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 filename passed as input is parsed to contain either a device name or index.
62 The device index can also be given by using -video_device_index.
63 A given device index will override any given device name.
64 If the desired device consists of numbers only, use -video_device_index to identify it.
65 The default device will be chosen if an empty string or the device name "default" is given.
66 The available devices can be enumerated by using -list_devices.
67 The pixel format can be set using -pixel_format.
69 monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,
70 bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10,
71 yuv420p, nv12, yuyv422, gray
74 ffmpeg -f avfoundation -i "0" out.mpg
78 ffmpeg -f avfoundation -video_device_index 0 -i "" out.mpg
82 ffmpeg -f avfoundation -pixel_format bgr0 -i "default" out.mpg
86 ffmpeg -f avfoundation -list_devices true -i ""
91 BSD video input device.
95 Windows DirectShow input device.
97 DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
98 Currently only audio and video devices are supported.
100 Multiple devices may be opened as separate inputs, but they may also be
101 opened on the same input, which should improve synchronism between them.
103 The input name should be in the format:
106 @var{TYPE}=@var{NAME}[:@var{TYPE}=@var{NAME}]
109 where @var{TYPE} can be either @var{audio} or @var{video},
110 and @var{NAME} is the device's name.
114 If no options are specified, the device's defaults are used.
115 If the device does not support the requested options, it will
121 Set the video size in the captured video.
124 Set the frame rate in the captured video.
127 Set the sample rate (in Hz) of the captured audio.
130 Set the sample size (in bits) of the captured audio.
133 Set the number of channels in the captured audio.
136 If set to @option{true}, print a list of devices and exit.
139 If set to @option{true}, print a list of selected device's options
142 @item video_device_number
143 Set video device number for devices with same name (starts at 0,
146 @item audio_device_number
147 Set audio device number for devices with same name (starts at 0,
151 Select pixel format to be used by DirectShow. This may only be set when
152 the video codec is not set or set to rawvideo.
154 @item audio_buffer_size
155 Set audio device buffer size in milliseconds (which can directly
156 impact latency, depending on the device).
157 Defaults to using the audio device's
158 default buffer size (typically some multiple of 500ms).
159 Setting this value too low can degrade performance.
161 @url{http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx}
170 Print the list of DirectShow supported devices and exit:
172 $ ffmpeg -list_devices true -f dshow -i dummy
176 Open video device @var{Camera}:
178 $ ffmpeg -f dshow -i video="Camera"
182 Open second video device with name @var{Camera}:
184 $ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
188 Open video device @var{Camera} and audio device @var{Microphone}:
190 $ ffmpeg -f dshow -i video="Camera":audio="Microphone"
194 Print the list of supported options in selected device and exit:
196 $ ffmpeg -list_options true -f dshow -i video="Camera"
203 Linux DV 1394 input device.
207 Linux framebuffer input device.
209 The Linux framebuffer is a graphic hardware-independent abstraction
210 layer to show graphics on a computer monitor, typically on the
211 console. It is accessed through a file device node, usually
214 For more detailed information read the file
215 Documentation/fb/framebuffer.txt included in the Linux source tree.
217 To record from the framebuffer device @file{/dev/fb0} with
220 ffmpeg -f fbdev -r 10 -i /dev/fb0 out.avi
223 You can take a single screenshot image with the command:
225 ffmpeg -f fbdev -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg
228 See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1).
232 Win32 GDI-based screen capture device.
234 This device allows you to capture a region of the display on Windows.
236 There are two options for the input filename:
242 title=@var{window_title}
245 The first option will capture the entire desktop, or a fixed region of the
246 desktop. The second option will instead capture the contents of a single
247 window, regardless of its position on the screen.
249 For example, to grab the entire desktop using @command{ffmpeg}:
251 ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
254 Grab a 640x480 region at position @code{10,20}:
256 ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
259 Grab the contents of the window named "Calculator"
261 ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
268 Specify whether to draw the mouse pointer. Use the value @code{0} to
269 not draw the pointer. Default value is @code{1}.
272 Set the grabbing frame rate. Default value is @code{ntsc},
273 corresponding to a frame rate of @code{30000/1001}.
276 Show grabbed region on screen.
278 If @var{show_region} is specified with @code{1}, then the grabbing
279 region will be indicated on screen. With this option, it is easy to
280 know what is being grabbed if only a portion of the screen is grabbed.
282 Note that @var{show_region} is incompatible with grabbing the contents
287 ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
291 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.
294 When capturing a region with @var{video_size}, set the distance from the left edge of the screen or desktop.
296 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.
299 When capturing a region with @var{video_size}, set the distance from the top edge of the screen or desktop.
301 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.
