how to convert 5.1 aac/mp4/ sound to low bit rate 5.1 aac/mp4

[forum king]

guys offlate i have been trying to make the audio from my DVDs which have 5.1 channelaudio into lowest possible bitrate 5.1 mp4 files using megui audio encoding option.
i am talking here bit rates like 36 kbps may be even lower.

i have tried using HE AAC 64 / 128 profiles but i am not able to achieve it.

is there a way to reencode 5.1 channel audio to lowest possible 5.1 mp4 files :)

[poisondeathray]

Use the "NDAAC-HE-multichannel-128kbps" profile , you can adjust the profile bitrate

[forum king]

Use the "NDAAC-HE-multichannel-128kbps" profile , you can adjust the profile bitrate
well dear i have tried it , but same rersult output is 2 channel. :(

kept the settings as :

output channels :keep original channels
Sample rate: keep original
normalize peaks to : 100
adaptive bitrate:36
profile:NDAAC-HE-multichannel-128kbps

the source has 6 channel sound in MP4

[poisondeathray]

Do you have a proper ac3 in mp4 splitter? If not try demuxing and input the audio separately.

I just tested on a 6-ch ac3 and it works fine, even adjusted the bitrate to 64kbps. Sounds like crap - I wouldn't go below 128kbps (actually I wouldn't go below 192kbps) but hey it's your ears right :)

EDIT: sorry, you are using AAC as input... DUH I'm stoopid

[DJ Bobo]

@ forum king
36kbps... for 5.1 sound??? Aren't you exagerating "a bit" here? If you have to go that low, downmix your audio to MONO!
5.1 shouldn't get less than 160kbps with AAC-HE to sound good.

[poisondeathray]

Just demux the 6-ch aac from the .mp4 (e.g. using yamb), and input it as a raw file, it works fine

Cheers

[forum king]

[QUOTE=poisondeathray;1256238]Just demux the 6-ch aac from the .mp4 (e.g. using yamb), and input it as a raw file, it works fine

well i have tried demuxing the aac audio from the mkv file ( sorry for njot telling this ) actually its an mkv file having aac audio track 6 channel sound,
i just select the mkv file as a whole in megui audio encoder and encoded it using 36 kbps sound settings and 128 profile of ndaaac.

i ll try again using yamb.

EDIT : nope yamb wont work on MKV.
i have tried everything , i have extracted the aac audio by virtualdubmod , but still no use.

[poisondeathray]

well if it's a .mkv source, you would probably have to use mkvextractgui :) , the point is the raw audio 5.1 aac seems to work fine, but not in a container

[Adub]

Make sure that you aren't reading the file using Directshowsource. If you are, then double check to make sure that you aren't downmixing in your decoder settings. For example, if you are using ffdshow, check the audio tab to make sure that the mixer is disabled.

[DJ Bobo]

Everybody is helping him achieving this non-sense?!
Euh... forum king, I don't know how much you know, but based on your post count, I would say you're a newbie, so may be you're thinking that when decompressing this low-bitrate encode, you'll regain the original quality? If that's the case, I shall warn you right now: what is lost is lost and can't be regained!