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CPU or VID card to improve Mpeg playback?

W

winterlude

Senior member
I've got a system with a 466 celeron and a 4 meg ATI video card. When I play back high quality mpeg 2's, it's choppy. Does the video card have anything to do with it, or is this primarily a CPU problem?

BTW, I have 224megs of SD ram, so i don't think that's the problem. Also, I've been able to play back DIVX 5.0 and mpeg 4 smoothly with my system before.

Thanks in advance
 
if the cards specs say that it can decode mpeg2 then it's likely a gfx card problem. with card that don't have a mpeg2 decoder the whole work gets done by the CPU so probably it's the Celeron's fault (since I guess the 4mb ATI card has no mpeg2 decoder)
 
Modern CPU's in excess of 300 MHz should have enough power to decode full-screen MPEG2 (DVD) streams by themselves. Most video cards have some sort of "decode-assist" hardware to help with the mathematics of IDCT transforms, but often the video-playing software fails to take advantage of this. In any case the bulk of the processing is done by the CPU.

Hardware MPEG2 decoders are all but useless at this point; when they were released (starting with the ReelMagic cards over five years ago), they could legitimately claim to be helping underpowered CPU's. Today, CPU's have far more power and don't really need the dedicated decoder board. Even high-quality TV output can be provided by a regular, dirt-cheap video card.

MPEG4 (DIVX 3 - 5) and similar video codes are much more heavily compressed and require more CPU power to decode. Tests at Tom's Hardware showed that a roughly 600 MHz chip was needed to guarantee full-screen full-motion playback. Recent versions of the DIVX codec may be further optimized for MMX, SSE and 3DNow!, allowing slower CPU's to decode in full-motion.

Now back to your question. The clue in your case is that you say you're able to playback DIVX 5 streams smoothly. That's a key point, because DIVX5 is much tougher on your system than MPEG2. So I would look to a configuration issue with one of your players. Some people use a different player for each codec, which is not really necessary. Once the codecs are in your system, any decent player will work.

Try a DIVX stream of the same quality as the MPEG2 you are playing. I bet it will also be jerky. You'll probably need a faster CPU, both in terms of MHz and bus speed. See if your motherboard can support a P3, then check the hot deals forum for anyone selling an old used chip.

Modus
 
A 466 MHz system should be fine for MPEG or DVIX playback
If the system is choppy I would have a tendency to believe that this is a DMA problem or his drives are running in DOS compatibility mode.
Make sure your hard drive and cd-roms are checked for DMA.
 


<< A 466 MHz system should be fine for MPEG or DVIX playback
If the system is choppy I would have a tendency to believe that this is a DMA problem or his drives are running in DOS compatibility mode.
Make sure your hard drive and cd-roms are checked for DMA. >>


I second that.
I watch DVDs on a Celeron 500 notebook with some crappy integrated graphics chipse.
 
Well,
I've got DMA checked on all my IDE devices. The player I'm using is Windows Media Player 7.1 with all the latest codecs. The mpeg I'm playing is an Mpeg 2 conversion of a DV film I made with Ulead Videostudios in High Quality mode. I don't have the specs with me right now for what Vstudios uses for high quality, but a 700 meg CD can hold about 30 mins of the mpeg 2. The DV also plays choppy and has the audio out of synch the same way the mpeg 2 does. Maybe the Vstudios does not encode mpeg 2 with mmx?

How much power should a system need to play DV smoothly?
 
Ok,
Now it sounds like something completely different 🙂

It's probably not the playbacks fault at all.
If you are actually ENCODING your own mpegs, then you are probaly dropping frames because your system isn't powerful enough to make high quality mpegs.
If you aren't running a RAID setup, your hard drives isn't keeping up.
If you have less than 256mb of ram you shouldn't be encoding either.

Try encoding a in a much less stressful enviorment for your pc. Try encoding at 240x180 or less. If your playback is smoother, you have your answer.


