.\" Manpage for ustreamer.
.\" Open an issue or pull request to https://github.com/pikvm/ustreamer to correct errors or typos
.TH USTREAMER 1 "version 2.2" "November 2020"

.SH NAME
ustreamer \- stream MJPG video from any V4L2 device to the network

.SH SYNOPSIS
.B ustreamer
.RI [OPTION]

.SH DESCRIPTION
µStreamer (\fBustreamer\fP) is a lightweight and very quick server to stream MJPG video from any V4L2 device to the network. All new browsers have native support of this video format, as well as most video players such as mplayer, VLC etc. µStreamer is a part of the Pi-KVM project designed to stream VGA and HDMI screencast hardware data with the highest resolution and FPS possible.

.SH OPTIONS
.SS "Capturing options"
.BR \-d\ \fI/dev/path ", " \-\-device\ \fI/dev/path
Path to V4L2 device. Default: /dev/video0.
.TP
.BR \-i\ \fIN ", " \-\-input\ \fIN
Input channel. Default: 0.
.TP
.BR \-r\ \fIWxH ", " \-\-resolution\ \fIWxH
Initial image resolution. Default: 640x480.
.TP
.BR \-m\ \fIfmt ", " \-\-format\ \fIfmt
Image format.
Available: YUYV, UYVY, RGB565, RGB24, JPEG; default: YUYV.
.TP
.BR \-a\ \fIstd ", " \-\-tv\-standard\ \fIstd
Force TV standard.
Available: PAL, NTSC, SECAM; default: disabled.
.TP
.BR \-I\ \fImethod ", " \-\-io\-method\ \fImethod
Set V4L2 IO method (see kernel documentation). Changing of this parameter may increase the performance. Or not.
Available: MMAP, USERPTR; default: MMAP.
.TP
.BR \-f\ \fIN ", " \-\-desired\-fps\ \fIN
Desired FPS. Default: maximum possible.
.TP
.BR \-z\ \fIN ", " \-\-min\-frame\-size\ \fIN
Drop frames smaller then this limit. Useful if the device produces small\-sized garbage frames. Default: 128 bytes.
.TP
.BR \-n ", " \-\-persistent
Don't re\-initialize device on timeout. Default: disabled.
.TP
.BR \-t ", " \-\-dv\-timings
Enable DV timings querying and events processing to automatic resolution change. Default: disabled.
.TP
.BR \-b\ \fIN ", " \-\-buffers\ \fIN
The number of buffers to receive data from the device. Each buffer may processed using an independent thread.
Default: 2 (the number of CPU cores (but not more than 4) + 1).
.TP
.BR \-w\ \fIN ", " \-\-workers\ \fIN
The number of worker threads but not more than buffers.
Default: 1 (the number of CPU cores (but not more than 4)).
.TP
.BR \-q\ \fIN ", " \-\-quality\ \fIN
Set quality of JPEG encoding from 1 to 100 (best). Default: 80.
Note: If HW encoding is used (JPEG source format selected), this parameter attempts to configure the camera or capture device hardware's internal encoder. It does not re\-encode MJPG to MJPG to change the quality level for sources that already output MJPG.
.TP
.BR \-c\ \fItype ", " \-\-encoder\ \fItype
Use specified encoder. It may affect the number of workers.
CPU ─ Software MJPG encoding (default). HW ─ Use pre-encoded MJPG frames directly from camera hardware.
Available: CPU, HW; default: CPU.
.TP
.BR \-\-device\-timeout\ \fIsec
Timeout for device querying. Default: 1.
.TP
.BR \-\-device\-error\-delay\ \fIsec
Delay before trying to connect to the device again after an error (timeout for example). Default: 1.

.SS "Image control options"
.BR \-\-image\-default
Reset all image settings bellow to default. Default: no change.
.TP
.BR \-\-brightness\ \fIN ", " \fIauto ", " \fIdefault
Set brightness. Default: no change.
.TP
.BR \-\-contrast\ \fIN ", " \fIdefault
Set contrast. Default: no change.
.TP
.BR \-\-saturation\ \fIN ", " \fIdefault
Set saturation. Default: no change.
.TP
.BR \-\-hue\ \fIN ", " \fIauto ", " \fIdefault
Set hue. Default: no change.
.TP
.BR \-\-gamma\ \fIN ", " \fIdefault
Set gamma. Default: no change.
.TP
.BR \-\-sharpness\ \fIN ", " \fIdefault
Set sharpness. Default: no change.
.TP
.BR \-\-backlight\-compensation\ \fIN ", " \fIdefault
Set backlight compensation. Default: no change.
.TP
.BR \-\-white\-balance\ \fIN ", " \fIauto ", " \fIdefault
Set white balance. Default: no change.
.TP
.BR \-\-gain\ \fIN ", " \fIauto ", " \fIdefault
Set gain. Default: no change.
.TP
.BR \-\-color\-effect\ \fIN ", " \fIdefault
Set color effect. Default: no change.
.TP
.BR \-\-flip\-vertical\ \fI1 ", " \fI0 ", " \fIdefault
Set vertical flip. Default: no change.
.TP
.BR \-\-flip\-horizontal\ \fI1 ", " \fI0 ", " \fIdefault
Set horizontal flip. Default: no change.

