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}.
236 @item format_code <FourCC>
237 This sets the input video format to the format given by the FourCC. To see
238 the supported values of your device(s) use @option{list_formats}.
239 Note that there is a FourCC @option{'pal '} that can also be used
240 as @option{pal} (3 letters).
243 If set to @samp{1}, video is captured in 10 bit v210 instead
244 of uyvy422. Not all Blackmagic devices support this option.
247 If set to nonzero, an additional teletext stream will be captured from the
248 vertical ancillary data. Both SD PAL (576i) and HD (1080i or 1080p)
249 sources are supported. In case of HD sources, OP47 packets are decoded.
251 This option is a bitmask of the SD PAL VBI lines captured, specifically lines 6
252 to 22, and lines 318 to 335. Line 6 is the LSB in the mask. Selected lines
253 which do not contain teletext information will be ignored. You can use the
254 special @option{all} constant to select all possible lines, or
255 @option{standard} to skip lines 6, 318 and 319, which are not compatible with
258 For SD sources, ffmpeg needs to be compiled with @code{--enable-libzvbi}. For
259 HD sources, on older (pre-4K) DeckLink card models you have to capture in 10
263 Defines number of audio channels to capture. Must be @samp{2}, @samp{8} or @samp{16}.
264 Defaults to @samp{2}.
267 Sets the decklink device duplex mode. Must be @samp{unset}, @samp{half} or @samp{full}.
268 Defaults to @samp{unset}.
271 Sets the video input source. Must be @samp{unset}, @samp{sdi}, @samp{hdmi},
272 @samp{optical_sdi}, @samp{component}, @samp{composite} or @samp{s_video}.
273 Defaults to @samp{unset}.
276 Sets the audio input source. Must be @samp{unset}, @samp{embedded},
277 @samp{aes_ebu}, @samp{analog}, @samp{analog_xlr}, @samp{analog_rca} or
278 @samp{microphone}. Defaults to @samp{unset}.
281 Sets the video packet timestamp source. Must be @samp{video}, @samp{audio},
282 @samp{reference} or @samp{wallclock}. Defaults to @samp{video}.
285 Sets the audio packet timestamp source. Must be @samp{video}, @samp{audio},
286 @samp{reference} or @samp{wallclock}. Defaults to @samp{audio}.
289 If set to @samp{true}, color bars are drawn in the event of a signal loss.
290 Defaults to @samp{true}.
293 Sets maximum input buffer size in bytes. If the buffering reaches this value,
294 incoming frames will be dropped.
295 Defaults to @samp{1073741824}.
306 ffmpeg -f decklink -list_devices 1 -i dummy
310 List supported formats:
312 ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
316 Capture video clip at 1080i50:
318 ffmpeg -format_code Hi50 -f decklink -i 'Intensity Pro' -acodec copy -vcodec copy output.avi
322 Capture video clip at 1080i50 10 bit:
324 ffmpeg -bm_v210 1 -format_code Hi50 -f decklink -i 'UltraStudio Mini Recorder' -acodec copy -vcodec copy output.avi
328 Capture video clip at 1080i50 with 16 audio channels:
330 ffmpeg -channels 16 -format_code Hi50 -f decklink -i 'UltraStudio Mini Recorder' -acodec copy -vcodec copy output.avi
335 @section libndi_newtek
337 The libndi_newtek input device provides capture capabilities for using NDI (Network
338 Device Interface, standard created by NewTek).
340 Input filename is a NDI source name that could be found by sending -find_sources 1
341 to command line - it has no specific syntax but human-readable formatted.
343 To enable this input device, you need the NDI SDK and you
344 need to configure with the appropriate @code{--extra-cflags}
345 and @code{--extra-ldflags}.
