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}.
398 @item wait_for_tc (@emph{bool})
399 Drop frames till a frame with timecode is received. Sometimes serial timecode
400 isn't received with the first input frame. If that happens, the stored stream
401 timecode will be inaccurate. If this option is set to @option{true}, input frames
402 are dropped till a frame with timecode is received.
403 Option @var{timecode_format} must be specified.
404 Defaults to @option{false}.
415 ffmpeg -f decklink -list_devices 1 -i dummy
419 List supported formats:
421 ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
425 Capture video clip at 1080i50:
427 ffmpeg -format_code Hi50 -f decklink -i 'Intensity Pro' -c:a copy -c:v copy output.avi
431 Capture video clip at 1080i50 10 bit:
433 ffmpeg -bm_v210 1 -format_code Hi50 -f decklink -i 'UltraStudio Mini Recorder' -c:a copy -c:v copy output.avi
437 Capture video clip at 1080i50 with 16 audio channels:
439 ffmpeg -channels 16 -format_code Hi50 -f decklink -i 'UltraStudio Mini Recorder' -c:a copy -c:v copy output.avi
446 Windows DirectShow input device.
448 DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
449 Currently only audio and video devices are supported.
451 Multiple devices may be opened as separate inputs, but they may also be
452 opened on the same input, which should improve synchronism between them.
454 The input name should be in the format:
457 @var{TYPE}=@var{NAME}[:@var{TYPE}=@var{NAME}]
460 where @var{TYPE} can be either @var{audio} or @var{video},
461 and @var{NAME} is the device's name or alternative name..
465 If no options are specified, the device's defaults are used.
466 If the device does not support the requested options, it will
472 Set the video size in the captured video.
475 Set the frame rate in the captured video.
478 Set the sample rate (in Hz) of the captured audio.
481 Set the sample size (in bits) of the captured audio.
484 Set the number of channels in the captured audio.
487 If set to @option{true}, print a list of devices and exit.
490 If set to @option{true}, print a list of selected device's options
493 @item video_device_number
494 Set video device number for devices with the same name (starts at 0,
497 @item audio_device_number
498 Set audio device number for devices with the same name (starts at 0,
502 Select pixel format to be used by DirectShow. This may only be set when
503 the video codec is not set or set to rawvideo.
505 @item audio_buffer_size
506 Set audio device buffer size in milliseconds (which can directly
507 impact latency, depending on the device).
508 Defaults to using the audio device's
509 default buffer size (typically some multiple of 500ms).
510 Setting this value too low can degrade performance.
512 @url{http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx}
515 Select video capture pin to use by name or alternative name.
518 Select audio capture pin to use by name or alternative name.
520 @item crossbar_video_input_pin_number
521 Select video input pin number for crossbar device. This will be
522 routed to the crossbar device's Video Decoder output pin.
523 Note that changing this value can affect future invocations
524 (sets a new default) until system reboot occurs.
526 @item crossbar_audio_input_pin_number
527 Select audio input pin number for crossbar device. This will be
528 routed to the crossbar device's Audio Decoder output pin.
529 Note that changing this value can affect future invocations
530 (sets a new default) until system reboot occurs.
532 @item show_video_device_dialog
533 If set to @option{true}, before capture starts, popup a display dialog
534 to the end user, allowing them to change video filter properties
535 and configurations manually.
536 Note that for crossbar devices, adjusting values in this dialog
537 may be needed at times to toggle between PAL (25 fps) and NTSC (29.97)
538 input frame rates, sizes, interlacing, etc. Changing these values can
539 enable different scan rates/frame rates and avoiding green bars at
540 the bottom, flickering scan lines, etc.
541 Note that with some devices, changing these properties can also affect future
542 invocations (sets new defaults) until system reboot occurs.
544 @item show_audio_device_dialog
545 If set to @option{true}, before capture starts, popup a display dialog
546 to the end user, allowing them to change audio filter properties
547 and configurations manually.
549 @item show_video_crossbar_connection_dialog
550 If set to @option{true}, before capture starts, popup a display
551 dialog to the end user, allowing them to manually
552 modify crossbar pin routings, when it opens a video device.
554 @item show_audio_crossbar_connection_dialog
555 If set to @option{true}, before capture starts, popup a display
556 dialog to the end user, allowing them to manually
557 modify crossbar pin routings, when it opens an audio device.
559 @item show_analog_tv_tuner_dialog
560 If set to @option{true}, before capture starts, popup a display
561 dialog to the end user, allowing them to manually
562 modify TV channels and frequencies.
