AutoGK and CBR/VBR audio

bollemanneke · 2nd June 2009, 21:23

Hi!

I'm a great fan of AutoGK, but there's something I don't understand...

What does VBR (variable bitrate) mean?
a. The MP3 auido kbps will differ throughout the whole movie, depending on the noise of the movie scenes.
2. The other settings, such as resolution, target quality etc. will decide the kbps, which will be used troughout the whole ovie without changing?

BigDid · 2nd June 2009, 22:53

Hi,

It's not really VBR, it's ABR; see lame infos here:
http://lame.sourceforge.net/about.php
http://lame.sourceforge.net/abr.php

So when you choose Lame-MP3 176-ABR and you get an average of 160Kbps (example) it is "roughly" equivalent to 176CBR in quality.
Knowing that the averaged audio bitrate may vary from movie to movie this is why the mp3 encoding is done before the video encodes so that the size of the audio is used to calculate the size of the video (for 2 pass)
Hence, everything else (resolution, matrix resizer...) will be calculated last in AGK.

Hope it gives clues to your questions.

Did

2nd June 2009, 21:23	#1 \| Link
bollemanneke Registered User Join Date: Jan 2009 Location: Belgium Posts: 105	AutoGK and CBR/VBR audio Hi! I'm a great fan of AutoGK, but there's something I don't understand... What does VBR (variable bitrate) mean? a. The MP3 auido kbps will differ throughout the whole movie, depending on the noise of the movie scenes. 2. The other settings, such as resolution, target quality etc. will decide the kbps, which will be used troughout the whole ovie without changing?

2nd June 2009, 22:53	#2 \| Link
BigDid Actually in reserve Join Date: Oct 2004 Posts: 1,605	Hi, It's not really VBR, it's ABR; see lame infos here: http://lame.sourceforge.net/about.php http://lame.sourceforge.net/abr.php So when you choose Lame-MP3 176-ABR and you get an average of 160Kbps (example) it is "roughly" equivalent to 176CBR in quality. Knowing that the averaged audio bitrate may vary from movie to movie this is why the mp3 encoding is done before the video encodes so that the size of the audio is used to calculate the size of the video (for 2 pass) Hence, everything else (resolution, matrix resizer...) will be calculated last in AGK. Hope it gives clues to your questions. Did __________________ Having a problem with AutoGK? Read & use the FAQ & MORE FAQ first Want to exchange on AutoGK? try doom10.org In reserve (inactive) for an undefined period of time.