 
What your saying could be right, but the DV playback is just as choppy, yet had no dropped frames when I transferred the DV to my harddrive. Also, when I transferred the edited DV (which also played choppy on my computer) back to my camcorder, the camcorder played it back as smooth as silk.
Also, one of the mpeg files I'm playing was encoded on a different machine (P3 933mhz) and played back fine on that rig, but is choppy on mine.
I'm not encoding in real time, so there's no reason I should be dropping frames (just have to wait a long time for it to encode).
The harddrive I'm using was in the other machine (40 gig Maxtor, 7200 rpm) and worked great. Also, I have more ram (224mhz) than the faster rig (128mhz), so I still think it comes down to either my video card, or my CPU.
I know that the problem is that the Mpeg 2's I'm playing are too "high quality". If I encode at a lower setting or in mpeg 1, I can play fine, but I am archiving my home videos on CD's and don't want to lower the quality anymore than I have to. So my question is, where is my bottle neck? My 466 celeron CPU or my 4 meg rage pro video card (which has no mpeg2 decoder)?

Thanks
 
MPEG4 (DIVX 3 - 5) and similar video codes are much more heavily compressed and require more CPU power to decode. Tests at Tom's Hardware showed that a roughly 600 MHz chip was needed to guarantee full-screen full-motion playback. Recent versions of the DIVX codec may be further optimized for MMX, SSE and 3DNow!, allowing slower CPU's to decode in full-motion.


Modus -

I have to add that for widescreen DivX that is true, 600MHz would be okay if the bit rate is not too high. But for 650x480 compressed DivX video there is no way 600Mhz will give stutter-free playback.
 
Do you have any other video windows open when you play the mpeg2 files? You can only have one overlay at one time, and without that overlay....

Perhaps youre encoding it wrong? Too many keyframes? Are you resizing it?

The DV is slow because its one hell of a video stream for anything to process (28 mbps).

But most importantly, (and I think this one is likely the winner since youve got only 4mb of vram), what res is your desktop running at? The Mpeg 2 video needs its own double buffered ram space and without that, its going to be choppy as hell. Try lowering your desktop to 640x480-16bit, and if it plays perfectly, get a new video card. Any old 16-32mb card should do just fine.
 
I think it might be a good idea to help the Celeron a bit more graphics wise. I don't think the Rage Pro Atis had usefull MPEG playback assitance -- but I've been able to view high bit rate MPEG2 (right out of a settop box) with a Rage 128 and a PII 450 quite nicely. Some used Rage 128 card should be very cheap to get.
 
Heres a thought...

Download and install CoolMon.

It displays the percentage of CPU usage on the desktop in real-time.

Then playback your choppy movie and see if the CPU is maxxed out at 100% - if it is, then time to upgrade the CPU. If it's not, then probably it's a bottleneck like the vidoe card thats slowing you down...

Good luck!
 
I think that the cpu "must" be the bottleneck because my vid card doesn't have an mpeg 2 decoder. Beyond that, I don't know what the vid card contributes to the output (watching the movie). I assumed that getting a 32 meg card with an mpeg 2 decoder should help with viewing the mpegs smoothly, but would it help with viewing the raw DV smoothly?
Correct me if I'm wrong, but my assumption is that the mpeg 2 decoder will only help with mpeg 2's and not with VCD's (mpeg1), DV, DIVX and mpeg 4; but upgrading to a 900+ celeron should help everything go faster/smoother.
I did try reducing the color depth (from 24-16bit) and resolution (down from 1024x768), but I cannot reduce it to 640x480 since the mpegs are 720x480.

Thanks for all the ideas and help. As much as I despise Intel for having so many different sockets and chipsets, it looks like I'll be hanging onto my socket 370 board a little while longer (at least until clawhammer). I had been waiting a long time for thoroughbred (from a year ago, they said it would come last Noverber, but AMD kept pushing back the date. Now it's May, and still no thoroughbred; but if I'm going to shell out for a new system, it's got to be a hammer.)
 
:frown:

WTF!?!?!?

I bought and installed a 32meg ATI Xpert 2000 AGP 4X because it has an mpeg 2 hardware decoder, but when I play back my mpeg2 files, they are just as choppy as they were with my 4 meg PCI rage pro.

What the hell? Does it only work for DVD's? Is there something I have to activate? What's the scoop?
 
Perhaps a bit late to dig this up, but as a FYI: the MPEG2 play back works nicely here with a Rage Fury, Windows 2000 + latest ATI drivers and Elecard MPEG player you can find here.
 
Early Celerons, and K6 family cpu's have a hard time handling mpeg4. My experience is with a k6-2 that played some movies ok, but many it didn't play ok. It comes down to how the movie is encoded, or what processes were used encoding it.
 
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