@chapter Output Devices@c man begin OUTPUT DEVICES Output devices are configured elements in FFmpeg that can writemultimedia data to an output device attached to your system. When you configure your FFmpeg build, all the supported output devicesare enabled by default. You can list all available ones using theconfigure option "--list-outdevs". You can disable all the output devices using the configure option"--disable-outdevs", and selectively enable an output device using theoption "--enable-outdev=@var{OUTDEV}", or you can disable a particularinput device using the option "--disable-outdev=@var{OUTDEV}". The option "-devices" of the ff* tools will display the list ofenabled output devices. A description of the currently available output devices follows. @section alsa ALSA (Advanced Linux Sound Architecture) output device. @subsection Examples @itemize@itemPlay a file on default ALSA device:@exampleffmpeg -i INPUT -f alsa default@end example @itemPlay a file on soundcard 1, audio device 7:@exampleffmpeg -i INPUT -f alsa hw:1,7@end example@end itemize @section AudioToolbox AudioToolbox output device. Allows native output to CoreAudio devices on OSX. The output filename can be empty (or @code{-}) to refer to the default system output device or a number that refers to the device index as shown using: @code{-list_devices true}. Alternatively, the audio input device can be chosen by index using the@option{ -audio_device_index <INDEX>}, overriding any device name or index given in the input filename. All available devices can be enumerated by using @option{-list_devices true}, listingall device names, UIDs and corresponding indices. @subsection Options AudioToolbox supports the following options: @table @option @item -audio_device_index <INDEX>Specify the audio device by its index. Overrides anything given in the output filename. @end table @subsection Examples @itemize @itemPrint the list of supported devices and output a sine wave to the default device:@example$ ffmpeg -f lavfi -i sine=r=44100 -f audiotoolbox -list_devices true -@end example @itemOutput a sine wave to the device with the index 2, overriding any output filename:@example$ ffmpeg -f lavfi -i sine=r=44100 -f audiotoolbox -audio_device_index 2 -@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 canhave 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_titleSet the CACA window title, if not specified default to the filenamespecified for the output device. @item window_sizeSet 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 driverSet display driver. @item algorithmSet dithering algorithm. Dithering is necessarybecause the picture being rendered has usually far more colours thanthe available palette.The accepted values are listed with @code{-list_dither algorithms}. @item antialiasSet antialias method. Antialiasing smoothens the renderedimage and avoids the commonly seen staircase effect.The accepted values are listed with @code{-list_dither antialiases}. @item charsetSet which characters are going to be used when rendering text.The accepted values are listed with @code{-list_dither charsets}. @item colorSet color to be used when rendering text.The accepted values are listed with @code{-list_dither colors}. @item list_driversIf set to @option{true}, print a list of available drivers and exit. @item list_ditherList 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@itemThe following command shows the @command{ffmpeg} output is anCACA window, forcing its size to 80x25:@exampleffmpeg -i INPUT -c:v rawvideo -pix_fmt rgb24 -window_size 80x25 -f caca -@end example @itemShow the list of available drivers and exit:@exampleffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_drivers true -@end example @itemShow the list of available dither colors and exit:@exampleffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_dither colors -@end example@end itemize @section decklink The decklink output device provides playback capabilities for BlackmagicDeckLink devices. To enable this output device, you need the Blackmagic DeckLink SDK and youneed 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 alwaysuyvy422, framerate, field order and video size must be determined for yourdevice with @command{-list_formats 1}. Audio sample rate is always 48 kHz. @subsection Options @table @option @item list_devicesIf set to @option{true}, print a list of devices and exit.Defaults to @option{false}. This option is deprecated, please use the@code{-sinks} option of ffmpeg to list the available output devices. @item list_formatsIf set to @option{true}, print a list of supported formats and exit.Defaults to @option{false}. @item prerollAmount of time to preroll video in seconds.Defaults to @option{0.5}. @item duplex_modeSets the decklink device duplex/profile mode. Must be @samp{unset}, @samp{half}, @samp{full},@samp{one_sub_device_full}, @samp{one_sub_device_half}, @samp{two_sub_device_full},@samp{four_sub_device_half}Defaults to @samp{unset}. Note: DeckLink SDK 11.0 have replaced the duplex property by a profile property.For the DeckLink Duo 2 and DeckLink Quad 2, a profile is shared between any 2sub-devices that utilize the same connectors. For the DeckLink 8K Pro, a profileis shared between all 4 sub-devices. So DeckLink 8K Pro support four profiles. Valid profile modes for DeckLink 8K Pro(with DeckLink SDK >= 11.0):@samp{one_sub_device_full}, @samp{one_sub_device_half}, @samp{two_sub_device_full},@samp{four_sub_device_half} Valid profile modes for DeckLink Quad 2 and DeckLink Duo 