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.
66 @section android_camera
68 Android camera input device.
70 This input devices uses the Android Camera2 NDK API which is
71 available on devices with API level 24+. The availability of
72 android_camera is autodetected during configuration.
74 This device allows capturing from all cameras on an Android device,
75 which are integrated into the Camera2 NDK API.
77 The available cameras are enumerated internally and can be selected
78 with the @var{camera_index} parameter. The input file string is
81 Generally the back facing camera has index 0 while the front facing
89 Set the video size given as a string such as 640x480 or hd720.
90 Falls back to the first available configuration reported by
91 Android if requested video size is not available or by default.
94 Set the video framerate.
95 Falls back to the first available configuration reported by
96 Android if requested framerate is not available or by default (-1).
99 Set the index of the camera to use. Default is 0.
101 @item input_queue_size
102 Set the maximum number of frames to buffer. Default is 5.
106 @section avfoundation
108 AVFoundation input device.
110 AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX >= 10.7 as well as on iOS.
112 The input filename has to be given in the following syntax:
114 -i "[[VIDEO]:[AUDIO]]"
116 The first entry selects the video input while the latter selects the audio input.
117 The stream has to be specified by the device name or the device index as shown by the device list.
118 Alternatively, the video and/or audio input device can be chosen by index using the
120 -video_device_index <INDEX>
124 -audio_device_index <INDEX>
127 device name or index given in the input filename.
129 All available devices can be enumerated by using @option{-list_devices true}, listing
130 all device names and corresponding indices.
132 There are two device name aliases:
136 Select the AVFoundation default device of the corresponding type.
139 Do not record the corresponding media type.
140 This is equivalent to specifying an empty device name or index.
146 AVFoundation supports the following options:
150 @item -list_devices <TRUE|FALSE>
151 If set to true, a list of all available input devices is given showing all
152 device names and indices.
154 @item -video_device_index <INDEX>
155 Specify the video device by its index. Overrides anything given in the input filename.
157 @item -audio_device_index <INDEX>
158 Specify the audio device by its index. Overrides anything given in the input filename.
160 @item -pixel_format <FORMAT>
161 Request the video device to use a specific pixel format.
162 If the specified format is not supported, a list of available formats is given
163 and the first one in this list is used instead. Available pixel formats are:
164 @code{monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,
165 bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10,
166 yuv420p, nv12, yuyv422, gray}
169 Set the grabbing frame rate. Default is @code{ntsc}, corresponding to a
170 frame rate of @code{30000/1001}.
173 Set the video frame size.
175 @item -capture_cursor
176 Capture the mouse pointer. Default is 0.
178 @item -capture_mouse_clicks
179 Capture the screen mouse clicks. Default is 0.
181 @item -capture_raw_data
182 Capture the raw device data. Default is 0.
183 Using this option may result in receiving the underlying data delivered to the AVFoundation framework. E.g. for muxed devices that sends raw DV data to the framework (like tape-based camcorders), setting this option to false results in extracted video frames captured in the designated pixel format only. Setting this option to true results in receiving the raw DV stream untouched.
191 Print the list of AVFoundation supported devices and exit:
193 $ ffmpeg -f avfoundation -list_devices true -i ""
197 Record video from video device 0 and audio from audio device 0 into out.avi:
199 $ ffmpeg -f avfoundation -i "0:0" out.avi
203 Record video from video device 2 and audio from audio device 1 into out.avi:
205 $ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi
209 Record video from the system default video device using the pixel format bgr0 and do not record any audio into out.avi:
211 $ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi
215 Record raw DV data from a suitable input device and write the output into out.dv:
217 $ ffmpeg -f avfoundation -capture_raw_data true -i "zr100:none" out.dv
225 BSD video input device.
235 Set the video frame size. Default is @code{vga}.
239 Available values are:
259 The decklink input device provides capture capabilities for Blackmagic
262 To enable this input device, you need the Blackmagic DeckLink SDK and you
263 need to configure with the appropriate @code{--extra-cflags}
264 and @code{--extra-ldflags}.
265 On Windows, you need to run the IDL files through @command{widl}.
267 DeckLink is very picky about the formats it supports. Pixel format of the
268 input can be set with @option{raw_format}.
269 Framerate and video size must be determined for your device with
270 @command{-list_formats 1}. Audio sample rate is always 48 kHz and the number
271 of channels can be 2, 8 or 16. Note that all audio channels are bundled in one single
279 If set to @option{true}, print a list of devices and exit.
280 Defaults to @option{false}. Alternatively you can use the @code{-sources}
281 option of ffmpeg to list the available input devices.
