Mp4 to AVI without losing multichannel

[socrates]

I have a number of moves in mp4 format (avc+aac). I want to convert them to avi format for viewing them in standalone players. I know sofwares that could convert mp4 to avi but in all of them I lost the 6.1 or 5.1 sound to mp3 stereo. Is there any guide or method for coverting mp4 to avi while preserving multichannel sound?
I have had tried Super and Xvid4PSP. Everything fails in the conversion of aac to ac3 5.1/6.1
Thanking all

[guns1inger]

In what way does Xvid4PSP fail ? I have been able to successfully do this type of conversion with it before. Need more details on your actual problems.

[socrates]

Hi guns1inger,

Thanks for the reply.
I am able to convert mp4 to avi with xvid4psp if I set the sound to mp3 stereo. The output comes ok with sound and good quality video. But I lose out on the 5.1 sound from the original.
If I set the sound to ac3 5.1, the output avi comes with no sound. I hope you understood...

[dfisher052]

I use Format Factory and have the same problem. In fact, if I convert anything to AVI in FF with 5.1 or 6.1 I loose the sound. Maybe someone here can resolve the problem for both of us. Or, if they can resolve it in xvid4psp, I just might switch to that.

[guns1inger]

Just tested this with a version 6.001 beta of Xvid4psp/ 720 res mp4 video with 6 channel aac. Output selected as 640 x nnn Xvid encoded AVI with 6 channel 384 kbps AC3. Tested output content with mediainfo and confirmed 5.1 AC3 audio track. Test played in The KM Player and confirmed 6 channel AC3 audio. I did add a channels and loudness filter using the default settings, but otherwise all standard presets only.

I don't know what you guys are doing wrong, in either your encoding or your testing, but it works fine for me.

[socrates]

I'm using the same one, xvid4psp 6.001 beta. For my conversion files, I used to select 'same as source' kbps for audio conversion setting, is that the problem? Anyway, in another forum, they suggested a software and I tried it out successully. For people who maybe reading this, try Avidemux. It is a free software and it converted mp4 with aac sound to ac3 with 5.1. For me, to convert a movie of 1.5GB mp4 (avc+aac 5.1), avidemux took a little over 3 hours. Maybe my laptop specs are weak. Anyway now I have ac3 5.1 sound for the movie avi (xvid+ac3). I find that the sound quality of ac3 very mildly low compared to aac. Is this normal?

[socrates]

Hello guns1inger,

You are right. Xvid4PSP converts fine. It was a mistake from my side. After I do conversion with Xvid4PSP, I usually try playing the file with VLC player and this error comes up 'not suitable decoder module, VLC doesnot support video-audio format "undf" ' and the video plays well. I thought that the file was missing audio. After reading your comments, I used Xvid4PSP and selected 384 Kbps multichannel. The file converted and gave the same error with VLC. But when I played in windows media player (1st time attempting), there is audio!!!! and that too ac3 5.1!. I guess the confusion was all because of VLC. Anyway problem solved now. Thank you

[socrates]

Hello all,

Those who are following this thread please note...

I have a pioneer dv-220kv standalone dvd/divx player. I tried playing both avi files (made with avidemux and xvid4psp) in it. The player plays both but the avi made with xvid4psp doesnot have sound. It says that the format was not supported. xvid4psp file was made in less that 1hr 30mins while avidemux took over 3hrs to make the avi. the avidemux made avi plays properly in my standalone player. Any reasons?
Xvid4PSP audio setting was 384 multichannel ac3
avidemux is 224 multichannel ac3
Please give me suggestions....

[davexnet]

I've seen similar things in my standalone. Often, just remuxing the file fixes the problem.
This leads me to believe the audio itself is OK, but an error or omission in the file header is somewhere to blame.

For example, I used Virtualdubmod to demux the audio. Set video to direct stream copy, turned off the existing audio
(under strreeams) and added the copy just taken. Save as a new AVI, file works fine now.

[guns1inger]

Probably why VLC isn't liking it either. My players must be more tolerant than yours of the missing marker.