2 @c man begin INPUT DEVICES
4 Input devices are configured elements in FFmpeg which enable accessing
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 The decklink input device provides capture capabilities for Blackmagic
158 To enable this input device, you need the Blackmagic DeckLink SDK and you
159 need to configure with the appropriate @code{--extra-cflags}
160 and @code{--extra-ldflags}.
161 On Windows, you need to run the IDL files through @command{widl}.
163 DeckLink is very picky about the formats it supports. Pixel format is
164 uyvy422 or v210, framerate and video size must be determined for your device with
165 @command{-list_formats 1}. Audio sample rate is always 48 kHz and the number
166 of channels can be 2, 8 or 16.
173 If set to @option{true}, print a list of devices and exit.
174 Defaults to @option{false}.
177 If set to @option{true}, print a list of supported formats and exit.
178 Defaults to @option{false}.
181 If set to @samp{1}, video is captured in 10 bit v210 instead
182 of uyvy422. Not all Blackmagic devices support this option.
193 ffmpeg -f decklink -list_devices 1 -i dummy
197 List supported formats:
199 ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
203 Capture video clip at 1080i50 (format 11):
205 ffmpeg -f decklink -i 'Intensity Pro@@11' -acodec copy -vcodec copy output.avi
209 Capture video clip at 1080i50 10 bit:
211 ffmpeg -bm_v210 1 -f decklink -i 'UltraStudio Mini Recorder@@11' -acodec copy -vcodec copy output.avi
215 Capture video clip at 720p50 with 32bit audio:
217 ffmpeg -bm_audiodepth 32 -f decklink -i 'UltraStudio Mini Recorder@@14' -acodec copy -vcodec copy output.avi
221 Capture video clip at 576i50 with 8 audio channels:
223 ffmpeg -bm_channels 8 -f decklink -i 'UltraStudio Mini Recorder@@3' -acodec copy -vcodec copy output.avi
230 Windows DirectShow input device.
232 DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
233 Currently only audio and video devices are supported.
235 Multiple devices may be opened as separate inputs, but they may also be
236 opened on the same input, which should improve synchronism between them.
238 The input name should be in the format:
241 @var{TYPE}=@var{NAME}[:@var{TYPE}=@var{NAME}]
244 where @var{TYPE} can be either @var{audio} or @var{video},
245 and @var{NAME} is the device's name or alternative name..
249 If no options are specified, the device's defaults are used.
250 If the device does not support the requested options, it will
256 Set the video size in the captured video.
259 Set the frame rate in the captured video.
262 Set the sample rate (in Hz) of the captured audio.
265 Set the sample size (in bits) of the captured audio.
268 Set the number of channels in the captured audio.
271 If set to @option{true}, print a list of devices and exit.
274 If set to @option{true}, print a list of selected device's options
277 @item video_device_number
278 Set video device number for devices with same name (starts at 0,
281 @item audio_device_number
282 Set audio device number for devices with same name (starts at 0,
286 Select pixel format to be used by DirectShow. This may only be set when
287 the video codec is not set or set to rawvideo.
289 @item audio_buffer_size
290 Set audio device buffer size in milliseconds (which can directly
291 impact latency, depending on the device).
292 Defaults to using the audio device's
293 default buffer size (typically some multiple of 500ms).
294 Setting this value too low can degrade performance.
296 @url{http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx}
299 Select video capture pin to use by name or alternative name.
302 Select audio capture pin to use by name or alternative name.
304 @item crossbar_video_input_pin_number
305 Select video input pin number for crossbar device. This will be
306 routed to the crossbar device's Video Decoder output pin.
307 Note that changing this value can affect future invocations
308 (sets a new default) until system reboot occurs.
310 @item crossbar_audio_input_pin_number
311 Select audio input pin number for crossbar device. This will be
312 routed to the crossbar device's Audio Decoder output pin.
313 Note that changing this value can affect future invocations
314 (sets a new default) until system reboot occurs.
316 @item show_video_device_dialog
317 If set to @option{true}, before capture starts, popup a display dialog
318 to the end user, allowing them to change video filter properties
319 and configurations manually.
