2 @c man begin INPUT DEVICES
4 Input devices are configured elements in FFmpeg which allow to access
5 the data coming from a multimedia device attached to your system.
7 When you configure your FFmpeg build, all the supported input devices
8 are enabled by default. You can list all available ones using the
9 configure option "--list-indevs".
11 You can disable all the input devices using the configure option
12 "--disable-indevs", and selectively enable an input device using the
13 option "--enable-indev=@var{INDEV}", or you can disable a particular
14 input device using the option "--disable-indev=@var{INDEV}".
16 The option "-devices" of the ff* tools will display the list of
17 supported input devices.
19 A description of the currently available input devices follows.
23 ALSA (Advanced Linux Sound Architecture) input device.
25 To enable this input device during configuration you need libasound
26 installed on your system.
28 This device allows capturing from an ALSA device. The name of the
29 device to capture has to be an ALSA card identifier.
31 An ALSA identifier has the syntax:
33 hw:@var{CARD}[,@var{DEV}[,@var{SUBDEV}]]
36 where the @var{DEV} and @var{SUBDEV} components are optional.
38 The three arguments (in order: @var{CARD},@var{DEV},@var{SUBDEV})
39 specify card number or identifier, device number and subdevice number
42 To see the list of cards currently recognized by your system check the
43 files @file{/proc/asound/cards} and @file{/proc/asound/devices}.
45 For example to capture with @command{ffmpeg} from an ALSA device with
46 card id 0, you may run the command:
48 ffmpeg -f alsa -i hw:0 alsaout.wav
51 For more information see:
52 @url{http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html}
56 AVFoundation input device.
58 AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX >= 10.7 as well as on iOS.
59 The older QTKit framework has been marked deprecated since OSX version 10.7.
61 The input filename has to be given in the following syntax:
63 -i "[[VIDEO]:[AUDIO]]"
65 The first entry selects the video input while the latter selects the audio input.
66 The stream has to be specified by the device name or the device index as shown by the device list.
67 Alternatively, the video and/or audio input device can be chosen by index using the
69 -video_device_index <INDEX>
73 -audio_device_index <INDEX>
76 device name or index given in the input filename.
78 All available devices can be enumerated by using @option{-list_devices true}, listing
79 all device names and corresponding indices.
81 There are two device name aliases:
85 Select the AVFoundation default device of the corresponding type.
88 Do not record the corresponding media type.
89 This is equivalent to specifying an empty device name or index.
95 AVFoundation supports the following options:
99 @item -list_devices <TRUE|FALSE>
100 If set to true, a list of all available input devices is given showing all
101 device names and indices.
103 @item -video_device_index <INDEX>
104 Specify the video device by its index. Overrides anything given in the input filename.
106 @item -audio_device_index <INDEX>
107 Specify the audio device by its index. Overrides anything given in the input filename.
109 @item -pixel_format <FORMAT>
110 Request the video device to use a specific pixel format.
111 If the specified format is not supported, a list of available formats is given
112 und the first one in this list is used instead. Available pixel formats are:
113 @code{monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,
114 bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10,
115 yuv420p, nv12, yuyv422, gray}
124 Print the list of AVFoundation supported devices and exit:
126 $ ffmpeg -f avfoundation -list_devices true -i ""
130 Record video from video device 0 and audio from audio device 0 into out.avi:
132 $ ffmpeg -f avfoundation -i "0:0" out.avi
136 Record video from video device 2 and audio from audio device 1 into out.avi:
138 $ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi
142 Record video from the system default video device using the pixel format bgr0 and do not record any audio into out.avi:
144 $ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi
151 BSD video input device.
155 Windows DirectShow input device.
157 DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
158 Currently only audio and video devices are supported.
160 Multiple devices may be opened as separate inputs, but they may also be
161 opened on the same input, which should improve synchronism between them.
163 The input name should be in the format:
166 @var{TYPE}=@var{NAME}[:@var{TYPE}=@var{NAME}]
169 where @var{TYPE} can be either @var{audio} or @var{video},
170 and @var{NAME} is the device's name or alternative name..
