Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / doc / outdevs.texi
1 @chapter Output Devices
2 @c man begin OUTPUT DEVICES
3
4 Output devices are configured elements in FFmpeg that can write
5 multimedia data to an output device attached to your system.
6
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".
10
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}".
15
16 The option "-devices" of the ff* tools will display the list of
17 enabled output devices.
18
19 A description of the currently available output devices follows.
20
21 @section alsa
22
23 ALSA (Advanced Linux Sound Architecture) output device.
24
25 @subsection Examples
26
27 @itemize
28 @item
29 Play a file on default ALSA device:
30 @example
31 ffmpeg -i INPUT -f alsa default
32 @end example
33
34 @item
35 Play a file on soundcard 1, audio device 7:
36 @example
37 ffmpeg -i INPUT -f alsa hw:1,7
38 @end example
39 @end itemize
40
41 @section caca
42
43 CACA output device.
44
45 This output device allows one 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.
48
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.
52
53 For more information about libcaca, check:
54 @url{http://caca.zoy.org/wiki/libcaca}
55
56 @subsection Options
57
58 @table @option
59
60 @item window_title
61 Set the CACA window title, if not specified default to the filename
62 specified for the output device.
63
64 @item window_size
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.
68
69 @item driver
70 Set display driver.
71
72 @item algorithm
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}.
77
78 @item antialias
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}.
82
83 @item charset
84 Set which characters are going to be used when rendering text.
85 The accepted values are listed with @code{-list_dither charsets}.
86
87 @item color
88 Set color to be used when rendering text.
89 The accepted values are listed with @code{-list_dither colors}.
90
91 @item list_drivers
92 If set to @option{true}, print a list of available drivers and exit.
93
94 @item list_dither
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}.
98 @end table
99
100 @subsection Examples
101
102 @itemize
103 @item
104 The following command shows the @command{ffmpeg} output is an
105 CACA window, forcing its size to 80x25:
106 @example
107 ffmpeg -i INPUT -vcodec rawvideo -pix_fmt rgb24 -window_size 80x25 -f caca -
108 @end example
109
110 @item
111 Show the list of available drivers and exit:
112 @example
113 ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_drivers true -
114 @end example
115
116 @item
117 Show the list of available dither colors and exit:
118 @example
119 ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_dither colors -
120 @end example
121 @end itemize
122
123 @section decklink
124
125 The decklink output device provides playback capabilities for Blackmagic
126 DeckLink devices.
127
128 To enable this output device, you need the Blackmagic DeckLink SDK and you
129 need to configure with the appropriate @code{--extra-cflags}
130 and @code{--extra-ldflags}.
131 On Windows, you need to run the IDL files through @command{widl}.
132
133 DeckLink is very picky about the formats it supports. Pixel format is always
134 uyvy422, framerate and video size must be determined for your device with
135 @command{-list_formats 1}. Audio sample rate is always 48 kHz.
136
137 @subsection Options
138
139 @table @option
140
141 @item list_devices
142 If set to @option{true}, print a list of devices and exit.
143 Defaults to @option{false}.
144
145 @item list_formats
146 If set to @option{true}, print a list of supported formats and exit.
147 Defaults to @option{false}.
148
149 @item preroll
150 Amount of time to preroll video in seconds.
151 Defaults to @option{0.5}.
152
153 @end table
154
155 @subsection Examples
156
157 @itemize
158
159 @item
160 List output devices:
161 @example
162 ffmpeg -i test.avi -f decklink -list_devices 1 dummy
163 @end example
164
165 @item
166 List supported formats:
167 @example
168 ffmpeg -i test.avi -f decklink -list_formats 1 'DeckLink Mini Monitor'
169 @end example
170
171 @item
172 Play video clip:
173 @example
174 ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 'DeckLink Mini Monitor'
175 @end example
176
177 @item
178 Play video clip with non-standard framerate or video size:
179 @example
180 ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 -s 720x486 -r 24000/1001 'DeckLink Mini Monitor'
181 @end example
182
183 @end itemize
184
185 @section fbdev
186
187 Linux framebuffer output device.
188
189 The Linux framebuffer is a graphic hardware-independent abstraction
190 layer to show graphics on a computer monitor, typically on the
191 console. It is accessed through a file device node, usually
192 @file{/dev/fb0}.