320 Note that for crossbar devices, adjusting values in this dialog
321 may be needed at times to toggle between PAL (25 fps) and NTSC (29.97)
322 input frame rates, sizes, interlacing, etc. Changing these values can
323 enable different scan rates/frame rates and avoiding green bars at
324 the bottom, flickering scan lines, etc.
325 Note that with some devices, changing these properties can also affect future
326 invocations (sets new defaults) until system reboot occurs.
328 @item show_audio_device_dialog
329 If set to @option{true}, before capture starts, popup a display dialog
330 to the end user, allowing them to change audio filter properties
331 and configurations manually.
333 @item show_video_crossbar_connection_dialog
334 If set to @option{true}, before capture starts, popup a display
335 dialog to the end user, allowing them to manually
336 modify crossbar pin routings, when it opens a video device.
338 @item show_audio_crossbar_connection_dialog
339 If set to @option{true}, before capture starts, popup a display
340 dialog to the end user, allowing them to manually
341 modify crossbar pin routings, when it opens an audio device.
343 @item show_analog_tv_tuner_dialog
344 If set to @option{true}, before capture starts, popup a display
345 dialog to the end user, allowing them to manually
346 modify TV channels and frequencies.
348 @item show_analog_tv_tuner_audio_dialog
349 If set to @option{true}, before capture starts, popup a display
350 dialog to the end user, allowing them to manually
351 modify TV audio (like mono vs. stereo, Language A,B or C).
353 @item audio_device_load
354 Load an audio capture filter device from file instead of searching
355 it by name. It may load additional parameters too, if the filter
356 supports the serialization of its properties to.
357 To use this an audio capture source has to be specified, but it can
358 be anything even fake one.
360 @item audio_device_save
361 Save the currently used audio capture filter device and its
362 parameters (if the filter supports it) to a file.
363 If a file with the same name exists it will be overwritten.
365 @item video_device_load
366 Load a video capture filter device from file instead of searching
367 it by name. It may load additional parameters too, if the filter
368 supports the serialization of its properties to.
369 To use this a video capture source has to be specified, but it can
370 be anything even fake one.
372 @item video_device_save
373 Save the currently used video capture filter device and its
374 parameters (if the filter supports it) to a file.
375 If a file with the same name exists it will be overwritten.
384 Print the list of DirectShow supported devices and exit:
386 $ ffmpeg -list_devices true -f dshow -i dummy
390 Open video device @var{Camera}:
392 $ ffmpeg -f dshow -i video="Camera"
396 Open second video device with name @var{Camera}:
398 $ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
402 Open video device @var{Camera} and audio device @var{Microphone}:
404 $ ffmpeg -f dshow -i video="Camera":audio="Microphone"
408 Print the list of supported options in selected device and exit:
410 $ ffmpeg -list_options true -f dshow -i video="Camera"
414 Specify pin names to capture by name or alternative name, specify alternative device name:
416 $ 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"
420 Configure a crossbar device, specifying crossbar pins, allow user to adjust video capture properties at startup:
422 $ ffmpeg -f dshow -show_video_device_dialog true -crossbar_video_input_pin_number 0
423 -crossbar_audio_input_pin_number 3 -i video="AVerMedia BDA Analog Capture":audio="AVerMedia BDA Analog Capture"
430 Linux DV 1394 input device.
434 Linux framebuffer input device.
436 The Linux framebuffer is a graphic hardware-independent abstraction
437 layer to show graphics on a computer monitor, typically on the
438 console. It is accessed through a file device node, usually
441 For more detailed information read the file
442 Documentation/fb/framebuffer.txt included in the Linux source tree.
444 To record from the framebuffer device @file{/dev/fb0} with
447 ffmpeg -f fbdev -r 10 -i /dev/fb0 out.avi
450 You can take a single screenshot image with the command:
452 ffmpeg -f fbdev -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg
455 See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1).
459 Win32 GDI-based screen capture device.
461 This device allows you to capture a region of the display on Windows.
463 There are two options for the input filename:
469 title=@var{window_title}
472 The first option will capture the entire desktop, or a fixed region of the
473 desktop. The second option will instead capture the contents of a single
474 window, regardless of its position on the screen.
476 For example, to grab the entire desktop using @command{ffmpeg}:
478 ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
481 Grab a 640x480 region at position @code{10,20}:
483 ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
486 Grab the contents of the window named "Calculator"
488 ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
495 Specify whether to draw the mouse pointer. Use the value @code{0} to
496 not draw the pointer. Default value is @code{1}.