564 @item show_analog_tv_tuner_audio_dialog
565 If set to @option{true}, before capture starts, popup a display
566 dialog to the end user, allowing them to manually
567 modify TV audio (like mono vs. stereo, Language A,B or C).
569 @item audio_device_load
570 Load an audio capture filter device from file instead of searching
571 it by name. It may load additional parameters too, if the filter
572 supports the serialization of its properties to.
573 To use this an audio capture source has to be specified, but it can
574 be anything even fake one.
576 @item audio_device_save
577 Save the currently used audio capture filter device and its
578 parameters (if the filter supports it) to a file.
579 If a file with the same name exists it will be overwritten.
581 @item video_device_load
582 Load a video capture filter device from file instead of searching
583 it by name. It may load additional parameters too, if the filter
584 supports the serialization of its properties to.
585 To use this a video capture source has to be specified, but it can
586 be anything even fake one.
588 @item video_device_save
589 Save the currently used video capture filter device and its
590 parameters (if the filter supports it) to a file.
591 If a file with the same name exists it will be overwritten.
600 Print the list of DirectShow supported devices and exit:
602 $ ffmpeg -list_devices true -f dshow -i dummy
606 Open video device @var{Camera}:
608 $ ffmpeg -f dshow -i video="Camera"
612 Open second video device with name @var{Camera}:
614 $ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
618 Open video device @var{Camera} and audio device @var{Microphone}:
620 $ ffmpeg -f dshow -i video="Camera":audio="Microphone"
624 Print the list of supported options in selected device and exit:
626 $ ffmpeg -list_options true -f dshow -i video="Camera"
630 Specify pin names to capture by name or alternative name, specify alternative device name:
632 $ 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"
636 Configure a crossbar device, specifying crossbar pins, allow user to adjust video capture properties at startup:
638 $ ffmpeg -f dshow -show_video_device_dialog true -crossbar_video_input_pin_number 0
639 -crossbar_audio_input_pin_number 3 -i video="AVerMedia BDA Analog Capture":audio="AVerMedia BDA Analog Capture"
646 Linux framebuffer input device.
648 The Linux framebuffer is a graphic hardware-independent abstraction
649 layer to show graphics on a computer monitor, typically on the
650 console. It is accessed through a file device node, usually
653 For more detailed information read the file
654 Documentation/fb/framebuffer.txt included in the Linux source tree.
656 See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1).
658 To record from the framebuffer device @file{/dev/fb0} with
661 ffmpeg -f fbdev -framerate 10 -i /dev/fb0 out.avi
664 You can take a single screenshot image with the command:
666 ffmpeg -f fbdev -framerate 1 -i /dev/fb0 -frames:v 1 screenshot.jpeg
674 Set the frame rate. Default is 25.
680 Win32 GDI-based screen capture device.
682 This device allows you to capture a region of the display on Windows.
684 There are two options for the input filename:
690 title=@var{window_title}
693 The first option will capture the entire desktop, or a fixed region of the
694 desktop. The second option will instead capture the contents of a single
695 window, regardless of its position on the screen.
697 For example, to grab the entire desktop using @command{ffmpeg}:
699 ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
702 Grab a 640x480 region at position @code{10,20}:
704 ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
707 Grab the contents of the window named "Calculator"
709 ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
716 Specify whether to draw the mouse pointer. Use the value @code{0} to
717 not draw the pointer. Default value is @code{1}.
720 Set the grabbing frame rate. Default value is @code{ntsc},
721 corresponding to a frame rate of @code{30000/1001}.
724 Show grabbed region on screen.
726 If @var{show_region} is specified with @code{1}, then the grabbing
727 region will be indicated on screen. With this option, it is easy to
728 know what is being grabbed if only a portion of the screen is grabbed.
730 Note that @var{show_region} is incompatible with grabbing the contents
735 ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
739 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.
742 When capturing a region with @var{video_size}, set the distance from the left edge of the screen or desktop.
744 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.
747 When capturing a region with @var{video_size}, set the distance from the top edge of the screen or desktop.
749 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.
755 FireWire DV/HDV input device using libiec61883.
757 To enable this input device, you need libiec61883, libraw1394 and
758 libavc1394 installed on your system. Use the configure option
759 @code{--enable-libiec61883} to compile with the device enabled.
761 The iec61883 capture device supports capturing from a video device
762 connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
763 FireWire stack (juju). This is the default DV/HDV input method in Linux
764 Kernel 2.6.37 and later, since the old FireWire stack was removed.
766 Specify the FireWire port to be used as input file, or "auto"
767 to choose the first port connected.