193
194 For more detailed information read the file
195 @file{Documentation/fb/framebuffer.txt} included in the Linux source tree.
196
197 @subsection Options
198 @table @option
199
200 @item xoffset
201 @item yoffset
202 Set x/y coordinate of top left corner. Default is 0.
203 @end table
204
205 @subsection Examples
206 Play a file on framebuffer device @file{/dev/fb0}.
207 Required pixel format depends on current framebuffer settings.
208 @example
209 ffmpeg -re -i INPUT -vcodec rawvideo -pix_fmt bgra -f fbdev /dev/fb0
210 @end example
211
212 See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1).
213
214 @section opengl
215 OpenGL output device.
216
217 To enable this output device you need to configure FFmpeg with @code{--enable-opengl}.
218
219 This output device allows one to render to OpenGL context.
220 Context may be provided by application or default SDL window is created.
221
222 When device renders to external context, application must implement handlers for following messages:
223 @code{AV_DEV_TO_APP_CREATE_WINDOW_BUFFER} - create OpenGL context on current thread.
224 @code{AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER} - make OpenGL context current.
225 @code{AV_DEV_TO_APP_DISPLAY_WINDOW_BUFFER} - swap buffers.
226 @code{AV_DEV_TO_APP_DESTROY_WINDOW_BUFFER} - destroy OpenGL context.
227 Application is also required to inform a device about current resolution by sending @code{AV_APP_TO_DEV_WINDOW_SIZE} message.
228
229 @subsection Options
230 @table @option
231
232 @item background
233 Set background color. Black is a default.
234 @item no_window
235 Disables default SDL window when set to non-zero value.
236 Application must provide OpenGL context and both @code{window_size_cb} and @code{window_swap_buffers_cb} callbacks when set.
237 @item window_title
238 Set the SDL window title, if not specified default to the filename specified for the output device.
239 Ignored when @option{no_window} is set.
240 @item window_size
241 Set preferred window size, can be a string of the form widthxheight or a video size abbreviation.
242 If not specified it defaults to the size of the input video, downscaled according to the aspect ratio.
243 Mostly usable when @option{no_window} is not set.
244
245 @end table
246
247 @subsection Examples
248 Play a file on SDL window using OpenGL rendering:
249 @example
250 ffmpeg -i INPUT -f opengl "window title"
251 @end example
252
253 @section oss
254
255 OSS (Open Sound System) output device.
256
257 @section pulse
258
259 PulseAudio output device.
260
261 To enable this output device you need to configure FFmpeg with @code{--enable-libpulse}.
262
263 More information about PulseAudio can be found on @url{http://www.pulseaudio.org}
264
265 @subsection Options
266 @table @option
267
268 @item server
269 Connect to a specific PulseAudio server, specified by an IP address.
270 Default server is used when not provided.
271
272 @item name
273 Specify the application name PulseAudio will use when showing active clients,
274 by default it is the @code{LIBAVFORMAT_IDENT} string.
275
276 @item stream_name
277 Specify the stream name PulseAudio will use when showing active streams,
278 by default it is set to the specified output name.
279
280 @item device
281 Specify the device to use. Default device is used when not provided.
282 List of output devices can be obtained with command @command{pactl list sinks}.
283
284 @item buffer_size
285 @item buffer_duration
286 Control the size and duration of the PulseAudio buffer. A small buffer
287 gives more control, but requires more frequent updates.
288
289 @option{buffer_size} specifies size in bytes while
290 @option{buffer_duration} specifies duration in milliseconds.
291
292 When both options are provided then the highest value is used
293 (duration is recalculated to bytes using stream parameters). If they
294 are set to 0 (which is default), the device will use the default
295 PulseAudio duration value. By default PulseAudio set buffer duration
296 to around 2 seconds.
297
298 @item prebuf
299 Specify pre-buffering size in bytes. The server does not start with
300 playback before at least @option{prebuf} bytes are available in the
301 buffer. By default this option is initialized to the same value as
302 @option{buffer_size} or @option{buffer_duration} (whichever is bigger).