2:@samp{half}, @samp{full} @item timing_offsetSets the genlock timing pixel offset on the used output.Defaults to @samp{unset}. @item linkSets the SDI video link configuration on the used output. Must be@samp{unset}, @samp{single} link SDI, @samp{dual} link SDI or @samp{quad} linkSDI.Defaults to @samp{unset}. @item sqdEnable Square Division Quad Split mode for Quad-link SDI output.Must be @samp{unset}, @samp{true} or @samp{false}.Defaults to @option{unset}. @item level_aEnable SMPTE Level A mode on the used output.Must be @samp{unset}, @samp{true} or @samp{false}.Defaults to @option{unset}. @item vanc_queue_sizeSets maximum output buffer size in bytes for VANC data. If the buffering reaches this value,outgoing VANC data will be dropped.Defaults to @samp{1048576}. @end table @subsection Examples @itemize @itemList output devices:@exampleffmpeg -sinks decklink@end example @itemList supported formats:@exampleffmpeg -i test.avi -f decklink -list_formats 1 'DeckLink Mini Monitor'@end example @itemPlay video clip:@exampleffmpeg -i test.avi -f decklink -pix_fmt uyvy422 'DeckLink Mini Monitor'@end example @itemPlay video clip with non-standard framerate or video size:@exampleffmpeg -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 abstractionlayer to show graphics on a computer monitor, typically on theconsole. 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 yoffsetSet x/y coordinate of top left corner. Default is 0.@end table @subsection ExamplesPlay a file on framebuffer device @file{/dev/fb0}.Required pixel format depends on current framebuffer settings.@exampleffmpeg -re -i INPUT -c:v rawvideo -pix_fmt bgra -f fbdev /dev/fb0@end example See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1). @section openglOpenGL output device. Deprecated and will be removed. 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 backgroundSet background color. Black is a default.@item no_windowDisables 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_titleSet 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_sizeSet 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 ExamplesPlay a file on SDL window using OpenGL rendering:@exampleffmpeg -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 serverConnect to a specific PulseAudio server, specified by an IP address.Default server is used when not provided. @item nameSpecify the application name PulseAudio will use when showing active clients,by default it is the @code{LIBAVFORMAT_IDENT} string. @item stream_nameSpecify the stream name PulseAudio will use when showing active streams,by default it is set to the specified output name. @item deviceSpecify 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_durationControl the size and duration of the PulseAudio buffer. A small buffergives 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 theyare set to 0 (which is default), the device will use the defaultPulseAudio duration value. By default PulseAudio set buffer durationto around 2 seconds. @item prebufSpecify pre-buffering size in bytes. The server does not start withplayback before at least @option{prebuf} bytes are available in thebuffer. By default this option is initialized to the same value as@option{buffer_size} or @option{buffer_duration} (whichever is bigger). @item minreqSpecify minimum request size in bytes. The server does not request lessthan @option{minreq} bytes from the client, instead waits until the bufferis free enough to request more bytes at once. It is recommended to not setthis option, which will initialize this to a value that is deemed sensibleby the server. @end table @subsection ExamplesPlay a file on default device on default server:@exampleffmpeg -i INPUT -f pulse "stream name"@end example @section sdl SDL (Simple DirectMedia Layer) output device. Deprecated and will be removed. For monitoring purposes in FFmpeg, pipes and a video player such as ffplay can be used: @exampleffmpeg -i INPUT -f nut -c:v rawvideo - | ffplay -@end example "sdl2" can be used as alias for "sdl". This output device allows one to show a video stream in an SDLwindow. Only one SDL window is allowed per application, so you canhave only one instance of this output device in an application. To enable this output device you need libsdl installed on your systemwhen configuring your build. For more information about SDL, check:@url{http://www.libsdl.org/} @subsection Options @table @option @item window_borderlessSet SDL window border off.Default value is 0 (enable window border). @item window_enable_quitEnable quit action (using window button or keyboard key)when non-zero value is provided.Default value is 1 (enable quit action). @item window_fullscreenSet fullscreen mode when non-zero value is provided.Default value is zero. @item window_sizeSet 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_titleSet the SDL window title, if not specified default to the filenamespecified for the output device. @item window_x@item window_ySet the position of the window on the screen.@end table @subsection Interactive commands The window created by the device can be controlled through thefollowing interactive commands. @table @key@item q, ESCQuit the device immediately.@end table @subsection Examples The following command shows the @command{ffmpeg} output is anSDL window, forcing its size to the qcif format:@exampleffmpeg -i INPUT -c:v rawvideo -pix_fmt yuv420p -window_size qcif -f sdl "SDL output"@end example @section sndio sndio audio output device. @section v4l2 Video4Linux2 output device. @section xv XV (XVideo) output device. This output device allows one to show a video stream in a X Window Systemwindow. @subsection Options @table @option@item display_nameSpecify the hardware display name, which determines the display andLines 1–500 of 561. Load more