774 Override autodetection of DV/HDV. This should only be used if auto
775 detection does not work, or if usage of a different device type
776 should be prohibited. Treating a DV device as HDV (or vice versa) will
777 not work and result in undefined behavior.
778 The values @option{auto}, @option{dv} and @option{hdv} are supported.
781 Set maximum size of buffer for incoming data, in frames. For DV, this
782 is an exact value. For HDV, it is not frame exact, since HDV does
783 not have a fixed frame size.
786 Select the capture device by specifying its GUID. Capturing will only
787 be performed from the specified device and fails if no device with the
788 given GUID is found. This is useful to select the input if multiple
789 devices are connected at the same time.
790 Look at /sys/bus/firewire/devices to find out the GUIDs.
799 Grab and show the input of a FireWire DV/HDV device.
801 ffplay -f iec61883 -i auto
805 Grab and record the input of a FireWire DV/HDV device,
806 using a packet buffer of 100000 packets if the source is HDV.
808 ffmpeg -f iec61883 -i auto -dvbuffer 100000 out.mpg
817 To enable this input device during configuration you need libjack
818 installed on your system.
820 A JACK input device creates one or more JACK writable clients, one for
821 each audio channel, with name @var{client_name}:input_@var{N}, where
822 @var{client_name} is the name provided by the application, and @var{N}
823 is a number which identifies the channel.
824 Each writable client will send the acquired data to the FFmpeg input
827 Once you have created one or more JACK readable clients, you need to
828 connect them to one or more JACK writable clients.
830 To connect or disconnect JACK clients you can use the @command{jack_connect}
831 and @command{jack_disconnect} programs, or do it through a graphical interface,
832 for example with @command{qjackctl}.
834 To list the JACK clients and their properties you can invoke the command
837 Follows an example which shows how to capture a JACK readable client
838 with @command{ffmpeg}.
840 # Create a JACK writable client with name "ffmpeg".
841 $ ffmpeg -f jack -i ffmpeg -y out.wav
843 # Start the sample jack_metro readable client.
844 $ jack_metro -b 120 -d 0.2 -f 4000
846 # List the current JACK clients.
855 # Connect metro to the ffmpeg writable client.
856 $ jack_connect metro:120_bpm ffmpeg:input_1
859 For more information read:
860 @url{http://jackaudio.org/}
867 Set the number of channels. Default is 2.
873 KMS video input device.
875 Captures the KMS scanout framebuffer associated with a specified CRTC or plane as a
876 DRM object that can be passed to other hardware functions.
878 Requires either DRM master or CAP_SYS_ADMIN to run.
880 If you don't understand what all of that means, you probably don't want this. Look at
881 @option{x11grab} instead.
888 DRM device to capture on. Defaults to @option{/dev/dri/card0}.
891 Pixel format of the framebuffer. Defaults to @option{bgr0}.
893 @item format_modifier
894 Format modifier to signal on output frames. This is necessary to import correctly into
895 some APIs, but can't be autodetected. See the libdrm documentation for possible values.
898 KMS CRTC ID to define the capture source. The first active plane on the given CRTC
902 KMS plane ID to define the capture source. Defaults to the first active plane found if
903 neither @option{crtc_id} nor @option{plane_id} are specified.
906 Framerate to capture at. This is not synchronised to any page flipping or framebuffer
907 changes - it just defines the interval at which the framebuffer is sampled. Sampling
908 faster than the framebuffer update rate will generate independent frames with the same
909 content. Defaults to @code{30}.
918 Capture from the first active plane, download the result to normal frames and encode.
919 This will only work if the framebuffer is both linear and mappable - if not, the result
920 may be scrambled or fail to download.
922 ffmpeg -f kmsgrab -i - -vf 'hwdownload,format=bgr0' output.mp4
926 Capture from CRTC ID 42 at 60fps, map the result to VAAPI, convert to NV12 and encode as H.264.
928 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
932 To capture only part of a plane the output can be cropped - this can be used to capture
933 a single window, as long as it has a known absolute position and size. For example, to
934 capture and encode the middle quarter of a 1920x1080 plane:
936 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
943 Libavfilter input virtual device.
945 This input device reads data from the open output pads of a libavfilter
948 For each filtergraph open output, the input device will create a
949 corresponding stream which is mapped to the generated output. Currently
950 only video data is supported. The filtergraph is specified through the
951 option @option{graph}.