174 If no options are specified, the device's defaults are used.
175 If the device does not support the requested options, it will
181 Set the video size in the captured video.
184 Set the frame rate in the captured video.
187 Set the sample rate (in Hz) of the captured audio.
190 Set the sample size (in bits) of the captured audio.
193 Set the number of channels in the captured audio.
196 If set to @option{true}, print a list of devices and exit.
199 If set to @option{true}, print a list of selected device's options
202 @item video_device_number
203 Set video device number for devices with same name (starts at 0,
206 @item audio_device_number
207 Set audio device number for devices with same name (starts at 0,
211 Select pixel format to be used by DirectShow. This may only be set when
212 the video codec is not set or set to rawvideo.
214 @item audio_buffer_size
215 Set audio device buffer size in milliseconds (which can directly
216 impact latency, depending on the device).
217 Defaults to using the audio device's
218 default buffer size (typically some multiple of 500ms).
219 Setting this value too low can degrade performance.
221 @url{http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx}
224 Select video capture pin to use by name or alternative name.
227 Select audio capture pin to use by name or alternative name.
229 @item crossbar_video_input_pin_number
230 Select video input pin number for crossbar device. This will be
231 routed to the crossbar device's Video Decoder output pin.
232 Note that changing this value can affect future invocations
233 (sets a new default) until system reboot occurs.
235 @item crossbar_audio_input_pin_number
236 Select audio input pin number for crossbar device. This will be
237 routed to the crossbar device's Audio Decoder output pin.
238 Note that changing this value can affect future invocations
239 (sets a new default) until system reboot occurs.
241 @item show_video_device_dialog
242 If set to @option{true}, before capture starts, popup a display dialog
243 to the end user, allowing them to change video filter properties
244 and configurations manually.
245 Note that for crossbar devices, adjusting values in this dialog
246 may be needed at times to toggle between PAL (25 fps) and NTSC (29.97)
247 input frame rates, sizes, interlacing, etc. Changing these values can
248 enable different scan rates/frame rates and avoiding green bars at
249 the bottom, flickering scan lines, etc.
250 Note that with some devices, changing these properties can also affect future
251 invocations (sets new defaults) until system reboot occurs.
253 @item show_audio_device_dialog
254 If set to @option{true}, before capture starts, popup a display dialog
255 to the end user, allowing them to change audio filter properties
256 and configurations manually.
258 @item show_video_crossbar_connection_dialog
259 If set to @option{true}, before capture starts, popup a display
260 dialog to the end user, allowing them to manually
261 modify crossbar pin routings, when it opens a video device.
263 @item show_audio_crossbar_connection_dialog
264 If set to @option{true}, before capture starts, popup a display
265 dialog to the end user, allowing them to manually
266 modify crossbar pin routings, when it opens an audio device.
268 @item show_analog_tv_tuner_dialog
269 If set to @option{true}, before capture starts, popup a display
270 dialog to the end user, allowing them to manually
271 modify TV channels and frequencies.
273 @item show_analog_tv_tuner_audio_dialog
274 If set to @option{true}, before capture starts, popup a display
275 dialog to the end user, allowing them to manually
276 modify TV audio (like mono vs. stereo, Language A,B or C).
285 Print the list of DirectShow supported devices and exit:
287 $ ffmpeg -list_devices true -f dshow -i dummy
291 Open video device @var{Camera}:
293 $ ffmpeg -f dshow -i video="Camera"
297 Open second video device with name @var{Camera}:
299 $ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
303 Open video device @var{Camera} and audio device @var{Microphone}:
305 $ ffmpeg -f dshow -i video="Camera":audio="Microphone"
309 Print the list of supported options in selected device and exit:
311 $ ffmpeg -list_options true -f dshow -i video="Camera"
315 Specify pin names to capture by name or alternative name, specify alternative device name:
317 $ ffmpeg -f dshow -audio_pin_name "Audio Out" -video_pin_name 2 -i video=video="@@device_pnp_\\?\pci#ven_1a0a&dev_6200&subsys_62021461&rev_01#4&e2c7dd6&0&00e1#@{65e8773d-8f56-11d0-a3b9-00a0c9223196@}\@{ca465100-deb0-4d59-818f-8c477184adf6@}":audio="Microphone"
321 Configure a crossbar device, specifying crossbar pins, allow user to adjust video capture properties at startup:
323 $ ffmpeg -f dshow -show_video_device_dialog true -crossbar_video_input_pin_number 0
324 -crossbar_audio_input_pin_number 3 -i video="AVerMedia BDA Analog Capture":audio="AVerMedia BDA Analog Capture"