352 If set to @option{true}, print a list of found/available NDI sources and exit.
353 Defaults to @option{false}.
356 Override time to wait until the number of online sources have changed.
357 Defaults to @option{0.5}.
359 @item allow_video_fields
360 When this flag is @option{false}, all video that you receive will be progressive.
361 Defaults to @option{true}.
372 ffmpeg -f libndi_newtek -find_sources 1 -i dummy
378 ffmpeg -f libndi_newtek -i "DEV-5.INTERNAL.M1STEREO.TV (NDI_SOURCE_NAME_1)" -f libndi_newtek -y NDI_SOURCE_NAME_2
385 Windows DirectShow input device.
387 DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
388 Currently only audio and video devices are supported.
390 Multiple devices may be opened as separate inputs, but they may also be
391 opened on the same input, which should improve synchronism between them.
393 The input name should be in the format:
396 @var{TYPE}=@var{NAME}[:@var{TYPE}=@var{NAME}]
399 where @var{TYPE} can be either @var{audio} or @var{video},
400 and @var{NAME} is the device's name or alternative name..
404 If no options are specified, the device's defaults are used.
405 If the device does not support the requested options, it will
411 Set the video size in the captured video.
414 Set the frame rate in the captured video.
417 Set the sample rate (in Hz) of the captured audio.
420 Set the sample size (in bits) of the captured audio.
423 Set the number of channels in the captured audio.
426 If set to @option{true}, print a list of devices and exit.
429 If set to @option{true}, print a list of selected device's options
432 @item video_device_number
433 Set video device number for devices with the same name (starts at 0,
436 @item audio_device_number
437 Set audio device number for devices with the same name (starts at 0,
441 Select pixel format to be used by DirectShow. This may only be set when
442 the video codec is not set or set to rawvideo.
444 @item audio_buffer_size
445 Set audio device buffer size in milliseconds (which can directly
446 impact latency, depending on the device).
447 Defaults to using the audio device's
448 default buffer size (typically some multiple of 500ms).
449 Setting this value too low can degrade performance.
451 @url{http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx}
454 Select video capture pin to use by name or alternative name.
457 Select audio capture pin to use by name or alternative name.
459 @item crossbar_video_input_pin_number
460 Select video input pin number for crossbar device. This will be
461 routed to the crossbar device's Video Decoder output pin.
462 Note that changing this value can affect future invocations
463 (sets a new default) until system reboot occurs.
465 @item crossbar_audio_input_pin_number
466 Select audio input pin number for crossbar device. This will be
467 routed to the crossbar device's Audio Decoder output pin.
468 Note that changing this value can affect future invocations
469 (sets a new default) until system reboot occurs.
471 @item show_video_device_dialog
472 If set to @option{true}, before capture starts, popup a display dialog
473 to the end user, allowing them to change video filter properties
474 and configurations manually.
475 Note that for crossbar devices, adjusting values in this dialog
476 may be needed at times to toggle between PAL (25 fps) and NTSC (29.97)
477 input frame rates, sizes, interlacing, etc. Changing these values can
478 enable different scan rates/frame rates and avoiding green bars at
479 the bottom, flickering scan lines, etc.
480 Note that with some devices, changing these properties can also affect future
481 invocations (sets new defaults) until system reboot occurs.
483 @item show_audio_device_dialog
484 If set to @option{true}, before capture starts, popup a display dialog
485 to the end user, allowing them to change audio filter properties
486 and configurations manually.
488 @item show_video_crossbar_connection_dialog
489 If set to @option{true}, before capture starts, popup a display
490 dialog to the end user, allowing them to manually
491 modify crossbar pin routings, when it opens a video device.
493 @item show_audio_crossbar_connection_dialog
494 If set to @option{true}, before capture starts, popup a display
495 dialog to the end user, allowing them to manually
496 modify crossbar pin routings, when it opens an audio device.
498 @item show_analog_tv_tuner_dialog
499 If set to @option{true}, before capture starts, popup a display
500 dialog to the end user, allowing them to manually
501 modify TV channels and frequencies.
503 @item show_analog_tv_tuner_audio_dialog
504 If set to @option{true}, before capture starts, popup a display
505 dialog to the end user, allowing them to manually
506 modify TV audio (like mono vs. stereo, Language A,B or C).
508 @item audio_device_load
509 Load an audio capture filter device from file instead of searching
510 it by name. It may load additional parameters too, if the filter
511 supports the serialization of its properties to.
512 To use this an audio capture source has to be specified, but it can
513 be anything even fake one.
