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}
59 Set the sample rate in Hz. Default is 48000.
62 Set the number of channels. Default is 2.
68 AVFoundation input device.
70 AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX >= 10.7 as well as on iOS.
71 The older QTKit framework has been marked deprecated since OSX version 10.7.
73 The input filename has to be given in the following syntax:
75 -i "[[VIDEO]:[AUDIO]]"
77 The first entry selects the video input while the latter selects the audio input.
78 The stream has to be specified by the device name or the device index as shown by the device list.
79 Alternatively, the video and/or audio input device can be chosen by index using the
81 -video_device_index <INDEX>
85 -audio_device_index <INDEX>
88 device name or index given in the input filename.
90 All available devices can be enumerated by using @option{-list_devices true}, listing
91 all device names and corresponding indices.
93 There are two device name aliases:
97 Select the AVFoundation default device of the corresponding type.
100 Do not record the corresponding media type.
101 This is equivalent to specifying an empty device name or index.
107 AVFoundation supports the following options:
111 @item -list_devices <TRUE|FALSE>
112 If set to true, a list of all available input devices is given showing all
113 device names and indices.
115 @item -video_device_index <INDEX>
116 Specify the video device by its index. Overrides anything given in the input filename.
118 @item -audio_device_index <INDEX>
119 Specify the audio device by its index. Overrides anything given in the input filename.
121 @item -pixel_format <FORMAT>
122 Request the video device to use a specific pixel format.
123 If the specified format is not supported, a list of available formats is given
124 and the first one in this list is used instead. Available pixel formats are:
125 @code{monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,
126 bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10,
127 yuv420p, nv12, yuyv422, gray}
130 Set the grabbing frame rate. Default is @code{ntsc}, corresponding to a
131 frame rate of @code{30000/1001}.
134 Set the video frame size.
136 @item -capture_cursor
137 Capture the mouse pointer. Default is 0.
139 @item -capture_mouse_clicks
140 Capture the screen mouse clicks. Default is 0.
149 Print the list of AVFoundation supported devices and exit:
151 $ ffmpeg -f avfoundation -list_devices true -i ""
155 Record video from video device 0 and audio from audio device 0 into out.avi:
157 $ ffmpeg -f avfoundation -i "0:0" out.avi
161 Record video from video device 2 and audio from audio device 1 into out.avi:
163 $ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi
167 Record video from the system default video device using the pixel format bgr0 and do not record any audio into out.avi:
169 $ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi
176 BSD video input device.
186 Set the video frame size. Default is @code{vga}.
190 Available values are:
210 The decklink input device provides capture capabilities for Blackmagic
213 To enable this input device, you need the Blackmagic DeckLink SDK and you
214 need to configure with the appropriate @code{--extra-cflags}
215 and @code{--extra-ldflags}.
216 On Windows, you need to run the IDL files through @command{widl}.
218 DeckLink is very picky about the formats it supports. Pixel format is
219 uyvy422 or v210, framerate and video size must be determined for your device with
220 @command{-list_formats 1}. Audio sample rate is always 48 kHz and the number
221 of channels can be 2, 8 or 16. Note that all audio channels are bundled in one single
229 If set to @option{true}, print a list of devices and exit.
230 Defaults to @option{false}.
233 If set to @option{true}, print a list of supported formats and exit.
234 Defaults to @option{false}.
237 If set to @samp{1}, video is captured in 10 bit v210 instead
238 of uyvy422. Not all Blackmagic devices support this option.
241 If set to nonzero, an additional teletext stream will be captured from the
242 vertical ancillary data. This option is a bitmask of the VBI lines checked,
243 specifically lines 6 to 22, and lines 318 to 335. Line 6 is the LSB in the mask.
244 Selected lines which do not contain teletext information will be ignored. You
245 can use the special @option{all} constant to select all possible lines, or
246 @option{standard} to skip lines 6, 318 and 319, which are not compatible with all
247 receivers. Capturing teletext only works for SD PAL sources in 8 bit mode.
