[FFmpeg-devel] [PATCH] AAC decoder channel layout support

[Alex Converse]

On Fri, Oct 16, 2009 at 1:01 PM, Jason Millard <jsm174 at gmail.com> wrote:
> I _think_ I have seen this issue before, demuxer passes and
>> incomplete/invalid first frame on to the decoder (which is fine so far),
>> but the decoder parses out some invalid stream properties out of that
>> broken frame and then sticks to them even if a valid frame comes up
>> later.
>> Which means that the first frame passed to the decoder must be "100%"
>> valid or it will decode nothing at all.
>> (note that in the details my description probably isn't right, but for
>> what I can tell that seemed to be the issue in a general sense as far as
>> I could figure out).
>>
>>
> Yeh, in the attachment sample, it threw out the junk before the first sync.
> But what it thought was the first sync actually isn't. The correct sync is
> actually trapped inside that first frame.
>
> [aac @ 0x103ae00]aac_decode_frame() - enter - show_bits: 0FFF
> [aac @ 0x103ae00]00000000 ?ff f0 32 c0 d0 04 80 60 3f ff f9 5c 80 2c c2 44
> ..2....`?..\.,.D
> [aac @ 0x103ae00]00000010 ?21 1b 55 65 91 90 92 37 88 86 21 60 aa 80 02 08
> !.Ue...7..!`....
>
>
> See ff f9
>

That is issue 999. http://roundup.ffmpeg.org/roundup/ffmpeg/issue999