958 Specify the filtergraph to use as input. Each video open output must be
959 labelled by a unique string of the form "out@var{N}", where @var{N} is a
960 number starting from 0 corresponding to the mapped input stream
961 generated by the device.
962 The first unlabelled output is automatically assigned to the "out0"
963 label, but all the others need to be specified explicitly.
965 The suffix "+subcc" can be appended to the output label to create an extra
966 stream with the closed captions packets attached to that output
967 (experimental; only for EIA-608 / CEA-708 for now).
968 The subcc streams are created after all the normal streams, in the order of
969 the corresponding stream.
970 For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
971 stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
973 If not specified defaults to the filename specified for the input
977 Set the filename of the filtergraph to be read and sent to the other
978 filters. Syntax of the filtergraph is the same as the one specified by
979 the option @var{graph}.
982 Dump graph to stderr.
990 Create a color video stream and play it back with @command{ffplay}:
992 ffplay -f lavfi -graph "color=c=pink [out0]" dummy
996 As the previous example, but use filename for specifying the graph
997 description, and omit the "out0" label:
999 ffplay -f lavfi color=c=pink
1003 Create three different video test filtered sources and play them:
1005 ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
1009 Read an audio stream from a file using the amovie source and play it
1010 back with @command{ffplay}:
1012 ffplay -f lavfi "amovie=test.wav"
1016 Read an audio stream and a video stream and play it back with
1019 ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
1023 Dump decoded frames to images and closed captions to a file (experimental):
1025 ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
1032 Audio-CD input device based on libcdio.
1034 To enable this input device during configuration you need libcdio
1035 installed on your system. It requires the configure option
1036 @code{--enable-libcdio}.
1038 This device allows playing and grabbing from an Audio-CD.
1040 For example to copy with @command{ffmpeg} the entire Audio-CD in @file{/dev/sr0},
1041 you may run the command:
1043 ffmpeg -f libcdio -i /dev/sr0 cd.wav
1049 Set drive reading speed. Default value is 0.
1051 The speed is specified CD-ROM speed units. The speed is set through
1052 the libcdio @code{cdio_cddap_speed_set} function. On many CD-ROM
1053 drives, specifying a value too large will result in using the fastest
1057 Set paranoia recovery mode flags. It accepts one of the following values:
1067 Default value is @samp{disable}.
1069 For more information about the available recovery modes, consult the
1070 paranoia project documentation.
1075 IIDC1394 input device, based on libdc1394 and libraw1394.
1077 Requires the configure option @code{--enable-libdc1394}.
1083 Set the frame rate. Default is @code{ntsc}, corresponding to a frame
1084 rate of @code{30000/1001}.
1087 Select the pixel format. Default is @code{uyvy422}.
1090 Set the video size given as a string such as @code{640x480} or @code{hd720}.
1091 Default is @code{qvga}.
1096 The OpenAL input device provides audio capture on all systems with a
1097 working OpenAL 1.1 implementation.
1099 To enable this input device during configuration, you need OpenAL
1100 headers and libraries installed on your system, and need to configure
1101 FFmpeg with @code{--enable-openal}.
1103 OpenAL headers and libraries should be provided as part of your OpenAL
1104 implementation, or as an additional download (an SDK). Depending on your
1105 installation you may need to specify additional flags via the
1106 @code{--extra-cflags} and @code{--extra-ldflags} for allowing the build
1107 system to locate the OpenAL headers and libraries.
1109 An incomplete list of OpenAL implementations follows:
1113 The official Windows implementation, providing hardware acceleration
1114 with supported devices and software fallback.
1115 See @url{http://openal.org/}.
1117 Portable, open source (LGPL) software implementation. Includes
1118 backends for the most common sound APIs on the Windows, Linux,
1119 Solaris, and BSD operating systems.
1120 See @url{http://kcat.strangesoft.net/openal.html}.
1122 OpenAL is part of Core Audio, the official Mac OS X Audio interface.
1123 See @url{http://developer.apple.com/technologies/mac/audio-and-video.html}
1126 This device allows one to capture from an audio input device handled
1129 You need to specify the name of the device to capture in the provided
1130 filename. If the empty string is provided, the device will
1131 automatically select the default device. You can get the list of the
1132 supported devices by using the option @var{list_devices}.
1139 Set the number of channels in the captured audio. Only the values
1140 @option{1} (monaural) and @option{2} (stereo) are currently supported.