331 Linux DV 1394 input device.
335 Linux framebuffer input device.
337 The Linux framebuffer is a graphic hardware-independent abstraction
338 layer to show graphics on a computer monitor, typically on the
339 console. It is accessed through a file device node, usually
342 For more detailed information read the file
343 Documentation/fb/framebuffer.txt included in the Linux source tree.
345 To record from the framebuffer device @file{/dev/fb0} with
348 ffmpeg -f fbdev -r 10 -i /dev/fb0 out.avi
351 You can take a single screenshot image with the command:
353 ffmpeg -f fbdev -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg
356 See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1).
360 Win32 GDI-based screen capture device.
362 This device allows you to capture a region of the display on Windows.
364 There are two options for the input filename:
370 title=@var{window_title}
373 The first option will capture the entire desktop, or a fixed region of the
374 desktop. The second option will instead capture the contents of a single
375 window, regardless of its position on the screen.
377 For example, to grab the entire desktop using @command{ffmpeg}:
379 ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
382 Grab a 640x480 region at position @code{10,20}:
384 ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
387 Grab the contents of the window named "Calculator"
389 ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
396 Specify whether to draw the mouse pointer. Use the value @code{0} to
397 not draw the pointer. Default value is @code{1}.
400 Set the grabbing frame rate. Default value is @code{ntsc},
401 corresponding to a frame rate of @code{30000/1001}.
404 Show grabbed region on screen.
406 If @var{show_region} is specified with @code{1}, then the grabbing
407 region will be indicated on screen. With this option, it is easy to
408 know what is being grabbed if only a portion of the screen is grabbed.
410 Note that @var{show_region} is incompatible with grabbing the contents
415 ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
419 Set the video frame size. The default is to capture the full screen if @file{desktop} is selected, or the full window size if @file{title=@var{window_title}} is selected.
422 When capturing a region with @var{video_size}, set the distance from the left edge of the screen or desktop.
424 Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned to the left of your primary monitor, you will need to use a negative @var{offset_x} value to move the region to that monitor.
427 When capturing a region with @var{video_size}, set the distance from the top edge of the screen or desktop.
429 Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned above your primary monitor, you will need to use a negative @var{offset_y} value to move the region to that monitor.
435 FireWire DV/HDV input device using libiec61883.
437 To enable this input device, you need libiec61883, libraw1394 and
438 libavc1394 installed on your system. Use the configure option
439 @code{--enable-libiec61883} to compile with the device enabled.
441 The iec61883 capture device supports capturing from a video device
442 connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
443 FireWire stack (juju). This is the default DV/HDV input method in Linux
444 Kernel 2.6.37 and later, since the old FireWire stack was removed.
446 Specify the FireWire port to be used as input file, or "auto"
447 to choose the first port connected.
454 Override autodetection of DV/HDV. This should only be used if auto
455 detection does not work, or if usage of a different device type
456 should be prohibited. Treating a DV device as HDV (or vice versa) will
457 not work and result in undefined behavior.
458 The values @option{auto}, @option{dv} and @option{hdv} are supported.
461 Set maximum size of buffer for incoming data, in frames. For DV, this
462 is an exact value. For HDV, it is not frame exact, since HDV does
463 not have a fixed frame size.
466 Select the capture device by specifying it's GUID. Capturing will only
467 be performed from the specified device and fails if no device with the
468 given GUID is found. This is useful to select the input if multiple
469 devices are connected at the same time.
470 Look at /sys/bus/firewire/devices to find out the GUIDs.
479 Grab and show the input of a FireWire DV/HDV device.
481 ffplay -f iec61883 -i auto
485 Grab and record the input of a FireWire DV/HDV device,
486 using a packet buffer of 100000 packets if the source is HDV.
