demux audio from avi then two audio sources(aac 2ch + ac3 6ch)

[fatcat23]

Hi I have a 720p xvid file with ac3 6 channel audio and I would like to convert it to to a x264 mp4 file with aac 2 channel so it is compatible with my xbox 360. But I would also like to retain the ac3 6 channel audio as a secondary audio track.

I guess I would have to demux the original file(how do i do this on a mac) and how would i remux it back into the mp4 file within ffmpegx.

any help is appreciated.

Edit: I also still have the original TS stream that i then converted to the 720p xvid. I at first choose to do the xvid so i could get the 5.1 AC3 to work on the xbox but the file is choppy on the xbox, propabally due to the fact that the file is just above 5000 bitrate(which is what the xbox's max setting is).

Anyway I would know like to convert the file to x264 with aac 2channel and 6ch ac3 if i want to play it on my mac. But i think the original ts is a different length because of ts packet errors(etc..) so i dont think i could demux that file and remux it to the mp4....not sure...does somebody know about this?

[FulciLives]

I don't have an XboX 360 (I do have a Sony PS3) but my understanding is that the XboX 360 does support 720p XviD with multi-channel AC-3 audio.

On the flip side the MP4 format can have 5.1 AAC or 2.0 AAC but while the Sony PS3 works with 5.1 AAC the XboX 360 does not as it needs to be 2.0 AAC so ...

The file should play "as is" on the XboX 360 although depending on how the XviD was recorded it may not in which case you will need to re-encode. You have the following options:

1.) MP4 with H.264 video and 2.0 AAC audio
2.) AVI with XviD or DivX video and 5.1 AC-3
3.) WMV with VC-1 video and 5.1 WMA

If I had an XboX 360 I would probably go with option #2

Also in case it isn't clear now let me say it straight ... you can't have AC-3 in a MP4 file. So your original idea is impossible OR even if it were it would not be compatible with the XboX 360.

Also to be even more clear ... DivX and XviD are compatible with the XboX 360 if the resolution is 720p or less but again the DivX and XviD have to be encoded "just right" or it will not work. I don't use a MAC so I cannot comment on how to properly encode 720p DivX/XviD so that it is compatible with the XboX 360 but it is possible!

- John "FulciLives" Coleman

[fatcat23]

ya i just edited my post....the xvid(HD 720p) file doesn't work properly in the xbox. My guess is that the bitrate is too high and I have tries lowering it too. I first started at 5000 and then went down to 4500, but it's still choppy. The file plays perfectly on my mac and pc, and MS states the max bitrate is 5000. I have tried converting it in handbrake and ffmpegx but the result is the same. The file is not streaming but rather coming from my HFS+ usb external drive.

Also non hd video with a lower bitrate recorder from the same source plays perfectly with the ac3 audio. So i just gave up on the xvid hd idea. But i will still do it for non hd recordings.

If I wanted to go with option 2, could I have two audio streams of AAC 2 channel and 6 channel? How Could i do this with ffmpegx or on a mac period.

Sorry another newb question: what is 5.1 AAC compatible with? Perian or vlc on mac, appletv?

Hopefully MS will add on 5.1 AAC with mp4 onto the Xbox sometime soon. I guess I'm asking to much of MS tho..lol

[FulciLives]

Well you might want to try VC-1 video with 5.1 WMA but how you encode that on a MAC I haven't a clue. However that is the format the XboX 360 seems to work best with although MP4 is very capable as well but you can't have 5.1 with MP4 on the XboX 360. I think they did it on purpose to force people to go with VC-1 and 5.1 WMA since both are Microsoft technologies.

I say go with MP4 and just deal with 2.0 AAC because it will make your life so much easier and video quality is much more important than stereo vs. gimmicky surround sound. Call me an "old fart" but I've always found surround sound to be gimmicky myself *shrugs*

Sorry but this will probably be my last post because I do not have a MAC and while I felt I could help with what the XboX 360 could and could not do and what your options are I cannot help with how to do anything on a MAC.

- John "FulciLives" Coleman

[fatcat23]

Thanks for the help, Converting to WMV with 5.1 on a mac is very hard and long, much longer than it is on a pc. Plus the x264 codec is better than vc-1.

So I'll stick it out with the mp4. For know I'll keep the 2ch channel audio but try some stuff out for 5.1 AAC.

Thanks again, this is a really good forum. Much better than many others ive tried. I have always found this site on my google searchs but finally registered today.