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jack-record - JACK Capture Client


jack-record [options] sound-file


-b : Set the disk buffer size in frames (default=4096). This value must be a power of two. If the JACK period size at any time exceeds this value the recorder will halt.

-f : Set the file format (default=0x10006). The number is a bitwise-or of two values, the first describes the file type, the second the data type. The default value of 0x10000 | 0x00006 describes a thirty-two bit floating point WAV file. 0x2 is 16-bit and 0x3 24-bit.

-m : Set the minimal disk transfer size in frames (default=32). This is an optimization switch.

-n : Set the number of input channels to create (default=2).

-o : Integer offset for port connection pattern (default=0).

-p : A pattern describing the JACK ports to connect to, ie. SuperCollider:out_%d (default=nil).

-s : Capture to a set of single channel sound files. The sound file name must be a valid template.

-t : Set a timer to stop the recording after the specified number of seconds (default=-1).


jack-record is a light-weight JACK capture client to write an arbitrary number of channels to disk. It implements no connection logic, use jack-plumbing(1) instead.

If the default mode a single multiple channel sound file is written. If the -s option is given a set of single channel sound files are written. In this case the sound file name must be a valid template, the substring %d is replaced with the channel number counting from zero.

jack-record will write files in any format supported by libsndfile. The table below shows the most common file format masks. For other values see the file sndfile.h.

Format Code Description ------ ---- ----------- SF_FORMAT_WAV 0x10000 Microsoft WAV format SF_FORMAT_AIFF 0x20000 Apple/SGI AIFF format SF_FORMAT_PCM_16 0x00002 Signed 16 bit data SF_FORMAT_PCM_24 0x00003 Signed 24 bit data SF_FORMAT_PCM_32 0x00004 Signed 32 bit data SF_FORMAT_FLOAT 0x00006 32 bit float data


Rohan Drape


jackd(1), libsndfile(3)


Rohan Drape <>