[FFmpeg-devel] who should set framesize?

Alex Converse alex.converse
Thu Jun 25 19:33:11 CEST 2009


On Thu, Jun 25, 2009 at 1:17 PM, Alex Converse<alex.converse at gmail.com> wrote:
> On Thu, Jun 25, 2009 at 11:15 AM, Luca Abeni<lucabe72 at email.it> wrote:
>> Ronald S. Bultje wrote:
>>>
>>> Hi,
>>>
>>> On Thu, Jun 25, 2009 at 10:11 AM, Alex Converse
>>> <alex.converse at gmail.com>wrote:
>>>
>>>> I'm a bit confused here. ffaac does not support SBR decoding at all.
>>>> faac does not support SBR encoding at all.
>>>
>>>
>>> Does faad do SBR decoding? Because faad "fails" as well in the same way as
>>> ffaac.
>>
>> Well, I do not know this stuff, but I've been told that faad supports SBR...
>> But when SBR is signalled the detected sample rate has to be multiplied by
>> two.
>>
>>
>
> It's not consistent with the way an HE-AAC stream sounds played back
> without the SBR. Without SBR HE-AAC streams play back with the upper
> frequencies missing at the appropriate tempo.
>
> Furthermore this stream plays back too fast at 22050 Hz but too slow
> at 11025 Hz.
>

More proof that it's not SBR related:

"ffmpeg -t 30 -i rtsp://qtss1.bgsu.edu/wfal08.sdp -acodec copy
stream.m4a && ffmpeg -i stream.m4a out.wav" works fine (though only
gives us 15.2785 seconds of ouput)

--Alex



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