h.264 Playback on P3 1ghz

[roket scyntist]

Hello Everyone...

I have done a bit of digging, and have not quite found the answer I'm looking for. I want to build a cheap media pc for our master bedroom, and wondered if I will get standard definition h.264 to play on the mentioned machine: 1Ghz p3, 512MB Ram, Geforce 5600 (with tv out which I will be using), Wireless card for streaming from my main server.

The source will be my own backed up dvd's, PAL, so max resolution will be 720x576 anamorphic, and they all have a dolby digital audio track, that will be played in plain stereo via the onboard sound card.

Nothing is installed on the machine currently, so before I go ahead with a install and buying a remote, does this machine have enough horsepower? Xvid I know plays fine, but most of my backups are h.264, dolby digital in mkv.

Thanks.

[nm]

It depends on the bitrate, but 1 GHz should be enough for most 576p25 encodings. If ffdshow or VLC/MPlayer are not fast enough, you could buy CoreAVC.

[audyovydeo]

Hello
... 1Ghz p3, 512MB Ram ...
... 720x576 ...
...h.264 ...

Thanks.


From my experience, forget it.
Indeed, I am _right now_ trying to find a set of x264 options that can play back on lower-end PCs.

I find that all the DV/PAL content I encode struggles to play back on Pentium4-class Celerons, or lower P4s.

Just to give you an idea, for the systems within my reach, my 720x576x25fps stuff encoded to High Profile Level 3.1 specs uses :

Intel Core2Duo T5200 - 1.6GHz - 2MB L2 = 15-20%
Intel Pentium M 745 - 1.8GHz - 2MB L2 = 30-50%
Intel Celeron M 370 - 1.5GHz - 1MB L2 = 50-70%
Intel Celeron D - 2.6GHz - ?????? = 100% bad stutttering
Intel Celeron Coppermine-128 - 700MHz - 128 KB = freezes windows, soft reboot needed



WinXP SP2 on all systems
playback with VLC 0.8.6x on all systems


cheers
audyovydeo

[roket scyntist]

Bitrate wise, I encode using CRF, so it varies, but the worst so far has been around 355 kilobytes per second (video only). Looks like I will need to install anyway to test low and high bitrate movies. I have just tried it on an old 1.2ghz P4, and it plays beautifully with CoreAvc, but less so with ffdshow or vlc.
Garrr!


Oh, forgot to mention, I'm using the crf sharktooth preset in megui.

[audyovydeo]

I have just tried it on an old 1.2ghz P4.


I also use crf, but target bitrates in the 2500-4000 kbps range.
Still, equal to DVD rates.

P4s seem OK. I'm saying P3s are problematic. You got a P3, right ?

cheers
a/v

[Sharktooth]

If you dont mind about the bitrate, disable CABAC in the CRF profile.
The resulting filesize will be about 10% bigger (at the same quality) but it will be easier for the CPU to decode

[Dark Shikari]

If you dont mind about the bitrate, disable CABAC in the CRF profile.
The resulting filesize will be about 10% bigger (at the same quality) but it will be easier for the CPU to decodeNote 10% is probably an underestimate; from the tests I've seen, CABAC gives at a minimum a 10-12% benefit, with the benefit greater at low bitrates and considerably greater for anime/cartoon sources (as high as 30-40% at high QPs).

Also note that since Trellis is CABAC-only, you lose the benefit of that also.

[weaver4]

As other alternatives you could:

> Order a PopcornHour A-100 they claim to be able to play H264 Level 4.1. $179

> Or record your movies in DivX. DivX movies need to be 25% larger for the same quality, but the processing power to Decode is roughly 30% of H264. I have got DivX to work with a 1Ghz via C7 processor.

[audyovydeo]

Also note that since Trellis is CABAC-only, you lose the benefit of that also.

I wasn't aware of that dependance.
Does that mean that when I specify --no-cabac, --trellis is set to zero or do I have to explicitly do it myself ?

I ask because I've just started playing with no-cabac in my tests, and kept -t 1.