499 Set the grabbing frame rate. Default value is @code{ntsc},
500 corresponding to a frame rate of @code{30000/1001}.
503 Show grabbed region on screen.
505 If @var{show_region} is specified with @code{1}, then the grabbing
506 region will be indicated on screen. With this option, it is easy to
507 know what is being grabbed if only a portion of the screen is grabbed.
509 Note that @var{show_region} is incompatible with grabbing the contents
514 ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
518 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.
521 When capturing a region with @var{video_size}, set the distance from the left edge of the screen or desktop.
523 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.
526 When capturing a region with @var{video_size}, set the distance from the top edge of the screen or desktop.
528 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.
534 FireWire DV/HDV input device using libiec61883.
536 To enable this input device, you need libiec61883, libraw1394 and
537 libavc1394 installed on your system. Use the configure option
538 @code{--enable-libiec61883} to compile with the device enabled.
540 The iec61883 capture device supports capturing from a video device
541 connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
542 FireWire stack (juju). This is the default DV/HDV input method in Linux
543 Kernel 2.6.37 and later, since the old FireWire stack was removed.
545 Specify the FireWire port to be used as input file, or "auto"
546 to choose the first port connected.
553 Override autodetection of DV/HDV. This should only be used if auto
554 detection does not work, or if usage of a different device type
555 should be prohibited. Treating a DV device as HDV (or vice versa) will
556 not work and result in undefined behavior.
557 The values @option{auto}, @option{dv} and @option{hdv} are supported.
560 Set maximum size of buffer for incoming data, in frames. For DV, this
561 is an exact value. For HDV, it is not frame exact, since HDV does
562 not have a fixed frame size.
565 Select the capture device by specifying it's GUID. Capturing will only
566 be performed from the specified device and fails if no device with the
567 given GUID is found. This is useful to select the input if multiple
568 devices are connected at the same time.
569 Look at /sys/bus/firewire/devices to find out the GUIDs.
578 Grab and show the input of a FireWire DV/HDV device.
580 ffplay -f iec61883 -i auto
584 Grab and record the input of a FireWire DV/HDV device,
585 using a packet buffer of 100000 packets if the source is HDV.
587 ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg
596 To enable this input device during configuration you need libjack
597 installed on your system.
599 A JACK input device creates one or more JACK writable clients, one for
600 each audio channel, with name @var{client_name}:input_@var{N}, where
601 @var{client_name} is the name provided by the application, and @var{N}
602 is a number which identifies the channel.
603 Each writable client will send the acquired data to the FFmpeg input
606 Once you have created one or more JACK readable clients, you need to
607 connect them to one or more JACK writable clients.
609 To connect or disconnect JACK clients you can use the @command{jack_connect}
610 and @command{jack_disconnect} programs, or do it through a graphical interface,
611 for example with @command{qjackctl}.
613 To list the JACK clients and their properties you can invoke the command
616 Follows an example which shows how to capture a JACK readable client
617 with @command{ffmpeg}.
619 # Create a JACK writable client with name "ffmpeg".
620 $ ffmpeg -f jack -i ffmpeg -y out.wav
622 # Start the sample jack_metro readable client.
623 $ jack_metro -b 120 -d 0.2 -f 4000
625 # List the current JACK clients.
634 # Connect metro to the ffmpeg writable client.
635 $ jack_connect metro:120_bpm ffmpeg:input_1
638 For more information read:
639 @url{http://jackaudio.org/}
643 Libavfilter input virtual device.
645 This input device reads data from the open output pads of a libavfilter
648 For each filtergraph open output, the input device will create a
649 corresponding stream which is mapped to the generated output. Currently
650 only video data is supported. The filtergraph is specified through the
651 option @option{graph}.
658 Specify the filtergraph to use as input. Each video open output must be
659 labelled by a unique string of the form "out@var{N}", where @var{N} is a
660 number starting from 0 corresponding to the mapped input stream
661 generated by the device.
662 The first unlabelled output is automatically assigned to the "out0"
663 label, but all the others need to be specified explicitly.
