Minimum required CPU for Mpeg 4 AVC playback at 720x576?

[kurkosdr]

Hi there,

What is the lowest CPU that's able to reliably play an Mpeg 4 avc video clip (mkv container) at 720x576 resolution (25fps)?

Is something in the Pentium III range enough? What Mhz?

Thanks.

[roozhou]

I think you forget bitrate.
My grandma is using a P3 667 and I can visit her this weekend and do some tests.

[kurkosdr]

I think you forget bitrate.
My grandma is using a P3 667 and I can visit her this weekend and do some tests.
What is the peak bitrate x264 produces when encoding videos in maximun quality, at 720x576 resolution?

I think we should find a "worst case" sample (= a video with lots of action scenes and such) and then encode it with x264 at maximum quality setting.

[nm]

What is the peak bitrate x264 produces when encoding videos in maximun quality, at 720x576 resolution?
x264's maximum quality is lossless, which may mean that the video is not compressed at all if it's white noise.

But for normal 576p25 sources encoded at CRF 20, I'd expect an average bitrate of 1 to 4 Mbps and peaks below 10 Mbps. A 1 GHz Pentium III should be enough with CoreAVC. I've successfully played low/medium-bitrate (1 Mbps average) PAL encodes on a 700 MHz Mobile Pentium III with libavcodec.

[AnonCrow]

Even playback of 1024x576p25 video is quite possible on a <1GHz P-III, if it's encoded at a low enough bitrate and with tune fast-decoding,
and you use a fast enough software decoder, or offload some of the decoding to a cheap PCI or AGP videocard.
http://forum.doom9.org/showthread.php?t=149117

[Blue_MiSfit]

Correct, if you disable CABAC and b-frames, plus use an efficient decoder and overlay mixer, you can get excellent decode of full 576p30 video on something like a 1 GHz Pentium III. I know for a fact, because I used to own a laptop with precisely those specs (and 192mb of RAM + Win2k). Battery life was a LOL in this case, because I usually averaged 80-90% CPU usage :)

A better solution still is to get a video card with DXVA capabilities, as AnonCrow mentioned. This will fully offload the decode to the GPU, and make life much easier for a slower PC.

~MiSfit

[OvejaNegra]

I had one old celeron 1200 MHz 512 mb with aopen mx3s-t (yes i changed the blowed capacitors) and even with ac3 audio i was able to playback fluid IF:
Using overlay mixer (i had an old ATI rage DX7 card 32 mb)
Using mplayer or coreAVC
If the encoded content had bpyramid, then a have to use coreAVC or get some frame skips
If not, then i was safe with FFDshow
Of course, no filters, levels or any other stuff.
2200 mbits more or less on all my encodes.

That old machine died recently :(

My actual dualcore eats anything, so no more critical encoding tests for me :)