tfcsolutions
Posts: 2
Joined: Wed May 15, 2013 11:57 am

Is there a straightforward way to demux? + audio

Wed May 15, 2013 12:14 pm

Hi all,

Hopefully someone can help me. I've recently been playing around with the broadcom libraries and have successfully managed to create my own bare-minimum AVC decoding example, based on the "hello_video" one. I now have a better understanding of how the ilclient library works and would love to try tackling demuxing with it. As a starting point I thought it'd be a good challenge to just demux a file that contains an AVC video stream and hand the demuxed video data to my existing decoding example.

The problem is, documentation is minimal, and I've not been able to find any straightforward examples online. I've noticed that many people seem to be using libav to perform tasks such as demux, but as far as I'm aware, we should be able to do this with the broadcom libraries (please correct me if I'm wrong).

I've already looked at the source for omxplayer, but it's far too complex and uncommented to be of much help to me. Does anyone know of a dead-basic example of demuxing with the BCM libraries? Alternatively, could you point me in the right direction to learn more about the subject? I'm pretty stumped right now, but I feel that if simple ~200-300 line examples can be made for video decoding, demuxing shouldn't be much worse (or should it?) Also, if there's a simple audio decoding example someone can provide (the built-in one only plays a sine wave, rather than decoding audio from a file), that'd be very helpful.

I'll be grateful for any help you can offer. Thanks

dom
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 5340
Joined: Wed Aug 17, 2011 7:41 pm
Location: Cambridge

Re: Is there a straightforward way to demux? + audio

Wed May 15, 2013 1:29 pm

Sorry, no demuxing is possible with OpenMAX libraries.

It's recommended you use libffmpeg or similar for demuxing. This is what omxplayer and xbmc do.

tfcsolutions
Posts: 2
Joined: Wed May 15, 2013 11:57 am

Re: Is there a straightforward way to demux? + audio

Wed May 15, 2013 1:50 pm

Thanks. Now I know ;)

8ob
Posts: 10
Joined: Wed Jan 30, 2013 12:50 pm

Re: Is there a straightforward way to demux? + audio

Mon May 20, 2013 12:32 pm

dom wrote:Sorry, no demuxing is possible with OpenMAX libraries.

It's recommended you use libffmpeg or similar for demuxing. This is what omxplayer and xbmc do.
But in an other post
dom wrote:the read_media/write_media components only have limited support for containers (e.g. no .ts files).
Is this possible to detect streams from a ps container (only with an ILclient and OpenMAX) ?

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