File information: How do I determine VBR or CBR?!?

[Skywalka]

Hi folks,

I am currently adding information to files that are already in the database while building my "Mylist". I am having a hard time determining whether a file is encoded in constant or variable bitrate (CBR = "regular" or VBR).

All the AVI file information utilities only tell me what the overall bitrate is (funny enough every program tells me a different bitrate - gspot says this, AVIInfo says that and ani-db-o-matic something that is way off but I saw that this is mentioned in the readme) but not whether the encode was done with VBR or CBR setting.

There is a difference for instance in DivX3 where the info utils tell me whether it was a slow-motion or a fast-motion encode. Can I derive the bitrate information from that? I guess not.

Maybe the information is only available from the original encoder.

In either way please leave me a PM so I can carry on with adding information to the database.

Oh and since I am new here thx EXP for this whole thing. I like it

[shaydwyrm]

In my experience gspot does in fact distinguish between VBR and CBR, I haven't found any other software that does the same.

[Guest]

It tell you if the Audio is VBR or CBR.

Another thing I found out in the last five hours of searching on the internet: in the Divx.com forums some users say that ALL DivX files are VBR since DivX is always VBR.

Puzzles me.

They also mention that AVI is only able to play CBR Audio files and that it has to be hacked to play VBR audio files and that most of the time VBR audio on AVIs will result in audio problems.

I feel like number five. Need input

[nwa]

well...as far as I know all the new divx encodes are VBR...it used to be CBR a long time ago...
and about the VBR audio files, I have never experienced a problem with them, I think all you need is just the right codec that can process MP3 VBR

[Iceman[grrrr]]

DivX 3 was VBR...

To know if it is VBR or CBR, check the value. If it fits perfectly (Like 128kb audio) then it certainly is CBR. If it has 5 numbers after the period, then you're almost sure it's VBR.

[Skywalka]

Hmmmm.... I understand.

So the VBR is solely about the AUDIO. That seems to be logical and fits everything I read in the past hours and after checking almost 1200 of my files.

Thanks for the info, I will use it accordingly.

Maybe this should be put into the FAQ about the bitrate?

[Iceman[grrrr]]

well not only for video since video is VBR most of the time... all divx codecs are, that's the point of doing multipass encoding!

[Skywalka]

Yeah well Duh! that's what I came up with in the end, BUT all single pass encodes are VBR as well - that is why you cannot determine what the actual filesize of a file will be. The size of a CBR SVCD or VCD encode can be _exactly_ caluclated.

That's why I do not understand the options "DivX3", "Divx3", "DivX4", "DivX4 VBR" et ceterea - every encode is "variable", nothing is constant when encoding a DivX file. Therefor (I think, in my humble opinion) these options for files on AniDB are a bit misleading, and on the other hand there is no way to find out whether a file was single pass encoded or multi pass (2 pass, 3pass ... n-pass) encoded - you only get the everage bitrate - and the various programs simply tell you how big the video and how big the audio part are, then takes those sizes and devides it by the number of seconds to give you the bitrate, and that is the average bitrate (of course).

That is my guess, but I'd really love to get other inputs. I guess I'll send a PM to one of the admins to ask about it

Thanks for your answer!

EDIT from wahaha: The thread continues in Merge CBR and VBR for video-codecs? in Feature Request.