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JACK-STDIN(1) General Commands Manual JACK-STDIN(1)


jack-stdin - write JACK audio data to stdin


jack-stdin [OPTIONS] port1 [ port2 ...]


jack-stdin reads raw audio data from standard-input and writes it to a JACK audio port.

The number of given ports detemine the number of audio channels that are used. If more than one channel is given, the input audio-sample data needs to be interleaved.


Specify the bit-depth of each sample. For integer-encoding this can be 16 or 24. The default is 16. This setting is only used for integer encoding: Floating-point samples will always be 32 bit wide.

Specify the time for which jack-stdin should run in seconds. A value less than 1 means to run indefinitely. The default is 0 which reads until end-of-file.

Set the input format of the data: signed-integer, unsigned-integer, floating-point (default: signed)

Read data from given file instead of standard-input.

Print a brief usage information

Pre-fill the buffer before starting audio output to JACK (default 50.0%). NOTE: disable pre-buffering (-p 0) or use a small buffer size to play back very short samples.

The input-data is in little-endian byte-order or native-byte-order float (this is the default)

Interpret input audio data in big-endian byte-order or swap the byte-order of floating-point.

Inhibit usual output. This affects information and buffer-overflow warnings but not setup-errors.

Choose the internal buffer-size in samples. The default size is 65536. The given value will be multiplied by the number of channels and bit-depth to get the size of the ring-buffer. Note: the buffersize must be larger than JACK's period size.


jack-stdout vlc_31994:out_1 vlc_31994:out_2 \ | sox -t raw -r 48k -e signed -b 16 -c 2 - \ -t raw -r 48k -e signed -b 16 -c 2 - \ tremolo 5 100 \ | ./jack-stdin system:playback_1 system:playback_2
cat /dev/dsp \ | jack-stdin system:playback_1 system:playback_2


jack-stdin is not suitable to play-back files shorter than twice the jack-period size.


Robin Gareus <>.


30 March 2011