2 @c man begin INPUT DEVICES
4 Input devices are configured elements in FFmpeg which enable accessing
5 the data coming from a multimedia device attached to your system.
7 When you configure your FFmpeg build, all the supported input devices
8 are enabled by default. You can list all available ones using the
9 configure option "--list-indevs".
11 You can disable all the input devices using the configure option
12 "--disable-indevs", and selectively enable an input device using the
13 option "--enable-indev=@var{INDEV}", or you can disable a particular
14 input device using the option "--disable-indev=@var{INDEV}".
16 The option "-devices" of the ff* tools will display the list of
17 supported input devices.
19 A description of the currently available input devices follows.
23 ALSA (Advanced Linux Sound Architecture) input device.
25 To enable this input device during configuration you need libasound
26 installed on your system.
28 This device allows capturing from an ALSA device. The name of the
29 device to capture has to be an ALSA card identifier.
31 An ALSA identifier has the syntax:
33 hw:@var{CARD}[,@var{DEV}[,@var{SUBDEV}]]
36 where the @var{DEV} and @var{SUBDEV} components are optional.
38 The three arguments (in order: @var{CARD},@var{DEV},@var{SUBDEV})
39 specify card number or identifier, device number and subdevice number
42 To see the list of cards currently recognized by your system check the
43 files @file{/proc/asound/cards} and @file{/proc/asound/devices}.
45 For example to capture with @command{ffmpeg} from an ALSA device with
46 card id 0, you may run the command:
48 ffmpeg -f alsa -i hw:0 alsaout.wav
51 For more information see:
52 @url{http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html}
59 Set the sample rate in Hz. Default is 48000.
62 Set the number of channels. Default is 2.
68 AVFoundation input device.
70 AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX >= 10.7 as well as on iOS.
71 The older QTKit framework has been marked deprecated since OSX version 10.7.
73 The input filename has to be given in the following syntax:
75 -i "[[VIDEO]:[AUDIO]]"
77 The first entry selects the video input while the latter selects the audio input.
78 The stream has to be specified by the device name or the device index as shown by the device list.
79 Alternatively, the video and/or audio input device can be chosen by index using the
81 -video_device_index <INDEX>
85 -audio_device_index <INDEX>
88 device name or index given in the input filename.
90 All available devices can be enumerated by using @option{-list_devices true}, listing
91 all device names and corresponding indices.
93 There are two device name aliases:
97 Select the AVFoundation default device of the corresponding type.
100 Do not record the corresponding media type.
101 This is equivalent to specifying an empty device name or index.
107 AVFoundation supports the following options:
111 @item -list_devices <TRUE|FALSE>
112 If set to true, a list of all available input devices is given showing all
113 device names and indices.
115 @item -video_device_index <INDEX>
116 Specify the video device by its index. Overrides anything given in the input filename.
118 @item -audio_device_index <INDEX>
119 Specify the audio device by its index. Overrides anything given in the input filename.
121 @item -pixel_format <FORMAT>
122 Request the video device to use a specific pixel format.
123 If the specified format is not supported, a list of available formats is given
124 and the first one in this list is used instead. Available pixel formats are:
125 @code{monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,
126 bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10,
127 yuv420p, nv12, yuyv422, gray}
130 Set the grabbing frame rate. Default is @code{ntsc}, corresponding to a
131 frame rate of @code{30000/1001}.
134 Set the video frame size.
136 @item -capture_cursor
137 Capture the mouse pointer. Default is 0.
139 @item -capture_mouse_clicks
140 Capture the screen mouse clicks. Default is 0.
149 Print the list of AVFoundation supported devices and exit:
151 $ ffmpeg -f avfoundation -list_devices true -i ""
155 Record video from video device 0 and audio from audio device 0 into out.avi:
157 $ ffmpeg -f avfoundation -i "0:0" out.avi
161 Record video from video device 2 and audio from audio device 1 into out.avi:
163 $ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi
167 Record video from the system default video device using the pixel format bgr0 and do not record any audio into out.avi:
169 $ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi
176 BSD video input device.
186 Set the video frame size. Default is @code{vga}.
190 Available values are:
210 The decklink input device provides capture capabilities for Blackmagic
213 To enable this input device, you need the Blackmagic DeckLink SDK and you
214 need to configure with the appropriate @code{--extra-cflags}
215 and @code{--extra-ldflags}.
