[vorbis-dev] Problem with 'ov_open'...

[Michael Smith]

On Tuesday 10 February 2004 06:49, Ryan Ashley wrote:
> Hey, I've coded an OGG player for Win32 (it uses AL for playback so it's
> portable to Linux/Mac), but every time the program gets to the 'ov_open()'
> function, the app completely freezes, and I have to use the task-manager to
> kill it.  I am supplying it with a valid file handle that was just opened
> (FILE*) and the vorbis file is also a pointer that is not in use (set to
> null).  Any ideas why this is happenening?  Here is my actual source.
>
> FILE *SoundFile;
> OggVorbis_File *OVFile;

This is wrong, you only have a pointer to the struct here, no actual struct. 
So you need to allocate some storage for it. You can stack-allocate this with
OggVorbis_File OvFile;

>
> if(SoundFile != NULL)
>   CloseOGG();

This is wrong, you haven't opened the file yet - you need to do this later 
(after the fopen()). 

>
> if((SoundFile = fopen(Filename, "rb")) == NULL)
>   return false;
>
> if((ov_open(SoundFile, OVFile, NULL, 0)) < 0)
>   return false;

And here, you need to actually pass a pointer to an OggVorbis_File, not just a 
pointer that doesn't point to anything at all. Given the suggestion above, 
this becomes:

 if((ov_open(SoundFile, &OVFile, NULL, 0)) < 0)
   return false;

>
> I've put debug messages that my log-class logs, and it logs everything just
> fine up to the ov_open() check, then nothing.

Why it's hanging here I don't know - given your code, I'd expect it to just 
crash. Perhaps Jon's suggestion that you're using the wrong libraries is 
correct? Also, make sure you have version 1.0.1 of the libraries - version 
1.0 had some bugs that could, for certain unusual streams (mostly very short 
ones, i think) cause some hangs.

Mike

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