515 @item audio_device_save
516 Save the currently used audio capture filter device and its
517 parameters (if the filter supports it) to a file.
518 If a file with the same name exists it will be overwritten.
520 @item video_device_load
521 Load a video capture filter device from file instead of searching
522 it by name. It may load additional parameters too, if the filter
523 supports the serialization of its properties to.
524 To use this a video capture source has to be specified, but it can
525 be anything even fake one.
527 @item video_device_save
528 Save the currently used video capture filter device and its
529 parameters (if the filter supports it) to a file.
530 If a file with the same name exists it will be overwritten.
539 Print the list of DirectShow supported devices and exit:
541 $ ffmpeg -list_devices true -f dshow -i dummy
545 Open video device @var{Camera}:
547 $ ffmpeg -f dshow -i video="Camera"
551 Open second video device with name @var{Camera}:
553 $ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
557 Open video device @var{Camera} and audio device @var{Microphone}:
559 $ ffmpeg -f dshow -i video="Camera":audio="Microphone"
563 Print the list of supported options in selected device and exit:
565 $ ffmpeg -list_options true -f dshow -i video="Camera"
569 Specify pin names to capture by name or alternative name, specify alternative device name:
571 $ 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"
575 Configure a crossbar device, specifying crossbar pins, allow user to adjust video capture properties at startup:
577 $ ffmpeg -f dshow -show_video_device_dialog true -crossbar_video_input_pin_number 0
578 -crossbar_audio_input_pin_number 3 -i video="AVerMedia BDA Analog Capture":audio="AVerMedia BDA Analog Capture"
585 Linux DV 1394 input device.
592 Set the frame rate. Default is 25.
596 Available values are:
604 Default value is @code{ntsc}.
610 Linux framebuffer input device.
612 The Linux framebuffer is a graphic hardware-independent abstraction
613 layer to show graphics on a computer monitor, typically on the
614 console. It is accessed through a file device node, usually
617 For more detailed information read the file
618 Documentation/fb/framebuffer.txt included in the Linux source tree.
620 See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1).
622 To record from the framebuffer device @file{/dev/fb0} with
625 ffmpeg -f fbdev -framerate 10 -i /dev/fb0 out.avi
628 You can take a single screenshot image with the command:
630 ffmpeg -f fbdev -framerate 1 -i /dev/fb0 -frames:v 1 screenshot.jpeg
638 Set the frame rate. Default is 25.
644 Win32 GDI-based screen capture device.
646 This device allows you to capture a region of the display on Windows.
648 There are two options for the input filename:
654 title=@var{window_title}
657 The first option will capture the entire desktop, or a fixed region of the
658 desktop. The second option will instead capture the contents of a single
659 window, regardless of its position on the screen.
661 For example, to grab the entire desktop using @command{ffmpeg}:
663 ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
666 Grab a 640x480 region at position @code{10,20}:
668 ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
671 Grab the contents of the window named "Calculator"
673 ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
680 Specify whether to draw the mouse pointer. Use the value @code{0} to
681 not draw the pointer. Default value is @code{1}.
684 Set the grabbing frame rate. Default value is @code{ntsc},
685 corresponding to a frame rate of @code{30000/1001}.
688 Show grabbed region on screen.
690 If @var{show_region} is specified with @code{1}, then the grabbing
691 region will be indicated on screen. With this option, it is easy to
692 know what is being grabbed if only a portion of the screen is grabbed.
694 Note that @var{show_region} is incompatible with grabbing the contents
699 ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
703 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.
706 When capturing a region with @var{video_size}, set the distance from the left edge of the screen or desktop.
708 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.
711 When capturing a region with @var{video_size}, set the distance from the top edge of the screen or desktop.
713 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.
719 FireWire DV/HDV input device using libiec61883.
721 To enable this input device, you need libiec61883, libraw1394 and
722 libavc1394 installed on your system. Use the configure option
723 @code{--enable-libiec61883} to compile with the device enabled.
725 The iec61883 capture device supports capturing from a video device
726 connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
727 FireWire stack (juju). This is the default DV/HDV input method in Linux
728 Kernel 2.6.37 and later, since the old FireWire stack was removed.
730 Specify the FireWire port to be used as input file, or "auto"
731 to choose the first port connected.