248 To use this option, ffmpeg needs to be compiled with @code{--enable-libzvbi}.
251 Defines number of audio channels to capture. Must be @samp{2}, @samp{8} or @samp{16}.
252 Defaults to @samp{2}.
263 ffmpeg -f decklink -list_devices 1 -i dummy
267 List supported formats:
269 ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
273 Capture video clip at 1080i50 (format 11):
275 ffmpeg -f decklink -i 'Intensity Pro@@11' -acodec copy -vcodec copy output.avi
279 Capture video clip at 1080i50 10 bit:
281 ffmpeg -bm_v210 1 -f decklink -i 'UltraStudio Mini Recorder@@11' -acodec copy -vcodec copy output.avi
285 Capture video clip at 1080i50 with 16 audio channels:
287 ffmpeg -channels 16 -f decklink -i 'UltraStudio Mini Recorder@@11' -acodec copy -vcodec copy output.avi
294 Windows DirectShow input device.
296 DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
297 Currently only audio and video devices are supported.
299 Multiple devices may be opened as separate inputs, but they may also be
300 opened on the same input, which should improve synchronism between them.
302 The input name should be in the format:
305 @var{TYPE}=@var{NAME}[:@var{TYPE}=@var{NAME}]
308 where @var{TYPE} can be either @var{audio} or @var{video},
309 and @var{NAME} is the device's name or alternative name..
313 If no options are specified, the device's defaults are used.
314 If the device does not support the requested options, it will
320 Set the video size in the captured video.
323 Set the frame rate in the captured video.
326 Set the sample rate (in Hz) of the captured audio.
329 Set the sample size (in bits) of the captured audio.
332 Set the number of channels in the captured audio.
335 If set to @option{true}, print a list of devices and exit.
338 If set to @option{true}, print a list of selected device's options
341 @item video_device_number
342 Set video device number for devices with the same name (starts at 0,
345 @item audio_device_number
346 Set audio device number for devices with the same name (starts at 0,
350 Select pixel format to be used by DirectShow. This may only be set when
351 the video codec is not set or set to rawvideo.
353 @item audio_buffer_size
354 Set audio device buffer size in milliseconds (which can directly
355 impact latency, depending on the device).
356 Defaults to using the audio device's
357 default buffer size (typically some multiple of 500ms).
358 Setting this value too low can degrade performance.
360 @url{http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx}
363 Select video capture pin to use by name or alternative name.
366 Select audio capture pin to use by name or alternative name.
368 @item crossbar_video_input_pin_number
369 Select video input pin number for crossbar device. This will be
370 routed to the crossbar device's Video Decoder output pin.
371 Note that changing this value can affect future invocations
372 (sets a new default) until system reboot occurs.
374 @item crossbar_audio_input_pin_number
375 Select audio input pin number for crossbar device. This will be
376 routed to the crossbar device's Audio Decoder output pin.
377 Note that changing this value can affect future invocations
378 (sets a new default) until system reboot occurs.
380 @item show_video_device_dialog
381 If set to @option{true}, before capture starts, popup a display dialog
382 to the end user, allowing them to change video filter properties
383 and configurations manually.
384 Note that for crossbar devices, adjusting values in this dialog
385 may be needed at times to toggle between PAL (25 fps) and NTSC (29.97)
386 input frame rates, sizes, interlacing, etc. Changing these values can
387 enable different scan rates/frame rates and avoiding green bars at
388 the bottom, flickering scan lines, etc.
389 Note that with some devices, changing these properties can also affect future
390 invocations (sets new defaults) until system reboot occurs.
392 @item show_audio_device_dialog
393 If set to @option{true}, before capture starts, popup a display dialog
394 to the end user, allowing them to change audio filter properties
395 and configurations manually.
397 @item show_video_crossbar_connection_dialog
398 If set to @option{true}, before capture starts, popup a display
399 dialog to the end user, allowing them to manually
400 modify crossbar pin routings, when it opens a video device.
402 @item show_audio_crossbar_connection_dialog
403 If set to @option{true}, before capture starts, popup a display
404 dialog to the end user, allowing them to manually
405 modify crossbar pin routings, when it opens an audio device.
407 @item show_analog_tv_tuner_dialog
408 If set to @option{true}, before capture starts, popup a display
409 dialog to the end user, allowing them to manually
410 modify TV channels and frequencies.
