roc-send - Man Page

send real-time audio


roc-send Options


Send real-time audio stream from a file or an audio device to a remote receiver.


-h,  --help

Print help and exit

-V,  --version

Print version and exit

-v,  --verbose

Increase verbosity level (may be used multiple times)


Input file or device


Input driver


Remote source port triplet


Remote repair port triplet


Number of source packets in FEC block


Number of repair packets in FEC block


Outgoing packet length, Time units


Maximum packet size, in bytes


Internal frame size, number of samples


Override input sample rate, Hz


Disable resampling  (default=off)


Resampler profile  (possible values="low", "medium", "high" default=`medium')


Resampler sinc table precision


Number of samples per resampler window


Enable packet interleaving  (default=off)


Enable uninitialized memory poisoning (default=off)


INPUT should be file name or device name, for example:

  • - (stdin)
  • file.wav (WAV file)
  • default (default input device)
  • front:CARD=PCH,DEV=0 (ALSA device)
  • alsa_input.pci-0000_00_1f.3.analog-stereo (PulseAudio source)

Interpretation of the device name depends on the selected driver.

If the input is omitted, some default input is selected. If the driver is omitted or it is a device driver, the default input device is seelcted. If the driver is a file driver, the stdin is selected.


DRIVER defines the type of the input file or device, for example:

  • wav
  • alsa
  • pulseaudio

If the driver is omitted, some default driver is selected. If the user did specify the input and it is a file with a known extension, the appropriate file driver is selected. Otherwise, the first device driver available on the system is selected.


PORT should be in one of the following forms:

  • protocol:ipv4addr:portnum
  • protocol:[ipv6addr]:portnum

For example:

  • rtp+rs8m:
  • rtp+rs8m:[::1]:10001

If FEC is enabled on sender, a pair of a source and repair ports should be used for communication between sender and receiver. If FEC is disabled, a single source port should be used instead.

Supported protocols for source ports:

  • rtp (bare RTP, no FEC scheme)
  • rtp+rs8m (RTP + Reed-Solomon m=8 FEC scheme)
  • rtp+ldpc (RTP + LDPC-Starircase FEC scheme)

Supported protocols for repair ports:

  • rs8m (Reed-Solomon m=8 FEC scheme)
  • ldpc (LDPC-Starircase FEC scheme)


TIME should have one of the following forms:

123ns, 123us, 123ms, 123s, 123m, 123h


Send WAV file:

$ roc-send -vv -s rtp+rs8m: -r rs8m: -i ./file.wav

Send WAV file to an IPv6 receiver:

$ roc-send -vv -s rtp+rs8m:[2001:db8::]:10001 -r rs8m:[2001:db8::]:10002 -i ./file.wav

Send WAV from stdin:

$ roc-send -vv -s rtp+rs8m: -r rs8m: -d wav -i - < ./file.wav

Capture sound from the default driver and device:

$ roc-send -vv -s rtp+rs8m: -r rs8m:

Capture sound from the default ALSA device:

$ roc-send -vv -s rtp+rs8m: -r rs8m: -d alsa

Capture sound from a specific PulseAudio device:

$ roc-send -vv -s rtp+rs8m: -r rs8m: -d pulseaudio -i <device>

Force a specific rate on the input device:

$ roc-send -vv -s rtp+rs8m: -r rs8m: --rate=44100

Select the LDPC-Staircase FEC scheme and a larger block size:

$ roc-send -vv -s rtp+ldpc: -r ldpc: -i ./file.wav \
  --nbsrc=1000 --nbrpr=500

Select bare RTP without FEC:

$ roc-send -vv -s rtp: -i ./file.wav

Select resampler profile:

$ roc-send -vv -s rtp+rs8m: -r rs8m: --resampler-profile=high

See Also

roc-recv(1), roc-conv(1), sox(1), the Roc web site at


Please report any bugs found via GitHub (


See authors page on the website for a list of maintainers and contributors.

Referenced By

roc-conv(1), roc-recv(1).

Oct 11, 2022 Roc Toolkit 0.1