I found my RasPi in my pigeon hole at work yesterday and have already started tinkering
I thought I'd take a look at JPEG decoding, having recently done a lot of work with libjpeg and libjpeg-turbo on other SOCs, and was pleased to find that it's possible to decode a JPEG in hardware, using the OMX API.
I hacked "hello_video" to decode a JPEG to screen (using the "video_render" sink) but haven't managed to get it to decode to an arbitrary user-mode buffer. I had a look at the available Broadcom OMX components, and whilst I can see file writers, I can't see one for "output to this buffer *here*".
The "source" component seems
to be what I want (please correct me if I'm wrong), allowing the creation of raw bitmaps in various colour formats. However, I can't seem to set it up correctly.
Is what I'm trying to achieve actually possible with the current firmware? Can it be done using another component, e.g., "eglrender"?
I also presume that there might be a penalty involved if there's a kernel -> user mode copy, unless we're able to use shared memory, or some other no-copy technique.
Any help much appreciated - thanks in advance!