216 On Windows, you need to run the IDL files through @command{widl}.
218 DeckLink is very picky about the formats it supports. Pixel format is
219 uyvy422 or v210, framerate and video size must be determined for your device with
220 @command{-list_formats 1}. Audio sample rate is always 48 kHz and the number
221 of channels can be 2, 8 or 16. Note that all audio channels are bundled in one single
229 If set to @option{true}, print a list of devices and exit.
230 Defaults to @option{false}.
233 If set to @option{true}, print a list of supported formats and exit.
234 Defaults to @option{false}.
237 If set to @samp{1}, video is captured in 10 bit v210 instead
238 of uyvy422. Not all Blackmagic devices support this option.
241 If set to nonzero, an additional teletext stream will be captured from the
242 vertical ancillary data. This option is a bitmask of the VBI lines checked,
243 specifically lines 6 to 22, and lines 318 to 335. Line 6 is the LSB in the mask.
244 Selected lines which do not contain teletext information will be ignored. You
245 can use the special @option{all} constant to select all possible lines, or
246 @option{standard} to skip lines 6, 318 and 319, which are not compatible with all
247 receivers. Capturing teletext only works for SD PAL sources in 8 bit mode.
248 To use this option, ffmpeg needs to be compiled with @code{--enable-libzvbi}.
251 Defines number of audio channels to capture. Must be @samp{2}, @samp{8} or @samp{16}.
252 Defaults to @samp{2}.
255 Sets the decklink device duplex mode. Must be @samp{unset}, @samp{half} or @samp{full}.
256 Defaults to @samp{unset}.
259 Sets the video input source. Must be @samp{unset}, @samp{sdi}, @samp{hdmi},
260 @samp{optical_sdi}, @samp{component}, @samp{composite} or @samp{s_video}.
261 Defaults to @samp{unset}.
264 Sets the audio input source. Must be @samp{unset}, @samp{embedded},
265 @samp{aes_ebu}, @samp{analog}, @samp{analog_xlr}, @samp{analog_rca} or
266 @samp{microphone}. Defaults to @samp{unset}.
269 Sets the video packet timestamp source. Must be @samp{video}, @samp{audio},
270 @samp{reference} or @samp{wallclock}. Defaults to @samp{video}.
273 Sets the audio packet timestamp source. Must be @samp{video}, @samp{audio},
274 @samp{reference} or @samp{wallclock}. Defaults to @samp{audio}.
285 ffmpeg -f decklink -list_devices 1 -i dummy
289 List supported formats:
291 ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
295 Capture video clip at 1080i50 (format 11):
297 ffmpeg -f decklink -i 'Intensity Pro@@11' -acodec copy -vcodec copy output.avi
301 Capture video clip at 1080i50 10 bit:
303 ffmpeg -bm_v210 1 -f decklink -i 'UltraStudio Mini Recorder@@11' -acodec copy -vcodec copy output.avi
307 Capture video clip at 1080i50 with 16 audio channels:
309 ffmpeg -channels 16 -f decklink -i 'UltraStudio Mini Recorder@@11' -acodec copy -vcodec copy output.avi
316 Windows DirectShow input device.
318 DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
319 Currently only audio and video devices are supported.
321 Multiple devices may be opened as separate inputs, but they may also be
322 opened on the same input, which should improve synchronism between them.
324 The input name should be in the format:
327 @var{TYPE}=@var{NAME}[:@var{TYPE}=@var{NAME}]
330 where @var{TYPE} can be either @var{audio} or @var{video},
331 and @var{NAME} is the device's name or alternative name..
