vsound - digitally record output of an OSS audio program

vsound [options] [program arguments]

vsound allows you to record the output of any standard OSS program (one that uses /dev/dsp for sound) without having to modify or recompile the program. It uses the same idea as the esddsp wrapper from the Enlightened Sound Daemon (in fact, vsound is based on esddsp). That is, it preloads a library that intercepts calls to open /dev/dsp, and instead returns a handle to a normal file. It also intercepts ioctl's on that file handle and logs them, to help convert the audio data from its raw form. Vsound then uses sox to convert the raw data to the desired file format.

The upshoot of this is that instead of playing sound to the sound card in your computer, the data is recorded to a file. This is similar to if you connected a loopback cable to the line in and line out jacks on your sound card, but no DA or AD conversions take place, so quality is not lost.

One use of vsound is to help convert real audio files to some other non-proprietary format. Since the real audio format is proprietary, and all we have is a player, we can use the vsound to create a wave file like so:

vsound -f output.wav realplay input.rm

This will run realplayer under vsound. You will notice that no sound is produced while the real audio file is being played. When the file has completed playing, exit realplayer, and the raw audio data will be converted to a wave file.

With the help of some other encoder, you would then be able to convert the wave file to Ogg Vorbis or other formats if you wanted. This method is probably the one that preserves the most data during the conversion.

There are probably many other possible uses for vsound. Just use your imagination.

This manual page was written for the Debian GNU/Linux distribution because the original program does not have a manual page.

-a, --autostop=SEC

kill the player after SEC seconds of inactivity

-d, --dspout

enable simulateous output to /dev/dsp and file

-f, --file=FILE

output file name

-h, --help

Show summary of options.

-k, --keep-temps

don't delete temporary files

-n, --no-convert

do not convert the AU file to WAV

-r, --resample

resample the output file to the given sample rate

-s, --stdout

write the intermediate (Sun AU format) file to stdout

-t, --timing

add timing delays to allow recording of streaming data

-v, --verbose

set to verbose output

-V, --version

show program version

sox(1), files in the /usr/share/doc/vsound/ directory.

First versions by James Henstridge <james@daa.com.au>. This version is based on the esddsp program by Manish Singh <yosh@gimp.org> and has been patched by Erik de Castro Lopo <erikd@zip.com.au> so that it works with the G2 release of the real media player. This manual page was written by Paul Seelig <pseelig@debian.org>, for the Debian GNU/Linux system (but may be used by others).