Trouble Finding Bitrate for DivX Xvid for CD-r

[4194]

I have seen several calculators and so far they have mostly worked for all types of files i have tried.

But i cannot figure out the bitrate using the DivX 6 codec. I am using aoa to make the file. The calculator states that basically for a 98 min CD the bit rate should be 750-795. (I have tried many different rates.) The problem is when it is encoding it shows the approximate file size at 1000+mb (too much for my cd-r)

I could wait for the entire file to create but even if it is a few over the 700 then it was all for nothing.

I am sure that the calculators are correct. So what am i missing? Thanks.

[4194]

It also seems to do the same for Xvid.

[jagabo]

Your calculated bitrate sounds right. Do you have the right audio bitrate? Divx and Xvid sometimes miss the mark. You can use GSpot to examine the resulting AVI file to check the audio and video bitrates.

[guns1inger]

Try using AutoGK for your encoding. It does both Divx and Xvid, and is pretty accurate. FWIW, when encoding 50 minute programs to 435MB, the Virtualdub (AutoGK uses virtualdub to drive the encoder) regularly shows the size to be between 500 - 600 MB throughout the process, but hits the target within a few 100KB every time.

[4194]

Try using AutoGK for your encoding. It does both Divx and Xvid, and is pretty accurate. FWIW, when encoding 50 minute programs to 435MB, the Virtualdub (AutoGK uses virtualdub to drive the encoder) regularly shows the size to be between 500 - 600 MB throughout the process, but hits the target within a few 100KB every time.

Thank you. I am still experimenting with what will work and what wont.

I think i did use aoa once with similar settings. It put it over the 700mb mark by like 7 mb. It wouldn't fit on my CD-R. Maybe i shouldn't be so impatient...

I will try again...

[guns1inger]

As was pointed out, Divx/Xvid aren't always as accurate as we might like, so build a little overhead into your calculations to allow for it.

[4194]

After experimenting a little i have found that when i try to make a 700mb file it becomes 706mb.

I set it at 690 and it was 696 when i woke up.

I also see that the last one i tried recorded the audio at 192. I cant really find a function to change this. This is probably why my calculations were off. I was figuring 128. Is 192 embedded in the codec or something?

[guns1inger]

Audio has nothing to do with the Xvid or Divx codec. Divx/Xvid is solely video. 192 kbps must be a default setting somewhere, but you can change it.

[4194]

Audio has nothing to do with the Xvid or Divx codec. Divx/Xvid is solely video. 192 kbps must be a default setting somewhere, but you can change it.

I see.

But if i put the wrong audio rate in the DivX calculator then that would explain why the files are going over the desired size. (I think?)

I will check some more...

Thanks!

[jagabo]

[quote="4194"]

But if i put the wrong audio rate in the DivX calculator then that would explain why the files are going over the desired size. (I think?)

It could go either way. If you put 128 in the calculator but encode at 256 the file will be bigger. If you put 128 in the caculator but encode at 64 the file will be smaller. In short:

file size = bitrate * running time

bitrate is the sum of the audio and video bitrates.