[FFmpeg-devel] PATCH: 5.1 AAC SMPTE channel order with libfaad

Alex Converse alex.converse
Mon Apr 5 23:04:02 CEST 2010

On Mon, Apr 5, 2010 at 7:35 AM, Jean-Yves Avenard <jyavenard at gmail.com> wrote:
> Hi
> On 5 April 2010 19:51, Benjamin Larsson <banan at ludd.ltu.se> wrote:
>> That is the unneded hunk. Does the channel output configuration match
>> the native decoder after your patch ?
> yes it does.. It makes 5.1 decoded audio plays just fine in MythTV or
> mplayer; just like when using ffmpeg internal decoder.
> ?[ Front Left ] [ Front Right ] [ Center ] [ LFE ] [ Surround Left ] [
> Surround Right ]
> It takes whatever libfaad output and put it back in that order (from
> what I've seen, libfaad always output C L R SL SR LFE
> There's a few more features than parametric stereo that makes libfaad
> a requirement (I'm talking from a mythtv perspective here). First the
> LATM/AAC patch available for libfaad (but my understanding is the
> author is working to get something working with the native ffmpeg AAC
> decoder)

I'm not sure if anyone is actually working on LATM at the moment.
(LATM ATM blol).

> and H264 HE-AAC used by few european countries for broadcast, and
> likely going to be more and more used as countries are moving to the
> new MPEG-4 AVC standard

we support decoding of HE-AACv1 and mono decoding of HE-AACv2 stereo
decoding of HE-AACv2 should be landing very soon.

> I saw that extra line after I had posted the patch ; there's also a
> mistake in a channel map array (-5 vs 5). I've attached an updated
> copy. Sorry for that
> I am very puzzled by M?ns Rullg?rd message. I don't see where else
> channel re-ordering could be done than within the codec , it's how all
> other codecs do it.
> Thanks for looking into it
> Jean-Yves

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