AC3 or Mp3?

[spud1980]

If I want to preserve the 6 Channel audio track what options do I have?

Do I have to use the ac3 track instead of the transcoded mp3 track?

Is mp3 able to support 6 channels audio?

If I select the 1x ac3 option under Interleaving & Avi overhead there seems to be a 'frames' setting just beside the radio check box what should that be set? There doesn't seem to be any mention of it in the online tutorials.

For mp3s, it seems that that I can't choose any pre-config higher than 160kbps under the lame customized settings. How do I go about doing that?

[hakko504]

MP3 can only handle 2 channel audio.
AC3 will do multichannel audio.
OGG is an alternative for multichannel audio. You can lower the bitrate quite much and still retain good quality 5.1 audio.

The frame value for AC3 should be quite low, 2 or 3 is the most common value. This value is the interleaving value, i.e.how often the audio should be mixed with the video in the final bitstream. For best playback without stuttering etc. it should be set to 64 or 96ms, but this require manual muxing in VirtualDubMod.

You can always use the manual settings for lame in order to get higher quality MP3. (--alt-preset 256). There is no real point in doing this - most of the time it is better to keep the AC3 audio instead if you want higher bitrates.

[jggimi]

The stereo mp3 can retain limited surround information (Dolby Surround), if the audio is played through a Dolby ProLogic decoder.

[Micro]

If you have newer surround receiver, it is better to use Dolby ProLogic II which has better frequency responce.
For DPL II compatible AC3->Mp3 transcoding use BeSweet or HeadAC3he.

Anyway, it is better to keep AC3 and use 2 cd-s,
they do no not cost much today.
As a container I would recommend .ogm or avi(muxed with avimux)