[Ffmpeg-devel] Bug: wav decoder decodes garbage at end of file

[Ulrich von Zadow]

Michael Niedermayer wrote:
>>If I read the ffmpeg code correctly, the chunk size is actually read and 
>>returned in find_tag (wav.c, 266ff) but then thrown away by wav_read_header 
>>(wav.c, 331ff). This value should be used in wav_read_packet to determine 
>>whether to set a logical eof state, I think.
>>
>>I made a short attempt at writing a patch, but ran into too many ffmpeg 
>>design questions to get very far. For starters, where should the chunk size 
>>be stored?
> 
> something like WAVContext, though it seems our wav demuxer doesnt have one,
> its private context size is 0, you will have to change that ...

Ok. Does this sound about right?

- Define a WAVContext struct in wav.c that contains a single member
   wave_chunk_len.
- Change wav_iformat so memory for the WAVContext is allocated.
- In wav_read_header, set wave_chunk_len
- In wav_read_packet, compare s->data_offset+wave_chunk_len to s->pb->pos to
   determine how many bytes are left to read. When none are left, set
   s->eof_reached=1.

Cheers,

   Uli