Minimum CPU to properly watch 640 X 480 ~1100 Kbps MPEG4-AVC files?

[simonhowson]

As the post title says, I'm wondering roughly the minimum CPU required to decode 640 X 480 MPEG4-AVC files. I use ~1000 Kbps for the video, and ~100 Kbps VBR AAC for the audio (so about 1100 Kbps for both the audio and video).

I play these on my iPod video, but have an old 2.8 GHz Pentium 4 CPU and motherboard in storage. I am wondering if this CPU would be powerful enough to playback these files without any dropped frames? Would these files work okay with FFDShow? Or would I need a faster decoder, like CoreAVC?

I'm considering using the board to make a Home Theatre PC for another room in my house. But am unsure if it will be fast enough to play these files.

[HowlerX]

A 2.8GHz P4 is more than adequate for 640x480 AVC files with FFDShow. I just watched a 1280x540 AVC on an overclocked 2.53GHz P4@2.85GHz with FFDShow and while CPU averaged between 80-100% the movie played flawlessly.

BTW, I am using Beta2a of the FFDShow tryouts.

[simonhowson]

A 2.8GHz P4 is more than adequate for 640x480 AVC files with FFDShow. I just watched a 1280x540 AVC on an overclocked 2.53GHz P4@2.85GHz with FFDShow and while CPU averaged between 80-100% the movie played flawlessly.

BTW, I am using Beta2a of the FFDShow tryouts.

Thanks very much for posting your experience. It is hard finding benchmarks using files of this type, on CPUs of this vintage. But your experience makes me think it is worth a shot.

[Awatef]

I confirm, it will definitely play the file!
I have a Celeron-M @ 1.3GHz (roughly equivalent to a P4@2GHz) and it can play 704x480 w/ AC3 5.1 sound & soft subs with 45% average load using CoreAVC.
So a 2.8GHz P4 will definitely be able to do it, even using ffdshow.

[simonhowson]

I confirm, it will definitely play the file!
I have a Celeron-M @ 1.3GHz (roughly equivalent to a P4@2GHz) and it can play 704x480 w/ AC3 5.1 sound & soft subs with 45% average load using CoreAVC.
So a 2.8GHz P4 will definitely be able to do it, even using ffdshow.
Excellent, this info helps.

Just one question though, is Dolby Digital harder to decode than AAC? I mean more CPU intensive?

Thanks for your help.

[Awatef]

AC3 & AAC decoding have almost the same impact on CPU load.

[simonhowson]

AC3 & AAC decoding have almost the same impact on CPU load.
Thanks again, very helpful.

[Awatef]

You're welcome!

To top it, here some numbers that will make you dribble!
You remember the 80 to 100% Howler was talking about?
Now I got 51% average load (75% peak) on a Celeron-D @ 2.4GHz playing a 6 Mbit/s 1280x544 AVC clip w/ 5.1 AAC sound (using CoreAVC).
If that does not sound good :cool:

[Shinigami-Sama]

To bad you can't buy CoreAVC anymore so benching against it is kinda moot. However I can play them fine on my old 3GHz P4 with an old FFDshow you should be good

[simonhowson]

I've just realised that I only have 512 MB RAM for this motherboard. Will that be enough, or would I need 1 GB?

Why isn't CoreAVC for sale at the moment?

[legoman666]

My 1.6ghz AMD Sempron plays 720p AVC with 5.1AC3 just fine. GPU is a nvidia 7300GS, so it isn't helping decode the video. The only time it hiccups are sections of the video with extremely high bitrate. It also only has 512mb ram. You'll be just fine.

[simonhowson]

My 1.6ghz AMD Sempron plays 720p AVC with 5.1AC3 just fine. GPU is a nvidia 7300GS, so it isn't helping decode the video. The only time it hiccups are sections of the video with extremely high bitrate. It also only has 512mb ram. You'll be just fine.

Thanks, sounds like this is worth a shot.

[Shinigami-Sama]

I've just realised that I only have 512 MB RAM for this motherboard. Will that be enough, or would I need 1 GB?