738 Override autodetection of DV/HDV. This should only be used if auto
739 detection does not work, or if usage of a different device type
740 should be prohibited. Treating a DV device as HDV (or vice versa) will
741 not work and result in undefined behavior.
742 The values @option{auto}, @option{dv} and @option{hdv} are supported.
745 Set maximum size of buffer for incoming data, in frames. For DV, this
746 is an exact value. For HDV, it is not frame exact, since HDV does
747 not have a fixed frame size.
750 Select the capture device by specifying its GUID. Capturing will only
751 be performed from the specified device and fails if no device with the
752 given GUID is found. This is useful to select the input if multiple
753 devices are connected at the same time.
754 Look at /sys/bus/firewire/devices to find out the GUIDs.
763 Grab and show the input of a FireWire DV/HDV device.
765 ffplay -f iec61883 -i auto
769 Grab and record the input of a FireWire DV/HDV device,
770 using a packet buffer of 100000 packets if the source is HDV.
772 ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg
781 To enable this input device during configuration you need libjack
782 installed on your system.
784 A JACK input device creates one or more JACK writable clients, one for
785 each audio channel, with name @var{client_name}:input_@var{N}, where
786 @var{client_name} is the name provided by the application, and @var{N}
787 is a number which identifies the channel.
788 Each writable client will send the acquired data to the FFmpeg input
791 Once you have created one or more JACK readable clients, you need to
792 connect them to one or more JACK writable clients.
794 To connect or disconnect JACK clients you can use the @command{jack_connect}
795 and @command{jack_disconnect} programs, or do it through a graphical interface,
796 for example with @command{qjackctl}.
798 To list the JACK clients and their properties you can invoke the command
801 Follows an example which shows how to capture a JACK readable client
802 with @command{ffmpeg}.
804 # Create a JACK writable client with name "ffmpeg".
805 $ ffmpeg -f jack -i ffmpeg -y out.wav
807 # Start the sample jack_metro readable client.
808 $ jack_metro -b 120 -d 0.2 -f 4000
810 # List the current JACK clients.
819 # Connect metro to the ffmpeg writable client.
820 $ jack_connect metro:120_bpm ffmpeg:input_1
823 For more information read:
824 @url{http://jackaudio.org/}
831 Set the number of channels. Default is 2.
837 Libavfilter input virtual device.
839 This input device reads data from the open output pads of a libavfilter
842 For each filtergraph open output, the input device will create a
843 corresponding stream which is mapped to the generated output. Currently
844 only video data is supported. The filtergraph is specified through the
845 option @option{graph}.
852 Specify the filtergraph to use as input. Each video open output must be
853 labelled by a unique string of the form "out@var{N}", where @var{N} is a
854 number starting from 0 corresponding to the mapped input stream
855 generated by the device.
856 The first unlabelled output is automatically assigned to the "out0"
857 label, but all the others need to be specified explicitly.
859 The suffix "+subcc" can be appended to the output label to create an extra
860 stream with the closed captions packets attached to that output
861 (experimental; only for EIA-608 / CEA-708 for now).
862 The subcc streams are created after all the normal streams, in the order of
863 the corresponding stream.
864 For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
865 stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
867 If not specified defaults to the filename specified for the input
871 Set the filename of the filtergraph to be read and sent to the other
872 filters. Syntax of the filtergraph is the same as the one specified by
873 the option @var{graph}.
876 Dump graph to stderr.
884 Create a color video stream and play it back with @command{ffplay}:
886 ffplay -f lavfi -graph "color=c=pink [out0]" dummy
890 As the previous example, but use filename for specifying the graph
891 description, and omit the "out0" label:
893 ffplay -f lavfi color=c=pink
897 Create three different video test filtered sources and play them:
899 ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
903 Read an audio stream from a file using the amovie source and play it
904 back with @command{ffplay}:
906 ffplay -f lavfi "amovie=test.wav"
910 Read an audio stream and a video stream and play it back with
913 ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
917 Dump decoded frames to images and closed captions to a file (experimental):
919 ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
926 Audio-CD input device based on libcdio.
928 To enable this input device during configuration you need libcdio
929 installed on your system. It requires the configure option
930 @code{--enable-libcdio}.
