I am trying to figure out ways to speed up encoding. I am using video captured from TV. 352x240 at MPEG1 15000bitrate encodes at about 30fps, 2pass (so 15fps) 640x480 using Divx5 12000bitrate encodes at abou 6fps, 2pass(so 3fps) 5 times slower doesnt sound right, I am thinking that I am setting something wrong. for the first one, I use MPEG1 quant and H.263 quat for the second source ,but I also deinterlace it.

Well It depenends, 1)The filters in you avs(the resolution also) 2)Chroma Motion 3)VHQ4 4)B-Frames(They are fast compared to CM and VHQ4) MoonWalker

how much does the resolution affect the speed? I used the same settings VHQ1, B-frames, Chroma The only diff is I used MPEG for my MPEG1 video (352x240) and H.263 for my Divx5 video (640x480) The MPEG1 goes at 30fps, the Divx5 goes at 6fps

Ok now I'm confused. You mention settings in XviD, but you also keep saying that you're using DivX 5. So are you encoding with XviD or DivX 5? And is the source uncompressed, huffyuv compressed or something else?

I am capturing video from TV using my TV Tuner. I do it in two ways. 1. (352x240) MPEG1 15000 bitrate 2. (640x480 Divx5 12000 bitrate Then I compress them to a smaller size (shooting for about 10mb/min) using XviD. (I'm still working on capturing with XviD)

Now I get it, thanks :). The only thing I can think of that can cause this is the fact that MPEG-4 compression (=DivX 5) is more difficult to decode than MPEG-1 compression. The higher resolution does slow things down, but not by as much as you're seeing. Best would be to capture with HuffYUV or VBLE because they're very fast to decode and lossless, which results in higher quality of your final video. If you have the disk space that is ;).

huffYUV worse than divx5 ? :D maybe after another recompress ...but at intermediate stage certainly not, huffYUV is lossless (except for eventual colorspace conversion) while the DivX at least applies the quantization if not even already denoising. And if you really want to recompress a lossy compressed file i think the quantizer matrix used could play a role, ie. watch out that you use twice the same. if you know what matrix divx used in the first encode i suggest you select that one if you do the reencode in xvid - this could avoid some unnecessary loss (i haven't done tests on this, i never even reencoded divxes or xvids for serious, im only talking theory :))

encoding speed is proportional to size. With your 640x480 / 352x240 this would account for 3.6x slower encoding for the higher resolution. The reason that your speed with divx5 is actually lower is because it is a more advanced / complex codec.

I notice this got moved over to the Divx5 forum. Actually, my question was asking about ways to speed up the XviD encoding.

- Don't use VHQ - Don't use QPel - Don't use B-frames - Don't use Chroma Motion I believe those are the things that slow down the most, in order of magnitude.