Why isn't CoreAVC for sale at the moment?

Probably due a myriad of complaints and support issues from the latest release. 512 should be enough for that resolution depending on how many background processes there are.

[Blue_MiSfit]

Indeed. My HTPC is a measly 1 GHz P3 with 256, and for low bitrate x264 (under 1mbit @ 640 stuff) and CoreAVC it works well.

~MiSfit

[Awatef]

Even with less than 512MB, 720p should be no problem.
I've got a P4@3GHz HT with 480MB available memory, the other 32MB being shared by the motherboard's IGP, and it plays 1280x720@30fps without a hitch using CoreAVC.

So you make sure you grab it when it is available for sale again, if you ever feel the need of playing 720p in the future, because it should work on your PC too! ;)

PS: I'm not interested in 1080p at this very moment, 'cause the best screen I have doesn't go beyond 1280x960, so I guess it's useless for me to even test it, sorry :)

[Inventive Software]

With a Celeron 800 MHz and an old pre-release build of CoreAVC (no I'm not giving ;)), I can play 720x576@25 FPS content at about 3000 kbps, pretty much flawlessly. There are a few occasions where the very high complexity of the scene makes it drop a couple of frames, but that's rare.

[Blue_MiSfit]

Impressive, my P3 doesn't play high bitrate (2200mb) backups that I've done recently with x264 using high settings, like high profile, 3 bframes and 6 refs. It drops frames all over the place...

~MiSfit

[Inventive Software]

Oh, I forgot, that's High Profile content, most of the time 4 refs 4 B-frames. ;)

[brucevangeorge]

I can play 720p x264 on a Athlon XP 1800+. (Pentium 4 1.9-2.0 GHz equivalent)

It stutters sometimes if I have stuff in the background. But without any other load it can play very well. Somewhere in the 6-8mbs range.

AC3 5.1 Audio. I guess its the bare minimum what I have to play these types of files.

FFdshow and MPlayer (best universal player ever) do it just fine.

[mitsubishi]

I can play 720p x264 on a Athlon XP 1800+. (Pentium 4 1.9-2.0 GHz equivalent)

It stutters sometimes if I have stuff in the background. But without any other load it can play very well. Somewhere in the 6-8mbs range.

AC3 5.1 Audio. I guess its the bare minimum what I have to play these types of files.

FFdshow and MPlayer (best universal player ever) do it just fine.

Really?

Core2duo E6300, 720p25 H.264 3227 kbit/s, AC3 stereo 384kbps

http://img521.imageshack.us/img521/8113/720pdl1.gif
Green: CoreAVC
White: VLC
Red: FFDshow

FFDshow can't keep up, drops frames and stutters, audio is quickly out of sync.

------------------

Forgot to say, this is a high profile, unrestricted encode (using Sharktooth's 'slowest' profile)

[foxyshadis]

The huge difference between ffdshow and VLC is odd, since they're usually not more than a couple % difference for most people. It is ffdshow-tryouts, right? (Or a recent CCCP, both have last year's h.264 speedups.) And no filters are enabled and YV12 or YUY2 output is used?

[Shinigami-Sama]

The huge difference between ffdshow and VLC is odd, since they're usually not more than a couple % difference for most people. It is ffdshow-tryouts, right? (Or a recent CCCP, both have last year's h.264 speedups.) And no filters are enabled and YV12 or YUY2 output is used?

seeing as how its so similar to Core, maybe they hacked it into VLC?
or maybe I'm just batty

[mitsubishi]

The huge difference between ffdshow and VLC is odd, since they're usually not more than a couple % difference for most people. It is ffdshow-tryouts, right? (Or a recent CCCP, both have last year's h.264 speedups.) And no filters are enabled and YV12 or YUY2 output is used?
Sorry yeah, I was too tired last night to realise that doesn't normally happen :rolleyes:

I opened the file in MPC, then dragged it over to my second monitor and went full screen, this seems to cock things up. Opening the file when MPC is already on my second monitor gives this:
http://img227.imageshack.us/img227/7793/720p2us0.gif

Virtually identical to VLC.