[Ffmpeg-devel] Re: redetect audioformat in mpeg-ts

Måns Rullgård mru
Wed Jul 6 16:36:12 CEST 2005


Nico Sabbi said:
> Patrick Fischer wrote:
>
>>>
>>> MPEG-TS doesn't (usually) contain any more detailed information than the
>>> codec used.  It's up to your mpeg audio decoder to detect a change,
>>> and do
>>> something sensible.  It's probably not a very good idea to be
>>> changing audio
>>> parameters midstream, as most players will not cope with it.  I'm not
>>> sure
>>> whether it's (dis)allowed by any standards.
>>>
>> Thanks.
>> But if you look at DVB you will see that the mpeg-ts can change the
>> audio-format.
>> DVB sends a consecutive mpeg-ts stream. Some Movies has Strereo and
>> some other has mono or some others.
>> I need to detect it.
>>
>
> maybe updating the tables, possibly sending a non-current table version
> in advance so that the decoder
> can prepare for the content update

I wouldn't rely on that, even though it's theoretically possible.  Most
mpeg audio decoders will deal with it properly, you just need to check
for changes after decoding each frame.  I don't think many applications
actually do this.

-- 
M?ns Rullg?rd
mru at inprovide.com





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