_comment(&vf,-1)->user_comments;
    vorbis_info *vi=ov_info(&vf,-1);
    while(*ptr){
      fprintf(stderr,"%s\n",*ptr);
      ++ptr;
    }
    fprintf(stderr,"\nBitstream is %d channel, %ldHz\n",vi->channels,vi->rate);
    fprintf(stderr,"\nDecoded length: %ld samples\n",
            (long)ov_pcm_total(&vf,-1));
    fprintf(stderr,"Encoded by: %s\n\n",ov_comment(&vf,-1)->vendor);
  }
  
  fprintf(stderr,"Decompressing...");
  while(!eof){
    long ret=ov_read(&vf,pcmout,sizeof(pcmout),0,2,1,&current_section);
    if (ret == 0) {
      /* EOF */
      eof=1;
    } else if (ret < 0) {
      if(ret==OV_EBADLINK){
        fprintf(stderr,"Corrupt bitstream section! Exiting.\n");
        exit(1);
      }

      /* some other error in the stream.  Not a problem, just reporting it in
         case we (the app) cares.  In this case, we don't. */
    } else {
      /* we don't bother dealing with sample rate changes, etc, but
         you'll have to*/
      fwrite(pcmout,1,ret,stdout);
    }
  }
  fprintf(stderr,"Decompressing finished.");

  /* cleanup */
  ov_clear(&vf);
    
  fprintf(stderr,"Done.\n");
  return(0);
}