335 If no options are specified, the device's defaults are used.
336 If the device does not support the requested options, it will
342 Set the video size in the captured video.
345 Set the frame rate in the captured video.
348 Set the sample rate (in Hz) of the captured audio.
351 Set the sample size (in bits) of the captured audio.
354 Set the number of channels in the captured audio.
357 If set to @option{true}, print a list of devices and exit.
360 If set to @option{true}, print a list of selected device's options
363 @item video_device_number
364 Set video device number for devices with the same name (starts at 0,
367 @item audio_device_number
368 Set audio device number for devices with the same name (starts at 0,
372 Select pixel format to be used by DirectShow. This may only be set when
373 the video codec is not set or set to rawvideo.
375 @item audio_buffer_size
376 Set audio device buffer size in milliseconds (which can directly
377 impact latency, depending on the device).
378 Defaults to using the audio device's
379 default buffer size (typically some multiple of 500ms).
380 Setting this value too low can degrade performance.
382 @url{http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx}
385 Select video capture pin to use by name or alternative name.
388 Select audio capture pin to use by name or alternative name.
390 @item crossbar_video_input_pin_number
391 Select video input pin number for crossbar device. This will be
392 routed to the crossbar device's Video Decoder output pin.
393 Note that changing this value can affect future invocations
394 (sets a new default) until system reboot occurs.
396 @item crossbar_audio_input_pin_number
397 Select audio input pin number for crossbar device. This will be
398 routed to the crossbar device's Audio Decoder output pin.
399 Note that changing this value can affect future invocations
400 (sets a new default) until system reboot occurs.
402 @item show_video_device_dialog
403 If set to @option{true}, before capture starts, popup a display dialog
404 to the end user, allowing them to change video filter properties
405 and configurations manually.
406 Note that for crossbar devices, adjusting values in this dialog
407 may be needed at times to toggle between PAL (25 fps) and NTSC (29.97)
408 input frame rates, sizes, interlacing, etc. Changing these values can
409 enable different scan rates/frame rates and avoiding green bars at
410 the bottom, flickering scan lines, etc.
411 Note that with some devices, changing these properties can also affect future
412 invocations (sets new defaults) until system reboot occurs.
414 @item show_audio_device_dialog
415 If set to @option{true}, before capture starts, popup a display dialog
416 to the end user, allowing them to change audio filter properties
417 and configurations manually.
419 @item show_video_crossbar_connection_dialog
420 If set to @option{true}, before capture starts, popup a display
421 dialog to the end user, allowing them to manually
422 modify crossbar pin routings, when it opens a video device.
424 @item show_audio_crossbar_connection_dialog
425 If set to @option{true}, before capture starts, popup a display
426 dialog to the end user, allowing them to manually
427 modify crossbar pin routings, when it opens an audio device.
429 @item show_analog_tv_tuner_dialog
430 If set to @option{true}, before capture starts, popup a display
431 dialog to the end user, allowing them to manually
432 modify TV channels and frequencies.
434 @item show_analog_tv_tuner_audio_dialog
435 If set to @option{true}, before capture starts, popup a display
436 dialog to the end user, allowing them to manually
437 modify TV audio (like mono vs. stereo, Language A,B or C).
439 @item audio_device_load
440 Load an audio capture filter device from file instead of searching
441 it by name. It may load additional parameters too, if the filter
442 supports the serialization of its properties to.
443 To use this an audio capture source has to be specified, but it can
444 be anything even fake one.
446 @item audio_device_save
447 Save the currently used audio capture filter device and its
448 parameters (if the filter supports it) to a file.
449 If a file with the same name exists it will be overwritten.
451 @item video_device_load
452 Load a video capture filter device from file instead of searching
453 it by name. It may load additional parameters too, if the filter
454 supports the serialization of its properties to.
455 To use this a video capture source has to be specified, but it can
456 be anything even fake one.
458 @item video_device_save
459 Save the currently used video capture filter device and its
460 parameters (if the filter supports it) to a file.