307 FireWire DV/HDV input device using libiec61883.
309 To enable this input device, you need libiec61883, libraw1394 and
310 libavc1394 installed on your system. Use the configure option
311 @code{--enable-libiec61883} to compile with the device enabled.
313 The iec61883 capture device supports capturing from a video device
314 connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
315 FireWire stack (juju). This is the default DV/HDV input method in Linux
316 Kernel 2.6.37 and later, since the old FireWire stack was removed.
318 Specify the FireWire port to be used as input file, or "auto"
319 to choose the first port connected.
326 Override autodetection of DV/HDV. This should only be used if auto
327 detection does not work, or if usage of a different device type
328 should be prohibited. Treating a DV device as HDV (or vice versa) will
329 not work and result in undefined behavior.
330 The values @option{auto}, @option{dv} and @option{hdv} are supported.
333 Set maxiumum size of buffer for incoming data, in frames. For DV, this
334 is an exact value. For HDV, it is not frame exact, since HDV does
335 not have a fixed frame size.
338 Select the capture device by specifying it's GUID. Capturing will only
339 be performed from the specified device and fails if no device with the
340 given GUID is found. This is useful to select the input if multiple
341 devices are connected at the same time.
342 Look at /sys/bus/firewire/devices to find out the GUIDs.
351 Grab and show the input of a FireWire DV/HDV device.
353 ffplay -f iec61883 -i auto
357 Grab and record the input of a FireWire DV/HDV device,
358 using a packet buffer of 100000 packets if the source is HDV.
360 ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg
369 To enable this input device during configuration you need libjack
370 installed on your system.
372 A JACK input device creates one or more JACK writable clients, one for
373 each audio channel, with name @var{client_name}:input_@var{N}, where
374 @var{client_name} is the name provided by the application, and @var{N}
375 is a number which identifies the channel.
376 Each writable client will send the acquired data to the FFmpeg input
379 Once you have created one or more JACK readable clients, you need to
380 connect them to one or more JACK writable clients.
382 To connect or disconnect JACK clients you can use the @command{jack_connect}
383 and @command{jack_disconnect} programs, or do it through a graphical interface,
384 for example with @command{qjackctl}.
386 To list the JACK clients and their properties you can invoke the command
389 Follows an example which shows how to capture a JACK readable client
390 with @command{ffmpeg}.
392 # Create a JACK writable client with name "ffmpeg".
393 $ ffmpeg -f jack -i ffmpeg -y out.wav
395 # Start the sample jack_metro readable client.
396 $ jack_metro -b 120 -d 0.2 -f 4000
398 # List the current JACK clients.
407 # Connect metro to the ffmpeg writable client.
408 $ jack_connect metro:120_bpm ffmpeg:input_1
411 For more information read:
412 @url{http://jackaudio.org/}
416 Libavfilter input virtual device.
418 This input device reads data from the open output pads of a libavfilter
421 For each filtergraph open output, the input device will create a
422 corresponding stream which is mapped to the generated output. Currently
423 only video data is supported. The filtergraph is specified through the
424 option @option{graph}.
431 Specify the filtergraph to use as input. Each video open output must be
432 labelled by a unique string of the form "out@var{N}", where @var{N} is a
433 number starting from 0 corresponding to the mapped input stream
434 generated by the device.
435 The first unlabelled output is automatically assigned to the "out0"
436 label, but all the others need to be specified explicitly.
438 If not specified defaults to the filename specified for the input
442 Set the filename of the filtergraph to be read and sent to the other
443 filters. Syntax of the filtergraph is the same as the one specified by
444 the option @var{graph}.
452 Create a color video stream and play it back with @command{ffplay}:
454 ffplay -f lavfi -graph "color=c=pink [out0]" dummy
458 As the previous example, but use filename for specifying the graph
459 description, and omit the "out0" label:
461 ffplay -f lavfi color=c=pink
465 Create three different video test filtered sources and play them:
467 ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
471 Read an audio stream from a file using the amovie source and play it
472 back with @command{ffplay}:
474 ffplay -f lavfi "amovie=test.wav"
478 Read an audio stream and a video stream and play it back with
481 ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
488 Audio-CD input device based on cdio.
490 To enable this input device during configuration you need libcdio
491 installed on your system. Requires the configure option
492 @code{--enable-libcdio}.
494 This device allows playing and grabbing from an Audio-CD.
496 For example to copy with @command{ffmpeg} the entire Audio-CD in /dev/sr0,
497 you may run the command:
499 ffmpeg -f libcdio -i /dev/sr0 cd.wav
504 IIDC1394 input device, based on libdc1394 and libraw1394.
506 Requires the configure option @code{--enable-libdc1394}.
510 The OpenAL input device provides audio capture on all systems with a
511 working OpenAL 1.1 implementation.