284 If set to @option{true}, print a list of supported formats and exit.
285 Defaults to @option{false}.
287 @item format_code <FourCC>
288 This sets the input video format to the format given by the FourCC. To see
289 the supported values of your device(s) use @option{list_formats}.
290 Note that there is a FourCC @option{'pal '} that can also be used
291 as @option{pal} (3 letters).
292 Default behavior is autodetection of the input video format, if the hardware
296 This is a deprecated option, you can use @option{raw_format} instead.
297 If set to @samp{1}, video is captured in 10 bit v210 instead
298 of uyvy422. Not all Blackmagic devices support this option.
301 Set the pixel format of the captured video.
302 Available values are:
317 If set to nonzero, an additional teletext stream will be captured from the
318 vertical ancillary data. Both SD PAL (576i) and HD (1080i or 1080p)
319 sources are supported. In case of HD sources, OP47 packets are decoded.
321 This option is a bitmask of the SD PAL VBI lines captured, specifically lines 6
322 to 22, and lines 318 to 335. Line 6 is the LSB in the mask. Selected lines
323 which do not contain teletext information will be ignored. You can use the
324 special @option{all} constant to select all possible lines, or
325 @option{standard} to skip lines 6, 318 and 319, which are not compatible with
328 For SD sources, ffmpeg needs to be compiled with @code{--enable-libzvbi}. For
329 HD sources, on older (pre-4K) DeckLink card models you have to capture in 10
333 Defines number of audio channels to capture. Must be @samp{2}, @samp{8} or @samp{16}.
334 Defaults to @samp{2}.
337 Sets the decklink device duplex mode. Must be @samp{unset}, @samp{half} or @samp{full}.
338 Defaults to @samp{unset}.
340 @item timecode_format
341 Timecode type to include in the frame and video stream metadata. Must be
342 @samp{none}, @samp{rp188vitc}, @samp{rp188vitc2}, @samp{rp188ltc},
343 @samp{rp188any}, @samp{vitc}, @samp{vitc2}, or @samp{serial}. Defaults to
344 @samp{none} (not included).
347 Sets the video input source. Must be @samp{unset}, @samp{sdi}, @samp{hdmi},
348 @samp{optical_sdi}, @samp{component}, @samp{composite} or @samp{s_video}.
349 Defaults to @samp{unset}.
352 Sets the audio input source. Must be @samp{unset}, @samp{embedded},
353 @samp{aes_ebu}, @samp{analog}, @samp{analog_xlr}, @samp{analog_rca} or
354 @samp{microphone}. Defaults to @samp{unset}.
357 Sets the video packet timestamp source. Must be @samp{video}, @samp{audio},
358 @samp{reference}, @samp{wallclock} or @samp{abs_wallclock}.
359 Defaults to @samp{video}.
362 Sets the audio packet timestamp source. Must be @samp{video}, @samp{audio},
363 @samp{reference}, @samp{wallclock} or @samp{abs_wallclock}.
364 Defaults to @samp{audio}.
367 If set to @samp{true}, color bars are drawn in the event of a signal loss.
368 Defaults to @samp{true}.
371 Sets maximum input buffer size in bytes. If the buffering reaches this value,
372 incoming frames will be dropped.
373 Defaults to @samp{1073741824}.
376 Sets the audio sample bit depth. Must be @samp{16} or @samp{32}.
377 Defaults to @samp{16}.
379 @item decklink_copyts
380 If set to @option{true}, timestamps are forwarded as they are without removing
382 Defaults to @option{false}.
384 @item timestamp_align
385 Capture start time alignment in seconds. If set to nonzero, input frames are
386 dropped till the system timestamp aligns with configured value.
387 Alignment difference of up to one frame duration is tolerated.
388 This is useful for maintaining input synchronization across N different
389 hardware devices deployed for 'N-way' redundancy. The system time of different
390 hardware devices should be synchronized with protocols such as NTP or PTP,
391 before using this option.
392 Note that this method is not foolproof. In some border cases input
393 synchronization may not happen due to thread scheduling jitters in the OS.
394 Either sync could go wrong by 1 frame or in a rarer case
395 @option{timestamp_align} seconds.