461 If a file with the same name exists it will be overwritten.
470 Print the list of DirectShow supported devices and exit:
472 $ ffmpeg -list_devices true -f dshow -i dummy
476 Open video device @var{Camera}:
478 $ ffmpeg -f dshow -i video="Camera"
482 Open second video device with name @var{Camera}:
484 $ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
488 Open video device @var{Camera} and audio device @var{Microphone}:
490 $ ffmpeg -f dshow -i video="Camera":audio="Microphone"
494 Print the list of supported options in selected device and exit:
496 $ ffmpeg -list_options true -f dshow -i video="Camera"
500 Specify pin names to capture by name or alternative name, specify alternative device name:
502 $ 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"
506 Configure a crossbar device, specifying crossbar pins, allow user to adjust video capture properties at startup:
508 $ ffmpeg -f dshow -show_video_device_dialog true -crossbar_video_input_pin_number 0
509 -crossbar_audio_input_pin_number 3 -i video="AVerMedia BDA Analog Capture":audio="AVerMedia BDA Analog Capture"
516 Linux DV 1394 input device.
523 Set the frame rate. Default is 25.
527 Available values are:
535 Default value is @code{ntsc}.
541 Linux framebuffer input device.
543 The Linux framebuffer is a graphic hardware-independent abstraction
544 layer to show graphics on a computer monitor, typically on the
545 console. It is accessed through a file device node, usually
548 For more detailed information read the file
549 Documentation/fb/framebuffer.txt included in the Linux source tree.
551 See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1).
553 To record from the framebuffer device @file{/dev/fb0} with
556 ffmpeg -f fbdev -framerate 10 -i /dev/fb0 out.avi
559 You can take a single screenshot image with the command:
561 ffmpeg -f fbdev -framerate 1 -i /dev/fb0 -frames:v 1 screenshot.jpeg
569 Set the frame rate. Default is 25.
575 Win32 GDI-based screen capture device.
577 This device allows you to capture a region of the display on Windows.
579 There are two options for the input filename:
585 title=@var{window_title}
588 The first option will capture the entire desktop, or a fixed region of the
589 desktop. The second option will instead capture the contents of a single
590 window, regardless of its position on the screen.
592 For example, to grab the entire desktop using @command{ffmpeg}:
594 ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
597 Grab a 640x480 region at position @code{10,20}:
599 ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
602 Grab the contents of the window named "Calculator"
604 ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
611 Specify whether to draw the mouse pointer. Use the value @code{0} to
612 not draw the pointer. Default value is @code{1}.
615 Set the grabbing frame rate. Default value is @code{ntsc},
616 corresponding to a frame rate of @code{30000/1001}.
619 Show grabbed region on screen.
621 If @var{show_region} is specified with @code{1}, then the grabbing
622 region will be indicated on screen. With this option, it is easy to
623 know what is being grabbed if only a portion of the screen is grabbed.
625 Note that @var{show_region} is incompatible with grabbing the contents
630 ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
634 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.
637 When capturing a region with @var{video_size}, set the distance from the left edge of the screen or desktop.
639 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.
642 When capturing a region with @var{video_size}, set the distance from the top edge of the screen or desktop.
644 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.
650 FireWire DV/HDV input device using libiec61883.
652 To enable this input device, you need libiec61883, libraw1394 and
653 libavc1394 installed on your system. Use the configure option
654 @code{--enable-libiec61883} to compile with the device enabled.
656 The iec61883 capture device supports capturing from a video device
657 connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
658 FireWire stack (juju). This is the default DV/HDV input method in Linux
659 Kernel 2.6.37 and later, since the old FireWire stack was removed.
661 Specify the FireWire port to be used as input file, or "auto"
662 to choose the first port connected.
669 Override autodetection of DV/HDV. This should only be used if auto
670 detection does not work, or if usage of a different device type
671 should be prohibited. Treating a DV device as HDV (or vice versa) will
672 not work and result in undefined behavior.
673 The values @option{auto}, @option{dv} and @option{hdv} are supported.
676 Set maximum size of buffer for incoming data, in frames. For DV, this
677 is an exact value. For HDV, it is not frame exact, since HDV does
678 not have a fixed frame size.
