[Asterisk-video] app_mp4 patch

[Klaus Darilion]

Sergio Garcia wrote:
> /* What for is this ? */ //	if (payload > 0) // 
> MP4AddRtpImmediateData(t->mp4, t->hint, f->data, payload);
> 
> 
> The inmediate data is the part of the rtp data that is specific to 
> the rtp payload. So when you receive a frame of a custom media you 
> have to decide which payload are you going to save in the rtp data 
> (the hint track) and which part in the media track and then set the 
> reference in the hint track. Yuo can also save all the media track in
>  the hint track (if you've ever used the qt pro that's what the
> option "optimize for server does").
> 
> If you discard the payload you'll lose the first byte when trying to 
> build the rtp packet again.


Oh. This was for testing only - and probably due to the problem that I
could not understand the meaning of it. Do you know a good description
of mp4, RTP and hint tracks?

By adding "payload" (which is 1 for AMR) to the hint track - what do you
achieve? The man pages are very confusing for me:

from: man MP4AddRtpImmediateData
> ...MP4AddRtpImmediateData adds immediate data to the current pending RTP
> packet. Typically, this is used to add RTP payload specific headers
> to RTP packets. Note that the size of a block of immediate data is
> limited to 14 bytes. But multiple immediate data blocks can be added
> if more space is needed....

What is RTP payload specific headers? Do they mean RTP extension headers 
or do they mean the AMR ToC?


> Could you send a patch file with the diffs?? Also, if you want I 
> could set up an svn account so you could patch the code directly.

The 2 most important things are:
1: correct malloc() of the ast_frame
2: use a dedicated audio_payload and video_payload variable in 
mp4_save() or otherwise the video-payload changes the audio payload too.

svn: yes, if it is possible to have a separate branch.

regards
klaus

> 
> Francesco, could you also patch the bitreverse bits stuff with your 
> latest version before??
> 
> 
> Best regards Sergio
> 
> 
> 
> 
> 
> 
> ---------- Original Message ---------------------------------- From: 
> Klaus Darilion <klaus.mailinglists at pernau.at> Reply-To: Development 
> discussion of video media support in 
> Asterisk<asterisk-video at lists.digium.com> Date:  Mon, 30 Jul 2007 
> 12:57:47 +0200
> 
>> regards klaus
>> 
>> 
>> 
> 
> 
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