Real Time Encoding

[threepacent]

Real Time Encoding

I am trying to encode x264, xvid, or Divx6/Helium in one pass at 20 fps. Currently I have a 3 Ghz Intel machine w/ HT. it is a requirement that it does the encode at 320x240, but it would be best if it could do the encode at 640x480. Which codec will make the best results?

Also I am thinking about getting dual-core processors. For the same cost as a 3Ghz i would probably be able to get a pentium d 820 and for a little more, a pentium d 830. Would I get a performance increase for the codecs. I have heard that xvid doesn't really have a difference whether its dual core or single. But is it worth it for the other codecs.

Also is the Helium Divx codec have such great performance increases as the Divx website says?

Thanks in advance

[Koepi]

It's absolutely possible to do a 640x480 @ 20 fps realtime encode with xvid, just don't use vhq, trellis and maybe even switch off b-frames (though with pure horse power like 3ghz p4 it might be able to cope with that).

I don't know if it's possible to tweak divx for these requirements with a comparable/acceptable quality.

x264 is still in early development and is quite a bit slower yet, I wouldn't dare trying that.

I hope this helps.

Cheers

Koepi

[threepacent]

I tried xvid and it worked very well. the Present VHQ mode was set to off, motion search precision was set to very high, Quant was set to h.263 so no b-frames. Now im going to try putting on some vhq, trellis, qpel, and some b-frames and see what works. Also in the ffdshow encoder, which is the only one thatworks for some reason, what quant. type should i use. It seems to have more options than the regular XviD codec interface. It has h.263, mpeg, modulated, modulated new, and mpeg custom-tables. Ill try setting to custom tables now.

Divx Helium doesn't seem to work, x264 vfw crashes the program, i just found out. Divx6 works as well @ 320x240 however with a few advanced options at 640x480 on it only get about 10 fps in "Better profile". After turning off GMC, the fps is still bad. Helium seems to get even worse fps. at the balanced setting, it gets 18 fps max, which I guess is alright. At fastest it gets 20.

Are the optimizations for dual-core processors good enough yet to be worth buying a dual core? For the same cost as a 3Ghz i would probably be able to get a pentium d 820 or pentium d 830. I know that Xvid would not be affected because there have not been optimizations put out, but would x264?

[Inventive Software]

VHQ will slow it down a lot. Don't enable it if you're trying to get above 20 FPS. H.263 will smooth the image and is recommended at low bitrates (below 1000 kbits/sec). Otherwise, use MPEG quantization. The others enable you to use your custom matrices, which I haven't dared venture into yet.

If you play with the settings in your XviD encoder, you can probably tweak it for acceptable quality against the speed you need.