(I don't agree about the linux-audio-* mailing list
announcement policy, so from now on, program announcements
will only be posted to linux-audio-announce(a)lists.linuxaudio.org !)
jack_capture is a program for recording soundfiles with jack.
The default operation of the program is executed by writing "jack_capture"
in the terminal without any extra command line options:
...which will record what you hear in your loudspeakers
into a stereo wav file.
Most important new features since 0.9.36
* Direct support for mp3 using liblame.
* Console cleanup. Terminal should not be messy
when quitting jack_capture.
* Better buffering schemes.
* Less used memory.
* 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 the input port, and make 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.
(handled by using lockless atomic fifo/lifo queues to store
temporary sound data instead of ringbuffers)
* 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)