932 This device allows playing and grabbing from an Audio-CD.
934 For example to copy with @command{ffmpeg} the entire Audio-CD in @file{/dev/sr0},
935 you may run the command:
937 ffmpeg -f libcdio -i /dev/sr0 cd.wav
943 Set drive reading speed. Default value is 0.
945 The speed is specified CD-ROM speed units. The speed is set through
946 the libcdio @code{cdio_cddap_speed_set} function. On many CD-ROM
947 drives, specifying a value too large will result in using the fastest
951 Set paranoia recovery mode flags. It accepts one of the following values:
961 Default value is @samp{disable}.
963 For more information about the available recovery modes, consult the
964 paranoia project documentation.
969 IIDC1394 input device, based on libdc1394 and libraw1394.
971 Requires the configure option @code{--enable-libdc1394}.
975 The OpenAL input device provides audio capture on all systems with a
976 working OpenAL 1.1 implementation.
978 To enable this input device during configuration, you need OpenAL
979 headers and libraries installed on your system, and need to configure
980 FFmpeg with @code{--enable-openal}.
982 OpenAL headers and libraries should be provided as part of your OpenAL
983 implementation, or as an additional download (an SDK). Depending on your
984 installation you may need to specify additional flags via the
985 @code{--extra-cflags} and @code{--extra-ldflags} for allowing the build
986 system to locate the OpenAL headers and libraries.
988 An incomplete list of OpenAL implementations follows:
992 The official Windows implementation, providing hardware acceleration
993 with supported devices and software fallback.
994 See @url{http://openal.org/}.
996 Portable, open source (LGPL) software implementation. Includes
997 backends for the most common sound APIs on the Windows, Linux,
998 Solaris, and BSD operating systems.
999 See @url{http://kcat.strangesoft.net/openal.html}.
1001 OpenAL is part of Core Audio, the official Mac OS X Audio interface.
1002 See @url{http://developer.apple.com/technologies/mac/audio-and-video.html}
1005 This device allows one to capture from an audio input device handled
1008 You need to specify the name of the device to capture in the provided
1009 filename. If the empty string is provided, the device will
1010 automatically select the default device. You can get the list of the
1011 supported devices by using the option @var{list_devices}.
1018 Set the number of channels in the captured audio. Only the values
1019 @option{1} (monaural) and @option{2} (stereo) are currently supported.
1020 Defaults to @option{2}.
1023 Set the sample size (in bits) of the captured audio. Only the values
1024 @option{8} and @option{16} are currently supported. Defaults to
1028 Set the sample rate (in Hz) of the captured audio.
1029 Defaults to @option{44.1k}.
1032 If set to @option{true}, print a list of devices and exit.
1033 Defaults to @option{false}.
1037 @subsection Examples
1039 Print the list of OpenAL supported devices and exit:
1041 $ ffmpeg -list_devices true -f openal -i dummy out.ogg
1044 Capture from the OpenAL device @file{DR-BT101 via PulseAudio}:
1046 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
1049 Capture from the default device (note the empty string '' as filename):
1051 $ ffmpeg -f openal -i '' out.ogg
1054 Capture from two devices simultaneously, writing to two different files,
1055 within the same @command{ffmpeg} command:
1057 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
1059 Note: not all OpenAL implementations support multiple simultaneous capture -
1060 try the latest OpenAL Soft if the above does not work.
1064 Open Sound System input device.
1066 The filename to provide to the input device is the device node
1067 representing the OSS input device, and is usually set to
1070 For example to grab from @file{/dev/dsp} using @command{ffmpeg} use the
1073 ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
1076 For more information about OSS see:
1077 @url{http://manuals.opensound.com/usersguide/dsp.html}
1084 Set the sample rate in Hz. Default is 48000.
1087 Set the number of channels. Default is 2.
1094 PulseAudio input device.
1096 To enable this output device you need to configure FFmpeg with @code{--enable-libpulse}.
1098 The filename to provide to the input device is a source device or the
1101 To list the PulseAudio source devices and their properties you can invoke
1102 the command @command{pactl list sources}.
