[vlc-devel] [PATCH] MPEG4 Audio Packetizer : Send atleast one frame without the ADTS header stripped off in the absence of decoder config extradata.

Jai Menon jmenon86 at gmail.com
Mon Aug 2 11:24:17 CEST 2010

At Sun, 1 Aug 2010 12:15:11 +0200,
Laurent Aimar wrote:
> On Sat, Jul 31, 2010 at 07:52:26PM +0530, Jai Menon wrote:
> > This is useful when we don't have an MPEG4AudioDecoderConfig available
> > at the time of codec initialization. We construct one later in the
> > packetizer but codecs like the libavcodec based AAC decoder, for example,
> > won't pick that up.
>  This will break the sout, no?

Hmm, I'm not sure. I did test it properly (playback, remux, re-encode)
but maybe there is some detail I'm missing.
>  You could modify the avcodec wrapper to allow delayed open of audio codecs
> (it is already done for video, like THEORA).

Okay, if that's what you prefer, I'll do that instead (and post in a
separate thread). I thought about doing it this way too, but wasn't sure
what happens to the packets received before extradata is set.

>  A better solution might be to create bitstream filters that convert from one
> bitstream format to another one, use them in the sout muxers, and let the
> packetizer split into frames but without changing the payload content. It will
> fixes some issues (like for example when the AAC properties change) but it's
> a lot of work.

Yeah, that's probably the more elegant way to do this (similar to
libavcodec parsers and bitstream filters).

Jai Menon

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