.SS "HTTP server options"
.BR \-s\ \fIaddress ", " \-\-host\ \fIaddress
Listen on Hostname or IP. Default: 127.0.0.1.
.TP
.BR \-p\ \fIN ", " \-\-port\ \fIN
Bind to this TCP port. Default: 8080.
.TP
.BR \-U\ \fIpath ", " \-\-unix\ \fIpath
Bind to UNIX domain socket. Default: disabled.
.TP
.BR \-D ", " \-\-unix\-rm
Try to remove old UNIX socket file before binding. Default: disabled.
.TP
.BR \-M\ \fImode ", " \-\-unix\-mode\ \fImode
Set UNIX socket file permissions (like 777). Default: disabled.
.TP
.BR \-\-user\ \fIname
HTTP basic auth user. Default: disabled.
.TP
.BR \-\-passwd\ \fIstr
HTTP basic auth passwd. Default: empty.
.TP
.BR \-\-static\ \fIpath
Path to dir with static files instead of embedded root index page. Symlinks are not supported for security reasons. Default: disabled.
.TP
.BR \-k\ \fIpath ", " \-\-blank\ \fIpath
Path to JPEG file that will be shown when the device is disconnected during the streaming. Default: black screen 640x480 with 'NO SIGNAL'.
.TP
.BR \-K\ \fIsec ", " \-\-last\-as\-blank\ \fIsec
Show the last frame received from the camera after it was disconnected, but no more than specified time (or endlessly if 0 is specified). If the device has not yet been online, display 'NO SIGNAL' or the image specified by option \-\-blank. Default: disabled.
.TP
.BR \-e\ \fIN ", " \-\-drop\-same\-frames\ \fIN
Don't send identical frames to clients, but no more than specified number. It can significantly reduce the outgoing traffic, but will increase the CPU loading. Don't use this option with analog signal sources or webcams, it's useless. Default: disabled.
.TP
.BR \-l ", " \-\-slowdown
Slowdown capturing to 1 FPS or less when no stream clients are connected. Useful to reduce CPU consumption. Default: disabled.
.TP
.BR \-R\ \fIWxH ", " \-\-fake\-resolution\ \fIWxH
Override image resolution for the /state. Default: disabled.
.TP
.BR \-\-tcp\-nodelay
Set TCP_NODELAY flag to the client /stream socket. Ignored for \-\-unix.
Default: disabled.
.TP
.BR \-\-allow\-origin\ \fIstr
Set Access\-Control\-Allow\-Origin header. Default: disabled.
.TP
.BR \-\-server\-timeout\ \fIsec
Timeout for client connections. Default: 10.

.SS "Process options"
.BR \-\-exit\-on\-parent\-death
Exit the program if the parent process is dead. Default: disabled.
.TP
.BR \-\-process\-name\-prefix\ \fIstr
Set process name prefix which will be displayed in the process list like '\fIstr: ustreamer \-\-blah\-blah\-blah'. Default: disabled.
.TP
.BR \-\-notify\-parent
Send SIGUSR2 to the parent process when the stream parameters are changed. Checking changes is performed for the online flag and image resolution.

.SS "Logging options"
.BR \-\-log\-level\ \fIN
Verbosity level of messages from 0 (info) to 3 (debug). Enabling debugging messages can slow down the program.
Available levels: 0 (info), 1 (performance), 2 (verbose), 3 (debug).
Default: 0.
.TP
.BR \-\-perf
Enable performance messages (same as \-\-log\-level=1). Default: disabled.
.TP
.BR \-\-verbose
Enable verbose messages and lower (same as \-\-log\-level=2). Default: disabled.
.TP
.BR \-\-debug
Enable debug messages and lower (same as \-\-log\-level=3). Default: disabled.
.TP
.BR \-\-force\-log\-colors
Force color logging. Default: colored if stdout is a TTY.
.TP
.BR \-\-no\-log\-colors
Disable color logging. Default: ditto.

.SS "Help options"
.BR \-h ", " \-\-help
Print this text and exit.
.TP
.BR \-v ", " \-\-version
Print version and exit.
.TP
.BR \-\-features
Print list of supported features.

.SH BUGS
Please file any bugs and issues at \fIhttps://github.com/pikvm/ustreamer/issues\fR

.SH AUTHOR
Maxim Devaev <mdevaev@gmail.com>

.SH HOMEPAGE
\fIhttps://pikvm.org/\fR

.SH COPYRIGHT
GNU General Public License v3.0