[FFmpeg-devel] Decoding the same audio frame twice produces different output
Benjamin Larsson
banan
Tue May 12 15:29:04 CEST 2009
Haakon Riiser wrote:
>> Haakon Riiser wrote:
>>
>>> As the subject states, I am wondering why libavcodec produces
>>> different output when the same audio frame is decoded twice in a
>>> row. As far as I know, every audio frame is as independent as an
>>> I-frame in video, so it should always produce the same output.
>>>
>>>
>>>
>> Most codec frames are dependent on the previous frame thus your
>> statement is false.
>>
>
> So how do you handle seeking to random locations in the stream?
>
It's a case by case situation, some codecs depend on more then one frame
(up to 16 IIRC). So what you can do is decode a few frames that you
don't use. In that case you wouldn't get any artifacts.
> I sometimes get horribly loud artifacts when seeking, which is why
> I'm investigating this problem. Are some audio frames the
> equivalent of key frames in video?
Might be in some codecs.
> Can I code audio so that every
> frame is independent?
>
Yes use the pcm codec.
MvH
Benjamin Larsson
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