396 Defaults to @samp{0}.
407 ffmpeg -f decklink -list_devices 1 -i dummy
411 List supported formats:
413 ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
417 Capture video clip at 1080i50:
419 ffmpeg -format_code Hi50 -f decklink -i 'Intensity Pro' -c:a copy -c:v copy output.avi
423 Capture video clip at 1080i50 10 bit:
425 ffmpeg -bm_v210 1 -format_code Hi50 -f decklink -i 'UltraStudio Mini Recorder' -c:a copy -c:v copy output.avi
429 Capture video clip at 1080i50 with 16 audio channels:
431 ffmpeg -channels 16 -format_code Hi50 -f decklink -i 'UltraStudio Mini Recorder' -c:a copy -c:v copy output.avi
438 Windows DirectShow input device.
440 DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
441 Currently only audio and video devices are supported.
443 Multiple devices may be opened as separate inputs, but they may also be
444 opened on the same input, which should improve synchronism between them.
446 The input name should be in the format:
449 @var{TYPE}=@var{NAME}[:@var{TYPE}=@var{NAME}]
452 where @var{TYPE} can be either @var{audio} or @var{video},
453 and @var{NAME} is the device's name or alternative name..
457 If no options are specified, the device's defaults are used.
458 If the device does not support the requested options, it will
464 Set the video size in the captured video.
467 Set the frame rate in the captured video.
470 Set the sample rate (in Hz) of the captured audio.
473 Set the sample size (in bits) of the captured audio.
476 Set the number of channels in the captured audio.
479 If set to @option{true}, print a list of devices and exit.
482 If set to @option{true}, print a list of selected device's options
485 @item video_device_number
486 Set video device number for devices with the same name (starts at 0,
489 @item audio_device_number
490 Set audio device number for devices with the same name (starts at 0,
494 Select pixel format to be used by DirectShow. This may only be set when
495 the video codec is not set or set to rawvideo.
497 @item audio_buffer_size
498 Set audio device buffer size in milliseconds (which can directly
499 impact latency, depending on the device).
500 Defaults to using the audio device's
501 default buffer size (typically some multiple of 500ms).
502 Setting this value too low can degrade performance.
504 @url{http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx}
507 Select video capture pin to use by name or alternative name.
510 Select audio capture pin to use by name or alternative name.
512 @item crossbar_video_input_pin_number
513 Select video input pin number for crossbar device. This will be
514 routed to the crossbar device's Video Decoder output pin.
515 Note that changing this value can affect future invocations
516 (sets a new default) until system reboot occurs.
518 @item crossbar_audio_input_pin_number
519 Select audio input pin number for crossbar device. This will be
520 routed to the crossbar device's Audio Decoder output pin.
521 Note that changing this value can affect future invocations
522 (sets a new default) until system reboot occurs.
524 @item show_video_device_dialog
525 If set to @option{true}, before capture starts, popup a display dialog
526 to the end user, allowing them to change video filter properties
527 and configurations manually.
528 Note that for crossbar devices, adjusting values in this dialog
529 may be needed at times to toggle between PAL (25 fps) and NTSC (29.97)
530 input frame rates, sizes, interlacing, etc. Changing these values can
531 enable different scan rates/frame rates and avoiding green bars at
532 the bottom, flickering scan lines, etc.
533 Note that with some devices, changing these properties can also affect future
534 invocations (sets new defaults) until system reboot occurs.
536 @item show_audio_device_dialog
537 If set to @option{true}, before capture starts, popup a display dialog
538 to the end user, allowing them to change audio filter properties
539 and configurations manually.
541 @item show_video_crossbar_connection_dialog
542 If set to @option{true}, before capture starts, popup a display
543 dialog to the end user, allowing them to manually
544 modify crossbar pin routings, when it opens a video device.
546 @item show_audio_crossbar_connection_dialog
547 If set to @option{true}, before capture starts, popup a display
548 dialog to the end user, allowing them to manually
549 modify crossbar pin routings, when it opens an audio device.
551 @item show_analog_tv_tuner_dialog
552 If set to @option{true}, before capture starts, popup a display
553 dialog to the end user, allowing them to manually
554 modify TV channels and frequencies.
556 @item show_analog_tv_tuner_audio_dialog
557 If set to @option{true}, before capture starts, popup a display
558 dialog to the end user, allowing them to manually
559 modify TV audio (like mono vs. stereo, Language A,B or C).
561 @item audio_device_load
562 Load an audio capture filter device from file instead of searching
563 it by name. It may load additional parameters too, if the filter
564 supports the serialization of its properties to.
565 To use this an audio capture source has to be specified, but it can
566 be anything even fake one.