1141 Defaults to @option{2}.
1144 Set the sample size (in bits) of the captured audio. Only the values
1145 @option{8} and @option{16} are currently supported. Defaults to
1149 Set the sample rate (in Hz) of the captured audio.
1150 Defaults to @option{44.1k}.
1153 If set to @option{true}, print a list of devices and exit.
1154 Defaults to @option{false}.
1158 @subsection Examples
1160 Print the list of OpenAL supported devices and exit:
1162 $ ffmpeg -list_devices true -f openal -i dummy out.ogg
1165 Capture from the OpenAL device @file{DR-BT101 via PulseAudio}:
1167 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
1170 Capture from the default device (note the empty string '' as filename):
1172 $ ffmpeg -f openal -i '' out.ogg
1175 Capture from two devices simultaneously, writing to two different files,
1176 within the same @command{ffmpeg} command:
1178 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
1180 Note: not all OpenAL implementations support multiple simultaneous capture -
1181 try the latest OpenAL Soft if the above does not work.
1185 Open Sound System input device.
1187 The filename to provide to the input device is the device node
1188 representing the OSS input device, and is usually set to
1191 For example to grab from @file{/dev/dsp} using @command{ffmpeg} use the
1194 ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
1197 For more information about OSS see:
1198 @url{http://manuals.opensound.com/usersguide/dsp.html}
1205 Set the sample rate in Hz. Default is 48000.
1208 Set the number of channels. Default is 2.
1214 PulseAudio input device.
1216 To enable this output device you need to configure FFmpeg with @code{--enable-libpulse}.
1218 The filename to provide to the input device is a source device or the
1221 To list the PulseAudio source devices and their properties you can invoke
1222 the command @command{pactl list sources}.
1224 More information about PulseAudio can be found on @url{http://www.pulseaudio.org}.
1229 Connect to a specific PulseAudio server, specified by an IP address.
1230 Default server is used when not provided.
1233 Specify the application name PulseAudio will use when showing active clients,
1234 by default it is the @code{LIBAVFORMAT_IDENT} string.
1237 Specify the stream name PulseAudio will use when showing active streams,
1238 by default it is "record".
1241 Specify the samplerate in Hz, by default 48kHz is used.
1244 Specify the channels in use, by default 2 (stereo) is set.
1247 Specify the number of bytes per frame, by default it is set to 1024.
1250 Specify the minimal buffering fragment in PulseAudio, it will affect the
1251 audio latency. By default it is unset.
1254 Set the initial PTS using the current time. Default is 1.
1258 @subsection Examples
1259 Record a stream from default device:
1261 ffmpeg -f pulse -i default /tmp/pulse.wav
1268 To enable this input device during configuration you need libsndio
1269 installed on your system.
1271 The filename to provide to the input device is the device node
1272 representing the sndio input device, and is usually set to
1275 For example to grab from @file{/dev/audio0} using @command{ffmpeg} use the
1278 ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
1286 Set the sample rate in Hz. Default is 48000.
1289 Set the number of channels. Default is 2.
1293 @section video4linux2, v4l2
1295 Video4Linux2 input video device.
1297 "v4l2" can be used as alias for "video4linux2".
1299 If FFmpeg is built with v4l-utils support (by using the
1300 @code{--enable-libv4l2} configure option), it is possible to use it with the
1301 @code{-use_libv4l2} input device option.
1303 The name of the device to grab is a file device node, usually Linux
1304 systems tend to automatically create such nodes when the device
1305 (e.g. an USB webcam) is plugged into the system, and has a name of the
1306 kind @file{/dev/video@var{N}}, where @var{N} is a number associated to
1309 Video4Linux2 devices usually support a limited set of
1310 @var{width}x@var{height} sizes and frame rates. You can check which are
1311 supported using @command{-list_formats all} for Video4Linux2 devices.
1312 Some devices, like TV cards, support one or more standards. It is possible
1313 to list all the supported standards using @command{-list_standards all}.
1315 The time base for the timestamps is 1 microsecond. Depending on the kernel
1316 version and configuration, the timestamps may be derived from the real time
1317 clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
1318 boot time, unaffected by NTP or manual changes to the clock). The
1319 @option{-timestamps abs} or @option{-ts abs} option can be used to force
1320 conversion into the real time clock.