681 Select the capture device by specifying it's GUID. Capturing will only
682 be performed from the specified device and fails if no device with the
683 given GUID is found. This is useful to select the input if multiple
684 devices are connected at the same time.
685 Look at /sys/bus/firewire/devices to find out the GUIDs.
694 Grab and show the input of a FireWire DV/HDV device.
696 ffplay -f iec61883 -i auto
700 Grab and record the input of a FireWire DV/HDV device,
701 using a packet buffer of 100000 packets if the source is HDV.
703 ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg
712 To enable this input device during configuration you need libjack
713 installed on your system.
715 A JACK input device creates one or more JACK writable clients, one for
716 each audio channel, with name @var{client_name}:input_@var{N}, where
717 @var{client_name} is the name provided by the application, and @var{N}
718 is a number which identifies the channel.
719 Each writable client will send the acquired data to the FFmpeg input
722 Once you have created one or more JACK readable clients, you need to
723 connect them to one or more JACK writable clients.
725 To connect or disconnect JACK clients you can use the @command{jack_connect}
726 and @command{jack_disconnect} programs, or do it through a graphical interface,
727 for example with @command{qjackctl}.
729 To list the JACK clients and their properties you can invoke the command
732 Follows an example which shows how to capture a JACK readable client
733 with @command{ffmpeg}.
735 # Create a JACK writable client with name "ffmpeg".
736 $ ffmpeg -f jack -i ffmpeg -y out.wav
738 # Start the sample jack_metro readable client.
739 $ jack_metro -b 120 -d 0.2 -f 4000
741 # List the current JACK clients.
750 # Connect metro to the ffmpeg writable client.
751 $ jack_connect metro:120_bpm ffmpeg:input_1
754 For more information read:
755 @url{http://jackaudio.org/}
762 Set the number of channels. Default is 2.
768 Libavfilter input virtual device.
770 This input device reads data from the open output pads of a libavfilter
773 For each filtergraph open output, the input device will create a
774 corresponding stream which is mapped to the generated output. Currently
775 only video data is supported. The filtergraph is specified through the
776 option @option{graph}.
783 Specify the filtergraph to use as input. Each video open output must be
784 labelled by a unique string of the form "out@var{N}", where @var{N} is a
785 number starting from 0 corresponding to the mapped input stream
786 generated by the device.
787 The first unlabelled output is automatically assigned to the "out0"
788 label, but all the others need to be specified explicitly.
790 The suffix "+subcc" can be appended to the output label to create an extra
791 stream with the closed captions packets attached to that output
792 (experimental; only for EIA-608 / CEA-708 for now).
793 The subcc streams are created after all the normal streams, in the order of
794 the corresponding stream.
795 For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
796 stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
798 If not specified defaults to the filename specified for the input
802 Set the filename of the filtergraph to be read and sent to the other
803 filters. Syntax of the filtergraph is the same as the one specified by
804 the option @var{graph}.
807 Dump graph to stderr.
815 Create a color video stream and play it back with @command{ffplay}:
817 ffplay -f lavfi -graph "color=c=pink [out0]" dummy
821 As the previous example, but use filename for specifying the graph
822 description, and omit the "out0" label:
824 ffplay -f lavfi color=c=pink
828 Create three different video test filtered sources and play them:
830 ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
834 Read an audio stream from a file using the amovie source and play it
835 back with @command{ffplay}:
837 ffplay -f lavfi "amovie=test.wav"
841 Read an audio stream and a video stream and play it back with
844 ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
848 Dump decoded frames to images and closed captions to a file (experimental):
850 ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
857 Audio-CD input device based on libcdio.
859 To enable this input device during configuration you need libcdio
860 installed on your system. It requires the configure option
861 @code{--enable-libcdio}.