665 The suffix "+subcc" can be appended to the output label to create an extra
666 stream with the closed captions packets attached to that output
667 (experimental; only for EIA-608 / CEA-708 for now).
668 The subcc streams are created after all the normal streams, in the order of
669 the corresponding stream.
670 For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
671 stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
673 If not specified defaults to the filename specified for the input
677 Set the filename of the filtergraph to be read and sent to the other
678 filters. Syntax of the filtergraph is the same as the one specified by
679 the option @var{graph}.
687 Create a color video stream and play it back with @command{ffplay}:
689 ffplay -f lavfi -graph "color=c=pink [out0]" dummy
693 As the previous example, but use filename for specifying the graph
694 description, and omit the "out0" label:
696 ffplay -f lavfi color=c=pink
700 Create three different video test filtered sources and play them:
702 ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
706 Read an audio stream from a file using the amovie source and play it
707 back with @command{ffplay}:
709 ffplay -f lavfi "amovie=test.wav"
713 Read an audio stream and a video stream and play it back with
716 ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
720 Dump decoded frames to images and closed captions to a file (experimental):
722 ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
729 Audio-CD input device based on libcdio.
731 To enable this input device during configuration you need libcdio
732 installed on your system. It requires the configure option
733 @code{--enable-libcdio}.
735 This device allows playing and grabbing from an Audio-CD.
737 For example to copy with @command{ffmpeg} the entire Audio-CD in @file{/dev/sr0},
738 you may run the command:
740 ffmpeg -f libcdio -i /dev/sr0 cd.wav
746 Set drive reading speed. Default value is 0.
748 The speed is specified CD-ROM speed units. The speed is set through
749 the libcdio @code{cdio_cddap_speed_set} function. On many CD-ROM
750 drives, specifying a value too large will result in using the fastest
754 Set paranoia recovery mode flags. It accepts one of the following values:
764 Default value is @samp{disable}.
766 For more information about the available recovery modes, consult the
767 paranoia project documentation.
772 IIDC1394 input device, based on libdc1394 and libraw1394.
774 Requires the configure option @code{--enable-libdc1394}.
778 The OpenAL input device provides audio capture on all systems with a
779 working OpenAL 1.1 implementation.
781 To enable this input device during configuration, you need OpenAL
782 headers and libraries installed on your system, and need to configure
783 FFmpeg with @code{--enable-openal}.
785 OpenAL headers and libraries should be provided as part of your OpenAL
786 implementation, or as an additional download (an SDK). Depending on your
787 installation you may need to specify additional flags via the
788 @code{--extra-cflags} and @code{--extra-ldflags} for allowing the build
789 system to locate the OpenAL headers and libraries.
791 An incomplete list of OpenAL implementations follows:
795 The official Windows implementation, providing hardware acceleration
796 with supported devices and software fallback.
797 See @url{http://openal.org/}.
799 Portable, open source (LGPL) software implementation. Includes
800 backends for the most common sound APIs on the Windows, Linux,
801 Solaris, and BSD operating systems.
802 See @url{http://kcat.strangesoft.net/openal.html}.
804 OpenAL is part of Core Audio, the official Mac OS X Audio interface.
805 See @url{http://developer.apple.com/technologies/mac/audio-and-video.html}
808 This device allows one to capture from an audio input device handled
811 You need to specify the name of the device to capture in the provided
812 filename. If the empty string is provided, the device will
813 automatically select the default device. You can get the list of the
814 supported devices by using the option @var{list_devices}.
821 Set the number of channels in the captured audio. Only the values
822 @option{1} (monaural) and @option{2} (stereo) are currently supported.
823 Defaults to @option{2}.
826 Set the sample size (in bits) of the captured audio. Only the values
827 @option{8} and @option{16} are currently supported. Defaults to
831 Set the sample rate (in Hz) of the captured audio.
832 Defaults to @option{44.1k}.
835 If set to @option{true}, print a list of devices and exit.
836 Defaults to @option{false}.
842 Print the list of OpenAL supported devices and exit:
844 $ ffmpeg -list_devices true -f openal -i dummy out.ogg
847 Capture from the OpenAL device @file{DR-BT101 via PulseAudio}:
849 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
852 Capture from the default device (note the empty string '' as filename):
854 $ ffmpeg -f openal -i '' out.ogg
857 Capture from two devices simultaneously, writing to two different files,
858 within the same @command{ffmpeg} command:
860 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
862 Note: not all OpenAL implementations support multiple simultaneous capture -
863 try the latest OpenAL Soft if the above does not work.
