[vorbis-dev] vorbis on playstation 2

[Segher Boessenkool]

David Etherton wrote:
>>MDCT should run fully from cache.  How big is your cache?
> 
> 
> It's a whopping 8k data cache, two-way-set-associative, 64 byte cache lines.

I recommend you use a DCT algorithm that uses O(lg N) precomputed
constants instead of one of the more usual O(N) algo's (of which
the one in libvorbis/Tremor is one), in this case.  Or handle
the DCT/windowing in one of the SIMD coprocessors.

> PS2 also has 16k of fast scratchpad memory which can be used as a DMA source
> or target.

That would be useful to transfer the decoded Huffman stream to
the coprocessor for DCT processing (and maybe the residue/floor
processing other than VLC decoding).

<p>Segher

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