A little clarification please

[Fabrian]

Sorry if this is too noobie and I posted in the wrong thread :o, but could someone either explain or point me in the right direction with what exactly is or the difference between AC3,CBR and the combinations below:

http://clanmr.org/genesis/web_pages/Fabrian/untitled.JPG

Thanks!

[jggimi]

Fabrian,

The section you are asking about is the AVI overhead calculator. AVI files produced by Gknot typically have: A video stream, in one of three MPEG-4 codecs. Your example shows DivX 5 chosen as the codec, consuming 1078MB of space within the AVI.

One or two audio streams. Your example shows a single audio stream of 311MB.

Information in the AVI file that keeps the streams in sync. This information is neither video nor audio, but consumes space, and is called overhead. Your example shows you have selected overhead for video with a single audio track that is variable bit rate MP3. But that is the incorrect overhead, since your audio track (311MB) is just the right size for a 448kbps Dolby Digital 5.1ch soundtrack for your 97 minute content.If you select the proper overhad calculation for Dolby Digital (.ac3), you will see the overhead reduce from 11MB to 8MB, providing 3MB additional space for your video.

Dolby Digital is constant bitrate, and because it's bitrrate never changes, it consumes a little less overhead to have it in the AVI container than variable bitrate sound. And, that is why both Dolby Digital and Constant Bitrate MP3 consume the same amount of overhead.

If, as you stated in your first thread (http://forum.doom9.org/showthread.php?s=&threadid=66162), you are still following Doom9's guides, you will see he uses variable bitrate MP3 in his step by step examples of Gknot, and also describes how to use Dolby Digital, as you are using.

And I hope you're finally using the DivX 5 guide instead of the SBC guide, since you're encoding in the DivX 5 codec. The procedures are similar, but there are also some significant differences that might cause you confusion.

[Fabrian]

Thanks for the quick and well explained response!

One other question though, which Divx guide are you refering to? The only one I found was more of an explaination of Divx rather than a ripping guide.

- Thanks

[jggimi]

@Fabrian,
Please review your previous thread in the Newbie's forum. You stated:Originally posted by Fabrian
To keep my response short and sweet, I followed the doom9 gknot guide to a tee HERE (http://www.doom9.org/index.html?/gknot-main2.htm)

**Edit - maybe there's a better guide to follow?...Manono replied:Originally posted by manono
...The guide to which you pointed is for DivX 3.11 SBC, and you said you're using DivX 5...I was trying to recommend Doom9's DivX 5 Guide (http://www.doom9.org/gknot-main3.htm), which you apparently have never seen.

[Fabrian]

Originally posted by jggimi
@Fabrian,
Please review your previous thread in the Newbie's forum. You stated:Manono replied:I was trying to recommend Doom9's DivX 5 Guide (http://www.doom9.org/gknot-main3.htm), which you apparently have never seen.

Thats the link I was looking for. I got confused, I thought the info on that divx page was the info on the gknot page. What did you mean by "I was trying to recommend Doom9's DivX 5 Guide (http://www.doom9.org/gknot-main3.htm), which you apparently have never seen."

I hope that wasn't sarcastic, I see no need to be treated that way if that's what you meant..

Thanks for the reply

[jggimi]

Pardon me, I wasn't trying to being sarcastic. Just concerned. From my point of view, you either had the wrong information, couldn't locate the right information, or both. It looked like: you had missed Doom9's DivX 5 guide entirely, since much of what you seemed to be asking about in this thread should have been answered by that guide, you'd originally pointed to the wrong guide, but never corrected or made any comment about to clarify that in the other thread, you didn't seem to follow my comment about using the correct guide.And for codec settings and encoding options, DivX Networks has a very good guide on codec usage in PDF format, which you may have already seen: http://www.divx.com/support/guides/DivXGuide51.pdf

[Fabrian]

I think there was just too much confusion on my part looking at different guides, besides trying to iron out the things I wasn't too sure of when I'm too tired. I wasn't aware of that pdf file, it's actually what I was looking for a while back.

I'm sorry if I misuderstood about your previous post, you've been more than helpful and I greatly appreciate it! It's nice to know someone can get the kind of response that you've given me at this forum. :)

[alexnoe]

Dolby Digital is constant bitrate, and because it's bitrrate never changes, it consumes a little less overhead to have it in the AVI container than variable bitrate sound.That does not make much sense...the chunks in a VBR stream must be of equal length. If you decide to put 10 frames into 1 chunk (instead of only 1), you have 240ms per chunk, which should still play fine, but have less overhead than AC3 (such large AC3 chunks cause some decoders to fail). I'll try that in AVI-Mux GUI somewhen...