--- name: "roc-send" section: "1" platform: "linux" package: "roc-toolkit" version: "0.4.0-3" release: "Arch Linux 2026-11-01" platforms: ["linux"] url: "https://new.carta.tech/roc-send" --- # roc-send(1) send real-time audio ## NAME roc-send - send real-time audio ## SYNOPSIS **roc-send** *OPTIONS* ## DESCRIPTION Read audio stream from an audio device or file and send it to remote receiver. ### Options - **-h, --help** Print help and exit - **-V, --version** Print version and exit - **-v, --verbose** Increase verbosity level (may be used multiple times) - **-L, --list-supported** list supported schemes and formats - **-i,***--input**=*****IO\_URI** Input file or device URI - **--input-format=***FILE\_FORMAT* Force input file format - **-s,***--source**=*****ENDPOINT\_URI** Remote source endpoint - **-r,***--repair**=*****ENDPOINT\_URI** Remote repair endpoint - **-c,***--control**=*****ENDPOINT\_URI** Remote control endpoint - **--reuseaddr** enable SO\_REUSEADDR when binding sockets - **--target-latency=***STRING* Target latency, TIME units - **--io-latency=***STRING* Recording target latency, TIME units - **--latency-tolerance=***STRING* Maximum deviation from target latency, TIME units - **--nbsrc=***INT* Number of source packets in FEC block - **--nbrpr=***INT* Number of repair packets in FEC block - **--packet-len=***STRING* Outgoing packet length, TIME units - **--frame-len=***TIME* Duration of the internal frames, TIME units - **--max-packet-size=***SIZE* Maximum packet size, in SIZE units - **--max-frame-size=***SIZE* Maximum internal frame size, in SIZE units - **--rate=***INT* Override input sample rate, Hz - **--latency-backend=***ENUM* Which latency to use in latency tuner (possible values="niq" default=\`niq') - **--latency-profile=***ENUM* Latency tuning profile (possible values="responsive", "gradual", "intact" default=\`intact') - **--resampler-backend=***ENUM* Resampler backend (possible values="default", "builtin", "speex", "speexdec" default=\`default') - **--resampler-profile=***ENUM* Resampler profile (possible values="low", "medium", "high" default=\`medium') - **--interleaving** Enable packet interleaving (default=off) - **--profiling** Enable self profiling (default=off) - **--color=***ENUM* Set colored logging mode for stderr output (possible values="auto", "always", "never" default=\`auto') ### Endpoint URI **--source**, **--repair**, and **--control** options define network endpoints to which to send the traffic. *ENDPOINT\_URI* should have the following form: **protocol://host\[:port\]\[/path\]\[?query\]** Examples: - • **rtsp://localhost:123/path?query** - • **rtp+rs8m://localhost:123** - • **rtp://127.0.0.1:123** - • **rtp://\[::1\]:123** - • **rtcp://10.9.8.3:123** The list of supported protocols can be retrieved using **--list-supported** option. The host field should be either FQDN (domain name), or IPv4 address, or IPv6 address in square brackets. The port field can be omitted if the protocol defines standard port. Otherwise, it is mandatory. The path and query fields are allowed only for protocols that support them, e.g. for RTSP. If FEC is enabled, a pair of a source and repair endpoints should be provided. The two endpoints should use compatible protocols, e.g. **rtp+rs8m://** for source endpoint, and **rs8m://** for repair endpoint. If FEC is disabled, a single source endpoint should be provided. Supported source and repair protocols: - • source **rtp://**, repair none (bare RTP without FEC) - • source **rtp+rs8m://**, repair **rs8m://** (RTP with Reed-Solomon FEC) - • source **rtp+ldpc://**, repair **ldpc://** (RTP with LDPC-Staircase FEC) In addition, it is recommended to provide control endpoint. It is used to exchange non-media information used to identify session, carry feedback, etc. If no control endpoint is provided, session operates in reduced fallback mode, which may be less robust and may not support all features. Supported control protocols: - • **rtcp://** ### IO URI **--input** option requires a device or file URI in one of the following forms: - • **DEVICE\_TYPE://DEVICE\_NAME** -- audio device - • **DEVICE\_TYPE://default** -- default audio device for given device type - • **file:///ABS/PATH** -- absolute file path - • **file://localhost/ABS/PATH** -- absolute file path (alternative form; only "localhost" host is supported) - • **file:/ABS/PATH** -- absolute file path (alternative form) - • **file:REL/PATH** -- relative file path - • **file://-** -- stdin - • **file:-** -- stdin (alternative form) Examples: - • **pulse://default** - • **pulse://alsa\_input.pci-0000\_00\_1f.3.analog-stereo** - • **alsa://hw:1,0** - • **file:///home/user/test.wav** - • **file://localhost/home/user/test.wav** - • **file:/home/user/test.wav** - • **file:./test.wav** - • **file:-** The list of supported schemes and file formats can be retrieved using **--list-supported** option. If the **--input** is omitted, the default driver and device are selected. The **--input-format** option can be used to force the input file format. If it is omitted, the file format is auto-detected. This option is always