513 To enable this input device during configuration, you need OpenAL
514 headers and libraries installed on your system, and need to configure
515 FFmpeg with @code{--enable-openal}.
517 OpenAL headers and libraries should be provided as part of your OpenAL
518 implementation, or as an additional download (an SDK). Depending on your
519 installation you may need to specify additional flags via the
520 @code{--extra-cflags} and @code{--extra-ldflags} for allowing the build
521 system to locate the OpenAL headers and libraries.
523 An incomplete list of OpenAL implementations follows:
527 The official Windows implementation, providing hardware acceleration
528 with supported devices and software fallback.
529 See @url{http://openal.org/}.
531 Portable, open source (LGPL) software implementation. Includes
532 backends for the most common sound APIs on the Windows, Linux,
533 Solaris, and BSD operating systems.
534 See @url{http://kcat.strangesoft.net/openal.html}.
536 OpenAL is part of Core Audio, the official Mac OS X Audio interface.
537 See @url{http://developer.apple.com/technologies/mac/audio-and-video.html}
540 This device allows one to capture from an audio input device handled
543 You need to specify the name of the device to capture in the provided
544 filename. If the empty string is provided, the device will
545 automatically select the default device. You can get the list of the
546 supported devices by using the option @var{list_devices}.
553 Set the number of channels in the captured audio. Only the values
554 @option{1} (monaural) and @option{2} (stereo) are currently supported.
555 Defaults to @option{2}.
558 Set the sample size (in bits) of the captured audio. Only the values
559 @option{8} and @option{16} are currently supported. Defaults to
563 Set the sample rate (in Hz) of the captured audio.
564 Defaults to @option{44.1k}.
567 If set to @option{true}, print a list of devices and exit.
568 Defaults to @option{false}.
574 Print the list of OpenAL supported devices and exit:
576 $ ffmpeg -list_devices true -f openal -i dummy out.ogg
579 Capture from the OpenAL device @file{DR-BT101 via PulseAudio}:
581 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
584 Capture from the default device (note the empty string '' as filename):
586 $ ffmpeg -f openal -i '' out.ogg
589 Capture from two devices simultaneously, writing to two different files,
590 within the same @command{ffmpeg} command:
592 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
594 Note: not all OpenAL implementations support multiple simultaneous capture -
595 try the latest OpenAL Soft if the above does not work.
599 Open Sound System input device.
601 The filename to provide to the input device is the device node
602 representing the OSS input device, and is usually set to
605 For example to grab from @file{/dev/dsp} using @command{ffmpeg} use the
608 ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
611 For more information about OSS see:
612 @url{http://manuals.opensound.com/usersguide/dsp.html}
616 PulseAudio input device.
618 To enable this output device you need to configure FFmpeg with @code{--enable-libpulse}.
620 The filename to provide to the input device is a source device or the
623 To list the PulseAudio source devices and their properties you can invoke
624 the command @command{pactl list sources}.
626 More information about PulseAudio can be found on @url{http://www.pulseaudio.org}.
631 Connect to a specific PulseAudio server, specified by an IP address.
632 Default server is used when not provided.
635 Specify the application name PulseAudio will use when showing active clients,
636 by default it is the @code{LIBAVFORMAT_IDENT} string.
639 Specify the stream name PulseAudio will use when showing active streams,
640 by default it is "record".
643 Specify the samplerate in Hz, by default 48kHz is used.
646 Specify the channels in use, by default 2 (stereo) is set.
649 Specify the number of bytes per frame, by default it is set to 1024.
652 Specify the minimal buffering fragment in PulseAudio, it will affect the
653 audio latency. By default it is unset.
657 Record a stream from default device:
659 ffmpeg -f pulse -i default /tmp/pulse.wav
666 The filename passed as input is parsed to contain either a device name or index.
667 The device index can also be given by using -video_device_index.
668 A given device index will override any given device name.
669 If the desired device consists of numbers only, use -video_device_index to identify it.
670 The default device will be chosen if an empty string or the device name "default" is given.
671 The available devices can be enumerated by using -list_devices.
674 ffmpeg -f qtkit -i "0" out.mpg
678 ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg
682 ffmpeg -f qtkit -i "default" out.mpg
686 ffmpeg -f qtkit -list_devices true -i ""
693 To enable this input device during configuration you need libsndio
694 installed on your system.
696 The filename to provide to the input device is the device node
697 representing the sndio input device, and is usually set to
700 For example to grab from @file{/dev/audio0} using @command{ffmpeg} use the
703 ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
706 @section video4linux2, v4l2
708 Video4Linux2 input video device.
710 "v4l2" can be used as alias for "video4linux2".
712 If FFmpeg is built with v4l-utils support (by using the
713 @code{--enable-libv4l2} configure option), it is possible to use it with the
714 @code{-use_libv4l2} input device option.
