Questions about 5.1 channels

[depeche101_Brazil]

Hi, everone.
I want to make a Divx with a film I have in DVD and I want it to keep all the 5.1 channels. I want to put the sound in mp3 instead of keeping the original AC3 file (because the AC3 file is huge) and I want to know if putting 128 or 160 kbps will keep all the channels. If it doesn't keep, in which bitrate of mp3 should I put?
Eduardo.

[depeche101_Brazil]

Anyone?

[Cornucopia]

As you probably know, MP3 stands for Mpeg 1, Layer 3.
Being from the MPEG1 spec, it supports at most 2 channels.

If you're wanting to go from AC3 5.1ch --> Mp3, the best you can do is downmix the 5.1 to Dolby Surround (4 ch. matrixed into 2) and encode the Lt and Rt as your 2 channels. In this configuration it's probably best to encode as Dual Channel, or as Stereo. DO NOT use Joint Stereo as this will screw with the Surround matrixing.

IIWY, I'd keep the bitrate as high as possible, certainly no lower than 128kpbs! Try 224 or 192.

In a way, it might be best to stick with the AC3 (and it's huge size), so you at least get to keep the 5.1.

Scott

[depeche101_Brazil]

Thank you for answering, Scott. I think I'll keep an mp3 with 2ch instead of keeping the original AC3. I prefer a better image quality.
Eduardo.