Provided by: roc-toolkit-tools_0.3.0+dfsg-7ubuntu2_amd64 
NAME
roc-recv - receive real-time audio
SYNOPSIS
roc-recv OPTIONS
DESCRIPTION
Receive audio streams from remote senders and write them to an audio device or file.
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
-o,--output=IO_URI
Output file or device URI
--output-format=FILE_FORMAT
Force output file format
--backup=IO_URI
Backup file or device URI (if set, used when there are no sessions)
--backup-format=FILE_FORMAT
Force backup file format
-s,--source=ENDPOINT_URI
Local source endpoint
-r,--repair=ENDPOINT_URI
Local repair endpoint
-c,--control=ENDPOINT_URI
Local control endpoint
--miface=MIFACE
IPv4 or IPv6 address of the network interface on which to join the multicast group
--reuseaddr
enable SO_REUSEADDR when binding sockets
--sess-latency=STRING
Session target latency, TIME units
--io-latency=STRING
Playback target latency, TIME units
--latency-tolerance=STRING
Maximum latency deviation, TIME units
--no-play-timeout=STRING
No playback timeout, TIME units
--choppy-play-timeout=STRING
Choppy playback timeout, TIME units
--packet-limit=INT
Maximum packet size, in bytes
--frame-limit=INT
Maximum internal frame size, in bytes
--frame-length=TIME
Duration of the internal frames, TIME units
--rate=INT
Override output sample rate, Hz
--clock-backend=ENUM
Clock synchronization backend (possible values="disable", "niq" default=`niq')
--clock-profile=ENUM
Clock synchronization profile (possible values="default", "responsive", "gradual"
default=`default')
--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')
-1, --oneshot
Exit when last connected client disconnects (default=off)
--profiling
Enable self-profiling (default=off)
--beep Enable beeping on packet loss (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 on which to receive 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://0.0.0.0:123
• rtp://[::1]:123
• rtcp://0.0.0.0:123
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. It may be 0.0.0.0 (for IPv4) or [::] (for IPv6) to bind endpoint to all
network interfaces.
The port field can be omitted if the protocol defines standard port. Otherwise, it is
mandatory. It may be set to zero to bind endpoint to a radomly chosen ephemeral port.
The path and query fields are allowed only for protocols that support them, e.g. for RTSP.
If FEC is enabled on sender, 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
--output and --backup options require 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://- -- stdout
• file:- -- stdout (alternative form)
Examples:
• pulse://default
• pulse://alsa_output.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 --output is omitted, the default driver and device are selected. If the --backup
is omitted, no backup source is used.
The --output-format and --backup-format options can be used to force the output or backup
file format. If the option is omitted, the file format is auto-detected. The option is
always required when the output or backup is stdout or 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].
Multicast interface
If --miface option is present, it defines an IP address of the network interface on which
to join the multicast group. If not present, no multicast group should be joined.
It's not possible to receive multicast traffic without joining a multicast group. The user
should either provide multicast interface, or join the group manually using foreign tools.
MIFACE should be an IP address of the network interface on which to join the multicast
group. It may be 0.0.0.0 (for IPv4) or :: (for IPv6) to join the multicast group on all
available interfaces.
Multiple slots
Multiple sets of endpoints can be specified to retrieve media from 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. All slots should also
have their own multicast interface option, if it's used.
SO_REUSEADDR
If --reuseaddr option is provided, SO_REUSEADDR socket option will be enabled for all
sockets (by default it's enabled only for multicast 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.
Backup audio
If --backup option is given, it defines input audio device or file which will be played
when there are no connected sessions. If it's not given, silence is played instead.
Backup file is restarted from the beginning each time when the last session disconnect.
The playback of of the backup file is automatically looped.
Time units
TIME should have one of the following forms:
123ns, 123us, 123ms, 123s, 123m, 123h
EXAMPLES
Endpoint examples
Bind one bare RTP endpoint on all IPv4 interfaces:
$ roc-recv -vv -s rtp://0.0.0.0:10001
Bind source, repair, and control endpoints to all IPv4 interfaces (but not IPv6):
$ roc-recv -vv -s rtp+rs8m://0.0.0.0:10001 -r rs8m://0.0.0.0:10002 \
-c rtcp://0.0.0.0:10003
Bind source, repair, and control endpoints to all IPv6 interfaces (but not IPv4):
$ roc-recv -vv -s rtp+rs8m://[::]:10001 -r rs8m://[::]:10002 -c rtcp://[::]:10003
Bind source, repair, and control endpoints to a particular network interface:
$ roc-recv -vv -s rtp+rs8m://192.168.0.3:10001 -r rs8m://192.168.0.3:10002 \
-c rtcp://192.168.0.3:10003
Bind endpoints to a particular multicast address and join to a multicast group on a
particular network interface:
$ roc-recv -vv -s rtp+rs8m://225.1.2.3:10001 -r rs8m://225.1.2.3:10002 \
-c rtcp://225.1.2.3:10003 \
--miface 192.168.0.3
Bind two sets of source, repair, and control endpoints (six endpoints in total):
$ roc-recv -vv \
-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
Output to the default device (omit -o):
$ roc-recv -vv -s rtp://0.0.0.0:10001
Output to the default ALSA device:
$ roc-recv -vv -s rtp://0.0.0.0:10001 -o alsa://default
Output to a specific PulseAudio device:
$ roc-recv -vv -s rtp://0.0.0.0:10001 -o pulse://alsa_input.pci-0000_00_1f.3.analog-stereo
Output to a file in WAV format (guess format by extension):
$ roc-recv -vv -s rtp://0.0.0.0:10001 -o file:./output.wav
Output to a file in WAV format (specify format manually):
$ roc-recv -vv -s rtp://0.0.0.0:10001 -o file:./output.file --output-format wav
Output to stdout in WAV format:
$ roc-recv -vv -s rtp://0.0.0.0:10001 -o file:- --output-format wav >./output.wav
Output to a file in WAV format (absolute path):
$ roc-recv -vv -s rtp://0.0.0.0:10001 -o file:///home/user/output.wav
Specify backup file:
$ roc-recv -vv -s rtp://0.0.0.0:10001 --backup file:./backup.wav
Tuning examples
Force a specific rate on the output device:
$ roc-recv -vv -s rtp://0.0.0.0:10001 --rate=44100
Select the LDPC-Staircase FEC scheme:
$ roc-recv -vv -s rtp+ldpc://0.0.0.0:10001 -r ldpc://0.0.0.0:10002 \
-c rtcp://0.0.0.0:10003
Select lower session latency:
$ roc-recv -vv -s rtp://0.0.0.0:10001 --sess-latency=50ms
Select lower I/O latency and frame length:
$ roc-recv -vv -s rtp://0.0.0.0:10001 \
--io-latency=20ms --frame-length 4ms
Manually specify thresholds and timeouts:
$ roc-recv -vv -s rtp://0.0.0.0:10001 \
--sess-latency=50ms --latency-tolerance=20ms \
--no-play-timeout=200s --choppy-play-timeout=500ms
Manually specify resampling parameters:
$ roc-recv -vv -s rtp://0.0.0.0:10001 \
--resampler-backend=speex --resampler-profile=high
Manually specify clock synchronization parameters:
$ roc-recv -vv -s rtp://0.0.0.0:10001 \
--clock-backend=niq --clock-profile=gradual
SEE ALSO
roc-send(1), 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.
COPYRIGHT
2023, Roc Streaming authors