View Full Version : keep the ac3 quality at the compressed file
Alexxander
30 Mar 2002, 04:39 AM
HI
Im a total Newbie in Converting DVDs to divx. I´ve heard that it would be impossible to convert the dvd to divX without to compress the ac3 audio to stereo. I would prefer to keep ac3 audio. Is this possible, and what kind of encoder should I use?
Is there a special guide for my Problem???
Thanks for your answers, Al
UncasMS
30 Mar 2002, 06:29 AM
you can transcode the videostream with any tool you prefer and OF COURSE KEEP AC3!
my one and only choice is NANDUB for the video stream and VOB2AUDIO to extract the sound from your vob files.
you can extract the AC3 and multiplex it with your video stream later on using nandub.
good luck
jrpeacey
31 Mar 2002, 01:59 PM
I don't know why the DivX+AC3 method isn't used more, but for whatever reason the playback is more difficult than when you use MP3 sound. Doom 9 has a guide about it:
http://www.doom9.org/divx__ac3.htm
There is also a FAQ in the Audio section of the Doom9 forum about using AC3 audio.
I have been able to play my DivX+AC3 movies after installing the filters even without going through all the Graphedit setup described in the howto. It must depend on system configuration. I think that playback of this format is a bit more demanding than with mp3 (need a fast system) and you may not be able to play movies directly from CD (need to transfer to hard drive.
If you wish to cut and rejoin Divx+ac3, NanDub or VirtualDub_148_ac3 will do it, but they are not perfect (sometimes there is an audible discontinuity and the rejoined file is not necessarily the same size as the original). I prefer to split the Video-only file onto cd's along with the original ac3 file, then join the video and multiplex the audio all in one 5 minute step before watching the movie from the hard drive.
I have been using the Gordian Knot package which includes SmartRipper, DVD2AVI (which will extract (demux) your ac3 tracks, VirtualDub (I am using DivX5 for encoding) and Nandub to multiplex the audio and video.
Good Luck,
setarip
31 Mar 2002, 03:10 PM
"you may not be able to play movies directly from CD (need to transfer to hard drive."
They'll play just as well from a CD...
Kola
31 Mar 2002, 03:58 PM
Never done AC3 sound in a DivX.. I should try it next time..
techno
31 Mar 2002, 06:28 PM
Yep, always find new ways!
:)
Techno
the method to get the best sound out of your AC3 file compressed is to use a Joint Stereo Mp3. That can be done using BeSweet (w/ GUI, of course ;-)). Doom9 has a good tutorial on exactly what you have to do. http://doom9.org/ac3tomp3.htm
Good luck!
--bzhk
UncasMS
1 Apr 2002, 07:50 PM
i doubt that JOINT stereo would be 'best' and from my tests, besweet is quite nice, but i prefer the sound quality i get out of vob2audio => wav => wavelab (normalizing + gaining 3db ) => mp3
Didnt mean to imply that this method was the best ;-). I have had good luck with it in the past, but I am always looking for different methods to increase quality.
--bzhk
UncasMS
2 Apr 2002, 03:06 AM
hi bzhk
of course besweet gives great rsults, but i'd rather use (true) STEREO instead of joined stereo.
if you're are interested in another way, take a look at the sound part of my guide.
i was testing the speed of both methods (besweet + wavelab) only yesterday.
actually there wasnt any sigificant difference concerning speed, but when i compared the final mp3 i was more than convinced that i'm NOT going to change my routine for besweet!
UncasMS,
You wouldnt happen to have an English version of your website, would you? Thanks.
--bzhk
haha, I spoke too soon :-). I found it.
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