Edit options disabled

[juanplata]

Hello,

I have a question about Audacity 1.3 Beta Version, I have to say I'm pretty novice and the doubts I have raised could be very obvious.

In the sound file extracted from a movie with ac3 format VirtualDubMod see multiple tracks but only two are above waveform.
In any case I take 27 seconds at the beginning and therefore select 27 seconds and then go to the menu Edit -> Select -> From the beginning to the point.
And then I'm stuck because the options in the Edit menu (and all from Undo Import to Duplicate are disabled).
What have I done wrong? What do I do to remove 27 seconds at the beginning of a soundtrack from a movie?

[kozikowski]

Dolby AC3 is a surround format. Are you saying you decoded the show sound into all six channels and you're trying to edit only two of them? How did your software prepare the tracks for editing? Is there an export or save command?

AC3 also has multiple channel formats available and we've been known to save DVD disk space by encoding straight stereo into AC3 and not include the standard PCM DVD sound track. Is that what you have? Export the two tracks as WAV and they should come out 48000, 16-bit, Stereo and drop right into Audacity for editing. That's the format of the sound tests on my web site.

You missed the step where you told us how you got from your software into Audacity -- easily the reason your tools won't work.

Koz

[juanplata]

Thank you for your help.

I have 6 channels,but I have erased four becase they have no wave, but it is the same.
I have got the file from a DVDrip film, and I have demuxed it witht VirtualDubMod. What have I to do in order Audacity works ?

[kozikowski]

I can't get the web site to tell me the right information.

Right Click on one of the sound files > Properties > General and Summary. See if you can tell what kind of sound file it is. Microsoft WAV, 48000, 16-bit, Mono?

Koz

[juanplata]

Hi,

VirtualDubMod is not a web site, it is a free video edition program.
The properties of the sound file is :

VLC media file (.wav)
308 MB (323.289.658 bytes)
384kbps
48 KHz
AC-3 ACM Codec
6 channels

[steve]

It sounds like Audacity may be having trouble importing the file and is getting stuck after the first 2 channels.
Are you able to import and edit other files (normal stereo WAV files, or MP3 files)?

Support for AC3 encoded files is provided by FFmpeg. I presume that you have FFmpeg installed?
http://manual.audacityteam.org/index.ph ... tallffmpeg

If you have FFmpeg installed but it is unable to import the file correctly, you will need to convert the file to a supported format before importing it into Audacity.

[juanplata]

Hi,

Yes I can edit without any problem another type of files like mp3.
I am not sure about FFmpeg, probaby that is the problem.
Any way, which is the best quality sound type of file that I can extract from a film, and how can I do it with VirtualDubMod ?

[steve]

which is the best quality sound type of file that I can extract from a film

I presume that you mean extracting from a DVD?

When you have FFmpeg installed, try directly importing a VOB file (not the very small VOB file that is on most DVDs as that will probably not have any audio in it).
I'm not sure if this will work, it depends on whether the Windows build of FFmpeg supports VOB, so if you try it I'd be interested to know the outcome.

(sorry, I can't help with VirtualDubMod)

[juanplata]

I have installed FFmpeg, but the problem is still there. I think Audacity has a bug about AC3, I can not even modify preferences of the program.

Which file format has good quality sound (al least stereo) in order to convert the original AC3 to it? Which converser program do you recommend ?

[steve]

I think Audacity has a bug about AC3,

Not exactly - "Audacity" does not support AC3 at all. Importing AC3 files is entirely down to FFmpeg, which is still being actively developed for improved support of some of these more esoteric formats. It is quite probable that FFmpeg may still only have partial support for AC3, though a search on the FFmpeg web site should provide more information.

Which file format has good quality sound (al least stereo) in order to convert the original AC3 to it?

WAV (Microsoft PCM WAV).

Which converser program do you recommend ?

I've used SUPER (by erightsoft) for converting stereo AC3 to stereo WAV. I've never tried with multi-channel AC3 though.
SUPER is free, so it will cost nothing to try it out, though downloading it is a bit of a link jungle. http://www.erightsoft.com/SUPER.html