863 This device allows playing and grabbing from an Audio-CD.
865 For example to copy with @command{ffmpeg} the entire Audio-CD in @file{/dev/sr0},
866 you may run the command:
868 ffmpeg -f libcdio -i /dev/sr0 cd.wav
874 Set drive reading speed. Default value is 0.
876 The speed is specified CD-ROM speed units. The speed is set through
877 the libcdio @code{cdio_cddap_speed_set} function. On many CD-ROM
878 drives, specifying a value too large will result in using the fastest
882 Set paranoia recovery mode flags. It accepts one of the following values:
892 Default value is @samp{disable}.
894 For more information about the available recovery modes, consult the
895 paranoia project documentation.
900 IIDC1394 input device, based on libdc1394 and libraw1394.
902 Requires the configure option @code{--enable-libdc1394}.
906 The OpenAL input device provides audio capture on all systems with a
907 working OpenAL 1.1 implementation.
909 To enable this input device during configuration, you need OpenAL
910 headers and libraries installed on your system, and need to configure
911 FFmpeg with @code{--enable-openal}.
913 OpenAL headers and libraries should be provided as part of your OpenAL
914 implementation, or as an additional download (an SDK). Depending on your
915 installation you may need to specify additional flags via the
916 @code{--extra-cflags} and @code{--extra-ldflags} for allowing the build
917 system to locate the OpenAL headers and libraries.
919 An incomplete list of OpenAL implementations follows:
923 The official Windows implementation, providing hardware acceleration
924 with supported devices and software fallback.
925 See @url{http://openal.org/}.
927 Portable, open source (LGPL) software implementation. Includes
928 backends for the most common sound APIs on the Windows, Linux,
929 Solaris, and BSD operating systems.
930 See @url{http://kcat.strangesoft.net/openal.html}.
932 OpenAL is part of Core Audio, the official Mac OS X Audio interface.
933 See @url{http://developer.apple.com/technologies/mac/audio-and-video.html}
936 This device allows one to capture from an audio input device handled
939 You need to specify the name of the device to capture in the provided
940 filename. If the empty string is provided, the device will
941 automatically select the default device. You can get the list of the
942 supported devices by using the option @var{list_devices}.
949 Set the number of channels in the captured audio. Only the values
950 @option{1} (monaural) and @option{2} (stereo) are currently supported.
951 Defaults to @option{2}.
954 Set the sample size (in bits) of the captured audio. Only the values
955 @option{8} and @option{16} are currently supported. Defaults to
959 Set the sample rate (in Hz) of the captured audio.
960 Defaults to @option{44.1k}.
963 If set to @option{true}, print a list of devices and exit.
964 Defaults to @option{false}.
970 Print the list of OpenAL supported devices and exit:
972 $ ffmpeg -list_devices true -f openal -i dummy out.ogg
975 Capture from the OpenAL device @file{DR-BT101 via PulseAudio}:
977 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
980 Capture from the default device (note the empty string '' as filename):
982 $ ffmpeg -f openal -i '' out.ogg
985 Capture from two devices simultaneously, writing to two different files,
986 within the same @command{ffmpeg} command:
988 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
990 Note: not all OpenAL implementations support multiple simultaneous capture -
991 try the latest OpenAL Soft if the above does not work.
995 Open Sound System input device.
997 The filename to provide to the input device is the device node
998 representing the OSS input device, and is usually set to
1001 For example to grab from @file{/dev/dsp} using @command{ffmpeg} use the
1004 ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
1007 For more information about OSS see:
1008 @url{http://manuals.opensound.com/usersguide/dsp.html}
1015 Set the sample rate in Hz. Default is 48000.
1018 Set the number of channels. Default is 2.
1025 PulseAudio input device.
1027 To enable this output device you need to configure FFmpeg with @code{--enable-libpulse}.
1029 The filename to provide to the input device is a source device or the
1032 To list the PulseAudio source devices and their properties you can invoke
1033 the command @command{pactl list sources}.
1035 More information about PulseAudio can be found on @url{http://www.pulseaudio.org}.
1040 Connect to a specific PulseAudio server, specified by an IP address.
1041 Default server is used when not provided.
1044 Specify the application name PulseAudio will use when showing active clients,
1045 by default it is the @code{LIBAVFORMAT_IDENT} string.
