[FFmpeg-devel] [PATCH] als in mp4

Baptiste Coudurier baptiste.coudurier
Fri Apr 3 19:58:22 CEST 2009


Hi Jai,

On 4/3/2009 3:00 AM, Jai Menon wrote:
> On 3/23/09, Baptiste Coudurier <baptiste.coudurier at gmail.com> wrote:
>> Jai Menon wrote:
>>  > On 3/23/09, Baptiste Coudurier <baptiste.coudurier at gmail.com> wrote:
>>  >> Jai Menon wrote:
>>  >>  >> [...]
>>  >>
>>  >>  >>
>>  >>  >> When were they initially set to the correct values?
>>  >>  >
>>  >>  > stsd atom/box? i think
>>  >>  >
>>  >>
>>  >>
>>  >> Hummm, stsd does not contain the correct sample number for everything
>>  >>  using 'mp4a' tag. Values are correct in 'esds' box.
>>  >
>>  > Which means we should parse the extradata (in this case als specific
>>  > conf) and get values from there? I can do this for als by maybe adding
>>  > a new function to mpeg4audio.c.
>>
>>
>> I don't know how exactly ALS works, but it might use the
>>  AudioSpecificConfig like others, this code might belong to mpeg4audio.c,
>>  yes.
> 
> So hows attached patch?
> 

I think the AOT_ALS case should be handled within mpeg4audio_get_config,
to retrieve correct sample_rate/channels if these are not set in
AudioSpecificCOnfig, I also beleve all AOT should be handled this way.

I'd like mpeg4 audio expert/maintainer to comment on this.

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
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