412 @item show_analog_tv_tuner_audio_dialog
413 If set to @option{true}, before capture starts, popup a display
414 dialog to the end user, allowing them to manually
415 modify TV audio (like mono vs. stereo, Language A,B or C).
417 @item audio_device_load
418 Load an audio capture filter device from file instead of searching
419 it by name. It may load additional parameters too, if the filter
420 supports the serialization of its properties to.
421 To use this an audio capture source has to be specified, but it can
422 be anything even fake one.
424 @item audio_device_save
425 Save the currently used audio capture filter device and its
426 parameters (if the filter supports it) to a file.
427 If a file with the same name exists it will be overwritten.
429 @item video_device_load
430 Load a video capture filter device from file instead of searching
431 it by name. It may load additional parameters too, if the filter
432 supports the serialization of its properties to.
433 To use this a video capture source has to be specified, but it can
434 be anything even fake one.
436 @item video_device_save
437 Save the currently used video capture filter device and its
438 parameters (if the filter supports it) to a file.
439 If a file with the same name exists it will be overwritten.
448 Print the list of DirectShow supported devices and exit:
450 $ ffmpeg -list_devices true -f dshow -i dummy
454 Open video device @var{Camera}:
456 $ ffmpeg -f dshow -i video="Camera"
460 Open second video device with name @var{Camera}:
462 $ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
466 Open video device @var{Camera} and audio device @var{Microphone}:
468 $ ffmpeg -f dshow -i video="Camera":audio="Microphone"
472 Print the list of supported options in selected device and exit:
474 $ ffmpeg -list_options true -f dshow -i video="Camera"
478 Specify pin names to capture by name or alternative name, specify alternative device name:
480 $ 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"
484 Configure a crossbar device, specifying crossbar pins, allow user to adjust video capture properties at startup:
486 $ ffmpeg -f dshow -show_video_device_dialog true -crossbar_video_input_pin_number 0
487 -crossbar_audio_input_pin_number 3 -i video="AVerMedia BDA Analog Capture":audio="AVerMedia BDA Analog Capture"
494 Linux DV 1394 input device.
501 Set the frame rate. Default is 25.
505 Available values are:
513 Default value is @code{ntsc}.
519 Linux framebuffer input device.
521 The Linux framebuffer is a graphic hardware-independent abstraction
522 layer to show graphics on a computer monitor, typically on the
523 console. It is accessed through a file device node, usually
526 For more detailed information read the file
527 Documentation/fb/framebuffer.txt included in the Linux source tree.
529 See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1).
531 To record from the framebuffer device @file{/dev/fb0} with
534 ffmpeg -f fbdev -framerate 10 -i /dev/fb0 out.avi
537 You can take a single screenshot image with the command:
539 ffmpeg -f fbdev -framerate 1 -i /dev/fb0 -frames:v 1 screenshot.jpeg
547 Set the frame rate. Default is 25.
553 Win32 GDI-based screen capture device.
555 This device allows you to capture a region of the display on Windows.
557 There are two options for the input filename:
563 title=@var{window_title}
566 The first option will capture the entire desktop, or a fixed region of the
567 desktop. The second option will instead capture the contents of a single
568 window, regardless of its position on the screen.
570 For example, to grab the entire desktop using @command{ffmpeg}:
572 ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
575 Grab a 640x480 region at position @code{10,20}:
577 ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
580 Grab the contents of the window named "Calculator"
582 ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
589 Specify whether to draw the mouse pointer. Use the value @code{0} to
590 not draw the pointer. Default value is @code{1}.
593 Set the grabbing frame rate. Default value is @code{ntsc},
594 corresponding to a frame rate of @code{30000/1001}.
597 Show grabbed region on screen.
599 If @var{show_region} is specified with @code{1}, then the grabbing
600 region will be indicated on screen. With this option, it is easy to
601 know what is being grabbed if only a portion of the screen is grabbed.
603 Note that @var{show_region} is incompatible with grabbing the contents
608 ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
612 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.
615 When capturing a region with @var{video_size}, set the distance from the left edge of the screen or desktop.
617 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.
620 When capturing a region with @var{video_size}, set the distance from the top edge of the screen or desktop.
622 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.
628 FireWire DV/HDV input device using libiec61883.
630 To enable this input device, you need libiec61883, libraw1394 and
631 libavc1394 installed on your system. Use the configure option
632 @code{--enable-libiec61883} to compile with the device enabled.
