Strange Problem when using AAC or mp4 !

[Tuning]

I used nero wave editor to create mp4 file.Then i muxed the file with avi usin vdubmod 1.5.4.1 as mp? stream.But the video doesn't play audio only video is played.I installed core AAC filter before performing this.Then i tried to play the mp4 file in WMP 9,it played effortlessly.What can be the problem ?Please give information on how can the mp4 audio can be properly muxed in avi and mkv.Any remarks on this subject is greatly appreciated.Thanks.

[hulkenstrong]

you need to have a splitter that supports aac to be able to hear the sound.http://www.3ivx.com/ that worked for my divx5/aac movie.

[calinb]

I'm muxing 5.1 VBR AAC+ and DIV5 into ogm. Yes, the 3ivx splitter works fine. I use graphedit. I don't think avi would be a good idea for my VBR AAC+ audio and I haven't tried Matroska yet. I think Nic is working on an updated OggMux to support it, though.

[berujio]

@calinb: short question, how do you produce 5.1 aac files? following the doom9-guide I always get a wrong channelmapping. nero on the other hand doesn't accept multichannel-wavefiles (causes error message).
can you give a hint how you are doing this?

[Tuning]

You need to replace WAV.dll for correct channel mapping in Nero Wave Editor.

[calinb]

Originally posted by berujio
how do you produce 5.1 aac files?

I have the Nero wav replacement plugin, but I use the Nero AC3 plugin (azid-based) and drop the AC3 file directly to the NeroMix playlist. Alternatively, I generate a 6ch aif with BeSweet, but read-on -- this isn't all that simple for AC3 >> 6ch aif with the correct channel order!

I'm not sure that I actually need the wav replacement plugin for my methods.

If I don't need to adjust the audio skew or change the sample rate, I just use the Nero AC3 plugin with the channel order we've posted in these forums:
C
L
R
SL
SR
LFE
Quick and dirty! Unfortunately, I'm not usually happy with the results. At the very least, I like to normalize gain and maybe use "normal" compression on AC3 sound. How do you know what settings to use in the Nero AC3 plugin without risking overflow and distortion? My solution is to setup the azid screen in BeSweet GUI to normalize/boost/compress as I desire and run the BeSweet 1st pass with BeSweet GUI. I don't need to let it actually transcode (I terminate it after the transcoding starts) -- I just want to see the gain value(s) from the BeSweet logfile so I can enter the proper gain into the Nero AC3 plugin.

I've found that BeSweet ignores the azid output speaker order when transcoding an AC3 file to 6ch aif (changing the order makes no difference) so it won't produce a 6ch aif file with correct order for Nero AAC anyway. If I want to make a 6ch aif file with the correct order for Nero AAC (usually, I don't go through this unless I want to use the audio delay and/or SSRC features of BeSweet), I first use BeSweet GUI to make 6 wav files (no problem exceeding the 2G limit like a 6ch wav will do) Oh yeah, don't forget to do all your audio delay, compression, boost, sample rate conversion, etc. in this step. The filenames of these 6 wave files go into a "list.mux" file. Then I use the BeSweet command line:

"C:\Program Files\BeSweet\BeSweet.exe" -core( -input ".\list.mux" -output ".\test.aif" -6chaiff -logfile ".\BeSweet.log" )

This muxes them all into a 6ch aif file with the correct order for Nero AAC. Oh yeah, the order of the filenames in the list.mux file should be the same as above. ie,
".\test-C.wav"
".\test-FL.wav"
".\test-FR.wav"
".\test-SL.wav"
".\test-SR.wav"
".\test-LFE.wav"

Hope this helps! Maybe the new "Nero Digital" will take care of all this AND mpeg4 video encoding AND muxing to mp4 or matroska...maybe :)

P.S. Why do I bother with all this? I've found that I can backup most movies with 5.1 HE-AAC sound, that I can tolerate, into a matroska container and a single XCD. Does it sound anywhere near as good as the original AC3 sound? No way (it's a WAY bigger difference than between DTS and AC3, typically)--but for movies, I can usually stand it.

[ChristianHJW]

Originally posted by Tuning Please give information on how can the mp4 audio can be properly muxed in avi and mkv.Any remarks on this subject is greatly appreciated.Thanks.

For AVI, AFAIK its currently not possible, and i dont know if somebody will have a look at it, now that MP4 container becomes more and more usable and was designed exactly for this purpose. The main advantages of AVI over MP4, the widespread support and the editability would become pointless as AAC audio in AVI was neither supported by most apps nor could you edit the files, so where is the point ? In addition to that, it required the same hack as for VBR MP3, and nobody knows how the M$ AVI splitter filter will behave then.

AS for AAC in MKV, there are 2 ways :

1. DirectShow, using either Graphedit manually ( you need 3ivX MP4 splitter and Gabest' matroskamuxer (http://sf.net/projects/guliverkli) filter for that), koepi's OggMux (http://sf.net/projects/oggmux) or Dark-Cracker's GUI. There is more about this in the new A/V formats section, simply search for posts originated by Dark-Cracker, there might be a few, but from the title you will find the right one easily.

2. The best way :
Use the new mkvmerge 0.7.0 ( win32 binaries ) from Mosu http://www.bunkus.org/videotools/mkvtoolnix/ , it now comes with a nice GUI and it can parse MP4 files, so you dont need to set the HE-AAC switch manually as when the source is a MPEG2 SBR AAC file ( MP4 container has a flag for telling if its SBR or not ).

For conversion :

As calinb says, i also cant use the AC3 plugin easily, because i always insist on a sampling rate conversion from 48 KHz down to 44,1 KHz, also because all current AAC encoders are only optimized for 44,1 KHz ( CD-Audio ) and not for 48 KHZ ( AC3 ) content.

My last trials with 5.1 HE-AAC were done a couple of weeks ago, and i gave up frustrated by the fact that there is no way to change the channel order on any side, either in BeSweet or Nero. menno told me that this is actually a BeSweet bug IMHO, as AIFF has a standard channel order for 5.1 files and they stick to it, while BeSweet obviously is using WAV order. However, if anybody came up with a good solution for that, it would be much appreciated ....

[calinb]

Originally posted by ChristianHJW
However, if anybody came up with a good solution for that, it would be much appreciated ....
Christian, I don't know if it's a good method, but it's A method. I was editing my post while you were posting...the only solution I've found is to first save to 6 separate wav files. You can then order them however you wish in a list.mux file and mux them all to a 6ch aif file with BeSweet. Yes, I think the straightforward method fails because of a BeSweet bug, but at least the list.mux file method works...and BeSweet command lines batch nicely too :|

[calinb]

Originally posted by ChristianHJW
Use the new mkvmerge 0.7.0 ( win32 binaries ) from Mosu http://www.bunkus.org/videotools/mkvtoolnix/ , it now comes with a nice GUI
Christian, One more thing. Thought I'd try the GUI, but it doesn't seem to like mkvmerge 7.0 -- says it's invalid when I supply the mkvmerge.exe path to the GUI. I'm looking forward to the SBR/mp4 handling of 7.0 though. Guess I'll checkout the manual skew adjust on some HE-AAC files too. Didn't seem to work previously and Mosu said he'd look into it.
Update -- Seems to be working in mkvmerge 7.0

[calinb]

Thread re-direction: New Nero6 AAC channel order and incompatibility with 3ivx splitter. See:
http://forum.doom9.org/showthread.php?s=&threadid=55173&perpage=20&pagenumber=7