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diff --git a/doc/outdevs.texi b/doc/outdevs.texi index dd7bd6475d..e68653fd7a 100644 --- a/doc/outdevs.texi +++ b/doc/outdevs.texi @@ -1,10 +1,10 @@ @chapter Output Devices @c man begin OUTPUT DEVICES -Output devices are configured elements in Libav which allow to write +Output devices are configured elements in FFmpeg that can write multimedia data to an output device attached to your system. -When you configure your Libav build, all the supported output devices +When you configure your FFmpeg build, all the supported output devices are enabled by default. You can list all available ones using the configure option "--list-outdevs". @@ -13,8 +13,8 @@ You can disable all the output devices using the configure option option "--enable-outdev=@var{OUTDEV}", or you can disable a particular input device using the option "--disable-outdev=@var{OUTDEV}". -The option "-formats" of the av* tools will display the list of -enabled output devices (amongst the muxers). +The option "-devices" of the ff* tools will display the list of +enabled output devices. A description of the currently available output devices follows. @@ -22,12 +22,429 @@ A description of the currently available output devices follows. ALSA (Advanced Linux Sound Architecture) output device. +@subsection Examples + +@itemize +@item +Play a file on default ALSA device: +@example +ffmpeg -i INPUT -f alsa default +@end example + +@item +Play a file on soundcard 1, audio device 7: +@example +ffmpeg -i INPUT -f alsa hw:1,7 +@end example +@end itemize + +@section caca + +CACA output device. + +This output device allows one to show a video stream in CACA window. +Only one CACA window is allowed per application, so you can +have only one instance of this output device in an application. + +To enable this output device you need to configure FFmpeg with +@code{--enable-libcaca}. +libcaca is a graphics library that outputs text instead of pixels. + +For more information about libcaca, check: +@url{http://caca.zoy.org/wiki/libcaca} + +@subsection Options + +@table @option + +@item window_title +Set the CACA window title, if not specified default to the filename +specified for the output device. + +@item window_size +Set the CACA window size, can be a string of the form +@var{width}x@var{height} or a video size abbreviation. +If not specified it defaults to the size of the input video. + +@item driver +Set display driver. + +@item algorithm +Set dithering algorithm. Dithering is necessary +because the picture being rendered has usually far more colours than +the available palette. +The accepted values are listed with @code{-list_dither algorithms}. + +@item antialias +Set antialias method. Antialiasing smoothens the rendered +image and avoids the commonly seen staircase effect. +The accepted values are listed with @code{-list_dither antialiases}. + +@item charset +Set which characters are going to be used when rendering text. +The accepted values are listed with @code{-list_dither charsets}. + +@item color +Set color to be used when rendering text. +The accepted values are listed with @code{-list_dither colors}. + +@item list_drivers +If set to @option{true}, print a list of available drivers and exit. + +@item list_dither +List available dither options related to the argument. +The argument must be one of @code{algorithms}, @code{antialiases}, +@code{charsets}, @code{colors}. +@end table + +@subsection Examples + +@itemize +@item +The following command shows the @command{ffmpeg} output is an +CACA window, forcing its size to 80x25: +@example +ffmpeg -i INPUT -vcodec rawvideo -pix_fmt rgb24 -window_size 80x25 -f caca - +@end example + +@item +Show the list of available drivers and exit: +@example +ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_drivers true - +@end example + +@item +Show the list of available dither colors and exit: +@example +ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_dither colors - +@end example +@end itemize + +@section decklink + +The decklink output device provides playback capabilities for Blackmagic +DeckLink devices. + +To enable this output device, you need the Blackmagic DeckLink SDK and you +need to configure with the appropriate @code{--extra-cflags} +and @code{--extra-ldflags}. +On Windows, you need to run the IDL files through @command{widl}. + +DeckLink is very picky about the formats it supports. Pixel format is always +uyvy422, framerate and video size must be determined for your device with +@command{-list_formats 1}. Audio sample rate is always 48 kHz. + +@subsection Options + +@table @option + +@item list_devices +If set to @option{true}, print a list of devices and exit. +Defaults to @option{false}. + +@item