Re: [ecasound] Selecting a portion of output

From: Linux Media <linuxmedia2@email-addr-hidden>
Date: Sat Feb 13 2010 - 01:02:46 EET

>>> I'm looking to get a clip of the output instead of the whole thing.
>>> I'm already using the -t switch to get the first few seconds of
>>> output
>>> as a preview, but is it possible to set a start time also? (ie. if I
>>> wanted to only get from the 10 second point to the 15 second point)
>>> Any help would be greatly appreciated.

>> ecasound -i:select,10,5,In.wav -o:out.wav
>> You may also need to set the file attributes with the -f switch. For
>> instance...
>> ecasound -i:select,10,5,In.wav -f:16,1,48000 -o:out.wav
>> This would indicate that you want 'out.wav' to be a 16 bit, one
>> channel
>> file sampled at 48000. If your input file is actually a wav file, then
>> attributes will already be set because of good header info in the wav
>> file. If not, then you may need to also set the file attributes just
>> in
>> front of the input file.
>> See 'man ecasound' for further explanation.

> Thanks for the quick reply. This should do the trick for selecting a
> portion of the final output once generated. It may be more efficient
> if there is a way to do this for mixing - ie. in a command where a few
> files are specified to be mixed, it only outputs the specific
> portion. I'm not sure this would be any more efficient than simply
> running this command on the output, since it would probably have to
> run through from start to end doing the mixing to determine the output.
> One example would be wanting to output only seconds 10-15 (say) of the
> final output of:
> ecasound -a:1 -i:Birthday1/malemain.wav -a:2 -
> i:Birthday1/1aged1moreyear.ewf -a:3 -i:Birthday1/2veryold.ewf -a:1,2,3
> -o previews/128.mp3 -t:75
> The -t:75 gives the first 75 seconds only, whereas it would be nice to
> specify an offset or range instead. I'll have a play with the command
> and see what I can do, if you have any ideas let me know?
> Thanks again,
> Brian

I'm not sure why you're using the EWF files. Kai created the 'select'
command and similar others as a way of using the EWF format internally
through commands as opposed to writing EWF files. The 'select' command
(and other commands in the section of the ecasound man page marked as
'Audio file sequencing') were created to give all the functionality of
the EWF files internally.

Also, I would use WAV files because you may have seeking problems with
mp3 (may or may not... not completely sure). But you can always use
ecasound or another program to convert to mp3 later with your final mix.

It's hard to tell exactly what you're trying to do, but in the
following... 3 files are mixed with each file extracting sound from
absolutely different spots in each of the files. But you could easily
select the exact same time in each if you wanted also. It's completely
flexible. You could also choose completely different times for how long
each file outputs separately also. It's a great benefit that Kai wrote
into ecasound at one point to make sequencing much easier than EWF files.

ecasound -a:1 -i:select,18,5,First.wav -a:2 -i:select,34,5,Second.wav
-a:3 -i:select,5,5,Third.wav -a:1,2,3 -o:jack,system

Obviously, you substitute 'jack,system' for an output file if you want
this to go from monitoring to mixing down.

Hope this helped,

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Received on Sat Feb 13 08:15:01 2010

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