568 @item audio_device_save
569 Save the currently used audio capture filter device and its
570 parameters (if the filter supports it) to a file.
571 If a file with the same name exists it will be overwritten.
573 @item video_device_load
574 Load a video capture filter device from file instead of searching
575 it by name. It may load additional parameters too, if the filter
576 supports the serialization of its properties to.
577 To use this a video capture source has to be specified, but it can
578 be anything even fake one.
580 @item video_device_save
581 Save the currently used video capture filter device and its
582 parameters (if the filter supports it) to a file.
583 If a file with the same name exists it will be overwritten.
592 Print the list of DirectShow supported devices and exit:
594 $ ffmpeg -list_devices true -f dshow -i dummy
598 Open video device @var{Camera}:
600 $ ffmpeg -f dshow -i video="Camera"
604 Open second video device with name @var{Camera}:
606 $ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
610 Open video device @var{Camera} and audio device @var{Microphone}:
612 $ ffmpeg -f dshow -i video="Camera":audio="Microphone"
616 Print the list of supported options in selected device and exit:
618 $ ffmpeg -list_options true -f dshow -i video="Camera"
622 Specify pin names to capture by name or alternative name, specify alternative device name:
624 $ 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"
628 Configure a crossbar device, specifying crossbar pins, allow user to adjust video capture properties at startup:
630 $ ffmpeg -f dshow -show_video_device_dialog true -crossbar_video_input_pin_number 0
631 -crossbar_audio_input_pin_number 3 -i video="AVerMedia BDA Analog Capture":audio="AVerMedia BDA Analog Capture"
638 Linux framebuffer input device.
640 The Linux framebuffer is a graphic hardware-independent abstraction
641 layer to show graphics on a computer monitor, typically on the
642 console. It is accessed through a file device node, usually
645 For more detailed information read the file
646 Documentation/fb/framebuffer.txt included in the Linux source tree.
648 See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1).
650 To record from the framebuffer device @file{/dev/fb0} with
653 ffmpeg -f fbdev -framerate 10 -i /dev/fb0 out.avi
656 You can take a single screenshot image with the command:
658 ffmpeg -f fbdev -framerate 1 -i /dev/fb0 -frames:v 1 screenshot.jpeg
666 Set the frame rate. Default is 25.
672 Win32 GDI-based screen capture device.
674 This device allows you to capture a region of the display on Windows.
676 There are two options for the input filename:
682 title=@var{window_title}
685 The first option will capture the entire desktop, or a fixed region of the
686 desktop. The second option will instead capture the contents of a single
687 window, regardless of its position on the screen.
689 For example, to grab the entire desktop using @command{ffmpeg}:
691 ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
694 Grab a 640x480 region at position @code{10,20}:
696 ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
699 Grab the contents of the window named "Calculator"
701 ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
708 Specify whether to draw the mouse pointer. Use the value @code{0} to
709 not draw the pointer. Default value is @code{1}.
712 Set the grabbing frame rate. Default value is @code{ntsc},
713 corresponding to a frame rate of @code{30000/1001}.
716 Show grabbed region on screen.
718 If @var{show_region} is specified with @code{1}, then the grabbing
719 region will be indicated on screen. With this option, it is easy to
720 know what is being grabbed if only a portion of the screen is grabbed.
722 Note that @var{show_region} is incompatible with grabbing the contents
727 ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
731 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.
734 When capturing a region with @var{video_size}, set the distance from the left edge of the screen or desktop.
736 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.
739 When capturing a region with @var{video_size}, set the distance from the top edge of the screen or desktop.
741 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.
747 FireWire DV/HDV input device using libiec61883.
749 To enable this input device, you need libiec61883, libraw1394 and
750 libavc1394 installed on your system. Use the configure option
751 @code{--enable-libiec61883} to compile with the device enabled.
753 The iec61883 capture device supports capturing from a video device
754 connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
755 FireWire stack (juju). This is the default DV/HDV input method in Linux
756 Kernel 2.6.37 and later, since the old FireWire stack was removed.
758 Specify the FireWire port to be used as input file, or "auto"
759 to choose the first port connected.
766 Override autodetection of DV/HDV. This should only be used if auto
767 detection does not work, or if usage of a different device type
768 should be prohibited. Treating a DV device as HDV (or vice versa) will
769 not work and result in undefined behavior.
770 The values @option{auto}, @option{dv} and @option{hdv} are supported.
773 Set maximum size of buffer for incoming data, in frames. For DV, this
774 is an exact value. For HDV, it is not frame exact, since HDV does
775 not have a fixed frame size.
