slackbuilds/audio/jack_capture/README

jack_capture is a program for recording sound files with JACK.

* Autogenerated filenames are unique and humanly readable.

* The 4GB size barrier for wav files is handled by continuing
  writing to new files when reaching 4GB.

* Supports all soundfile formats supported by sndfile.
  (wav, aiff, ogg, flac, wavex, au, etc.)       (option: -f <format>)

* Supports mp3 by using liblame.                (option: -mp3)

* Option for writing raw 16 bit data to stdout. (option: -ws)

* Built-in console meter, plus option for automatically starting and
  stopping the Meterbridge jack meter program. Port connections to
  Meterbridge are done automatically, and on the fly, by jack_capture.

* jack_capture can connect to any input or output jack port.

  When "connecting" to a jack input port (i.e. a writable port),
  jack_capture constantly monitors which jack ports which are
  connected to that input port, and makes sure jack_capture is always
  connected to the same ports.

  In other words, jack_capture will reconnect its ports automatically
  during recording to match the connections of the ports.  This is
  for instance convenient when recording the playback ports since
  jack_capture can be started first, and then other programs can start
  and stop at any moment while all sound still should be recorded.

* No limit on the number of jack ports jack_capture can connect to.
  (I.e. the --port argument can be specified more than once, plus that
  it accepts wildcard arguments. For instance, jack_capture --port "*"
  will connect to all current jack ports, both input and output ports,
  except jack_capture's own ports.)

* Buffers are automatically increased during runtime to prevent
  underruns and to avoid wasting memory by preallocating too much.

* The disk thread is automatically reniced to a higher priority when
  using more than half of the buffer.

* Significantly better recording performance than Ardour, probably
  because jack_capture writes all channels into only one file and that
  it is not creating peak files). (tested on athlonXP)

* No problem writing at least 256 channels of 32 bit wav at once to a
  local hard drive. (tested on icore7)

Optional runtime dependencies are meterbridge and lame.

This package uses POSIX filesystem capabilities to execute with
elevated privileges (required for realtime audio processing). This
may be considered a security/stability risk. Please read
http://www.slackbuilds.org/caps/ for more information. To disable
capabilities, pass SETCAP=no to the script.