AC3 5.1 to 2ch Dolby Prologic II w/o Handbrake?

[a2gin2]

Friends,

I have a number of .mp4 videos encoded with 5.1 (6 Channel) AAC audio. I would like to end up with an .mp4 with AC3 5.1 and 2 channel AAC encoded for Dolby Prologic II (such as the way Handbrake will do when encoding a video using AC3 passthough). I do not need to re-encode the video.

So... using Xilisoft's Video Converter, I can get myself a good 5.1 ac3 file from the original 5.1 (6 ch) AAC file. The problem is that I haven't found anything on the mac that gives me an DPLII encoded 2ch AAC. I can pop into Windows and use MEGUI and the Nero AAC encoder to encode, but as we all know, one doesn't really just "pop" into Windows unless you absolutely have to.

So, is there a mac tool into which I can feed either a 5.1 ac3 file or a 6ch AAC file which will spit out a 2ch AAC file encoded for DPLII?

Of course, once I get the ac3, aac, and video together, I can just use Subler to mux it all back up.

Many thanks in advance!

 

[Cave Man]

Handbrake already takes DD and puts it into DPLII. I don't think it can take 5.1 discrete and put it into DPLII and DD, though. But I'm sure one of the HB devs will chime in.

 

[a2gin2]

Hey Cave, thanks for the quick reply. Just to be clear - I did not want to use handbrake at all. I don't need to re-encode video, just audio. So, to put it another way: when re-encoding an a file, handbrake is able to take ac3 audio and encode it to DPLII - that is what I would like to do with an audio file only.

Because handbrake (as far as I know) does not accept just audio files, then I can't use it to encode my ac3 to an aac. That is why I am looking for an alternative.