867 Open Sound System input device.
869 The filename to provide to the input device is the device node
870 representing the OSS input device, and is usually set to
873 For example to grab from @file{/dev/dsp} using @command{ffmpeg} use the
876 ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
879 For more information about OSS see:
880 @url{http://manuals.opensound.com/usersguide/dsp.html}
884 PulseAudio input device.
886 To enable this output device you need to configure FFmpeg with @code{--enable-libpulse}.
888 The filename to provide to the input device is a source device or the
891 To list the PulseAudio source devices and their properties you can invoke
892 the command @command{pactl list sources}.
894 More information about PulseAudio can be found on @url{http://www.pulseaudio.org}.
899 Connect to a specific PulseAudio server, specified by an IP address.
900 Default server is used when not provided.
903 Specify the application name PulseAudio will use when showing active clients,
904 by default it is the @code{LIBAVFORMAT_IDENT} string.
907 Specify the stream name PulseAudio will use when showing active streams,
908 by default it is "record".
911 Specify the samplerate in Hz, by default 48kHz is used.
914 Specify the channels in use, by default 2 (stereo) is set.
917 Specify the number of bytes per frame, by default it is set to 1024.
920 Specify the minimal buffering fragment in PulseAudio, it will affect the
921 audio latency. By default it is unset.
925 Record a stream from default device:
927 ffmpeg -f pulse -i default /tmp/pulse.wav
934 The filename passed as input is parsed to contain either a device name or index.
935 The device index can also be given by using -video_device_index.
936 A given device index will override any given device name.
937 If the desired device consists of numbers only, use -video_device_index to identify it.
938 The default device will be chosen if an empty string or the device name "default" is given.
939 The available devices can be enumerated by using -list_devices.
942 ffmpeg -f qtkit -i "0" out.mpg
946 ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg
950 ffmpeg -f qtkit -i "default" out.mpg
954 ffmpeg -f qtkit -list_devices true -i ""
961 To enable this input device during configuration you need libsndio
962 installed on your system.
964 The filename to provide to the input device is the device node
965 representing the sndio input device, and is usually set to
968 For example to grab from @file{/dev/audio0} using @command{ffmpeg} use the
971 ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
974 @section video4linux2, v4l2
976 Video4Linux2 input video device.
978 "v4l2" can be used as alias for "video4linux2".
980 If FFmpeg is built with v4l-utils support (by using the
981 @code{--enable-libv4l2} configure option), it is possible to use it with the
982 @code{-use_libv4l2} input device option.
984 The name of the device to grab is a file device node, usually Linux
985 systems tend to automatically create such nodes when the device
986 (e.g. an USB webcam) is plugged into the system, and has a name of the
987 kind @file{/dev/video@var{N}}, where @var{N} is a number associated to
990 Video4Linux2 devices usually support a limited set of
991 @var{width}x@var{height} sizes and frame rates. You can check which are
992 supported using @command{-list_formats all} for Video4Linux2 devices.
993 Some devices, like TV cards, support one or more standards. It is possible
994 to list all the supported standards using @command{-list_standards all}.
996 The time base for the timestamps is 1 microsecond. Depending on the kernel
997 version and configuration, the timestamps may be derived from the real time
998 clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
999 boot time, unaffected by NTP or manual changes to the clock). The
1000 @option{-timestamps abs} or @option{-ts abs} option can be used to force
1001 conversion into the real time clock.
1003 Some usage examples of the video4linux2 device with @command{ffmpeg}
1004 and @command{ffplay}:
1007 List supported formats for a video4linux2 device:
1009 ffplay -f video4linux2 -list_formats all /dev/video0
1013 Grab and show the input of a video4linux2 device:
1015 ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
1019 Grab and record the input of a video4linux2 device, leave the
1020 frame rate and size as previously set:
1022 ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
1026 For more information about Video4Linux, check @url{http://linuxtv.org/}.
1032 Set the standard. Must be the name of a supported standard. To get a
1033 list of the supported standards, use the @option{list_standards}
1037 Set the input channel number. Default to -1, which means using the
1038 previously selected channel.