778 Select the capture device by specifying its GUID. Capturing will only
779 be performed from the specified device and fails if no device with the
780 given GUID is found. This is useful to select the input if multiple
781 devices are connected at the same time.
782 Look at /sys/bus/firewire/devices to find out the GUIDs.
791 Grab and show the input of a FireWire DV/HDV device.
793 ffplay -f iec61883 -i auto
797 Grab and record the input of a FireWire DV/HDV device,
798 using a packet buffer of 100000 packets if the source is HDV.
800 ffmpeg -f iec61883 -i auto -dvbuffer 100000 out.mpg
809 To enable this input device during configuration you need libjack
810 installed on your system.
812 A JACK input device creates one or more JACK writable clients, one for
813 each audio channel, with name @var{client_name}:input_@var{N}, where
814 @var{client_name} is the name provided by the application, and @var{N}
815 is a number which identifies the channel.
816 Each writable client will send the acquired data to the FFmpeg input
819 Once you have created one or more JACK readable clients, you need to
820 connect them to one or more JACK writable clients.
822 To connect or disconnect JACK clients you can use the @command{jack_connect}
823 and @command{jack_disconnect} programs, or do it through a graphical interface,
824 for example with @command{qjackctl}.
826 To list the JACK clients and their properties you can invoke the command
829 Follows an example which shows how to capture a JACK readable client
830 with @command{ffmpeg}.
832 # Create a JACK writable client with name "ffmpeg".
833 $ ffmpeg -f jack -i ffmpeg -y out.wav
835 # Start the sample jack_metro readable client.
836 $ jack_metro -b 120 -d 0.2 -f 4000
838 # List the current JACK clients.
847 # Connect metro to the ffmpeg writable client.
848 $ jack_connect metro:120_bpm ffmpeg:input_1
851 For more information read:
852 @url{http://jackaudio.org/}
859 Set the number of channels. Default is 2.
865 KMS video input device.
867 Captures the KMS scanout framebuffer associated with a specified CRTC or plane as a
868 DRM object that can be passed to other hardware functions.
870 Requires either DRM master or CAP_SYS_ADMIN to run.
872 If you don't understand what all of that means, you probably don't want this. Look at
873 @option{x11grab} instead.
880 DRM device to capture on. Defaults to @option{/dev/dri/card0}.
883 Pixel format of the framebuffer. Defaults to @option{bgr0}.
885 @item format_modifier
886 Format modifier to signal on output frames. This is necessary to import correctly into
887 some APIs, but can't be autodetected. See the libdrm documentation for possible values.
890 KMS CRTC ID to define the capture source. The first active plane on the given CRTC
894 KMS plane ID to define the capture source. Defaults to the first active plane found if
895 neither @option{crtc_id} nor @option{plane_id} are specified.
898 Framerate to capture at. This is not synchronised to any page flipping or framebuffer
899 changes - it just defines the interval at which the framebuffer is sampled. Sampling
900 faster than the framebuffer update rate will generate independent frames with the same
901 content. Defaults to @code{30}.
910 Capture from the first active plane, download the result to normal frames and encode.
911 This will only work if the framebuffer is both linear and mappable - if not, the result
912 may be scrambled or fail to download.
914 ffmpeg -f kmsgrab -i - -vf 'hwdownload,format=bgr0' output.mp4
918 Capture from CRTC ID 42 at 60fps, map the result to VAAPI, convert to NV12 and encode as H.264.
920 ffmpeg -crtc_id 42 -framerate 60 -f kmsgrab -i - -vf 'hwmap=derive_device=vaapi,scale_vaapi=w=1920:h=1080:format=nv12' -c:v h264_vaapi output.mp4
924 To capture only part of a plane the output can be cropped - this can be used to capture
925 a single window, as long as it has a known absolute position and size. For example, to
926 capture and encode the middle quarter of a 1920x1080 plane:
928 ffmpeg -f kmsgrab -i - -vf 'hwmap=derive_device=vaapi,crop=960:540:480:270,scale_vaapi=960:540:nv12' -c:v h264_vaapi output.mp4
935 Libavfilter input virtual device.
937 This input device reads data from the open output pads of a libavfilter
940 For each filtergraph open output, the input device will create a
941 corresponding stream which is mapped to the generated output. Currently
942 only video data is supported. The filtergraph is specified through the
943 option @option{graph}.
