Vorbis - Apr 2004 - Is this a bug in ogg ?

I have a problem i suspect to be a bug in ogg:

Assume i have a simple archive "chou_s_test1_test2.pak", created by
simply
concatenating binary files together:

chou_s.jpg (3403 bytes)
test1.ogg (5196 bytes)
test2.ogg (6128 bytes)

If i place the a filepointer passed to ov_open to the beginning of
test1.ogg, this ogg gets opened and decoded correctly. But if i place it to
the beginning of test2.ogg, ov_open returns error code -123 (OV_EBADLINK ).
Any idea ?

Here is the source code i encounter the problem with:
( you can download a zip file with the ogg files i used here:
http://www.videofiles.de/ogg_bug.zip )

<p>#include<stdio.h>
#include <vorbis/vorbisfile.h>

int main(int argc, char *argv[])
{

        OggVorbis_File vf;
        FILE *fp=NULL;
        // chou_s_test1_test2.pak is created by simply concatenating
chou_s.jpg (3403 bytes), test1.ogg (5196 bytes) and test2.ogg (6128 bytes)
        fp=fopen("chou_s_test1_test2.pak","rb");

        //fseek(fp,3403, SEEK_SET); // place to the beginning of test1.ogg
        fseek(fp,3403 + 5196,SEEK_SET); // place to the beginning of
test2.ogg

        fprintf(stderr, " ov_open_return_code:%i\n",ov_open(fp,
&vf, NULL,
0));

        int xx = ov_raw_total(&vf,-1);
        int yy =  (long)ov_pcm_total(&vf, -1);
        printf("oggtotalraw:%i",xx);
        printf("oggtotalpcm:%i",yy);
}

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On Sat, Apr 24, 2004 at 03:29:57PM +0200, Andre Krause
wrote:
> I have a problem i suspect to be a bug in ogg:
> 
> Assume i have a simple archive "chou_s_test1_test2.pak", created
by simply
> concatenating binary files together:
> 
> chou_s.jpg (3403 bytes)
> test1.ogg (5196 bytes)
> test2.ogg (6128 bytes)
> 
> If i place the a filepointer passed to ov_open to the beginning of
> test1.ogg, this ogg gets opened and decoded correctly. But if i place it to
> the beginning of test2.ogg, ov_open returns error code -123 (OV_EBADLINK ).
> Any idea ?
Vorbisfile only accidentally managed to make this work; having that
jpg in the stream (unencapsulated) renders the file invalid, strictly
speaking.  Other vorbis decoders are very likely to reject it and it
certainly won't work on any portable devices I'm aware of.

Regardless...  The behavior does make me curious as to why one worked
and the other did not.

I'll look at this.  Neither should have been expected to work, but the
fact I can't say why this happens might mean something more
significant.

Monty
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Andre,

Sorry, I originally answered this mail before going back and scanning
your previous messages. Is this using any callback tricks or trying to
set up an 'unseekable' stream?

<p>Monty
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