488 ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg
497 To enable this input device during configuration you need libjack
498 installed on your system.
500 A JACK input device creates one or more JACK writable clients, one for
501 each audio channel, with name @var{client_name}:input_@var{N}, where
502 @var{client_name} is the name provided by the application, and @var{N}
503 is a number which identifies the channel.
504 Each writable client will send the acquired data to the FFmpeg input
507 Once you have created one or more JACK readable clients, you need to
508 connect them to one or more JACK writable clients.
510 To connect or disconnect JACK clients you can use the @command{jack_connect}
511 and @command{jack_disconnect} programs, or do it through a graphical interface,
512 for example with @command{qjackctl}.
514 To list the JACK clients and their properties you can invoke the command
517 Follows an example which shows how to capture a JACK readable client
518 with @command{ffmpeg}.
520 # Create a JACK writable client with name "ffmpeg".
521 $ ffmpeg -f jack -i ffmpeg -y out.wav
523 # Start the sample jack_metro readable client.
524 $ jack_metro -b 120 -d 0.2 -f 4000
526 # List the current JACK clients.
535 # Connect metro to the ffmpeg writable client.
536 $ jack_connect metro:120_bpm ffmpeg:input_1
539 For more information read:
540 @url{http://jackaudio.org/}
544 Libavfilter input virtual device.
546 This input device reads data from the open output pads of a libavfilter
549 For each filtergraph open output, the input device will create a
550 corresponding stream which is mapped to the generated output. Currently
551 only video data is supported. The filtergraph is specified through the
552 option @option{graph}.
559 Specify the filtergraph to use as input. Each video open output must be
560 labelled by a unique string of the form "out@var{N}", where @var{N} is a
561 number starting from 0 corresponding to the mapped input stream
562 generated by the device.
563 The first unlabelled output is automatically assigned to the "out0"
564 label, but all the others need to be specified explicitly.
566 The suffix "+subcc" can be appended to the output label to create an extra
567 stream with the closed captions packets attached to that output
568 (experimental; only for EIA-608 / CEA-708 for now).
569 The subcc streams are created after all the normal streams, in the order of
570 the corresponding stream.
571 For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
572 stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
574 If not specified defaults to the filename specified for the input
578 Set the filename of the filtergraph to be read and sent to the other
579 filters. Syntax of the filtergraph is the same as the one specified by
580 the option @var{graph}.
588 Create a color video stream and play it back with @command{ffplay}:
590 ffplay -f lavfi -graph "color=c=pink [out0]" dummy
594 As the previous example, but use filename for specifying the graph
595 description, and omit the "out0" label:
597 ffplay -f lavfi color=c=pink
601 Create three different video test filtered sources and play them:
603 ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
607 Read an audio stream from a file using the amovie source and play it
608 back with @command{ffplay}:
610 ffplay -f lavfi "amovie=test.wav"
614 Read an audio stream and a video stream and play it back with
617 ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
621 Dump decoded frames to images and closed captions to a file (experimental):
623 ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
630 Audio-CD input device based on libcdio.
632 To enable this input device during configuration you need libcdio
633 installed on your system. It requires the configure option
634 @code{--enable-libcdio}.
636 This device allows playing and grabbing from an Audio-CD.
638 For example to copy with @command{ffmpeg} the entire Audio-CD in @file{/dev/sr0},
639 you may run the command:
641 ffmpeg -f libcdio -i /dev/sr0 cd.wav
647 Set drive reading speed. Default value is 0.
649 The speed is specified CD-ROM speed units. The speed is set through
650 the libcdio @code{cdio_cddap_speed_set} function. On many CD-ROM
651 drives, specifying a value too large will result in using the fastest
655 Set paranoia recovery mode flags. It accepts one of the following values:
665 Default value is @samp{disable}.
667 For more information about the available recovery modes, consult the
668 paranoia project documentation.
673 IIDC1394 input device, based on libdc1394 and libraw1394.
675 Requires the configure option @code{--enable-libdc1394}.
679 The OpenAL input device provides audio capture on all systems with a
680 working OpenAL 1.1 implementation.