1322 Some usage examples of the video4linux2 device with @command{ffmpeg}
1323 and @command{ffplay}:
1326 List supported formats for a video4linux2 device:
1328 ffplay -f video4linux2 -list_formats all /dev/video0
1332 Grab and show the input of a video4linux2 device:
1334 ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
1338 Grab and record the input of a video4linux2 device, leave the
1339 frame rate and size as previously set:
1341 ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
1345 For more information about Video4Linux, check @url{http://linuxtv.org/}.
1351 Set the standard. Must be the name of a supported standard. To get a
1352 list of the supported standards, use the @option{list_standards}
1356 Set the input channel number. Default to -1, which means using the
1357 previously selected channel.
1360 Set the video frame size. The argument must be a string in the form
1361 @var{WIDTH}x@var{HEIGHT} or a valid size abbreviation.
1364 Select the pixel format (only valid for raw video input).
1367 Set the preferred pixel format (for raw video) or a codec name.
1368 This option allows one to select the input format, when several are
1372 Set the preferred video frame rate.
1375 List available formats (supported pixel formats, codecs, and frame
1378 Available values are:
1381 Show all available (compressed and non-compressed) formats.
1384 Show only raw video (non-compressed) formats.
1387 Show only compressed formats.
1390 @item list_standards
1391 List supported standards and exit.
1393 Available values are:
1396 Show all supported standards.
1399 @item timestamps, ts
1400 Set type of timestamps for grabbed frames.
1402 Available values are:
1405 Use timestamps from the kernel.
1408 Use absolute timestamps (wall clock).
1411 Force conversion from monotonic to absolute timestamps.
1414 Default value is @code{default}.
1417 Use libv4l2 (v4l-utils) conversion functions. Default is 0.
1423 VfW (Video for Windows) capture input device.
1425 The filename passed as input is the capture driver number, ranging from
1426 0 to 9. You may use "list" as filename to print a list of drivers. Any
1427 other filename will be interpreted as device number 0.
1434 Set the video frame size.
1437 Set the grabbing frame rate. Default value is @code{ntsc},
1438 corresponding to a frame rate of @code{30000/1001}.
1444 X11 video input device.
1446 To enable this input device during configuration you need libxcb
1447 installed on your system. It will be automatically detected during
1450 This device allows one to capture a region of an X11 display.
1452 The filename passed as input has the syntax:
1454 [@var{hostname}]:@var{display_number}.@var{screen_number}[+@var{x_offset},@var{y_offset}]
1457 @var{hostname}:@var{display_number}.@var{screen_number} specifies the
1458 X11 display name of the screen to grab from. @var{hostname} can be
1459 omitted, and defaults to "localhost". The environment variable
1460 @env{DISPLAY} contains the default display name.
1462 @var{x_offset} and @var{y_offset} specify the offsets of the grabbed
1463 area with respect to the top-left border of the X11 screen. They
1466 Check the X11 documentation (e.g. @command{man X}) for more detailed
1469 Use the @command{xdpyinfo} program for getting basic information about
1470 the properties of your X11 display (e.g. grep for "name" or
1473 For example to grab from @file{:0.0} using @command{ffmpeg}:
1475 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
1478 Grab at position @code{10,20}:
1480 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
1487 Specify whether to draw the mouse pointer. A value of @code{0} specifies
1488 not to draw the pointer. Default value is @code{1}.
1491 Make the grabbed area follow the mouse. The argument can be
1492 @code{centered} or a number of pixels @var{PIXELS}.
1494 When it is specified with "centered", the grabbing region follows the mouse
1495 pointer and keeps the pointer at the center of region; otherwise, the region
1496 follows only when the mouse pointer reaches within @var{PIXELS} (greater than
1497 zero) to the edge of region.
1501 ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
1504 To follow only when the mouse pointer reaches within 100 pixels to edge:
1506 ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
1510 Set the grabbing frame rate. Default value is @code{ntsc},
1511 corresponding to a frame rate of @code{30000/1001}.
1514 Show grabbed region on screen.
1516 If @var{show_region} is specified with @code{1}, then the grabbing
1517 region will be indicated on screen. With this option, it is easy to
1518 know what is being grabbed if only a portion of the screen is grabbed.
1521 Set the region border thickness if @option{-show_region 1} is used.
1522 Range is 1 to 128 and default is 3 (XCB-based x11grab only).
1526 ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
1529 With @var{follow_mouse}:
1531 ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
1535 Set the video frame size. Default value is @code{vga}.
1539 Set the grabbing region coordinates. They are expressed as offset from
1540 the top left corner of the X11 window and correspond to the
1541 @var{x_offset} and @var{y_offset} parameters in the device name. The
1542 default value for both options is 0.
1545 @c man end INPUT DEVICES