Quicky question about encoding - please help me !!!

[BV2001]

Here is my scenerio.

I try to encode AVI files ( capture from canopus ADVC-100 ) and convert them into xvcd ( 352x240 @ 1800kbps ), this way I can put 280 min into 1 DVDR. I am about to increase the bitrate to 2100kbps and keep the resolution at 352x240, I am able to put about 230 min. My question is will I get a BETTER quality or WORST ?? since the source is from VHS ?? Generally, increasing the bitrate make videos better but will it increase the artifacts also ??? The reason I ask because when I watch the AVI files, they looks way worst than the one convert to xvcd.

THanks

[petar]

Higher bitrate will give you better (or at least the same) quality whatever the source, providing the rest of the encoding parameters are properly set for the given bitrate.

The reason I ask because when I watch the AVI files, they looks way worst than the one convert to xvcd.

DV looks way worse than mpeg at 1800 kbps? Something must be wrong with your player or maybe it's not set up properly. Also, do you watch both in same screen size (full screen, for example)?

[BV2001]

I watch on my LCD screeen. Somehow, I found that there are more artifact with AVI and after convert, it is smoother. Anyway, with the bitrate that high, should I increase the res to 352x480 instead. I want the best picture as possible.

352x240@2000kbps or 352x480@2000kbps.

Which will give the best look ??
thanks guys

[petar]

Lower resolution will give you better picture for the same bitrate. If you think about it, higher resolution has more information per frame. So if you keep the same bitrate there's less "space" for the encoder to compress each image. In your example 352x240 will give you better picture.

All this depends on the bitrate. If you, for example, choose to use 4000 kbps then it's better to increase the resolution because 4000 kbps for 352x240 will probably be wasted and a higher resolution will give you better image (though it depends on the resolution of the source as well - if your source was 352x240 then resizing to a higher resolution isn't going to give you much benefit).

Hope this makes sense.

[BV2001]

absolutely make sense to me.
THanks.

Also, encode to mpgg2 ( DVD ) and xvcd ( mpg1 ) given them at same resolution and same bitrate ? Will it make a different ?? DVD will yield smoother, better pictures ???

[petar]

I can't speak from experience because I've never done mpeg2 vs mpeg1 test nor I've used mpeg2 at very low bitrate. But from what I've read mpeg2 was optimised for (relatively) high bitrates and at low bitrates it's not much better than mpeg1.