716 The name of the device to grab is a file device node, usually Linux
717 systems tend to automatically create such nodes when the device
718 (e.g. an USB webcam) is plugged into the system, and has a name of the
719 kind @file{/dev/video@var{N}}, where @var{N} is a number associated to
722 Video4Linux2 devices usually support a limited set of
723 @var{width}x@var{height} sizes and frame rates. You can check which are
724 supported using @command{-list_formats all} for Video4Linux2 devices.
725 Some devices, like TV cards, support one or more standards. It is possible
726 to list all the supported standards using @command{-list_standards all}.
728 The time base for the timestamps is 1 microsecond. Depending on the kernel
729 version and configuration, the timestamps may be derived from the real time
730 clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
731 boot time, unaffected by NTP or manual changes to the clock). The
732 @option{-timestamps abs} or @option{-ts abs} option can be used to force
733 conversion into the real time clock.
735 Some usage examples of the video4linux2 device with @command{ffmpeg}
736 and @command{ffplay}:
739 Grab and show the input of a video4linux2 device:
741 ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
745 Grab and record the input of a video4linux2 device, leave the
746 frame rate and size as previously set:
748 ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
752 For more information about Video4Linux, check @url{http://linuxtv.org/}.
758 Set the standard. Must be the name of a supported standard. To get a
759 list of the supported standards, use the @option{list_standards}
763 Set the input channel number. Default to -1, which means using the
764 previously selected channel.
767 Set the video frame size. The argument must be a string in the form
768 @var{WIDTH}x@var{HEIGHT} or a valid size abbreviation.
771 Select the pixel format (only valid for raw video input).
774 Set the preferred pixel format (for raw video) or a codec name.
775 This option allows one to select the input format, when several are
779 Set the preferred video frame rate.
782 List available formats (supported pixel formats, codecs, and frame
785 Available values are:
788 Show all available (compressed and non-compressed) formats.
791 Show only raw video (non-compressed) formats.
794 Show only compressed formats.
798 List supported standards and exit.
800 Available values are:
803 Show all supported standards.
807 Set type of timestamps for grabbed frames.
809 Available values are:
812 Use timestamps from the kernel.
815 Use absolute timestamps (wall clock).
818 Force conversion from monotonic to absolute timestamps.
821 Default value is @code{default}.
826 VfW (Video for Windows) capture input device.
828 The filename passed as input is the capture driver number, ranging from
829 0 to 9. You may use "list" as filename to print a list of drivers. Any
830 other filename will be interpreted as device number 0.
834 X11 video input device.
836 Depends on X11, Xext, and Xfixes. Requires the configure option
837 @code{--enable-x11grab}.
839 This device allows one to capture a region of an X11 display.
841 The filename passed as input has the syntax:
843 [@var{hostname}]:@var{display_number}.@var{screen_number}[+@var{x_offset},@var{y_offset}]
846 @var{hostname}:@var{display_number}.@var{screen_number} specifies the
847 X11 display name of the screen to grab from. @var{hostname} can be
848 omitted, and defaults to "localhost". The environment variable
849 @env{DISPLAY} contains the default display name.
851 @var{x_offset} and @var{y_offset} specify the offsets of the grabbed
852 area with respect to the top-left border of the X11 screen. They
855 Check the X11 documentation (e.g. man X) for more detailed information.
857 Use the @command{dpyinfo} program for getting basic information about the
858 properties of your X11 display (e.g. grep for "name" or "dimensions").
860 For example to grab from @file{:0.0} using @command{ffmpeg}:
862 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
865 Grab at position @code{10,20}:
867 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
874 Specify whether to draw the mouse pointer. A value of @code{0} specify
875 not to draw the pointer. Default value is @code{1}.
878 Make the grabbed area follow the mouse. The argument can be
879 @code{centered} or a number of pixels @var{PIXELS}.
881 When it is specified with "centered", the grabbing region follows the mouse
882 pointer and keeps the pointer at the center of region; otherwise, the region
883 follows only when the mouse pointer reaches within @var{PIXELS} (greater than
884 zero) to the edge of region.
888 ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
891 To follow only when the mouse pointer reaches within 100 pixels to edge:
893 ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
897 Set the grabbing frame rate. Default value is @code{ntsc},
898 corresponding to a frame rate of @code{30000/1001}.
901 Show grabbed region on screen.
903 If @var{show_region} is specified with @code{1}, then the grabbing
904 region will be indicated on screen. With this option, it is easy to
905 know what is being grabbed if only a portion of the screen is grabbed.
909 ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
912 With @var{follow_mouse}:
914 ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
918 Set the video frame size. Default value is @code{vga}.
921 Use the MIT-SHM extension for shared memory. Default value is @code{1}.
922 It may be necessary to disable it for remote displays.
925 @c man end INPUT DEVICES