Re: [ecasound] Merging two mono files into one stereo etc.

New Message Reply Date view Thread view Subject view Author view Other groups

Subject: Re: [ecasound] Merging two mono files into one stereo etc.
From: Kai Vehmanen (
Date: Tue Mar 07 2000 - 22:41:42 EET

On Tue, 7 Mar 2000, Tobias Galitzien wrote:

> 1. I can divide a stereo sample into two mono samples without problems.
> But what can I do to merge them together again into a stereo sample, one
> into each channel, e.g. after processing the channels seperately?

Yep, this needs a bit of trickery, but is possible:

ecasound -a:1 -f:16,1,44100 -i mono-1.wav \
         -a:2 -f:16,1,44100 -i mono-2.wav -erc:1,2 -eac:0,1 \
         -a:1,2 -f:16,2,44100 -o stereo.wav

Btw; this is affected by the "mono-bug". You have to use the 1.7.2d11
(I'll put this to CVS) or with old versions, convert all inputs first
to stereo and then use the above command.

> 2. Is there a general possibility to apply some effect to one channel
> only in a stereo sample while leaving the other channel untouched?

Yes, but you'll have to use command-line constructs like the one
above. So you connect the input to multiple chains, process chains
indepently, and then combine the chains back to a multichannel output
file. This is a bit cumbersome, but we

> 3. Can I delete one channel of a stereo sample?

Yep, using the same method. So something like:

ecasound -a:1 -f:16,2,44100 -i stereo.wav -erc:2,1 \
              -f:16,1,44100 -o mono-right.wav

Only copy the right (second) channel.

> 4. Is it possible to somehow put marks into a sample or just see a
> continuous display of the actual position in a sample so that I can
> write down the number where I want to have a split while Im listening
> to the sample? In the moment I do fiddling with fw, rw, setpos etc. and
> that does always get me out of the "flow" somehow. Maybe this could be
> an idea for future development: While the sample plays one could press a
> key and the actual position is appended into a text file.

This is not possible at the moment. And as ecasound's engine runs
in its own thread, keypresses in the user-interface thread wouldn't
give accurate results. Ecawave might be better suited for this kind
of editing (although the current 0.1.0r1 version isn't that usable just
yet). Have you tried using "fs" (ie. "fstatus")?

> 5. When I apply the -eca compressor effect (with all parameters set to
> the defaults) to a sample and do a ecatools_normalize to this sample
> afterwards, the sample clips. Why is that?

Hmm, it shouldn't cause clipping. Are you sure it is the wave file
that is clipping (mixer setting aren't too high, etc.)? I'll have
to test this myself.

Kai Vehmanen <> -------- CS, University of Turku, Finland
 . - linux multitrack audio processing
 . - ambient-idm-rock-... mp3/ra/wav

-- To unsubscribe send message 'unsubscribe' in the body of the message to <>.

New Message Reply Date view Thread view Subject view Author view Other groups

This archive was generated by hypermail 2a24 : Tue Mar 07 2000 - 21:53:12 EET