joshhighley
Posts: 26
Joined: Mon Nov 05, 2012 9:36 pm
Location: Kansas City, MO, USA

hardware transcode

Fri Nov 09, 2012 8:27 pm

I'm looking for a way to convert mpeg2 to h264 using the RPi GPU. Despite lots of searching, I haven't found any programs that do this in hardware. The OpenMAX examples have a video decode example and the video encode example -- has anyone looked at "hooking" those together? Finding good OpenMAX docs has also been a challenge, but I'm wondering if I could create a tunnel from the video_decode component to the video_encode component? I'm a programmer, but haven't worked much with C or audio/video. Any pointers to existing work, examples, documentation, information, etc will be much appreciated.

Thanks,

Josh

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 23709
Joined: Sat Jul 30, 2011 7:41 pm

Re: hardware transcode

Fri Nov 09, 2012 8:41 pm

The Khronos website has all the references fro OpenMAX, but it's challenging (at least I find it so). You should be able to tunnel from decode to encode, but 1080p30 won't work in real time - you may need to reduce the clock component speed (somehow) to make it run about half speed. SD should transcode pretty fast.
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joshhighley
Posts: 26
Joined: Mon Nov 05, 2012 9:36 pm
Location: Kansas City, MO, USA

Re: hardware transcode

Fri Nov 09, 2012 8:49 pm

I don't need real-time.

I'm trying to setup a low-power PVR: I already have a Roku on my TV that I use a lot, so I want to use it to play the recorded videos. It only supports h264. I've already setup mythtv backend and mythweb on my RPi and tested recording OTA broadcasts from an HDHomeRun, which is mpeg2. I may end up moving the myth backend to a pogoplug if the RPi needs to be solely devoted to transcoding. My intention is to transcode the mpeg2 videos after recording is finished and then delete the mpeg2 files.

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