682 To enable this input device during configuration, you need OpenAL
683 headers and libraries installed on your system, and need to configure
684 FFmpeg with @code{--enable-openal}.
686 OpenAL headers and libraries should be provided as part of your OpenAL
687 implementation, or as an additional download (an SDK). Depending on your
688 installation you may need to specify additional flags via the
689 @code{--extra-cflags} and @code{--extra-ldflags} for allowing the build
690 system to locate the OpenAL headers and libraries.
692 An incomplete list of OpenAL implementations follows:
696 The official Windows implementation, providing hardware acceleration
697 with supported devices and software fallback.
698 See @url{http://openal.org/}.
700 Portable, open source (LGPL) software implementation. Includes
701 backends for the most common sound APIs on the Windows, Linux,
702 Solaris, and BSD operating systems.
703 See @url{http://kcat.strangesoft.net/openal.html}.
705 OpenAL is part of Core Audio, the official Mac OS X Audio interface.
706 See @url{http://developer.apple.com/technologies/mac/audio-and-video.html}
709 This device allows one to capture from an audio input device handled
712 You need to specify the name of the device to capture in the provided
713 filename. If the empty string is provided, the device will
714 automatically select the default device. You can get the list of the
715 supported devices by using the option @var{list_devices}.
722 Set the number of channels in the captured audio. Only the values
723 @option{1} (monaural) and @option{2} (stereo) are currently supported.
724 Defaults to @option{2}.
727 Set the sample size (in bits) of the captured audio. Only the values
728 @option{8} and @option{16} are currently supported. Defaults to
732 Set the sample rate (in Hz) of the captured audio.
733 Defaults to @option{44.1k}.
736 If set to @option{true}, print a list of devices and exit.
737 Defaults to @option{false}.
743 Print the list of OpenAL supported devices and exit:
745 $ ffmpeg -list_devices true -f openal -i dummy out.ogg
748 Capture from the OpenAL device @file{DR-BT101 via PulseAudio}:
750 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
753 Capture from the default device (note the empty string '' as filename):
755 $ ffmpeg -f openal -i '' out.ogg
758 Capture from two devices simultaneously, writing to two different files,
759 within the same @command{ffmpeg} command:
761 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
763 Note: not all OpenAL implementations support multiple simultaneous capture -
764 try the latest OpenAL Soft if the above does not work.
768 Open Sound System input device.
770 The filename to provide to the input device is the device node
771 representing the OSS input device, and is usually set to
774 For example to grab from @file{/dev/dsp} using @command{ffmpeg} use the
777 ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
780 For more information about OSS see:
781 @url{http://manuals.opensound.com/usersguide/dsp.html}
785 PulseAudio input device.
787 To enable this output device you need to configure FFmpeg with @code{--enable-libpulse}.
789 The filename to provide to the input device is a source device or the
792 To list the PulseAudio source devices and their properties you can invoke
793 the command @command{pactl list sources}.
795 More information about PulseAudio can be found on @url{http://www.pulseaudio.org}.
800 Connect to a specific PulseAudio server, specified by an IP address.
801 Default server is used when not provided.
804 Specify the application name PulseAudio will use when showing active clients,
805 by default it is the @code{LIBAVFORMAT_IDENT} string.
808 Specify the stream name PulseAudio will use when showing active streams,
809 by default it is "record".
812 Specify the samplerate in Hz, by default 48kHz is used.
815 Specify the channels in use, by default 2 (stereo) is set.
818 Specify the number of bytes per frame, by default it is set to 1024.
821 Specify the minimal buffering fragment in PulseAudio, it will affect the
822 audio latency. By default it is unset.
826 Record a stream from default device:
828 ffmpeg -f pulse -i default /tmp/pulse.wav
835 The filename passed as input is parsed to contain either a device name or index.
836 The device index can also be given by using -video_device_index.
837 A given device index will override any given device name.
838 If the desired device consists of numbers only, use -video_device_index to identify it.
839 The default device will be chosen if an empty string or the device name "default" is given.
840 The available devices can be enumerated by using -list_devices.
843 ffmpeg -f qtkit -i "0" out.mpg
847 ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg
851 ffmpeg -f qtkit -i "default" out.mpg
855 ffmpeg -f qtkit -list_devices true -i ""
862 To enable this input device during configuration you need libsndio
863 installed on your system.
