1 @chapter Output Devices
2 @c man begin OUTPUT DEVICES
4 Output devices are configured elements in FFmpeg that can write
5 multimedia data to an output device attached to your system.
7 When you configure your FFmpeg build, all the supported output devices
8 are enabled by default. You can list all available ones using the
9 configure option "--list-outdevs".
11 You can disable all the output devices using the configure option
12 "--disable-outdevs", and selectively enable an output device using the
13 option "--enable-outdev=@var{OUTDEV}", or you can disable a particular
14 input device using the option "--disable-outdev=@var{OUTDEV}".
16 The option "-formats" of the ff* tools will display the list of
17 enabled output devices (amongst the muxers).
19 A description of the currently available output devices follows.
23 ALSA (Advanced Linux Sound Architecture) output device.
29 Play a file on default ALSA device:
31 ffmpeg -i INPUT -f alsa default
35 Play a file on soundcard 1, audio device 7:
37 ffmpeg -i INPUT -f alsa hw:1,7
45 This output device allows to show a video stream in CACA window.
46 Only one CACA window is allowed per application, so you can
47 have only one instance of this output device in an application.
49 To enable this output device you need to configure FFmpeg with
50 @code{--enable-libcaca}.
51 libcaca is a graphics library that outputs text instead of pixels.
53 For more information about libcaca, check:
54 @url{http://caca.zoy.org/wiki/libcaca}
61 Set the CACA window title, if not specified default to the filename
62 specified for the output device.
65 Set the CACA window size, can be a string of the form
66 @var{width}x@var{height} or a video size abbreviation.
67 If not specified it defaults to the size of the input video.
73 Set dithering algorithm. Dithering is necessary
74 because the picture being rendered has usually far more colours than
75 the available palette.
76 The accepted values are listed with @code{-list_dither algorithms}.
79 Set antialias method. Antialiasing smoothens the rendered
80 image and avoids the commonly seen staircase effect.
81 The accepted values are listed with @code{-list_dither antialiases}.
84 Set which characters are going to be used when rendering text.
85 The accepted values are listed with @code{-list_dither charsets}.
88 Set color to be used when rendering text.
89 The accepted values are listed with @code{-list_dither colors}.
92 If set to @option{true}, print a list of available drivers and exit.
95 List available dither options related to the argument.
96 The argument must be one of @code{algorithms}, @code{antialiases},
97 @code{charsets}, @code{colors}.
104 The following command shows the @command{ffmpeg} output is an
105 CACA window, forcing its size to 80x25:
107 ffmpeg -i INPUT -vcodec rawvideo -pix_fmt rgb24 -window_size 80x25 -f caca -
111 Show the list of available drivers and exit:
113 ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_drivers true -
117 Show the list of available dither colors and exit:
119 ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_dither colors -
125 Linux framebuffer output device.
127 The Linux framebuffer is a graphic hardware-independent abstraction
128 layer to show graphics on a computer monitor, typically on the
129 console. It is accessed through a file device node, usually
132 For more detailed information read the file
133 @file{Documentation/fb/framebuffer.txt} included in the Linux source tree.
140 Set x/y coordinate of top left corner. Default is 0.
144 Play a file on framebuffer device @file{/dev/fb0}.
145 Required pixel format depends on current framebuffer settings.
147 ffmpeg -re -i INPUT -vcodec rawvideo -pix_fmt bgra -f fbdev /dev/fb0
150 See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1).
154 OSS (Open Sound System) output device.
158 PulseAudio output device.
160 To enable this output device you need to configure FFmpeg with @code{--enable-libpulse}.
162 More information about PulseAudio can be found on @url{http://www.pulseaudio.org}
168 Connect to a specific PulseAudio server, specified by an IP address.
169 Default server is used when not provided.
172 Specify the application name PulseAudio will use when showing active clients,
173 by default it is the @code{LIBAVFORMAT_IDENT} string.
176 Specify the stream name PulseAudio will use when showing active streams,
177 by default it is set to the specified output name.
180 Specify the device to use. Default device is used when not provided.
181 List of output devices can be obtained with command @command{pactl list sinks}.
184 @item buffer_duration
185 Control the size and duration of the PulseAudio buffer. A small buffer
186 gives more control, but requires more frequent updates.
188 @option{buffer_size} specifies size in bytes while
189 @option{buffer_duration} specifies duration in milliseconds.
191 When both options are provided then the highest value is used
192 (duration is recalculated to bytes using stream parameters). If they
193 are set to 0 (which is default), the device will use the default
194 PulseAudio duration value. By default PulseAudio set buffer duration
199 Play a file on default device on default server:
201 ffmpeg -i INPUT -f pulse "stream name"
206 SDL (Simple DirectMedia Layer) output device.
208 This output device allows to show a video stream in an SDL
209 window. Only one SDL window is allowed per application, so you can
210 have only one instance of this output device in an application.
212 To enable this output device you need libsdl installed on your system
213 when configuring your build.
215 For more information about SDL, check:
216 @url{http://www.libsdl.org/}
223 Set the SDL window title, if not specified default to the filename
224 specified for the output device.
227 Set the name of the iconified SDL window, if not specified it is set
228 to the same value of @var{window_title}.
231 Set the SDL window size, can be a string of the form
232 @var{width}x@var{height} or a video size abbreviation.
233 If not specified it defaults to the size of the input video,
234 downscaled according to the aspect ratio.
236 @item window_fullscreen
237 Set fullscreen mode when non-zero value is provided.
238 Default value is zero.
241 @subsection Interactive commands
243 The window created by the device can be controlled through the
244 following interactive commands.
248 Quit the device immediately.
253 The following command shows the @command{ffmpeg} output is an
254 SDL window, forcing its size to the qcif format:
256 ffmpeg -i INPUT -vcodec rawvideo -pix_fmt yuv420p -window_size qcif -f sdl "SDL output"
261 sndio audio output device.
265 XV (XVideo) output device.
267 This output device allows to show a video stream in a X Window System
274 Specify the hardware display name, which determines the display and
275 communications domain to be used.
277 The display name or DISPLAY environment variable can be a string in
278 the format @var{hostname}[:@var{number}[.@var{screen_number}]].
280 @var{hostname} specifies the name of the host machine on which the
281 display is physically attached. @var{number} specifies the number of
282 the display server on that host machine. @var{screen_number} specifies
283 the screen to be used on that server.
285 If unspecified, it defaults to the value of the DISPLAY environment
288 For example, @code{dual-headed:0.1} would specify screen 1 of display
289 0 on the machine named ``dual-headed''.
291 Check the X11 specification for more detailed information about the
295 Set the created window size, can be a string of the form
296 @var{width}x@var{height} or a video size abbreviation. If not
297 specified it defaults to the size of the input video.
301 Set the X and Y window offsets for the created window. They are both
302 set to 0 by default. The values may be ignored by the window manager.
305 Set the window title, if not specified default to the filename
306 specified for the output device.
309 For more information about XVideo see @url{http://www.x.org/}.
315 Decode, display and encode video input with @command{ffmpeg} at the
318 ffmpeg -i INPUT OUTPUT -f xv display
322 Decode and display the input video to multiple X11 windows:
324 ffmpeg -i INPUT -f xv normal -vf negate -f xv negated
328 @c man end OUTPUT DEVICES