FLACCL: CUDA-enabled FLAC encoder by Gregory S. Chudov (prev. FlaCuda), Formerly "lossless codecs and CUDA" Options

[gib]

With my recent purchase of a 9000 series nVidia graphics card, I started thinking, has anyone investigated if nVidia's CUDA could be useful for lossless compression? I'm not even remotely close to being a programmer, so I haven't a clue how the code works, but it seems like CUDA is valuable for coding/decoding. I know nVidia is already holding a contest to speed up LAME (which ends in about 2 weeks), so perhaps it could be used to speed up lossless compressors? The fastest modes of several codecs are already blazing fast, approaching the limits of hard drives, but perhaps the high-compression modes could be sped-up through CUDA. Maybe, if the speed-up is enough, developers could even implement more ways to gain compression while still maintaining good encoding rates. It would be pretty cool if compression levels like La's best could be done at 50x or something.

Anyway, my curiosity is large, so just thought I'd ask. :)

[guruboolez]

My results on a old Core2Duo E6300 and small Nvidia GeForce 9400 GT. I took two disks: one solo piano disc that compress very well (<400 kbps) and a baroque orchestral work that doesn't (750 kbps).


PIANO MUSIC

CODE

WAV        594.191 KB
FLAC -5    163.122 KB    49313 milliseconds    x69.94
FLAC -8    159.276 KB   116641 milliseconds    x29.57
CUDA -0    158.750 KB    60188 milliseconds    x57.30
CUDA -4    158.024 KB    88531 milliseconds    x38.96
CUDA -8    156.881 KB   176656 milliseconds    x19.52
CUDA 11    156.799 KB   527922 milliseconds     x6.53

VIVALDI

CODE

WAV        754.037 KB
FLAC -5    393.834 KB    68047 milliseconds    x64.32
FLAC -8    393.279 KB   160109 milliseconds    x27.33
CUDA -0    394.796 KB    78688 milliseconds    x55.62
CUDA -4    394.034 KB   111469 milliseconds    x39.26
CUDA -8    393.191 KB   223328 milliseconds    x19.59
CUDA 11    392.079 KB    675656 milliseconds    x6.47

On this cheap GPU, FlaCuda 0.2 performs rather well. It can't be as fast as the CPU but this encoder could approach this speed at -0 and sometimes compress better than flac.exe -8! Nevertheless the CPU has two cores and only one was used for this benchmark.
If I'm not wrong a similar 9400 GPU is used in the ION system. It means that cheap and powerless nettops or netbooks with ION chipset could perfectly be used for batch flac encoding. To be confirmed...

SMALL DECODING SPEED:

CODE

FLAC -8:   x409
CUDA -8:   x392
CUDA 11:   x285

As you can see there's a drastic fall in decoding speed with flacuda -11 (tested with latest foobar2000). On my Sansa Clip (2GB) the playback seems to be fine (I just tried one file though).


More tests are needed but it looks like a very interesting encoder which should work nicely on a ION chipset.