634 The iec61883 capture device supports capturing from a video device
635 connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
636 FireWire stack (juju). This is the default DV/HDV input method in Linux
637 Kernel 2.6.37 and later, since the old FireWire stack was removed.
639 Specify the FireWire port to be used as input file, or "auto"
640 to choose the first port connected.
647 Override autodetection of DV/HDV. This should only be used if auto
648 detection does not work, or if usage of a different device type
649 should be prohibited. Treating a DV device as HDV (or vice versa) will
650 not work and result in undefined behavior.
651 The values @option{auto}, @option{dv} and @option{hdv} are supported.
654 Set maximum size of buffer for incoming data, in frames. For DV, this
655 is an exact value. For HDV, it is not frame exact, since HDV does
656 not have a fixed frame size.
659 Select the capture device by specifying it's GUID. Capturing will only
660 be performed from the specified device and fails if no device with the
661 given GUID is found. This is useful to select the input if multiple
662 devices are connected at the same time.
663 Look at /sys/bus/firewire/devices to find out the GUIDs.
672 Grab and show the input of a FireWire DV/HDV device.
674 ffplay -f iec61883 -i auto
678 Grab and record the input of a FireWire DV/HDV device,
679 using a packet buffer of 100000 packets if the source is HDV.
681 ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg
690 To enable this input device during configuration you need libjack
691 installed on your system.
693 A JACK input device creates one or more JACK writable clients, one for
694 each audio channel, with name @var{client_name}:input_@var{N}, where
695 @var{client_name} is the name provided by the application, and @var{N}
696 is a number which identifies the channel.
697 Each writable client will send the acquired data to the FFmpeg input
700 Once you have created one or more JACK readable clients, you need to
701 connect them to one or more JACK writable clients.
703 To connect or disconnect JACK clients you can use the @command{jack_connect}
704 and @command{jack_disconnect} programs, or do it through a graphical interface,
705 for example with @command{qjackctl}.
707 To list the JACK clients and their properties you can invoke the command
710 Follows an example which shows how to capture a JACK readable client
711 with @command{ffmpeg}.
713 # Create a JACK writable client with name "ffmpeg".
714 $ ffmpeg -f jack -i ffmpeg -y out.wav
716 # Start the sample jack_metro readable client.
717 $ jack_metro -b 120 -d 0.2 -f 4000
719 # List the current JACK clients.
728 # Connect metro to the ffmpeg writable client.
729 $ jack_connect metro:120_bpm ffmpeg:input_1
732 For more information read:
733 @url{http://jackaudio.org/}
740 Set the number of channels. Default is 2.
746 Libavfilter input virtual device.
748 This input device reads data from the open output pads of a libavfilter
751 For each filtergraph open output, the input device will create a
752 corresponding stream which is mapped to the generated output. Currently
753 only video data is supported. The filtergraph is specified through the
754 option @option{graph}.
761 Specify the filtergraph to use as input. Each video open output must be
762 labelled by a unique string of the form "out@var{N}", where @var{N} is a
763 number starting from 0 corresponding to the mapped input stream
764 generated by the device.
765 The first unlabelled output is automatically assigned to the "out0"
766 label, but all the others need to be specified explicitly.
768 The suffix "+subcc" can be appended to the output label to create an extra
769 stream with the closed captions packets attached to that output
770 (experimental; only for EIA-608 / CEA-708 for now).
771 The subcc streams are created after all the normal streams, in the order of
772 the corresponding stream.
773 For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
774 stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
776 If not specified defaults to the filename specified for the input
780 Set the filename of the filtergraph to be read and sent to the other
781 filters. Syntax of the filtergraph is the same as the one specified by
782 the option @var{graph}.
785 Dump graph to stderr.
793 Create a color video stream and play it back with @command{ffplay}:
795 ffplay -f lavfi -graph "color=c=pink [out0]" dummy
799 As the previous example, but use filename for specifying the graph
800 description, and omit the "out0" label:
802 ffplay -f lavfi color=c=pink
806 Create three different video test filtered sources and play them:
808 ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
812 Read an audio stream from a file using the amovie source and play it
813 back with @command{ffplay}:
815 ffplay -f lavfi "amovie=test.wav"
819 Read an audio stream and a video stream and play it back with
822 ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
826 Dump decoded frames to images and closed captions to a file (experimental):
828 ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
835 Audio-CD input device based on libcdio.
837 To enable this input device during configuration you need libcdio
838 installed on your system. It requires the configure option
839 @code{--enable-libcdio}.