1104 More information about PulseAudio can be found on @url{http://www.pulseaudio.org}.
1109 Connect to a specific PulseAudio server, specified by an IP address.
1110 Default server is used when not provided.
1113 Specify the application name PulseAudio will use when showing active clients,
1114 by default it is the @code{LIBAVFORMAT_IDENT} string.
1117 Specify the stream name PulseAudio will use when showing active streams,
1118 by default it is "record".
1121 Specify the samplerate in Hz, by default 48kHz is used.
1124 Specify the channels in use, by default 2 (stereo) is set.
1127 Specify the number of bytes per frame, by default it is set to 1024.
1130 Specify the minimal buffering fragment in PulseAudio, it will affect the
1131 audio latency. By default it is unset.
1134 Set the initial PTS using the current time. Default is 1.
1138 @subsection Examples
1139 Record a stream from default device:
1141 ffmpeg -f pulse -i default /tmp/pulse.wav
1148 The filename passed as input is parsed to contain either a device name or index.
1149 The device index can also be given by using -video_device_index.
1150 A given device index will override any given device name.
1151 If the desired device consists of numbers only, use -video_device_index to identify it.
1152 The default device will be chosen if an empty string or the device name "default" is given.
1153 The available devices can be enumerated by using -list_devices.
1156 ffmpeg -f qtkit -i "0" out.mpg
1160 ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg
1164 ffmpeg -f qtkit -i "default" out.mpg
1168 ffmpeg -f qtkit -list_devices true -i ""
1176 Set frame rate. Default is 30.
1179 If set to @code{true}, print a list of devices and exit. Default is
1182 @item video_device_index
1183 Select the video device by index for devices with the same name (starts at 0).
1191 To enable this input device during configuration you need libsndio
1192 installed on your system.
1194 The filename to provide to the input device is the device node
1195 representing the sndio input device, and is usually set to
1198 For example to grab from @file{/dev/audio0} using @command{ffmpeg} use the
1201 ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
1209 Set the sample rate in Hz. Default is 48000.
1212 Set the number of channels. Default is 2.
1216 @section video4linux2, v4l2
1218 Video4Linux2 input video device.
1220 "v4l2" can be used as alias for "video4linux2".
1222 If FFmpeg is built with v4l-utils support (by using the
1223 @code{--enable-libv4l2} configure option), it is possible to use it with the
1224 @code{-use_libv4l2} input device option.
1226 The name of the device to grab is a file device node, usually Linux
1227 systems tend to automatically create such nodes when the device
1228 (e.g. an USB webcam) is plugged into the system, and has a name of the
1229 kind @file{/dev/video@var{N}}, where @var{N} is a number associated to
1232 Video4Linux2 devices usually support a limited set of
1233 @var{width}x@var{height} sizes and frame rates. You can check which are
1234 supported using @command{-list_formats all} for Video4Linux2 devices.
1235 Some devices, like TV cards, support one or more standards. It is possible
1236 to list all the supported standards using @command{-list_standards all}.
1238 The time base for the timestamps is 1 microsecond. Depending on the kernel
1239 version and configuration, the timestamps may be derived from the real time
1240 clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
1241 boot time, unaffected by NTP or manual changes to the clock). The
1242 @option{-timestamps abs} or @option{-ts abs} option can be used to force
1243 conversion into the real time clock.
1245 Some usage examples of the video4linux2 device with @command{ffmpeg}
1246 and @command{ffplay}:
1249 List supported formats for a video4linux2 device:
1251 ffplay -f video4linux2 -list_formats all /dev/video0
1255 Grab and show the input of a video4linux2 device:
1257 ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
1261 Grab and record the input of a video4linux2 device, leave the
1262 frame rate and size as previously set:
1264 ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
1268 For more information about Video4Linux, check @url{http://linuxtv.org/}.
1274 Set the standard. Must be the name of a supported standard. To get a
1275 list of the supported standards, use the @option{list_standards}
1279 Set the input channel number. Default to -1, which means using the
1280 previously selected channel.