950 Specify the filtergraph to use as input. Each video open output must be
951 labelled by a unique string of the form "out@var{N}", where @var{N} is a
952 number starting from 0 corresponding to the mapped input stream
953 generated by the device.
954 The first unlabelled output is automatically assigned to the "out0"
955 label, but all the others need to be specified explicitly.
957 The suffix "+subcc" can be appended to the output label to create an extra
958 stream with the closed captions packets attached to that output
959 (experimental; only for EIA-608 / CEA-708 for now).
960 The subcc streams are created after all the normal streams, in the order of
961 the corresponding stream.
962 For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
963 stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
965 If not specified defaults to the filename specified for the input
969 Set the filename of the filtergraph to be read and sent to the other
970 filters. Syntax of the filtergraph is the same as the one specified by
971 the option @var{graph}.
974 Dump graph to stderr.
982 Create a color video stream and play it back with @command{ffplay}:
984 ffplay -f lavfi -graph "color=c=pink [out0]" dummy
988 As the previous example, but use filename for specifying the graph
989 description, and omit the "out0" label:
991 ffplay -f lavfi color=c=pink
995 Create three different video test filtered sources and play them:
997 ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
1001 Read an audio stream from a file using the amovie source and play it
1002 back with @command{ffplay}:
1004 ffplay -f lavfi "amovie=test.wav"
1008 Read an audio stream and a video stream and play it back with
1011 ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
1015 Dump decoded frames to images and closed captions to a file (experimental):
1017 ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
1024 Audio-CD input device based on libcdio.
1026 To enable this input device during configuration you need libcdio
1027 installed on your system. It requires the configure option
1028 @code{--enable-libcdio}.
1030 This device allows playing and grabbing from an Audio-CD.
1032 For example to copy with @command{ffmpeg} the entire Audio-CD in @file{/dev/sr0},
1033 you may run the command:
1035 ffmpeg -f libcdio -i /dev/sr0 cd.wav
1041 Set drive reading speed. Default value is 0.
1043 The speed is specified CD-ROM speed units. The speed is set through
1044 the libcdio @code{cdio_cddap_speed_set} function. On many CD-ROM
1045 drives, specifying a value too large will result in using the fastest
1049 Set paranoia recovery mode flags. It accepts one of the following values:
1059 Default value is @samp{disable}.
1061 For more information about the available recovery modes, consult the
1062 paranoia project documentation.
1067 IIDC1394 input device, based on libdc1394 and libraw1394.
1069 Requires the configure option @code{--enable-libdc1394}.
1075 Set the frame rate. Default is @code{ntsc}, corresponding to a frame
1076 rate of @code{30000/1001}.
1079 Select the pixel format. Default is @code{uyvy422}.
1082 Set the video size given as a string such as @code{640x480} or @code{hd720}.
1083 Default is @code{qvga}.
1088 The OpenAL input device provides audio capture on all systems with a
1089 working OpenAL 1.1 implementation.
1091 To enable this input device during configuration, you need OpenAL
1092 headers and libraries installed on your system, and need to configure
1093 FFmpeg with @code{--enable-openal}.
1095 OpenAL headers and libraries should be provided as part of your OpenAL
1096 implementation, or as an additional download (an SDK). Depending on your
1097 installation you may need to specify additional flags via the
1098 @code{--extra-cflags} and @code{--extra-ldflags} for allowing the build
1099 system to locate the OpenAL headers and libraries.
1101 An incomplete list of OpenAL implementations follows:
1105 The official Windows implementation, providing hardware acceleration
1106 with supported devices and software fallback.
1107 See @url{http://openal.org/}.
1109 Portable, open source (LGPL) software implementation. Includes
1110 backends for the most common sound APIs on the Windows, Linux,
1111 Solaris, and BSD operating systems.
1112 See @url{http://kcat.strangesoft.net/openal.html}.
1114 OpenAL is part of Core Audio, the official Mac OS X Audio interface.
1115 See @url{http://developer.apple.com/technologies/mac/audio-and-video.html}
1118 This device allows one to capture from an audio input device handled
1121 You need to specify the name of the device to capture in the provided
1122 filename. If the empty string is provided, the device will
1123 automatically select the default device. You can get the list of the
1124 supported devices by using the option @var{list_devices}.
1131 Set the number of channels in the captured audio. Only the values
1132 @option{1} (monaural) and @option{2} (stereo) are currently supported.
