Which program can swap channels of mpa file?

[thuongshoo]

Hi!
I have some Karaoke files. Unfortunately, "voice channel" of some files is right channel and others is left channel

I want to swapt channels but I dont want to re-encode. You know! Re-encode will degrade quality of sound

Thank you!

[Kurtnoise]

ffdshow audio filter during the playback ?!!...

[thuongshoo]

I'm using Kmplayer. IT has "swap channel" feature.
My audio amplifier only have one channel. So sometimes, I must have to choose that feature. It is too uncomfortable. I must click, click to listen music ??

[setarip_old]

Hi!

An audio editor, such as GoldWave, should readily do this...

[thuongshoo]

Thank setarip_old! Is there any free program ? :)

[tebasuna51]

Audacity, Wavosaur are free audio editors.

But audio editors can't do the job without re-encoding.

AFAIK you can't swap channels without re-encode process.

[thuongshoo]

Site http://www.wavosaur.com/ was died.

I don't know whether structure of mpa file is similar to structure of WAV file.
With WAV file, we can swap data of channels

[tebasuna51]

Site http://www.wavosaur.com/ was died.
? Is working for me, with the last version 1.0.0.9000 from 2007-07-01

I don't know whether structure of mpa file is similar to structure of WAV file.

mpa (MPEG Audio) is normally mp2 (I see ac3 stream extracted like mpa) MPEG I Layer 2.
Then is a compressed format and I don't know how swap channels without decompress

With WAV file, we can swap data of channels
Of course, you can use any audio editor to swap the channels without loss quality or re-encode, because wav is uncompress data.

[thuongshoo]

tebasuna! Do you have any document which describe structure of mp2 file?
I have been searching by Google but I have only documents which deal with Header

[tebasuna51]

@thuongshoo
Sorry, I only know also documents about the header.

[thuongshoo]

Is there anyone has the document ?
Thank! :)

[Kurtnoise]

http://www.cmis.csiro.au/maaate/docs/layer2.txt