865 The filename to provide to the input device is the device node
866 representing the sndio input device, and is usually set to
869 For example to grab from @file{/dev/audio0} using @command{ffmpeg} use the
872 ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
875 @section video4linux2, v4l2
877 Video4Linux2 input video device.
879 "v4l2" can be used as alias for "video4linux2".
881 If FFmpeg is built with v4l-utils support (by using the
882 @code{--enable-libv4l2} configure option), it is possible to use it with the
883 @code{-use_libv4l2} input device option.
885 The name of the device to grab is a file device node, usually Linux
886 systems tend to automatically create such nodes when the device
887 (e.g. an USB webcam) is plugged into the system, and has a name of the
888 kind @file{/dev/video@var{N}}, where @var{N} is a number associated to
891 Video4Linux2 devices usually support a limited set of
892 @var{width}x@var{height} sizes and frame rates. You can check which are
893 supported using @command{-list_formats all} for Video4Linux2 devices.
894 Some devices, like TV cards, support one or more standards. It is possible
895 to list all the supported standards using @command{-list_standards all}.
897 The time base for the timestamps is 1 microsecond. Depending on the kernel
898 version and configuration, the timestamps may be derived from the real time
899 clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
900 boot time, unaffected by NTP or manual changes to the clock). The
901 @option{-timestamps abs} or @option{-ts abs} option can be used to force
902 conversion into the real time clock.
904 Some usage examples of the video4linux2 device with @command{ffmpeg}
905 and @command{ffplay}:
908 Grab and show the input of a video4linux2 device:
910 ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
914 Grab and record the input of a video4linux2 device, leave the
915 frame rate and size as previously set:
917 ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
921 For more information about Video4Linux, check @url{http://linuxtv.org/}.
927 Set the standard. Must be the name of a supported standard. To get a
928 list of the supported standards, use the @option{list_standards}
932 Set the input channel number. Default to -1, which means using the
933 previously selected channel.
936 Set the video frame size. The argument must be a string in the form
937 @var{WIDTH}x@var{HEIGHT} or a valid size abbreviation.
940 Select the pixel format (only valid for raw video input).
943 Set the preferred pixel format (for raw video) or a codec name.
944 This option allows one to select the input format, when several are
948 Set the preferred video frame rate.
951 List available formats (supported pixel formats, codecs, and frame
954 Available values are:
957 Show all available (compressed and non-compressed) formats.
960 Show only raw video (non-compressed) formats.
963 Show only compressed formats.
967 List supported standards and exit.
969 Available values are:
972 Show all supported standards.
976 Set type of timestamps for grabbed frames.
978 Available values are:
981 Use timestamps from the kernel.
984 Use absolute timestamps (wall clock).
987 Force conversion from monotonic to absolute timestamps.
990 Default value is @code{default}.
995 VfW (Video for Windows) capture input device.
997 The filename passed as input is the capture driver number, ranging from
998 0 to 9. You may use "list" as filename to print a list of drivers. Any
999 other filename will be interpreted as device number 0.
1003 X11 video input device.
1005 To enable this input device during configuration you need libxcb
1006 installed on your system. It will be automatically detected during
1009 Alternatively, the configure option @option{--enable-x11grab} exists
1010 for legacy Xlib users.
1012 This device allows one to capture a region of an X11 display.
1014 The filename passed as input has the syntax:
1016 [@var{hostname}]:@var{display_number}.@var{screen_number}[+@var{x_offset},@var{y_offset}]
1019 @var{hostname}:@var{display_number}.@var{screen_number} specifies the
1020 X11 display name of the screen to grab from. @var{hostname} can be
1021 omitted, and defaults to "localhost". The environment variable
1022 @env{DISPLAY} contains the default display name.