1133 Defaults to @option{2}.
1136 Set the sample size (in bits) of the captured audio. Only the values
1137 @option{8} and @option{16} are currently supported. Defaults to
1141 Set the sample rate (in Hz) of the captured audio.
1142 Defaults to @option{44.1k}.
1145 If set to @option{true}, print a list of devices and exit.
1146 Defaults to @option{false}.
1150 @subsection Examples
1152 Print the list of OpenAL supported devices and exit:
1154 $ ffmpeg -list_devices true -f openal -i dummy out.ogg
1157 Capture from the OpenAL device @file{DR-BT101 via PulseAudio}:
1159 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
1162 Capture from the default device (note the empty string '' as filename):
1164 $ ffmpeg -f openal -i '' out.ogg
1167 Capture from two devices simultaneously, writing to two different files,
1168 within the same @command{ffmpeg} command:
1170 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
1172 Note: not all OpenAL implementations support multiple simultaneous capture -
1173 try the latest OpenAL Soft if the above does not work.
1177 Open Sound System input device.
1179 The filename to provide to the input device is the device node
1180 representing the OSS input device, and is usually set to
1183 For example to grab from @file{/dev/dsp} using @command{ffmpeg} use the
1186 ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
1189 For more information about OSS see:
1190 @url{http://manuals.opensound.com/usersguide/dsp.html}
1197 Set the sample rate in Hz. Default is 48000.
1200 Set the number of channels. Default is 2.
1206 PulseAudio input device.
1208 To enable this output device you need to configure FFmpeg with @code{--enable-libpulse}.
1210 The filename to provide to the input device is a source device or the
1213 To list the PulseAudio source devices and their properties you can invoke
1214 the command @command{pactl list sources}.
1216 More information about PulseAudio can be found on @url{http://www.pulseaudio.org}.
1221 Connect to a specific PulseAudio server, specified by an IP address.
1222 Default server is used when not provided.
1225 Specify the application name PulseAudio will use when showing active clients,
1226 by default it is the @code{LIBAVFORMAT_IDENT} string.
1229 Specify the stream name PulseAudio will use when showing active streams,
1230 by default it is "record".
1233 Specify the samplerate in Hz, by default 48kHz is used.
1236 Specify the channels in use, by default 2 (stereo) is set.
1239 Specify the number of bytes per frame, by default it is set to 1024.
1242 Specify the minimal buffering fragment in PulseAudio, it will affect the
1243 audio latency. By default it is unset.
1246 Set the initial PTS using the current time. Default is 1.
1250 @subsection Examples
1251 Record a stream from default device:
1253 ffmpeg -f pulse -i default /tmp/pulse.wav
1260 To enable this input device during configuration you need libsndio
1261 installed on your system.
1263 The filename to provide to the input device is the device node
1264 representing the sndio input device, and is usually set to
1267 For example to grab from @file{/dev/audio0} using @command{ffmpeg} use the
1270 ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
1278 Set the sample rate in Hz. Default is 48000.
1281 Set the number of channels. Default is 2.
1285 @section video4linux2, v4l2
1287 Video4Linux2 input video device.
1289 "v4l2" can be used as alias for "video4linux2".
1291 If FFmpeg is built with v4l-utils support (by using the
1292 @code{--enable-libv4l2} configure option), it is possible to use it with the
1293 @code{-use_libv4l2} input device option.
1295 The name of the device to grab is a file device node, usually Linux
1296 systems tend to automatically create such nodes when the device
1297 (e.g. an USB webcam) is plugged into the system, and has a name of the
1298 kind @file{/dev/video@var{N}}, where @var{N} is a number associated to
1301 Video4Linux2 devices usually support a limited set of
1302 @var{width}x@var{height} sizes and frame rates. You can check which are
1303 supported using @command{-list_formats all} for Video4Linux2 devices.
1304 Some devices, like TV cards, support one or more standards. It is possible
1305 to list all the supported standards using @command{-list_standards all}.
1307 The time base for the timestamps is 1 microsecond. Depending on the kernel
1308 version and configuration, the timestamps may be derived from the real time
1309 clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
1310 boot time, unaffected by NTP or manual changes to the clock). The
1311 @option{-timestamps abs} or @option{-ts abs} option can be used to force
1312 conversion into the real time clock.