841 This device allows playing and grabbing from an Audio-CD.
843 For example to copy with @command{ffmpeg} the entire Audio-CD in @file{/dev/sr0},
844 you may run the command:
846 ffmpeg -f libcdio -i /dev/sr0 cd.wav
852 Set drive reading speed. Default value is 0.
854 The speed is specified CD-ROM speed units. The speed is set through
855 the libcdio @code{cdio_cddap_speed_set} function. On many CD-ROM
856 drives, specifying a value too large will result in using the fastest
860 Set paranoia recovery mode flags. It accepts one of the following values:
870 Default value is @samp{disable}.
872 For more information about the available recovery modes, consult the
873 paranoia project documentation.
878 IIDC1394 input device, based on libdc1394 and libraw1394.
880 Requires the configure option @code{--enable-libdc1394}.
884 The OpenAL input device provides audio capture on all systems with a
885 working OpenAL 1.1 implementation.
887 To enable this input device during configuration, you need OpenAL
888 headers and libraries installed on your system, and need to configure
889 FFmpeg with @code{--enable-openal}.
891 OpenAL headers and libraries should be provided as part of your OpenAL
892 implementation, or as an additional download (an SDK). Depending on your
893 installation you may need to specify additional flags via the
894 @code{--extra-cflags} and @code{--extra-ldflags} for allowing the build
895 system to locate the OpenAL headers and libraries.
897 An incomplete list of OpenAL implementations follows:
901 The official Windows implementation, providing hardware acceleration
902 with supported devices and software fallback.
903 See @url{http://openal.org/}.
905 Portable, open source (LGPL) software implementation. Includes
906 backends for the most common sound APIs on the Windows, Linux,
907 Solaris, and BSD operating systems.
908 See @url{http://kcat.strangesoft.net/openal.html}.
910 OpenAL is part of Core Audio, the official Mac OS X Audio interface.
911 See @url{http://developer.apple.com/technologies/mac/audio-and-video.html}
914 This device allows one to capture from an audio input device handled
917 You need to specify the name of the device to capture in the provided
918 filename. If the empty string is provided, the device will
919 automatically select the default device. You can get the list of the
920 supported devices by using the option @var{list_devices}.
927 Set the number of channels in the captured audio. Only the values
928 @option{1} (monaural) and @option{2} (stereo) are currently supported.
929 Defaults to @option{2}.
932 Set the sample size (in bits) of the captured audio. Only the values
933 @option{8} and @option{16} are currently supported. Defaults to
937 Set the sample rate (in Hz) of the captured audio.
938 Defaults to @option{44.1k}.
941 If set to @option{true}, print a list of devices and exit.
942 Defaults to @option{false}.
948 Print the list of OpenAL supported devices and exit:
950 $ ffmpeg -list_devices true -f openal -i dummy out.ogg
953 Capture from the OpenAL device @file{DR-BT101 via PulseAudio}:
955 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
958 Capture from the default device (note the empty string '' as filename):
960 $ ffmpeg -f openal -i '' out.ogg
963 Capture from two devices simultaneously, writing to two different files,
964 within the same @command{ffmpeg} command:
966 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
968 Note: not all OpenAL implementations support multiple simultaneous capture -
969 try the latest OpenAL Soft if the above does not work.
973 Open Sound System input device.
975 The filename to provide to the input device is the device node
976 representing the OSS input device, and is usually set to
979 For example to grab from @file{/dev/dsp} using @command{ffmpeg} use the
982 ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
985 For more information about OSS see:
986 @url{http://manuals.opensound.com/usersguide/dsp.html}
993 Set the sample rate in Hz. Default is 48000.
996 Set the number of channels. Default is 2.
1003 PulseAudio input device.
1005 To enable this output device you need to configure FFmpeg with @code{--enable-libpulse}.
1007 The filename to provide to the input device is a source device or the
1010 To list the PulseAudio source devices and their properties you can invoke
1011 the command @command{pactl list sources}.