1048 Specify the stream name PulseAudio will use when showing active streams,
1049 by default it is "record".
1052 Specify the samplerate in Hz, by default 48kHz is used.
1055 Specify the channels in use, by default 2 (stereo) is set.
1058 Specify the number of bytes per frame, by default it is set to 1024.
1061 Specify the minimal buffering fragment in PulseAudio, it will affect the
1062 audio latency. By default it is unset.
1065 Set the initial PTS using the current time. Default is 1.
1069 @subsection Examples
1070 Record a stream from default device:
1072 ffmpeg -f pulse -i default /tmp/pulse.wav
1079 The filename passed as input is parsed to contain either a device name or index.
1080 The device index can also be given by using -video_device_index.
1081 A given device index will override any given device name.
1082 If the desired device consists of numbers only, use -video_device_index to identify it.
1083 The default device will be chosen if an empty string or the device name "default" is given.
1084 The available devices can be enumerated by using -list_devices.
1087 ffmpeg -f qtkit -i "0" out.mpg
1091 ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg
1095 ffmpeg -f qtkit -i "default" out.mpg
1099 ffmpeg -f qtkit -list_devices true -i ""
1107 Set frame rate. Default is 30.
1110 If set to @code{true}, print a list of devices and exit. Default is
1113 @item video_device_index
1114 Select the video device by index for devices with the same name (starts at 0).
1122 To enable this input device during configuration you need libsndio
1123 installed on your system.
1125 The filename to provide to the input device is the device node
1126 representing the sndio input device, and is usually set to
1129 For example to grab from @file{/dev/audio0} using @command{ffmpeg} use the
1132 ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
1140 Set the sample rate in Hz. Default is 48000.
1143 Set the number of channels. Default is 2.
1147 @section video4linux2, v4l2
1149 Video4Linux2 input video device.
1151 "v4l2" can be used as alias for "video4linux2".
1153 If FFmpeg is built with v4l-utils support (by using the
1154 @code{--enable-libv4l2} configure option), it is possible to use it with the
1155 @code{-use_libv4l2} input device option.
1157 The name of the device to grab is a file device node, usually Linux
1158 systems tend to automatically create such nodes when the device
1159 (e.g. an USB webcam) is plugged into the system, and has a name of the
1160 kind @file{/dev/video@var{N}}, where @var{N} is a number associated to
1163 Video4Linux2 devices usually support a limited set of
1164 @var{width}x@var{height} sizes and frame rates. You can check which are
1165 supported using @command{-list_formats all} for Video4Linux2 devices.
1166 Some devices, like TV cards, support one or more standards. It is possible
1167 to list all the supported standards using @command{-list_standards all}.
1169 The time base for the timestamps is 1 microsecond. Depending on the kernel
1170 version and configuration, the timestamps may be derived from the real time
1171 clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
1172 boot time, unaffected by NTP or manual changes to the clock). The
1173 @option{-timestamps abs} or @option{-ts abs} option can be used to force
1174 conversion into the real time clock.
1176 Some usage examples of the video4linux2 device with @command{ffmpeg}
1177 and @command{ffplay}:
1180 List supported formats for a video4linux2 device:
1182 ffplay -f video4linux2 -list_formats all /dev/video0
1186 Grab and show the input of a video4linux2 device:
1188 ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
1192 Grab and record the input of a video4linux2 device, leave the
1193 frame rate and size as previously set:
1195 ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
1199 For more information about Video4Linux, check @url{http://linuxtv.org/}.
1205 Set the standard. Must be the name of a supported standard. To get a
1206 list of the supported standards, use the @option{list_standards}
1210 Set the input channel number. Default to -1, which means using the
1211 previously selected channel.
1214 Set the video frame size. The argument must be a string in the form
1215 @var{WIDTH}x@var{HEIGHT} or a valid size abbreviation.