1041 Set the video frame size. The argument must be a string in the form
1042 @var{WIDTH}x@var{HEIGHT} or a valid size abbreviation.
1045 Select the pixel format (only valid for raw video input).
1048 Set the preferred pixel format (for raw video) or a codec name.
1049 This option allows one to select the input format, when several are
1053 Set the preferred video frame rate.
1056 List available formats (supported pixel formats, codecs, and frame
1059 Available values are:
1062 Show all available (compressed and non-compressed) formats.
1065 Show only raw video (non-compressed) formats.
1068 Show only compressed formats.
1071 @item list_standards
1072 List supported standards and exit.
1074 Available values are:
1077 Show all supported standards.
1080 @item timestamps, ts
1081 Set type of timestamps for grabbed frames.
1083 Available values are:
1086 Use timestamps from the kernel.
1089 Use absolute timestamps (wall clock).
1092 Force conversion from monotonic to absolute timestamps.
1095 Default value is @code{default}.
1100 VfW (Video for Windows) capture input device.
1102 The filename passed as input is the capture driver number, ranging from
1103 0 to 9. You may use "list" as filename to print a list of drivers. Any
1104 other filename will be interpreted as device number 0.
1108 X11 video input device.
1110 To enable this input device during configuration you need libxcb
1111 installed on your system. It will be automatically detected during
1114 Alternatively, the configure option @option{--enable-x11grab} exists
1115 for legacy Xlib users.
1117 This device allows one to capture a region of an X11 display.
1119 The filename passed as input has the syntax:
1121 [@var{hostname}]:@var{display_number}.@var{screen_number}[+@var{x_offset},@var{y_offset}]
1124 @var{hostname}:@var{display_number}.@var{screen_number} specifies the
1125 X11 display name of the screen to grab from. @var{hostname} can be
1126 omitted, and defaults to "localhost". The environment variable
1127 @env{DISPLAY} contains the default display name.
1129 @var{x_offset} and @var{y_offset} specify the offsets of the grabbed
1130 area with respect to the top-left border of the X11 screen. They
1133 Check the X11 documentation (e.g. @command{man X}) for more detailed
1136 Use the @command{xdpyinfo} program for getting basic information about
1137 the properties of your X11 display (e.g. grep for "name" or
1140 For example to grab from @file{:0.0} using @command{ffmpeg}:
1142 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
1145 Grab at position @code{10,20}:
1147 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
1154 Specify whether to draw the mouse pointer. A value of @code{0} specify
1155 not to draw the pointer. Default value is @code{1}.
1158 Make the grabbed area follow the mouse. The argument can be
1159 @code{centered} or a number of pixels @var{PIXELS}.
1161 When it is specified with "centered", the grabbing region follows the mouse
1162 pointer and keeps the pointer at the center of region; otherwise, the region
1163 follows only when the mouse pointer reaches within @var{PIXELS} (greater than
1164 zero) to the edge of region.
1168 ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
1171 To follow only when the mouse pointer reaches within 100 pixels to edge:
1173 ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
1177 Set the grabbing frame rate. Default value is @code{ntsc},
1178 corresponding to a frame rate of @code{30000/1001}.
1181 Show grabbed region on screen.
1183 If @var{show_region} is specified with @code{1}, then the grabbing
1184 region will be indicated on screen. With this option, it is easy to
1185 know what is being grabbed if only a portion of the screen is grabbed.
1188 Set the region border thickness if @option{-show_region 1} is used.
1189 Range is 1 to 128 and default is 3 (XCB-based x11grab only).
1193 ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
1196 With @var{follow_mouse}:
1198 ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
1202 Set the video frame size. Default value is @code{vga}.
1205 Use the MIT-SHM extension for shared memory. Default value is @code{1}.
1206 It may be necessary to disable it for remote displays (legacy x11grab
1210 @subsection @var{grab_x} @var{grab_y} AVOption
1214 -grab_x @var{x_offset} -grab_y @var{y_offset}
1217 Set the grabbing region coordinates. They are expressed as offset from the top left
1218 corner of the X11 window. The default value is 0.
1221 @c man end INPUT DEVICES