[FFmpeg-devel] Special optimization for PS3 Cell processor

Sakur sakur.deagod
Thu May 10 07:46:26 CEST 2007


Hi
> ----------------------------------------------------------------------
>
> Hadn't tested mpeg4 decoding, I assume the bottleneck would be the video
> > out, not the decoding...
>
> Nope, overhead is in CSC and in iDCT. Blitting to the framebuffer,
> while a SW blit, is still fast (in the 100's of frames/sec)
>
   I am using DirectFB to blit the frame into PS3 FB. Though not using
Sony provided ioctl ,DirectFB has some similar ioctl to control PS3
framebuffer. On PS3, Linux FB driver actually worked on a virtual
framebuffer allocated from the main memory with a double buffer flip
support.(I still got occational crash ).
>
>> > Please start reading the code and try to thinks way to make it more
>> > threaded for Cell (and Sun's T1/T2) while keeping it single thread for
>> > system with less core availability, that is probably the hardest part.
>>
> The big issue with optimising ffmpeg or any codec for the PS3 is that in order to make optimal use of the SPUs major code changes may have to be made. This is based on doing double or triple buffering data for the SPU code as is recommended in the SPU programming guides. This is something that pretty much has to be done to optimise for any specialised coprocessor like the SPU or GPU. - john
> [...]
>
CellSDK provided ALF programming library to facilitate Cell
programming.  But I just seek ways to put the stuff in .  To test SPUs
with those DSP funcs is my first step .  Though everything seems hard,
I should make the first try :). Thanks




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