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[firmware] MJPEG decoding support

Sun Dec 23, 2012 1:12 pm

I'm working with a webcam that captures MJPEG video, now I want to analyze it with OpenCV but it uses a lot of CPU since it seems that the CPU decodes MJPEG.

Can MJPEG support get enabled in the Pi's firmware? ( Maybe Theora/VPX too )

If the GPU can decode MJPEG, I could spend more CPU power on analyzing frames ;)

Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
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Re: [firmware] MJPEG decoding support

Sun Dec 23, 2012 1:22 pm

Dom adds: As an aside, the GPU can hardware decode H264, MPEG1/2/4, VC1, AVS, MJPG at 1080p30. It can software (but still vector accelerated) decode VP6, VP7, VP8, RV, Theora, WMV9 at DVD resolutions. We are restricted due to licensing what we can support. We should be able to support VP8, MJPG and Theora, as I believe they are license free.
I wasn't able to find anything about mjpg requiring a license.


Re: [firmware] MJPEG decoding support

Sun Dec 23, 2012 5:52 pm

A MJPEG stream is just a number of normal individual JPEG images send after each other.
Tried using the normal JPEG Openmax routines?

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Joined: Wed Jan 09, 2013 12:57 am

Re: [firmware] MJPEG decoding support

Fri Jan 11, 2013 10:24 pm

What is the status of MJPEG support in the video decoder? The quote about the hardware supporting MJPEG is encouraging, but I've tried using the decoder for MJPEG, and I'm finding the hello_video example errors when MJPEG is used.

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Joined: Sat Oct 27, 2012 12:41 pm

Re: [firmware] MJPEG decoding support

Fri Jan 11, 2013 11:56 pm

Don't forget encoding. MJPEG encoding would be nice too.

Basically, encoding is as interesting as decoding, when you want to apply changes to a video stream for example.

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