Best settings for slow cpu playback

[maormini]

Hi!

I was wondering what are the best settings for getting a file to playback with no jitters or stutters and have good sync with audio (even when jumping through seens in MP) on a relativly slow CPU, say Celeron 700?

B-frames GMC, Psycho etc... which one/s make it harder to decode on slow CPU's and which one/s may help?

[jggimi]

B-frames can siginificantly increase perceived quality, but they do require more processing to decode. AFAIK, the other options (GMC, PM, QPEL, etc.) don't alter the decoding process at all.

I recommend using ffdshow for playback; I find it works better for me than the DivX codec for playback.

If you're skipping ahead, you won't get a viewable image until you hit the first I-frame; that's just the nature of GOPs. With a typical 250-300 frames between keyframes, it could take a few seconds.

[maormini]

I am encoding a 3 hr movie onto 1CD using 64kb ogg mono audio. (I am doing this as a project for someone and the requirments are to compress 3hrs of video to 1cd with best possible quality and with no playback problems on old computers):mad:
The most important for me is to get the maximum quality possible for such a thing.
Usually for this kind of thing I use an extremly low resolution of 352x288 (PAL source).

My question is now what settings will give my best overall quality while maintaining the possibility to playback on slower computers.

If I understood you well ffdshow will give me a gain in decoding on slow computers.

If anyone has any suggestions on how to get a good quality/performance ratio please fell free to reply! ;)

btw: If you think I should use a different codec, It could be a possibilty as long as I get the above results.

[hakko504]

Well, I've done a few encodes like that - cramming 2.5~3h movies onto 1CD with 352x288@25fps and quite frankly, they won't look good. Acceptable:yes, good:no.
First of all you won't be able to make it even acceptable unless you enable b-frames, there just isn't the bits for anything else. Secondly, if you use DivX5.02 you can limit the minimum quantizer to 3, that will save some bits but leave some parts not looking quite as good as possible. You won't notice it because it's not very many frames that gets quantizer 2 anyway when you have such a low bitrate.
Third, at this point you will definitely gain from the multipasses of DivX 5.03+. It will give you the possibility to get every last bit out of the encoder, and put it at the precise point where they are needed. You might even want to try changing the bitrate modulation parameters up and down a few times to get the best possible encode.

Good luck.

[dTb]

I can't speak from experience because I don't use qpel but afaik it can have a fairly significant impact on decoding speed so I would recommend against using this. I'm not sure if psychovisual enhancements have much impact but they may be worth using to squeeze a little more quality out. Also make sure to use DivX 5.0.5, you should be able to get better quality out of this than say 5.0.2.

[shootimus_maximus]

Psychovisual enhancements won't affect decoding performance, it just affects the way the encoder allocates bits. As far as I can tell, all psychovisual enhancements does is allocate bits away from areas with very high luminosity (bright areas that the human eye can't see too well) into other areas of the picture where they can be better used. This can make it look worse, especially at high-bitrate encodes, but if you're going for maximum cramming, then turn it on. Setting it to strong sometimes causes hideous blocking in very bright areas though, so be careful.