1013 More information about PulseAudio can be found on @url{http://www.pulseaudio.org}.
1018 Connect to a specific PulseAudio server, specified by an IP address.
1019 Default server is used when not provided.
1022 Specify the application name PulseAudio will use when showing active clients,
1023 by default it is the @code{LIBAVFORMAT_IDENT} string.
1026 Specify the stream name PulseAudio will use when showing active streams,
1027 by default it is "record".
1030 Specify the samplerate in Hz, by default 48kHz is used.
1033 Specify the channels in use, by default 2 (stereo) is set.
1036 Specify the number of bytes per frame, by default it is set to 1024.
1039 Specify the minimal buffering fragment in PulseAudio, it will affect the
1040 audio latency. By default it is unset.
1043 Set the initial PTS using the current time. Default is 1.
1047 @subsection Examples
1048 Record a stream from default device:
1050 ffmpeg -f pulse -i default /tmp/pulse.wav
1057 The filename passed as input is parsed to contain either a device name or index.
1058 The device index can also be given by using -video_device_index.
1059 A given device index will override any given device name.
1060 If the desired device consists of numbers only, use -video_device_index to identify it.
1061 The default device will be chosen if an empty string or the device name "default" is given.
1062 The available devices can be enumerated by using -list_devices.
1065 ffmpeg -f qtkit -i "0" out.mpg
1069 ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg
1073 ffmpeg -f qtkit -i "default" out.mpg
1077 ffmpeg -f qtkit -list_devices true -i ""
1085 Set frame rate. Default is 30.
1088 If set to @code{true}, print a list of devices and exit. Default is
1091 @item video_device_index
1092 Select the video device by index for devices with the same name (starts at 0).
1100 To enable this input device during configuration you need libsndio
1101 installed on your system.
1103 The filename to provide to the input device is the device node
1104 representing the sndio input device, and is usually set to
1107 For example to grab from @file{/dev/audio0} using @command{ffmpeg} use the
1110 ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
1118 Set the sample rate in Hz. Default is 48000.
1121 Set the number of channels. Default is 2.
1125 @section video4linux2, v4l2
1127 Video4Linux2 input video device.
1129 "v4l2" can be used as alias for "video4linux2".
1131 If FFmpeg is built with v4l-utils support (by using the
1132 @code{--enable-libv4l2} configure option), it is possible to use it with the
1133 @code{-use_libv4l2} input device option.
1135 The name of the device to grab is a file device node, usually Linux
1136 systems tend to automatically create such nodes when the device
1137 (e.g. an USB webcam) is plugged into the system, and has a name of the
1138 kind @file{/dev/video@var{N}}, where @var{N} is a number associated to
1141 Video4Linux2 devices usually support a limited set of
1142 @var{width}x@var{height} sizes and frame rates. You can check which are
1143 supported using @command{-list_formats all} for Video4Linux2 devices.
1144 Some devices, like TV cards, support one or more standards. It is possible
1145 to list all the supported standards using @command{-list_standards all}.
1147 The time base for the timestamps is 1 microsecond. Depending on the kernel
1148 version and configuration, the timestamps may be derived from the real time
1149 clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
1150 boot time, unaffected by NTP or manual changes to the clock). The
1151 @option{-timestamps abs} or @option{-ts abs} option can be used to force
1152 conversion into the real time clock.
1154 Some usage examples of the video4linux2 device with @command{ffmpeg}
1155 and @command{ffplay}:
1158 List supported formats for a video4linux2 device:
1160 ffplay -f video4linux2 -list_formats all /dev/video0
1164 Grab and show the input of a video4linux2 device:
1166 ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
1170 Grab and record the input of a video4linux2 device, leave the
1171 frame rate and size as previously set:
1173 ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
1177 For more information about Video4Linux, check @url{http://linuxtv.org/}.
1183 Set the standard. Must be the name of a supported standard. To get a
1184 list of the supported standards, use the @option{list_standards}
1188 Set the input channel number. Default to -1, which means using the
1189 previously selected channel.
1192 Set the video frame size. The argument must be a string in the form
1193 @var{WIDTH}x@var{HEIGHT} or a valid size abbreviation.