@sharktooth, ot : ciao from another Genova fan.


cheers
audyovydeo

[Dark Shikari]

I wasn't aware of that dependance.
Does that mean that when I specify --no-cabac, --trellis is set to zero or do I have to explicitly do it myself ?

I ask because I've just started playing with no-cabac in my tests, and kept -t 1.

@sharktooth, ot : ciao from another Genova fan.


cheers
audyovydeo
From x264 help:
-t, --trellis <integer> Trellis RD quantization. Requires CABAC. [0]
- 0: disabled
- 1: enabled only on the final encode of a MB
- 2: enabled on all mode decisions

[roket scyntist]

Yup, its a p3.

I might try the no cabac route, but I will do an encode or three to test. I'm too curious now anyway, so I'm installing the machine now.

I have unfortunately done quite a bit of encoding, since I'm using a AMD Sempron 3200+ as my media pc in my living room, and that has handled everything except h.264 1080i/p.

I will let you guys now when i'm done testing.

[audyovydeo]

hear palm of my hand striking my jaw, hard.

and no, I didnt cure my new year's hangover with more drinks ...

cheers
audyovydeo

[roket scyntist]

The popcornhour looks pretty cool.

As far as I understand the wikipedia article on AVC, the only difference between high profile 4.1 and 5.1 is the resolution and bitrate restrictions right? But feature wise (CABAC etc.) they are the same?

[Dark Shikari]

The popcornhour looks pretty cool.

As far as I understand the wikipedia article on AVC, the only difference between high profile 4.1 and 5.1 is the resolution and bitrate restrictions right? But feature wise (CABAC etc.) they are the same?There are also DPB restrictions--number of reference frames for a given resolution.

[Sagekilla]

On a P3, you should be able to decode standard DVD resolution (720x480 @ 24 fps) fine on a P3 with CoreAVC as your decoder. I had no trouble getting it to work on an even slower P3 machine we have. It's about half the speed (above 500 MHz at least I believe) as yours and does fine on not-so-insane encodings.

I know from first hand experience, my computer gets a MASSIVE boost when I use CoreAVC as the decoder. I couldn't even decode 720p properly on my 2 GHz Opteron, but with it I can decode up to 1080p easily, even with settings practically maxed out.

Edit: This was considering I encoded anamorphically @ 720x480 to save bitrate and increase speed a bit since I have roughly 16% less pixels to decode. Lower resolution and bitrate helped me out a lot.

[roket scyntist]

So I have completed the install....

FFdshow and VLC battled a bit, and in the end would not have worked, but CoreAVC gave very good results. The video stutters for the first 2 seconds, but then runs fine. Joy!

Installed with WinXP home.

[Inventive Software]

If you dont mind about the bitrate, disable CABAC in the CRF profile.
The resulting filesize will be about 10% bigger (at the same quality) but it will be easier for the CPU to decode

Seconded. This was the only way I could get SD H.264 to play back on my Celeron (Coppermine core) 800 MHz with ffdshow. With it enabled, I have a pre-release version of CoreAVC that has no trouble with it.

[((( atom )))]

One other thing which might be worth a try is mplayer with -lavdopts skiploopfilter=all and maybe also :fast. But if you are happy with CoreAVC then I guess I aam too late..

[Irwin]

Pentium M 800mhz (Intel A110 8x100mhz):
1280x720 h264 2000kbps and TCPMP player - about 90% cpu usage (with CoreAVC 100% and many dropped frames, and freeze screens)
720x576 h264 2000kbps/TCPMP - about 70%

[bond]

SD with normal options enabled will work on your cpu, but its of course at the borderline.

checkout the decoder comparison (http://forum.doom9.org/showthread.php?t=99402). it has been done on a p3 866mhz and also shows which encoding options influence decoding on various decoders (yeah coreavc is not included)

i would say that with coreavc you shouldnt have a problem with loop (i normally use low settings though) and cabac been enabled.

if you still get problems or use slower players/decoders you might want to use a lower res, like 640x...

but still you need to try it yourself to be sure