Subject: [linux-audio-dev] recording large audio files (was: Re: Question to developers of sound editors.)
From: Kai Vehmanen (kaiv_AT_wakkanet.fi)
Date: Tue Jun 05 2001 - 01:31:48 EEST
On Mon, 4 Jun 2001, Jay Ts wrote:
>> freeze up while recording an hour of music. We really
>> need something that can handle large stereo files.
> If all you want to do is record live audio, there is
> a very simple command line utility called "wavrec" (I
[...]
> wavrec -b 16 -s 44100 -S filename.wav
ecasound -f:16,2,44100 -i /dev/dsp -o filename.wav
Now I just couldn't resist the temptation. ;) Now if wavrec and other
simple tools handle the job, why use 'monsters' like ecasound? Well, a
quick list of what you get by doing the above with ecasound:
- ecasound can provide double-buffering (-z:db)
- lock-free communication between disk and audio threads (-z:db)
- support for realtime scheduling (-r)
- better control over buffering done by soundcard
drivers (-b:bsize and -z:intbuf + -z:nointbuf)
- support more other formats than just 16bit/stereo (32bit, multich, ...)
- support for OSS, various ALSA versions, aRts (C-API), LADPSA, LAAGA, ...
- support for various file formats other than wav (mp3, ogg, libaudiofile)
- ...
... and even with the simple use case above, these options can be useful.
If for nothing else, then for recording reliability.
> to record in stereo at 16-bit and 44.1 KHz. You just
> give it a Control-C to stop it, although this will cause
> the header info to not match the actual length of the
> recording (not usually fatal).
Like with ecasound except ecasound handles the wav header properly. ;)
> Or you can use the -t option to specify how long to record.
Same -t option works with ecasound (-t:rec_len_in_seconds).
Also, few things about ecasound that are not often mentioned:
- easy to install (rpms and debs available, _very_ few dependencies)
- up-to-date documentation (man pages in sync with the CVS-tree)
... now it'd be great if more Linux distros included the basic ecasound
package. This would be especially useful for scripting audio tasks.
Dependencies shouldn't be a problem (basicly just ncurses and even that
can be turned off). I guess the biggest problem is the binary size...
(about 1,1MB). But oh well, we'll see what happens... enough for the
marketing speech... :)
-- http://www.eca.cx Audio software for Linux!
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