Video Decoding?

[jbrown96]

I just bought a used computer as a Media Center PC. I am using Kubuntu on it, but I'm having some serious performance issues. The system is a P4 3GHz, 2GB RAM, Nvidia Quadro FX 540. I can play most video fine, but I have several high def movies ripped to my hard drive (720p mkv videos). The video is completely trashed; it plays okay when there is little motion, but otherwise it freezes or is really pixelated. I have heard that the Nvidia drivers don't support "Purevideo" (I guess decoding on the GPU), so the processor has to do all the work. The CPU runs 90-100% when trying to watch 720p videos.
Is there any way to utilize the GPU at all. I would be willing to upgrade the GPU to something that would be able to, although I don't want to spend a ton of money. A friend suggested that ATI might support decoding in their Linux drivers now. Could someone give me some advice on where to go?
As a side-note, I have a laptop with a Core 2 Duo 2GHz, 2GB Ram, Nvidia Quadro FX 570m that plays any high-def great, and the processor usage is only 10-15%. Is that the GPU, graphics driver, or the CPU being way more efficient?

Thanks for the help.

[curaga]

That's the laptop cpu being many generations better.
Heck, I can play 1080p scaled to 1024x768 on my Core 2 Duo that has only Ati Rage II+dvd card (ie 2d card without even XV acceleration)

[sloggerKhan]

I think on linux the bottom line right now is that you need a cpu that can handle decoding high def, and if you have that, your playback will be okay.

I have a 2 ghz turion and a 2.1 ghz x2 and they both decode 720p with ease, but definitely seem to struggle with 1080p decode, though the 2nd core does make a big difference.

[deanjo]

If you don't mide spending a few bucks a worthwhile investment is picking up core codec that can be used with mplayer through a patch. It drastically cuts the sys requirements for high def content.

[Redeeman]

do you know if core codec still degrades quality in order to speed up decoding?

[deanjo]

do you know if core codec still degrades quality in order to speed up decoding?

Compared to the other options out there right now for linux short of upgrading hardware it is your best option. FFMPEG and x264 still doesn't thread all that great and suffer the same quality loss (if not more).

[Redeeman]

erhm.. no

ffmpeg might decode too slow for realtime, but it does not degrade the quality...

also, x264 is an ENCODER, and it has excellent threading..

all i want to know is, does corecodec H264 still degrade quality to achieve speed?

[deanjo]

erhm.. no

ffmpeg might decode too slow for realtime, but it does not degrade the quality...

also, x264 is an ENCODER, and it has excellent threading..

all i want to know is, does corecodec H264 still degrade quality to achieve speed?

ffmpeg is horrible at decoding in cpu AND overall quality

http://techdigger.wordpress.com/2008/05/21/mp4-hd-video-codec-review-coreavc-ffmpeg/

[Redeeman]

first off, ffmpeg is one of the faster decoders (obviously not as fast as coreavc), and secondly, i call that comparisin useless, for many reasons

1: its not even the same frames
2: those results are produced on winblows i think?
3: its not at all the same filters that are running?
4: this looks an AWFUL lot like the result of filters and not the decoding(unless coreavc now has postprocessing in the actual decoder, which would then need be enabled on ffmpeg aswell)
5: these results do not corrospond to other tests i've seen

[deanjo]

first off, ffmpeg is one of the faster decoders (obviously not as fast as coreavc), and secondly, i call that comparisin useless, for many reasons

1: its not even the same frames
2: those results are produced on winblows i think?
3: its not at all the same filters that are running?
4: this looks an AWFUL lot like the result of filters and not the decoding(unless coreavc now has postprocessing in the actual decoder, which would then need be enabled on ffmpeg aswell)
5: these results do not corrospond to other tests i've seen

So give links. Results here produce the same results.

Also I am aware that x264 is a encoder, but because of x264 not supporting slices anymore the decoding performance on any hurts on any software decoder as they all use multi-slice decode on threading.