1196 Select the pixel format (only valid for raw video input).
1199 Set the preferred pixel format (for raw video) or a codec name.
1200 This option allows one to select the input format, when several are
1204 Set the preferred video frame rate.
1207 List available formats (supported pixel formats, codecs, and frame
1210 Available values are:
1213 Show all available (compressed and non-compressed) formats.
1216 Show only raw video (non-compressed) formats.
1219 Show only compressed formats.
1222 @item list_standards
1223 List supported standards and exit.
1225 Available values are:
1228 Show all supported standards.
1231 @item timestamps, ts
1232 Set type of timestamps for grabbed frames.
1234 Available values are:
1237 Use timestamps from the kernel.
1240 Use absolute timestamps (wall clock).
1243 Force conversion from monotonic to absolute timestamps.
1246 Default value is @code{default}.
1249 Use libv4l2 (v4l-utils) conversion functions. Default is 0.
1255 VfW (Video for Windows) capture input device.
1257 The filename passed as input is the capture driver number, ranging from
1258 0 to 9. You may use "list" as filename to print a list of drivers. Any
1259 other filename will be interpreted as device number 0.
1266 Set the video frame size.
1269 Set the grabbing frame rate. Default value is @code{ntsc},
1270 corresponding to a frame rate of @code{30000/1001}.
1276 X11 video input device.
1278 To enable this input device during configuration you need libxcb
1279 installed on your system. It will be automatically detected during
1282 Alternatively, the configure option @option{--enable-x11grab} exists
1283 for legacy Xlib users.
1285 This device allows one to capture a region of an X11 display.
1287 The filename passed as input has the syntax:
1289 [@var{hostname}]:@var{display_number}.@var{screen_number}[+@var{x_offset},@var{y_offset}]
1292 @var{hostname}:@var{display_number}.@var{screen_number} specifies the
1293 X11 display name of the screen to grab from. @var{hostname} can be
1294 omitted, and defaults to "localhost". The environment variable
1295 @env{DISPLAY} contains the default display name.
1297 @var{x_offset} and @var{y_offset} specify the offsets of the grabbed
1298 area with respect to the top-left border of the X11 screen. They
1301 Check the X11 documentation (e.g. @command{man X}) for more detailed
1304 Use the @command{xdpyinfo} program for getting basic information about
1305 the properties of your X11 display (e.g. grep for "name" or
1308 For example to grab from @file{:0.0} using @command{ffmpeg}:
1310 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
1313 Grab at position @code{10,20}:
1315 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
1322 Specify whether to draw the mouse pointer. A value of @code{0} specify
1323 not to draw the pointer. Default value is @code{1}.
1326 Make the grabbed area follow the mouse. The argument can be
1327 @code{centered} or a number of pixels @var{PIXELS}.
1329 When it is specified with "centered", the grabbing region follows the mouse
1330 pointer and keeps the pointer at the center of region; otherwise, the region
1331 follows only when the mouse pointer reaches within @var{PIXELS} (greater than
1332 zero) to the edge of region.
1336 ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
1339 To follow only when the mouse pointer reaches within 100 pixels to edge:
1341 ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
1345 Set the grabbing frame rate. Default value is @code{ntsc},
1346 corresponding to a frame rate of @code{30000/1001}.
1349 Show grabbed region on screen.
1351 If @var{show_region} is specified with @code{1}, then the grabbing
1352 region will be indicated on screen. With this option, it is easy to
1353 know what is being grabbed if only a portion of the screen is grabbed.
1356 Set the region border thickness if @option{-show_region 1} is used.
1357 Range is 1 to 128 and default is 3 (XCB-based x11grab only).
1361 ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
1364 With @var{follow_mouse}:
1366 ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
1370 Set the video frame size. Default value is @code{vga}.
1373 Use the MIT-SHM extension for shared memory. Default value is @code{1}.
1374 It may be necessary to disable it for remote displays (legacy x11grab
1379 Set the grabbing region coordinates. They are expressed as offset from
1380 the top left corner of the X11 window and correspond to the
1381 @var{x_offset} and @var{y_offset} parameters in the device name. The
1382 default value for both options is 0.
1385 @c man end INPUT DEVICES