CBR AND VBR

[jakecb]

PLEASE GIVE A SIMPLE DEFINITION , CBR AND VBR OR PLEASE
EXPLAIN THE DIFFERENCE. ALSO WHEN USING TMPENC VBR DOES
NOT SHOW PREVIEW, IS THIS VFAPI PLUGIN PRIOITY OR WHAT?

[FT Shark]

I found that the constant bitrate selection gives me the best quality svcd. Variable bitrate will lag at times because it changes the bitrate depending on when the software thinks it needs to bump it up or down (this doesn't always works so good). I suggest a CBR of 2300 kb/s.

[therick]

answer the man's questions...

CBR = Constant BitRate
VBR = Variable BitRate

The reason you are not seeing a preview with two pass VBR in Tmpeg is that no encoding is done on the first pass-the video is simply scanned and bitrate is handed out based on the average, maximum, and minimum that you specified in settings-the encoding is handled in the second pass, you should see the preview then.

[adam]

If size is of no concern then just use cbr at the highest settigns since its faster.

With vbr you can achieve the same or better quality as cbr but in a much smaller filesize.

[ktnwin]

For me, VBR gives better quality. I understood that with VBR, TMPGenc will give lower bit rate to very low motion scenes (which occur quite a bit in a lot of home videos and movies) and give higher bitrate to high motion scenes.
For example, with VBR ranging from 800 to 2520, high motion scenes will get 2520 bitrate and low motion scenes will get 800 (assuming there is no noise in the source AVI files)
This way, the result MPEG file is smaller (can fit more video on one CD). Or another way to look at it, I can go to higher bitrate than with CBR.
I have done lots of CBR SVCD (2400) and results look good but not as good as VBR (800 - 2520).
When I use Hi8 tapes as my source video, VBR still give me near the max bitrate (due to noise level in the video) so the quality is similar to CBR.
For DV tape, it's a different story, I can normally fit more video on one CD using VBR.
It's just what I found out - no intention to start another CBR/VBR war here.