1283 Set the video frame size. The argument must be a string in the form
1284 @var{WIDTH}x@var{HEIGHT} or a valid size abbreviation.
1287 Select the pixel format (only valid for raw video input).
1290 Set the preferred pixel format (for raw video) or a codec name.
1291 This option allows one to select the input format, when several are
1295 Set the preferred video frame rate.
1298 List available formats (supported pixel formats, codecs, and frame
1301 Available values are:
1304 Show all available (compressed and non-compressed) formats.
1307 Show only raw video (non-compressed) formats.
1310 Show only compressed formats.
1313 @item list_standards
1314 List supported standards and exit.
1316 Available values are:
1319 Show all supported standards.
1322 @item timestamps, ts
1323 Set type of timestamps for grabbed frames.
1325 Available values are:
1328 Use timestamps from the kernel.
1331 Use absolute timestamps (wall clock).
1334 Force conversion from monotonic to absolute timestamps.
1337 Default value is @code{default}.
1340 Use libv4l2 (v4l-utils) conversion functions. Default is 0.
1346 VfW (Video for Windows) capture input device.
1348 The filename passed as input is the capture driver number, ranging from
1349 0 to 9. You may use "list" as filename to print a list of drivers. Any
1350 other filename will be interpreted as device number 0.
1357 Set the video frame size.
1360 Set the grabbing frame rate. Default value is @code{ntsc},
1361 corresponding to a frame rate of @code{30000/1001}.
1367 X11 video input device.
1369 To enable this input device during configuration you need libxcb
1370 installed on your system. It will be automatically detected during
1373 This device allows one to capture a region of an X11 display.
1375 The filename passed as input has the syntax:
1377 [@var{hostname}]:@var{display_number}.@var{screen_number}[+@var{x_offset},@var{y_offset}]
1380 @var{hostname}:@var{display_number}.@var{screen_number} specifies the
1381 X11 display name of the screen to grab from. @var{hostname} can be
1382 omitted, and defaults to "localhost". The environment variable
1383 @env{DISPLAY} contains the default display name.
1385 @var{x_offset} and @var{y_offset} specify the offsets of the grabbed
1386 area with respect to the top-left border of the X11 screen. They
1389 Check the X11 documentation (e.g. @command{man X}) for more detailed
1392 Use the @command{xdpyinfo} program for getting basic information about
1393 the properties of your X11 display (e.g. grep for "name" or
1396 For example to grab from @file{:0.0} using @command{ffmpeg}:
1398 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
1401 Grab at position @code{10,20}:
1403 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
1410 Specify whether to draw the mouse pointer. A value of @code{0} specifies
1411 not to draw the pointer. Default value is @code{1}.
1414 Make the grabbed area follow the mouse. The argument can be
1415 @code{centered} or a number of pixels @var{PIXELS}.
1417 When it is specified with "centered", the grabbing region follows the mouse
1418 pointer and keeps the pointer at the center of region; otherwise, the region
1419 follows only when the mouse pointer reaches within @var{PIXELS} (greater than
1420 zero) to the edge of region.
1424 ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
1427 To follow only when the mouse pointer reaches within 100 pixels to edge:
1429 ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
1433 Set the grabbing frame rate. Default value is @code{ntsc},
1434 corresponding to a frame rate of @code{30000/1001}.
1437 Show grabbed region on screen.
1439 If @var{show_region} is specified with @code{1}, then the grabbing
1440 region will be indicated on screen. With this option, it is easy to
1441 know what is being grabbed if only a portion of the screen is grabbed.
1444 Set the region border thickness if @option{-show_region 1} is used.
1445 Range is 1 to 128 and default is 3 (XCB-based x11grab only).
1449 ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
1452 With @var{follow_mouse}:
1454 ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
1458 Set the video frame size. Default value is @code{vga}.
1462 Set the grabbing region coordinates. They are expressed as offset from
1463 the top left corner of the X11 window and correspond to the
1464 @var{x_offset} and @var{y_offset} parameters in the device name. The
1465 default value for both options is 0.
1468 @c man end INPUT DEVICES