list_formats +If set to @option{true}, print a list of supported formats and exit. +Defaults to @option{false}. + +@item preroll +Amount of time to preroll video in seconds. +Defaults to @option{0.5}. + +@end table + +@subsection Examples + +@itemize + +@item +List output devices: +@example +ffmpeg -i test.avi -f decklink -list_devices 1 dummy +@end example + +@item +List supported formats: +@example +ffmpeg -i test.avi -f decklink -list_formats 1 'DeckLink Mini Monitor' +@end example + +@item +Play video clip: +@example +ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 'DeckLink Mini Monitor' +@end example + +@item +Play video clip with non-standard framerate or video size: +@example +ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 -s 720x486 -r 24000/1001 'DeckLink Mini Monitor' +@end example + +@end itemize + +@section fbdev + +Linux framebuffer output device. + +The Linux framebuffer is a graphic hardware-independent abstraction +layer to show graphics on a computer monitor, typically on the +console. It is accessed through a file device node, usually +@file{/dev/fb0}. + +For more detailed information read the file +@file{Documentation/fb/framebuffer.txt} included in the Linux source tree. + +@subsection Options +@table @option + +@item xoffset +@item yoffset +Set x/y coordinate of top left corner. Default is 0. +@end table + +@subsection Examples +Play a file on framebuffer device @file{/dev/fb0}. +Required pixel format depends on current framebuffer settings. +@example +ffmpeg -re -i INPUT -vcodec rawvideo -pix_fmt bgra -f fbdev /dev/fb0 +@end example + +See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1). + +@section opengl +OpenGL output device. + +To enable this output device you need to configure FFmpeg with @code{--enable-opengl}. + +This output device allows one to render to OpenGL context. +Context may be provided by application or default SDL window is created. + +When device renders to external context, application must implement handlers for following messages: +@code{AV_DEV_TO_APP_CREATE_WINDOW_BUFFER} - create OpenGL context on current thread. +@code{AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER} - make OpenGL context current. +@code{AV_DEV_TO_APP_DISPLAY_WINDOW_BUFFER} - swap buffers. +@code{AV_DEV_TO_APP_DESTROY_WINDOW_BUFFER} - destroy OpenGL context. +Application is also required to inform a device about current resolution by sending @code{AV_APP_TO_DEV_WINDOW_SIZE} message. + +@subsection Options +@table @option + +@item background +Set background color. Black is a default. +@item no_window +Disables default SDL window when set to non-zero value. +Application must provide OpenGL context and both @code{window_size_cb} and @code{window_swap_buffers_cb} callbacks when set. +@item window_title +Set the SDL window title, if not specified default to the filename specified for the output device. +Ignored when @option{no_window} is set. +@item window_size +Set preferred window size, can be a string of the form widthxheight or a video size abbreviation. +If not specified it defaults to the size of the input video, downscaled according to the aspect ratio. +Mostly usable when @option{no_window} is not set. + +@end table + +@subsection Examples +Play a file on SDL window using OpenGL rendering: +@example +ffmpeg -i INPUT -f opengl "window title" +@end example + @section oss OSS (Open Sound System) output device. +@section pulse + +PulseAudio output device. + +To enable this output device you need to configure FFmpeg with @code{--enable-libpulse}. + +More information about PulseAudio can be found on @url{http://www.pulseaudio.org} + +@subsection Options +@table @option + +@item server +Connect to a specific PulseAudio server, specified by an IP address. +Default server is used when not provided. + +@item name +Specify the application name PulseAudio will use when showing active clients, +by default it is the @code{LIBAVFORMAT_IDENT} string. + +@item stream_name +Specify the stream name PulseAudio will use when showing active streams, +by default it is set to the specified output name. + +@item device +Specify the device to use. Default device is used when not provided. +List of output devices can be obtained with command @command{pactl list sinks}. + +@item buffer_size +@item buffer_duration +Control the size and duration of the PulseAudio buffer. A small buffer +gives more control, but requires more frequent updates. + +@option{buffer_size} specifies size in bytes while +@option{buffer_duration} specifies duration in milliseconds. + +When both options are provided then the highest value is used +(duration is recalculated to bytes using stream parameters). If they +are set to 0 (which is default), the