1314 Some usage examples of the video4linux2 device with @command{ffmpeg}
1315 and @command{ffplay}:
1318 List supported formats for a video4linux2 device:
1320 ffplay -f video4linux2 -list_formats all /dev/video0
1324 Grab and show the input of a video4linux2 device:
1326 ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
1330 Grab and record the input of a video4linux2 device, leave the
1331 frame rate and size as previously set:
1333 ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
1337 For more information about Video4Linux, check @url{http://linuxtv.org/}.
1343 Set the standard. Must be the name of a supported standard. To get a
1344 list of the supported standards, use the @option{list_standards}
1348 Set the input channel number. Default to -1, which means using the
1349 previously selected channel.
1352 Set the video frame size. The argument must be a string in the form
1353 @var{WIDTH}x@var{HEIGHT} or a valid size abbreviation.
1356 Select the pixel format (only valid for raw video input).
1359 Set the preferred pixel format (for raw video) or a codec name.
1360 This option allows one to select the input format, when several are
1364 Set the preferred video frame rate.
1367 List available formats (supported pixel formats, codecs, and frame
1370 Available values are:
1373 Show all available (compressed and non-compressed) formats.
1376 Show only raw video (non-compressed) formats.
1379 Show only compressed formats.
1382 @item list_standards
1383 List supported standards and exit.
1385 Available values are:
1388 Show all supported standards.
1391 @item timestamps, ts
1392 Set type of timestamps for grabbed frames.
1394 Available values are:
1397 Use timestamps from the kernel.
1400 Use absolute timestamps (wall clock).
1403 Force conversion from monotonic to absolute timestamps.
1406 Default value is @code{default}.
1409 Use libv4l2 (v4l-utils) conversion functions. Default is 0.
1415 VfW (Video for Windows) capture input device.
1417 The filename passed as input is the capture driver number, ranging from
1418 0 to 9. You may use "list" as filename to print a list of drivers. Any
1419 other filename will be interpreted as device number 0.
1426 Set the video frame size.
1429 Set the grabbing frame rate. Default value is @code{ntsc},
1430 corresponding to a frame rate of @code{30000/1001}.
1436 X11 video input device.
1438 To enable this input device during configuration you need libxcb
1439 installed on your system. It will be automatically detected during
1442 This device allows one to capture a region of an X11 display.
1444 The filename passed as input has the syntax:
1446 [@var{hostname}]:@var{display_number}.@var{screen_number}[+@var{x_offset},@var{y_offset}]
1449 @var{hostname}:@var{display_number}.@var{screen_number} specifies the
1450 X11 display name of the screen to grab from. @var{hostname} can be
1451 omitted, and defaults to "localhost". The environment variable
1452 @env{DISPLAY} contains the default display name.
1454 @var{x_offset} and @var{y_offset} specify the offsets of the grabbed
1455 area with respect to the top-left border of the X11 screen. They
1458 Check the X11 documentation (e.g. @command{man X}) for more detailed
1461 Use the @command{xdpyinfo} program for getting basic information about
1462 the properties of your X11 display (e.g. grep for "name" or
1465 For example to grab from @file{:0.0} using @command{ffmpeg}:
1467 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
1470 Grab at position @code{10,20}:
1472 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
1479 Specify whether to draw the mouse pointer. A value of @code{0} specifies
1480 not to draw the pointer. Default value is @code{1}.
1483 Make the grabbed area follow the mouse. The argument can be
1484 @code{centered} or a number of pixels @var{PIXELS}.
1486 When it is specified with "centered", the grabbing region follows the mouse
1487 pointer and keeps the pointer at the center of region; otherwise, the region
1488 follows only when the mouse pointer reaches within @var{PIXELS} (greater than
1489 zero) to the edge of region.
1493 ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
1496 To follow only when the mouse pointer reaches within 100 pixels to edge:
1498 ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
1502 Set the grabbing frame rate. Default value is @code{ntsc},
1503 corresponding to a frame rate of @code{30000/1001}.
1506 Show grabbed region on screen.
1508 If @var{show_region} is specified with @code{1}, then the grabbing
1509 region will be indicated on screen. With this option, it is easy to
1510 know what is being grabbed if only a portion of the screen is grabbed.
1513 Set the region border thickness if @option{-show_region 1} is used.
1514 Range is 1 to 128 and default is 3 (XCB-based x11grab only).
1518 ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
1521 With @var{follow_mouse}:
1523 ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
1527 Set the video frame size. Default value is @code{vga}.
1531 Set the grabbing region coordinates. They are expressed as offset from
1532 the top left corner of the X11 window and correspond to the
1533 @var{x_offset} and @var{y_offset} parameters in the device name. The
1534 default value for both options is 0.
1537 @c man end INPUT DEVICES