Problem Converting Stereo to Mono in ProCoder 3

[Theoldadam]

Hello,

I'm using Procoder 3 for some time now and I'm having some trouble with the Audio channels.

for example, when I work on a video which has 2 Audio channels(meaning Stereo) I set my profile so that the converted media file will be mono but for an unknown reason the converted file is getting Stereo, its the same when I use a Video file which has only 1 channel (meaning Mono) which in this case ruining my Audio because it creates a new channel which doesn't exist and all I get is some noisy sound.

I Installed K-lite pack plus when I'm trying to use other AC3 Decoder other then 'Rhozet AC3 Decoder' it doesn't allow me and gives me errors
I've been trying to use 'AC3 Filter' & 'FFDshow Audio Decoder' with no success so far.

I'd appreciate any help in this matter, maybe my adjustment of those Decoders I maintained above is not correct.

[Ghitulescu]

Maybe it's useful to state what format is the input audio and what is the target, as some targets do not accept mono. In this case you should use an audio editor to place eg the mono channel on the center speaker, while letting the rest of the channels in "audio mute".

[Theoldadam]

True

The Source is DVD, I've ripped it.

The Audio stream is AC3, 1 channel 192kbps -> Target is AAC-LC , 128kbps, Channels-mono.

Additional Info, Video format is H.264 and My container is MP4
The Video comes out perfectly its only Audio problems that I have.

I would like to avoid Encoding the Video & Audio stream separately since I've many files that I would like to convert and procoder allows me to use Batch mode.
As I Wrote before I think the problem is in the settings of the decoders themselves but I'm not sure.

I hope that would help me get some answers, Thanks a lot.

[tebasuna51]

Yes, is a know decoder problem, see http://forum.doom9.org/showthread.php?p=1226135#post1226135

But I don't get noisy sound, just replicate the channel.
Using ffdshow (I think Ac3Filter don't support AAC decode) I get two identical channels and the difference with the mono decoded with NeroAacDec is less than -90 dB.

Put a sample to test.

I don't know a DirectShow decoder without the problem.

[Theoldadam]

I'm not sure I understand you, are suggesting that I'll use NeroAacDec ?

I'll guess that is a yes.

and if its a no I'll come back.

btw how do I install this NeroAacDec

and why do I've got the feeling I need to do manually?

Thank you.

[tebasuna51]

You can't use NeroAacDec to play a mp4 video movie. Is only a reference to probe the encoded aac is mono.

BTW, a correct option to play a mono audio, in a stereo audio system, is put the same audio in left and right speakers, you obtain a phantom center channel. If you have a surround audio system you can select the Dolby ProLogic decoder to obtain a real unic center channel (instead phantom)

[Theoldadam]

What should I do then?

Will I have to do it manually?

[tebasuna51]

Nothing.
Internally the stream is mono. Is played in stereo audio system with two identical Left and Right channel then you have a phantom Center channel mono, in surround audio system you can select also a real mono Center channel if put the receiver in DPL mode.

Other question is if you have noise not present in source. To test this you can upload a sample of your source Ac3 and the converted AAC.