VBR and CBR

[datascab]

Hi,

I've been doing some avi to mpv conversions.

On some files, even though I specify an avg. bitrate of 4500kbs, i get 3000kbs etc thus the file is undersize.

As I understand it, this means that the source didnt require such a high bitrate, something like quality saturation.

If I input the corresponding bitrate for CBR encoding I get the calculated file size.

However does this mean I am wasting bits?

Since I am burning to dvd, this is not a problem since the aim is to fill the disk and achieve best quality.

Is there any downside to encoding CBR and achieving 100% file size (making full use of the disk)?

One this that does appeal to me is that the CBR process is 1 pass so encoding times are reduced by 1/2.

Some files i have encoded have made full use of the disk with 2-p VBR encoding. These seem to be the 2 cd rip versions.

In the case of these.... would CBR 1-p encoding yield as good results as the 2-p VBR method?

THanks

Data

[Kedirekin]

Alot of people would say you're wasting bits encoding CBR. However, if you're satisfied with the results, there's really no reason *not* to use CBR. The down side is that 4500 kbps may not be enough to give good quality on demanding scenes. That's when VBR is your friend.

CCE should produce VBR encodes at the predicted file size. CCE will use the average bitrate no matter what the footage is. I would recommend that you confirm that your 4500 average bitrate entry is sticking and being used. For example, if you enter an average bitrate of 4500 while the max bitrate field says 3000, CCE will change the average to 3000 - you need to increase the max before you set the average.

[datascab]

Hi,

Thanks for your advice.

I tried using CCE as follows: -

Opened *.avs... selected 1p vbr... q40, 0 and 9800....

Encoded that....

Then selected multipass vbr, 3 passes.... with 0 min and calculated avg and max bitrate.

From this I got the correct 32mb file :)

This leads me to this.....

Why is Mainconcepts encoder ignores the requested average on some encodes?

Seems to be the 1cd rip avis at the moment.

Thanks

Data