303
304 @item minreq
305 Specify minimum request size in bytes. The server does not request less
306 than @option{minreq} bytes from the client, instead waits until the buffer
307 is free enough to request more bytes at once. It is recommended to not set
308 this option, which will initialize this to a value that is deemed sensible
309 by the server.
310
311 @end table
312
313 @subsection Examples
314 Play a file on default device on default server:
315 @example
316 ffmpeg -i INPUT -f pulse "stream name"
317 @end example
318
319 @section sdl
320
321 SDL (Simple DirectMedia Layer) output device.
322
323 This output device allows one to show a video stream in an SDL
324 window. Only one SDL window is allowed per application, so you can
325 have only one instance of this output device in an application.
326
327 To enable this output device you need libsdl installed on your system
328 when configuring your build.
329
330 For more information about SDL, check:
331 @url{http://www.libsdl.org/}
332
333 @subsection Options
334
335 @table @option
336
337 @item window_title
338 Set the SDL window title, if not specified default to the filename
339 specified for the output device.
340
341 @item icon_title
342 Set the name of the iconified SDL window, if not specified it is set
343 to the same value of @var{window_title}.
344
345 @item window_size
346 Set the SDL window size, can be a string of the form
347 @var{width}x@var{height} or a video size abbreviation.
348 If not specified it defaults to the size of the input video,
349 downscaled according to the aspect ratio.
350
351 @item window_fullscreen
352 Set fullscreen mode when non-zero value is provided.
353 Default value is zero.
354 @end table
355
356 @subsection Interactive commands
357
358 The window created by the device can be controlled through the
359 following interactive commands.
360
361 @table @key
362 @item q, ESC
363 Quit the device immediately.
364 @end table
365
366 @subsection Examples
367
368 The following command shows the @command{ffmpeg} output is an
369 SDL window, forcing its size to the qcif format:
370 @example
371 ffmpeg -i INPUT -vcodec rawvideo -pix_fmt yuv420p -window_size qcif -f sdl "SDL output"
372 @end example
373
374 @section sndio
375
376 sndio audio output device.
377
378 @section xv
379
380 XV (XVideo) output device.
381
382 This output device allows one to show a video stream in a X Window System
383 window.
384
385 @subsection Options
386
387 @table @option
388 @item display_name
389 Specify the hardware display name, which determines the display and
390 communications domain to be used.
391
392 The display name or DISPLAY environment variable can be a string in
393 the format @var{hostname}[:@var{number}[.@var{screen_number}]].
394
395 @var{hostname} specifies the name of the host machine on which the
396 display is physically attached. @var{number} specifies the number of
397 the display server on that host machine. @var{screen_number} specifies
398 the screen to be used on that server.
399
400 If unspecified, it defaults to the value of the DISPLAY environment
401 variable.
402
403 For example, @code{dual-headed:0.1} would specify screen 1 of display
404 0 on the machine named ``dual-headed''.
405
406 Check the X11 specification for more detailed information about the
407 display name format.
408
409 @item window_id
410 When set to non-zero value then device doesn't create new window,
411 but uses existing one with provided @var{window_id}. By default
412 this options is set to zero and device creates its own window.
413
414 @item window_size
415 Set the created window size, can be a string of the form
416 @var{width}x@var{height} or a video size abbreviation. If not
417 specified it defaults to the size of the input video.
418 Ignored when @var{window_id} is set.
419
420 @item window_x
421 @item window_y
422 Set the X and Y window offsets for the created window. They are both
423 set to 0 by default. The values may be ignored by the window manager.
424 Ignored when @var{window_id} is set.
425
426 @item window_title
427 Set the window title, if not specified default to the filename
428 specified for the output device. Ignored when @var{window_id} is set.
429 @end table
430
431 For more information about XVideo see @url{http://www.x.org/}.
432
433 @subsection Examples
434
435 @itemize
436 @item
437 Decode, display and encode video input with @command{ffmpeg} at the
438 same time:
439 @example
440 ffmpeg -i INPUT OUTPUT -f xv display
441 @end example
442
443 @item
444 Decode and display the input video to multiple X11 windows:
445 @example
446 ffmpeg -i INPUT -f xv normal -vf negate -f xv negated
447 @end example
448 @end itemize
449
450 @c man end OUTPUT DEVICES