1024 @var{x_offset} and @var{y_offset} specify the offsets of the grabbed
1025 area with respect to the top-left border of the X11 screen. They
1028 Check the X11 documentation (e.g. @command{man X}) for more detailed
1031 Use the @command{xdpyinfo} program for getting basic information about
1032 the properties of your X11 display (e.g. grep for "name" or
1035 For example to grab from @file{:0.0} using @command{ffmpeg}:
1037 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
1040 Grab at position @code{10,20}:
1042 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
1049 Specify whether to draw the mouse pointer. A value of @code{0} specify
1050 not to draw the pointer. Default value is @code{1}.
1053 Make the grabbed area follow the mouse. The argument can be
1054 @code{centered} or a number of pixels @var{PIXELS}.
1056 When it is specified with "centered", the grabbing region follows the mouse
1057 pointer and keeps the pointer at the center of region; otherwise, the region
1058 follows only when the mouse pointer reaches within @var{PIXELS} (greater than
1059 zero) to the edge of region.
1063 ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
1066 To follow only when the mouse pointer reaches within 100 pixels to edge:
1068 ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
1072 Set the grabbing frame rate. Default value is @code{ntsc},
1073 corresponding to a frame rate of @code{30000/1001}.
1076 Show grabbed region on screen.
1078 If @var{show_region} is specified with @code{1}, then the grabbing
1079 region will be indicated on screen. With this option, it is easy to
1080 know what is being grabbed if only a portion of the screen is grabbed.
1083 Set the region border thickness if @option{-show_region 1} is used.
1084 Range is 1 to 128 and default is 3 (XCB-based x11grab only).
1088 ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
1091 With @var{follow_mouse}:
1093 ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
1097 Set the video frame size. Default value is @code{vga}.
1100 Use the MIT-SHM extension for shared memory. Default value is @code{1}.
1101 It may be necessary to disable it for remote displays (legacy x11grab
1105 @subsection @var{grab_x} @var{grab_y} AVOption
1109 -grab_x @var{x_offset} -grab_y @var{y_offset}
1112 Set the grabing region coordinates. The are expressed as offset from the top left
1113 corner of the X11 window. The default value is 0.
1117 The decklink input device provides capture capabilities for Blackmagic
1120 To enable this input device, you need the Blackmagic DeckLink SDK and you
1121 need to configure with the appropriate @code{--extra-cflags}
1122 and @code{--extra-ldflags}.
1123 On Windows, you need to run the IDL files through @command{widl}.
1125 DeckLink is very picky about the formats it supports. Pixel format is
1126 uyvy422 or v210, framerate and video size must be determined for your device with
1127 @command{-list_formats 1}. Audio sample rate is always 48 kHz and the number
1128 of channels can be 2, 8 or 16.
1135 If set to @option{true}, print a list of devices and exit.
1136 Defaults to @option{false}.
1139 If set to @option{true}, print a list of supported formats and exit.
1140 Defaults to @option{false}.
1143 If set to @samp{1}, video is captured in 10 bit v210 instead
1144 of uyvy422. Not all Blackmagic devices support this option.
1146 @item bm_channels <CHANNELS>
1147 Number of audio channels, can be 2, 8 or 16
1149 @item bm_audiodepth <BITDEPTH>
1150 Audio bit depth, can be 16 or 32.
1154 @subsection Examples
1161 ffmpeg -f decklink -list_devices 1 -i dummy
1165 List supported formats:
1167 ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
1171 Capture video clip at 1080i50 (format 11):
1173 ffmpeg -f decklink -i 'Intensity Pro@@11' -acodec copy -vcodec copy output.avi
1177 Capture video clip at 1080i50 10 bit:
1179 ffmpeg -bm_v210 1 -f decklink -i 'UltraStudio Mini Recorder@@11' -acodec copy -vcodec copy output.avi
1183 Capture video clip at 720p50 with 32bit audio:
1185 ffmpeg -bm_audiodepth 32 -f decklink -i 'UltraStudio Mini Recorder@@14' -acodec copy -vcodec copy output.avi
1189 Capture video clip at 576i50 with 8 audio channels:
1191 ffmpeg -bm_channels 8 -f decklink -i 'UltraStudio Mini Recorder@@3' -acodec copy -vcodec copy output.avi
1197 @c man end INPUT DEVICES