[vorbis-dev] Re: Optimizing Vorbis for a DSP
Adam D. Moss
adam at gimp.org
Fri Apr 9 06:42:05 PDT 2004
Johannes Sandvall wrote:
> On Sun 28 Mar 2004 23:23:46 CEST, Graham Mitchell wrote:
>>>I have recently ported Vorbis to a Texas instruments DSP (TMS320C5510),
>>>The problem I have is that it is not decoding the audio in real time(
>>>about 50% of real time). Could any one give me a clue in which area I
>>>could start to optimize the code.
>>Well, a few weeks ago Johannes Sandvall posted to the list about "replacing
>>the IMDCT with a N/4 FFT", which I seem to recall gave a large speedup; his
>>report is here:
>>And my crufty brain seems to recall that profiling has determined that more
>>time is spent in the function "mdct_backward" than any other, but I could be
>>way off base.
>>Others on the list are much more qualified than I am, but sometimes a faster,
>>mediocre response is better than a slower, perfect one. At least that's
>>what I'm banking on, anyway.
> Here is maybe a patch of the code. Should include both optimized TI
> assembler and reference c code. Patch available at:
Anyone been able to take a look at this patch? I haven't had an
opportunity yet, myself...
--- >8 ----
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