1218 Select the pixel format (only valid for raw video input).
1221 Set the preferred pixel format (for raw video) or a codec name.
1222 This option allows one to select the input format, when several are
1226 Set the preferred video frame rate.
1229 List available formats (supported pixel formats, codecs, and frame
1232 Available values are:
1235 Show all available (compressed and non-compressed) formats.
1238 Show only raw video (non-compressed) formats.
1241 Show only compressed formats.
1244 @item list_standards
1245 List supported standards and exit.
1247 Available values are:
1250 Show all supported standards.
1253 @item timestamps, ts
1254 Set type of timestamps for grabbed frames.
1256 Available values are:
1259 Use timestamps from the kernel.
1262 Use absolute timestamps (wall clock).
1265 Force conversion from monotonic to absolute timestamps.
1268 Default value is @code{default}.
1271 Use libv4l2 (v4l-utils) conversion functions. Default is 0.
1277 VfW (Video for Windows) capture input device.
1279 The filename passed as input is the capture driver number, ranging from
1280 0 to 9. You may use "list" as filename to print a list of drivers. Any
1281 other filename will be interpreted as device number 0.
1288 Set the video frame size.
1291 Set the grabbing frame rate. Default value is @code{ntsc},
1292 corresponding to a frame rate of @code{30000/1001}.
1298 X11 video input device.
1300 To enable this input device during configuration you need libxcb
1301 installed on your system. It will be automatically detected during
1304 Alternatively, the configure option @option{--enable-x11grab} exists
1305 for legacy Xlib users.
1307 This device allows one to capture a region of an X11 display.
1309 The filename passed as input has the syntax:
1311 [@var{hostname}]:@var{display_number}.@var{screen_number}[+@var{x_offset},@var{y_offset}]
1314 @var{hostname}:@var{display_number}.@var{screen_number} specifies the
1315 X11 display name of the screen to grab from. @var{hostname} can be
1316 omitted, and defaults to "localhost". The environment variable
1317 @env{DISPLAY} contains the default display name.
1319 @var{x_offset} and @var{y_offset} specify the offsets of the grabbed
1320 area with respect to the top-left border of the X11 screen. They
1323 Check the X11 documentation (e.g. @command{man X}) for more detailed
1326 Use the @command{xdpyinfo} program for getting basic information about
1327 the properties of your X11 display (e.g. grep for "name" or
1330 For example to grab from @file{:0.0} using @command{ffmpeg}:
1332 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
1335 Grab at position @code{10,20}:
1337 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
1344 Specify whether to draw the mouse pointer. A value of @code{0} specify
1345 not to draw the pointer. Default value is @code{1}.
1348 Make the grabbed area follow the mouse. The argument can be
1349 @code{centered} or a number of pixels @var{PIXELS}.
1351 When it is specified with "centered", the grabbing region follows the mouse
1352 pointer and keeps the pointer at the center of region; otherwise, the region
1353 follows only when the mouse pointer reaches within @var{PIXELS} (greater than
1354 zero) to the edge of region.
1358 ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
1361 To follow only when the mouse pointer reaches within 100 pixels to edge:
1363 ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
1367 Set the grabbing frame rate. Default value is @code{ntsc},
1368 corresponding to a frame rate of @code{30000/1001}.
1371 Show grabbed region on screen.
1373 If @var{show_region} is specified with @code{1}, then the grabbing
1374 region will be indicated on screen. With this option, it is easy to
1375 know what is being grabbed if only a portion of the screen is grabbed.
1378 Set the region border thickness if @option{-show_region 1} is used.
1379 Range is 1 to 128 and default is 3 (XCB-based x11grab only).
1383 ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
1386 With @var{follow_mouse}:
1388 ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
1392 Set the video frame size. Default value is @code{vga}.
1395 Use the MIT-SHM extension for shared memory. Default value is @code{1}.
1396 It may be necessary to disable it for remote displays (legacy x11grab
1401 Set the grabbing region coordinates. They are expressed as offset from
1402 the top left corner of the X11 window and correspond to the
1403 @var{x_offset} and @var{y_offset} parameters in the device name. The
1404 default value for both options is 0.
1407 @c man end INPUT DEVICES