1RC3 playback freezing, Koepi's build 3/2/04

[lordadmira]

Using 1.0RC3. Koepi's build 3/2/04. I have been getting playback freezes pretty consistently with the last few Xvid releases. I encoded the video with VirtualDubMod and used the built in "Default" Xvid settings and wrote to OGM format. It also does it with my custom encoding settings. Decoder settings were all at default. I don't think it has anything to do with the encoder side since it freezes seemingly regardless of those settings.

Basically after a few keyframes have gone by at the beginning of the video the video just freezes and I can tell by the CPU usage that no frames are being decoded. e.g. 90% -> 15%. It stays frozen until the next keyframe comes by. It then continues normally. The audio continues fine, doesn't stop. It doesn't even freeze at the same point each time, but only in the same vicinity. The freeze doesn't occur on a keyframe boundary. There are no errors in the stream. VDub ok's the video and the skipped portion can be played by clicking on the seek slider to give the decoder another whack at it. Sometimes it will play through fine, other times it will freeze at a still different frame. Sometimes farther along in the video it will freeze at some other random point, showing the same behavior. The only consistent thing seems to be that it most often occurs near the beginning or the end of the video. It also does it if I write to avi format, although less often than ogm. If I totally disable B frames then it doesn't freeze, but I'ld have to do some more testing to be able to say with any confidence that it never freezes with B frames turned off. When I encode with max B frames set to 1 it still freezes sometimes but definately the least often.

I have 98SE, 1.4GHz Celeron, 384MB, DirectX 9, ATI AIW Radeon 9000 with latest drivers, Media Player 6.4.07.1117. I searched the forum but there doesn't seem to be anything about this in the past year. And those posts didn't list a cause or resolution.

Any ideas Koepi?

[ObiKenobi]

are you using ffdshow, divx or the xvid decoder to play the files?

[el divx]

I'm not Koepi but I have a suggestion.

First, use Gabest's Media Player Classic. It's like Media Player 6.4 but way better.

Second, do the following: 1)copy the XviD Decoder Filter "xvid.ax" brom the System dir and put it temporarily on another directory. Then go to gam3r's site (http://xvid.gamrdev.com/) and get the latest binary put it over your existing xvid installation. Then copy or move the "xvid.ax" you copied earlier back to the System directory and register it by going to C:\Windows\System with command prompt and typing regsvr32 xvid.ax.

That should do the trick.

[Leak]

Originally posted by lordadmira
Basically after a few keyframes have gone by at the beginning of the video the video just freezes and I can tell by the CPU usage that no frames are being decoded. e.g. 90% -> 15%.

See, that's your problem right there - if the decoder can't keep up with the video (i.e. if it hits 100% CPU usage and takes too long to decode a frame) it'll skip decoding the video until the next keyframe, as only keyframes allow you to restart decoding. That's just how the decoder is designed.

Turn down your postprocessing settings or use the latest ffdshow build from http://athos.leffe.dnsalias.com/ which will try to catch up again in that case, but if it always pegs the CPU it'll horribly lag behind the audio then.

Of course, not using CPU intensive features like QPel when encoding also helps keeping the CPU usage down when decoding - have a look at Crusty's FAQ, I guess you'll find info about which features affect CPU usage the most there.

np: Plastikman - Locomotion (Consumed)

[lordadmira]

Originally posted by el divx
First, use Gabest's Media Player Classic. It's like Media Player 6.4 but way better.

It's all directshow filters. The decoder has no "knowledge" of what program is calling it. Besides, it does it in BS Player too.

Second, do the following: 1)copy the XviD Decoder Filter "xvid.ax" brom the System dir and put it temporarily on another directory. Then go to gam3r's site (http://xvid.gamrdev.com/) and get the latest binary put it over your existing xvid installation. Then copy or move the "xvid.ax" you copied earlier back to the System directory and register it by going to C:\Windows\System with command prompt and typing regsvr32 xvid.ax.

That is a total hack. What good will keeping Koepi's directshow filter and replacing the dll's make? Ur saying u know of a bug in Koepi's build?

[lordadmira]

Originally posted by Leak
[B]See, that's your problem right there - if the decoder can't keep up with the video (i.e. if it hits 100% CPU usage and takes too long to decode a frame)

It never hits 100%. FFDSHOW uses even more CPU than Xvid. I'm quite aware of CPU considerations in video encoding and decoding.

[Didée]

Originally posted by lordadmira
FFDSHOW uses even more CPU than Xvid.
Well, if it's so, then something is utterly wrong on your side. I could describe now how much less CPU consuming ffdshow is compared to XviD - but since you are so aware of CPU considerations in video encoding and decoding, there's no need for that. ( :D )

- Didée

[lordadmira]

Originally posted by Didée
[B]Well, if it's so, then something is utterly wrong on your side. I could describe now how much less CPU consuming ffdshow is compared to XviD - but since you are so aware of CPU considerations in video encoding and decoding, there's no need for that. ( :D )

Heh, well it has been a while since I last used ffdshow. Maybe it's better now. I also had a far slower CPU back then. Heck back then I even stayed away from xvid because of it's cpu usage. With this CPU I can play back full DVD res Xvid.

I wish there was some way of tracing the filter's frame decoding activities while this is happening. Any special debug builds out there?

[lordadmira]

I just had a clip with B frames disabled freeze on me. Although I don't normally encode without B frames. Here's a sample clip of what I'm talking about, this one does have B frames. This clip freezes almost every time I play it. Even just sitting there and hitting play over and over again. I'ld be interested to see how it behaves on various setups. If you play this can u tell me what ur setup is and how it acted? Xvid version, OS, etc.


http://w3.goodnews.net/~wagnerc/frag1.ogm

[Zarxrax]

It plays fine for me. Decoding with latest ffdshow in media player classic on windows xp.

[Caspar]

It plays fine on my system, but with some insane CPU usage: ~70%.

OS: Win2k
CPU: AMD XP2600+
Codec: XviD 1.0RC3 Koepi's build silent update version.

[lordadmira]

I went on a scavenger hunt and managed to find the latest version of ffdshow. It's totally different than the last time I saw it! Anyway, it too freezes at the same points as the Xvid.ax filter. Although less often. The Xvid decoder freezes basically every time, ffdshow freezes maybe 1/3 to 1/2 the time. I used the overlays and it froze on both P and B frames. Once it even froze on an I frame. It almost seems like there's something about the source material itself that is horking up the encoder or decoder. It makes no sense to me that it would freeze only at the very beginning or very end of the clip. Can anybody comment on that? Somebody who knows the guts of this thing. We need to find out the theoretical basis for a freeze first and foremost.

Also can anybody try this on a 98 system?