required when the input is stdin. The path component of the provided URI is *percent-decoded*. For convenience, unencoded characters are allowed as well, except that **%** should be always encoded as **%25**. For example, the file named **/foo/bar%/\[baz\]** may be specified using either of the following URIs: **file:///foo%2Fbar%25%2F%5Bbaz%5D** and **file:///foo/bar%25/\[baz\]**. ### Multiple slots Multiple sets of endpoints can be specified to send media to multiple addresses. Such endpoint sets are called slots. All slots should have the same set of endpoint types (source, repair, etc) and should use the same protocols for them. ### SO\_REUSEADDR If **--reuseaddr** option is provided, **SO\_REUSEADDR** socket option will be enabled for all sockets. For TCP, it allows immediately reusing recently closed socket in TIME\_WAIT state, which may be useful you want to be able to restart server quickly. For UDP, it allows multiple processes to bind to the same address, which may be useful if you're using systemd socket activation. Regardless of the option, **SO\_REUSEADDR** is always disabled when binding to ephemeral port. ### Time units - ***TIME* should have one of the following forms:** 123ns; 1.23us; 1.23ms; 1.23s; 1.23m; 1.23h; ### Size units - ***SIZE* should have one of the following forms:** 123; 1.23K; 1.23M; 1.23G; ## EXAMPLES ### Endpoint examples Send file to receiver with one bare RTP endpoint: ``` $ roc-send -vv -i file:./input.wav -s rtp://192.168.0.3:10001 ``` Send file to receiver with IPv4 source, repair, and control endpoints: ``` $ roc-send -vv -i file:./input.wav -s rtp+rs8m://192.168.0.3:10001 \ -r rs8m://192.168.0.3:10002 -c rtcp://192.168.0.3:10003 ``` Send file to receiver with IPv6 source, repair, and control endpoints: ``` $ roc-send -vv -i file:./input.wav -s rtp+rs8m://[2001:db8::]:10001 \ -r rs8m://[2001:db8::]:10002 -r rtcp://[2001:db8::]:10003 ``` Send file to two receivers, each with three endpoints: ``` $ roc-send -vv \ -i file:./input.wav \ -s rtp+rs8m://192.168.0.3:10001 -r rs8m://192.168.0.3:10002 \ -c rtcp://192.168.0.3:10003 \ -s rtp+rs8m://198.214.0.7:10001 -r rs8m://198.214.0.7:10002 \ -c rtcp://198.214.0.7:10003 ``` ### I/O examples Capture sound from the default device (omit **-i**): ``` $ roc-send -vv -s rtp://192.168.0.3:10001 ``` Capture sound from the default ALSA device: ``` $ roc-send -vv -s rtp://192.168.0.3:10001 -i alsa://default ``` Capture sound from a specific PulseAudio device: ``` $ roc-send -vv -s rtp://192.168.0.3:10001 -i pulse://alsa_input.pci-0000_00_1f.3.analog-stereo ``` Send WAV file (guess format by extension): ``` $ roc-send -vv -s rtp://192.168.0.3:10001 -i file:./input.wav ``` Send WAV file (specify format manually): ``` $ roc-send -vv -s rtp://192.168.0.3:10001 -i file:./input.file --input-format wav ``` Send WAV from stdin: ``` $ roc-send -vv -s rtp://192.168.0.3:10001 -i file:- --input-format wav <./input.wav ``` Send WAV file (specify absolute path): ``` $ roc-send -vv -s rtp://192.168.0.3:10001 -i file:///home/user/input.wav ``` ### Tuning examples Force a specific rate on the input device: ``` $ roc-send -vv -s rtp://192.168.0.3:10001 --rate=44100 ``` Select the LDPC-Staircase FEC scheme and a larger block size: ``` $ roc-send -vv -i file:./input.wav -s rtp+ldpc://192.168.0.3:10001 \ -r ldpc://192.168.0.3:10002 -c ldpc://192.168.0.3:10003 \ --nbsrc=1000 --nbrpr=500 ``` Select smaller packet length: ``` $ roc-send -vv -i file:./input.wav -s rtp+ldpc://192.168.0.3:10001 \ --packet-len 2500us ``` Select lower I/O latency and frame length: ``` $ roc-send -vv -s rtp://192.168.0.3:10001 \ --io-latency=20ms --frame-len 4ms ``` Manually specify resampling parameters: ``` $ roc-send -vv -s rtp://192.168.0.3:10001 \ --resampler-backend=speex --resampler-profile=high ``` Perform latency tuning on sender instead of receiver: ``` $ roc-recv -vv -o pulse://default -s rtp+rs8m://0.0.0.0:10001 \ -r rs8m://0.0.0.0:10002 -c rtcp://0.0.0.0:10003 \ --latency-profile=intact --target-latency=200ms $ roc-send -vv -i file:./input.wav -s rtp+rs8m://192.168.0.3:10001 \ -r rs8m://192.168.0.3:10002 -c rtcp://192.168.0.3:10003 \ --latency-profile=gradual --target-latency=200ms ``` ## ENVIRONMENT VARIABLES The following environment variables are supported: - **NO\_COLOR** By default, terminal coloring is automatically detected. This environment variable can be set to a non-empty string to disable terminal coloring. It has lower precedence than **--color** option. - **FORCE\_COLOR** By default, terminal coloring is automatically detected. This environment variable can be set to a positive integer to enable/force terminal coloring. It has lower precedence than **NO\_COLOR** variable and **--color** option. ## SEE ALSO **[roc-recv(1)](/roc-recv/1.md)**, and the Roc web site at *https://roc-streaming.org/* ## BUGS Please report any bugs found via GitHub (*https://github.com/roc-streaming/roc-toolkit/*). ## AUTHORS See authors page on the website for a list of maintainers and contributors (*https://roc-streaming.org/toolkit/docs/about\_project/authors.html*). ## COPYRIGHT 2024, Roc Streaming authors