[FFmpeg-devel] Patch for chained OGG files

[David Conrad]

On Apr 3, 2010, at 12:37 PM, M?ns Rullg?rd wrote:

> Cyril Zorin <cyril.zorin at gmail.com> writes:
> 
>> Hi!
>> 
>> Attached is a patch that lets ffmpeg handle chained OGG files, often used in
>> internet radio streams. Let me know if there's anything to change.
>> 
>> +static int
>> +ogg_read_packet (AVFormatContext * s, AVPacket * pkt)
>> +{
>> +  const int result = ogg_read_packet_internal(s, pkt);
>> +  if (result >= 0)
>> +    return result;
>> +
>> +  ogg_read_close(s);
>> +  memset(s->priv_data, 0, sizeof(struct ogg));
>> +  if (ogg_read_header(s, 0) < 0)
>> +    return AVERROR(EIO);
>> +
>> +  return ogg_read_packet_internal(s, pkt);
>> +}
> 
> This won't work if the parameters of the new set of streams don't
> exactly match the old.  Libavformat simply doesn't support randomly
> changing streams halfway through a file.

I'd imagine that the most common (only?) usage of chained ogg is to update metadata mid-stream for streaming radio, so only really working for this case seems OK to me.