[Tremor] LOW_ACCURACY mode and MDCT improvements

[Daniel Kahn Gillmor]

On 03/22/2010 01:33 AM, Daniel Kahn Gillmor wrote:
> i haven't had time to profile the patch yet on my hardware.

OK, running the patched sources on an NSLU2 -- 32MB RAM, debian
2.6.32-trunk-ixp4xx armel kernel, de-underclocked 266MHz processor,
running the ivorbisfile_example program to decode a CD-quality audio
file, i see no significant difference (in fact, the new version is a
hair *slower* than the old one, though that could be due to some other
confounding factor).

Before the upgrade:

> 0 dkg at igor:~/src/tremor/examples$ time ./ivorbisfile_example < rovingrambler.ogg | dd >/dev/null
> title=Roving Rambler
> artist=Country Gentleman
> date=
> album=Country songs, old and new
> tracknumber=1
> 
> Bitstream is 2 channel, 44100Hz
> 
> Decoded length: 8408400 samples
> Encoded by: Xiphophorus libVorbis I 20010813
> 
> Done.
> 65690+1 records in
> 65690+1 records out
> 33633600 bytes (34 MB) copied, 36.6966 s, 917 kB/s
> 
> real    0m36.889s
> user    0m32.110s
> sys     0m4.580s
> 0 dkg at igor:~/src/tremor/examples$

after the upgrade:

> 0 dkg at igor:~/src/tremor/examples$ time ./ivorbisfile_example < rovingrambler.ogg | dd >/dev/null
> title=Roving Rambler
> artist=Country Gentleman
> date=
> album=Country songs, old and new
> tracknumber=1
> 
> Bitstream is 2 channel, 44100Hz
> 
> Decoded length: 8408400 samples
> Encoded by: Xiphophorus libVorbis I 20010813
> 
> Done.
> 65690+1 records in
> 65690+1 records out
> 33633600 bytes (34 MB) copied, 39.5597 s, 850 kB/s
> 
> real    0m39.717s
> user    0m35.490s
> sys     0m3.970s
> 0 dkg at igor:~/src/tremor/examples$ 

So i'm afraid i'm not seeing any improvement on this hardware.  Should i
be?  Am i measuring the wrong thing?

	--dkg

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