device will use the default +PulseAudio duration value. By default PulseAudio set buffer duration +to around 2 seconds. + +@item prebuf +Specify pre-buffering size in bytes. The server does not start with +playback before at least @option{prebuf} bytes are available in the +buffer. By default this option is initialized to the same value as +@option{buffer_size} or @option{buffer_duration} (whichever is bigger). + +@item minreq +Specify minimum request size in bytes. The server does not request less +than @option{minreq} bytes from the client, instead waits until the buffer +is free enough to request more bytes at once. It is recommended to not set +this option, which will initialize this to a value that is deemed sensible +by the server. + +@end table + +@subsection Examples +Play a file on default device on default server: +@example +ffmpeg -i INPUT -f pulse "stream name" +@end example + +@section sdl + +SDL (Simple DirectMedia Layer) output device. + +This output device allows one to show a video stream in an SDL +window. Only one SDL window is allowed per application, so you can +have only one instance of this output device in an application. + +To enable this output device you need libsdl installed on your system +when configuring your build. + +For more information about SDL, check: +@url{http://www.libsdl.org/} + +@subsection Options + +@table @option + +@item window_title +Set the SDL window title, if not specified default to the filename +specified for the output device. + +@item icon_title +Set the name of the iconified SDL window, if not specified it is set +to the same value of @var{window_title}. + +@item window_size +Set the SDL window size, can be a string of the form +@var{width}x@var{height} or a video size abbreviation. +If not specified it defaults to the size of the input video, +downscaled according to the aspect ratio. + +@item window_fullscreen +Set fullscreen mode when non-zero value is provided. +Default value is zero. +@end table + +@subsection Interactive commands + +The window created by the device can be controlled through the +following interactive commands. + +@table @key +@item q, ESC +Quit the device immediately. +@end table + +@subsection Examples + +The following command shows the @command{ffmpeg} output is an +SDL window, forcing its size to the qcif format: +@example +ffmpeg -i INPUT -vcodec rawvideo -pix_fmt yuv420p -window_size qcif -f sdl "SDL output" +@end example + @section sndio sndio audio output device. +@section xv + +XV (XVideo) output device. + +This output device allows one to show a video stream in a X Window System +window. + +@subsection Options + +@table @option +@item display_name +Specify the hardware display name, which determines the display and +communications domain to be used. + +The display name or DISPLAY environment variable can be a string in +the format @var{hostname}[:@var{number}[.@var{screen_number}]]. + +@var{hostname} specifies the name of the host machine on which the +display is physically attached. @var{number} specifies the number of +the display server on that host machine. @var{screen_number} specifies +the screen to be used on that server. + +If unspecified, it defaults to the value of the DISPLAY environment +variable. + +For example, @code{dual-headed:0.1} would specify screen 1 of display +0 on the machine named ``dual-headed''. + +Check the X11 specification for more detailed information about the +display name format. + +@item window_id +When set to non-zero value then device doesn't create new window, +but uses existing one with provided @var{window_id}. By default +this options is set to zero and device creates its own window. + +@item window_size +Set the created window size, can be a string of the form +@var{width}x@var{height} or a video size abbreviation. If not +specified it defaults to the size of the input video. +Ignored when @var{window_id} is set. + +@item window_x +@item window_y +Set the X and Y window offsets for the created window. They are both +set to 0 by default. The values may be ignored by the window manager. +Ignored when @var{window_id} is set. + +@item window_title +Set the window title, if not specified default to the filename +specified for the output device. Ignored when @var{window_id} is set. +@end table + +For more information about XVideo see @url{http://www.x.org/}. + +@subsection Examples + +@itemize +@item +Decode, display and encode video input with @command{ffmpeg} at the +same time: +@example +ffmpeg -i INPUT OUTPUT -f xv display +@end example + +@item +Decode and display the input video to multiple X11 windows: +@example +ffmpeg -i INPUT -f xv normal -vf negate -f xv negated +@end example +@end itemize + @c man end OUTPUT DEVICES |