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"A collection of spu programs to accelerate media related applications for the CellBE ( PS3 ) platform" - unsolo

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unsolo
Posts: 155
Joined: Mon Apr 16, 2007 2:39 am
Location: OSLO Norway

Ideas Wall

Post by unsolo »

Idea for mpeg2 decoding with regards to motion

store all I and P frames temporary in RAM so that

384Bytes 16x16 Y 8x8 U and 8x8 V for yuv420
512Bytes 16x16Y 8x16U and 8x16 V for yuv 422
and
762 Bytes for 16x16Y 16x16U and 16x16V yuv 444

can be retrived into the spu for forward and backward motion.

Hence when making the I frame you have to store it as a vector and at the same time generate the Image.


Simple loop
I frame is recreated and stored as a vector and sendt to display as Image at the same time

The P frame is then generated into ram as a vector.

B frames are created and rendered into image

P frame is rendered to display as an image

etc etc
Don't do it alone.
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Jim
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Joined: Sat Jul 02, 2005 10:06 pm
Location: Sydney
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Post by Jim »

Might be worth keeping a cache of these decoded macroblocks to avoid too much reloading, and also might be worth pre-caching strips of decoded macroblocks - 3 (or is it 5?) screen-sized horizontal lines of decoded macroblocks would cover most (all?) cases.

Jim
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