dvd audio stream conversion

[ricardouk]

hi everyone.

i have a dvd that im going to backup to divx, it has 2 audio streams(5.1 dd and 2.0 ch)

which one should i convert to mp3

sizes 5.1 dd-----400mg

2.0ch-----190mg

is it really worth having a few extra mg by converting the 5.1 stream?

thanks people

[lumis]

convert them both & see which sounds better to you.. the size difference shouldnt be too dramatic if you're going VBR.. no difference if you're going CBR.. it shouldnt take too long to convert to mp3.

[mats.hogberg]

They should come out identical as MP3, as IIRC mp3 is stereo only, so the 5.1 sound should get downmixed to 2 channels. The size of your source audio files is irrelevant. If I was you, I'd not convert to MP3 at all, but just take the 2 channel or 5.1 channel audio (AC3?) and use that in your AVI/DivX.

/Mats

[ricardouk]

thanks

i heard that for computer playback keeping the ac3 is ok, but im backing up to divx to watch it on dvd/divx player and i have heard that a lot of them are fussy about playng the ac3 muxed with divx

I know i could compreess and test the results myself, but i was interested in finding out from videohelpmembers their opinions about this subjcet.
does it sound better 5.1 or2.0 compressed to mp3?

thanks

[mats.hogberg]

does it sound better 5.1 or2.0 compressed to mp3?

My educated guess is that you wont hear any difference. If I should pick one before the other, I'd go for the 2 channel source, as that's made to be 2 channels to start with. Downmixing 5.1 to 2 channels may or may not sound that great, depending on how the 5.1 is made, and what you use to downmix. If you think you're better at this than the studio, use the 5.1 - if not, go for the pre made 2 channels.

/Mats

[Richard_G]

One thing to bear in mind. If this is a commercial DVD the 2 channel soundtrack is often the Directors Commentary, the 5.1 is the proper soundtrack that goes with the movie. If you decide to just keep the 2 channel, check it first to make sure it really does contain what you think it does.

[ricardouk]

Thanks Mat

If I should pick one before the other, I'd go for the 2 channel source, as that's made to be 2 channels to start with. Downmixing 5.1 to 2 channels may or may not sound that great, depending on how the 5.1 is made, and what you use to downmix.

thats what i thought just wanted to hear a second opinion

it is a comercial dvd it offers 5.1 and 2.0 and besides that it has 2.0 directors commentary, altogether it has 3 audio streams.(star wars)

thanks for your advice once again.

[/quote]

[wulf109]

Most standalone DVD players that support DIVX will play the ac3,so why convert to mp3?