@chapter Output Devices @c man begin OUTPUT DEVICES Output devices are configured elements in FFmpeg that can write multimedia data to an output device attached to your system. 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". You can disable all the output devices using the configure option "--disable-outdevs", and selectively enable an output device using the option "--enable-outdev=@var{OUTDEV}", or you can disable a particular input device using the option "--disable-outdev=@var{OUTDEV}". The option "-devices" of the ff* tools will display the list of enabled output devices. A description of the currently available output devices follows. @section alsa 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 AudioToolbox AudioToolbox output device. Allows native output to CoreAudio devices on OSX. The output filename can be empty (or @code{-}) to refer to the default system output device or a number that refers to the device index as shown using: @code{-list_devices true}. Alternatively, the audio input device can be chosen by index using the @option{ -audio_device_index <INDEX> } , overriding any device name or index given in the input filename. All available devices can be enumerated by using @option{-list_devices true}, listing all device names, UIDs and corresponding indices. @subsection Options AudioToolbox supports the following options: @table @option @item -audio_device_index <INDEX> Specify the audio device by its index. Overrides anything given in the output filename. @end table @subsection Examples @itemize @item Print the list of supported devices and output a sine wave to the default device: @example $ ffmpeg -f lavfi -i sine=r=44100 -f audiotoolbox -list_devices true - @end example @item Output a sine wave to the device with the index 2, overriding any output filename: @example $ ffmpeg -f lavfi -i sine=r=44100 -f audiotoolbox -audio_device_index 2 - @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 -c:v 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, field order 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}. This option is deprecated, please use the @code{-sinks} option of ffmpeg to list the available output devices. @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}. @item duplex_mode Sets the decklink device duplex/profile mode. Must be @samp{unset}, @samp{half}, @samp{full}, @samp{one_sub_device_full}, @samp{one_sub_device_half}, @samp{two_sub_device_full}, @samp{four_sub_device_half} Defaults to @samp{unset}. Note: DeckLink SDK 11.0 have replaced the duplex property by a profile property. For the DeckLink Duo 2 and DeckLink Quad 2, a profile is shared between any 2 sub-devices that utilize the same connectors. For the DeckLink 8K Pro, a profile is shared between all 4 sub-devices. So DeckLink 8K Pro support four profiles. Valid profile modes for DeckLink 8K Pro(with DeckLink SDK >= 11.0): @samp{one_sub_device_full}, @samp{one_sub_device_half}, @samp{two_sub_device_full}, @samp{four_sub_device_half} Valid profile modes for DeckLink Quad 2 and DeckLink Duo 2: @samp{half}, @samp{full} @item timing_offset Sets the genlock timing pixel offset on the used output. Defaults to @samp{unset}. @item link Sets the SDI video link configuration on the used output. Must be @samp{unset}, @samp{single} link SDI, @samp{dual} link SDI or @samp{quad} link SDI. Defaults to @samp{unset}. @item sqd Enable Square Division Quad Split mode for Quad-link SDI output. Must be @samp{unset}, @samp{true} or @samp{false}. Defaults to @option{unset}. @item level_a Enable SMPTE Level A mode on the used output. Must be @samp{unset}, @samp{true} or @samp{false}. Defaults to @option{unset}. @item vanc_queue_size Sets maximum output buffer size in bytes for VANC data. If the buffering reaches this value, outgoing VANC data will be dropped. Defaults to @samp{1048576}. @end table @subsection Examples @itemize @item List output devices: @example ffmpeg -sinks decklink @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 -c:v 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. Deprecated and will be removed. 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. Deprecated and will be removed. For monitoring purposes in FFmpeg, pipes and a video player such as ffplay can be used: @example ffmpeg -i INPUT -f nut -c:v rawvideo - | ffplay - @end example "sdl2" can be used as alias for "sdl". 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_borderless Set SDL window border off. Default value is 0 (enable window border). @item window_enable_quit Enable quit action (using window button or keyboard key) when non-zero value is provided. Default value is 1 (enable quit action). @item window_fullscreen Set fullscreen mode when non-zero value is provided. Default value is zero. @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_title Set the SDL window title, if not specified default to the filename specified for the output device. @item window_x @item window_y Set the position of the window on the screen. @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 -c:v rawvideo -pix_fmt yuv420p -window_size qcif -f sdl "SDL output" @end example @section sndio sndio audio output device. @section v4l2 Video4Linux2 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