AC3 audio editor.

[dishwara]

But it converts to mono instead of 6 channel.

[Bully9]

No - i just demuxed the new mkv again, opened the ac3 file in audacity and rechecked. It definitely converts back to six channel.

[zenzen1]

[quote]Anyway to edit ac3 files u can use nero wave editor.
go to http://www.bitburners.com/software/dolby-ac3-v10032/3810/
download the file & paste it in C:\Program Files\Common Files\Nero\AudioPlugins or C:\Program Files\Common Files\ahead\AudioPlugins. u will see other nxMy***.dll files.
In nero wave editor, go to Options->Audio format settings->dolby digital (Ac3). click configure & in output channel sequence click 5.1 instead of downmix.
Now u can open ac3 files & see five or six separate channels.
Also in bottom left corner u see a speaker graphics displaying separate channels. Also u can volume change INDIVIDUAL channels.
in volume change ->active channels select the only channel u want to edit.
Try different options. UnQuote



OK Done all this and now I see five separate channels. I am presuming that they are LF Centre RF LR LR and Sub
from top to bottom with the Centre Channel being the second one down. Can anyone confirm this please ??

[darkflux]

you are correct in your ordering guess! but don't you mean you see 6 channels? or was the center one not showing up?
at any rate, you can change the settings for ac3 by going to Options > Audio Format Settings > Dolby Digital (AC3) and clicking Configure...
enjoy!

[zenzen1]

Thanks Darkflux....Yep you are right: There are 6 channels. Maybe too much Christmas cheer (beer) when I first looked at it.

[darkflux]

i understand i was rather cheerful (beerful?) myself when i first saw it, so i had to read it twice to be sure

[dishwara]

u r right it shows all the channels. in ur case 5.

[Ankin]

hi, I was wondering, is there a tool that can delete a bad channel in a stereo .ac3 file without recompression and copy the second channel in it as well (thus turn it into mono). The sound quality is so poor, I'd hate to recompress it again
I've read the discussion, but since it's been a couple years..

[AlanHK]

hi, I was wondering, is there a tool that can delete a bad channel in a stereo .ac3 file without recompression and copy the second channel in it as well (thus turn it into mono). The sound quality is so poor, I'd hate to recompress it again
I've read the discussion, but since it's been a couple years..

I don't know of any.

Also I think that AC3, like MP3, encodes the two tracks together, so there are not two separate streams until you decode it.

I would just use the most recent version of Audacity with ffmpeg in/output and open the AC3.

You can do the rest from there and even apply some noise reduction if necessary, and save it back to AC3 at the end, if you use the same or slightly higher bitrate then the input any loss in quality should be negligible.

Also, you could just encode the one good track as mono without duplicating it, by duplicating the tracks you would be making a nominally stereo track and just wasting some bits (though not much, as above the tracks are encoded together in AC3, which would compress them back to almost the same size).

[Ankin]

AlanHK, thanks for the tip!

[newnews]

Alan, i'm not aware of ANY audio editing software that DOESN'T open files as temporary WAV files.

For MP3 there's MP3DirectCut.
For AC3, DelayCut can cut segments from AC3, and Audioscale can stretch or compress the length, by dropping or duplicating frames.

But anything that does any filtering/effects will need to decompress them.
And I suppose there must be a transient uncompressed stream to play audio, or display the waveform.

in fact, Audacity opens ac3's as wav files, too.

That's what I meant by "import" and "export", though it actually uses its own ".au" format files when working, which can be saved as a "project".

Hi, Alan:

How to use delay on DelayCut if the delay is in the middle of audio. For example, I the audio plays fine from 0 - 1hour, but then it need 500ms delay after 1 hour

[AlanHK]

How to use delay on DelayCut if the delay is in the middle of audio. For example, I the audio plays fine from 0 - 1hour, but then it need 500ms delay after 1 hour

Cut it in two, (A, B) delay the second part and join A + Delayed-B.

see https://forum.videohelp.com/threads/213080-Join-AC3-files

[newnews]

How to use delay on DelayCut if the delay is in the middle of audio. For example, I the audio plays fine from 0 - 1hour, but then it need 500ms delay after 1 hour

Cut it in two, (A, B) delay the second part and join A + Delayed-B.

see https://forum.videohelp.com/threads/213080-Join-AC3-files

thanks