@chapter Input Devices

 @c man begin INPUT DEVICES
 

 Input devices are configured elements in FFmpeg which enable accessing

 the data coming from a multimedia device attached to your system.
 

 When you configure your FFmpeg build, all the supported input devices

 are enabled by default. You can list all available ones using the
 configure option "--list-indevs".

 
 You can disable all the input devices using the configure option
 "--disable-indevs", and selectively enable an input device using the
 option "--enable-indev=@var{INDEV}", or you can disable a particular
 input device using the option "--disable-indev=@var{INDEV}".
 

 The option "-devices" of the ff* tools will display the list of
 supported input devices.

 
 A description of the currently available input devices follows.
 
 @section alsa
 
 ALSA (Advanced Linux Sound Architecture) input device.
 
 To enable this input device during configuration you need libasound
 installed on your system.
 

 This device allows capturing from an ALSA device. The name of the

 device to capture has to be an ALSA card identifier.
 
 An ALSA identifier has the syntax:
 @example
 hw:@var{CARD}[,@var{DEV}[,@var{SUBDEV}]]
 @end example
 
 where the @var{DEV} and @var{SUBDEV} components are optional.
 
 The three arguments (in order: @var{CARD},@var{DEV},@var{SUBDEV})
 specify card number or identifier, device number and subdevice number
 (-1 means any).
 
 To see the list of cards currently recognized by your system check the
 files @file{/proc/asound/cards} and @file{/proc/asound/devices}.
 

 For example to capture with @command{ffmpeg} from an ALSA device with

 card id 0, you may run the command:
 @example
 ffmpeg -f alsa -i hw:0 alsaout.wav
 @end example
 
 For more information see:
 @url{http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html}
 

 @subsection Options
 
 @table @option
 
 @item sample_rate
 Set the sample rate in Hz. Default is 48000.
 
 @item channels
 Set the number of channels. Default is 2.
 
 @end table
 

 @section avfoundation
 
 AVFoundation input device.
 
 AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX >= 10.7 as well as on iOS.
 The older QTKit framework has been marked deprecated since OSX version 10.7.
 

 The input filename has to be given in the following syntax:
 @example
 -i "[[VIDEO]:[AUDIO]]"
 @end example
 The first entry selects the video input while the latter selects the audio input.
 The stream has to be specified by the device name or the device index as shown by the device list.
 Alternatively, the video and/or audio input device can be chosen by index using the
 @option{
     -video_device_index <INDEX>
 }
 and/or
 @option{
     -audio_device_index <INDEX>
 }
 , overriding any
 device name or index given in the input filename.
 
 All available devices can be enumerated by using @option{-list_devices true}, listing
 all device names and corresponding indices.
 
 There are two device name aliases:
 @table @code
 
 @item default
 Select the AVFoundation default device of the corresponding type.
 
 @item none
 Do not record the corresponding media type.

 This is equivalent to specifying an empty device name or index.

 
 @end table
 
 @subsection Options
 
 AVFoundation supports the following options:
 
 @table @option
 
 @item -list_devices <TRUE|FALSE>
 If set to true, a list of all available input devices is given showing all
 device names and indices.
 
 @item -video_device_index <INDEX>
 Specify the video device by its index. Overrides anything given in the input filename.
 
 @item -audio_device_index <INDEX>
 Specify the audio device by its index. Overrides anything given in the input filename.
 
 @item -pixel_format <FORMAT>
 Request the video device to use a specific pixel format.
 If the specified format is not supported, a list of available formats is given
 und the first one in this list is used instead. Available pixel formats are:

 @code{monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,

  bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10,

  yuv420p, nv12, yuyv422, gray}

 @item -framerate
 Set the grabbing frame rate. Default is @code{ntsc}, corresponding to a
 frame rate of @code{30000/1001}.
 
 @item -video_size
 Set the video frame size.
 
 @item -capture_cursor
 Capture the mouse pointer. Default is 0.
 
 @item -capture_mouse_clicks
 Capture the screen mouse clicks. Default is 0.
 

 @end table
 
 @subsection Examples
 
 @itemize
 
 @item
 Print the list of AVFoundation supported devices and exit:

 @example

 $ ffmpeg -f avfoundation -list_devices true -i ""

 @end example
 

 @item
 Record video from video device 0 and audio from audio device 0 into out.avi:

 @example

 $ ffmpeg -f avfoundation -i "0:0" out.avi

 @end example
 

 @item
 Record video from video device 2 and audio from audio device 1 into out.avi:

 @example

 $ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi

 @end example
 

 @item
 Record video from the system default video device using the pixel format bgr0 and do not record any audio into out.avi:

 @example

 $ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi

 @end example
 

 @end itemize
 

 @section bktr
 
 BSD video input device.
 

 @subsection Options
 
 @table @option
 
 @item framerate
 Set the frame rate.
 
 @item video_size
 Set the video frame size. Default is @code{vga}.
 
 @item standard
 
 Available values are:
 @table @samp
 @item pal
 
 @item ntsc
 
 @item secam
 
 @item paln
 
 @item palm
 
 @item ntscj
 
 @end table
 
 @end table
 

 @section decklink
 
 The decklink input device provides capture capabilities for Blackmagic
 DeckLink devices.
 
 To enable this input device, you need the Blackmagic DeckLink SDK and you
 need to configure with the appropriate @code{--extra-cflags}
 and @code{--extra-ldflags}.
 On Windows, you need to run the IDL files through @command{widl}.
 
 DeckLink is very picky about the formats it supports. Pixel format is
 uyvy422 or v210, framerate and video size must be determined for your device with
 @command{-list_formats 1}. Audio sample rate is always 48 kHz and the number
 of channels can be 2, 8 or 16.
 
 @subsection Options
 
 @table @option
 
 @item list_devices
 If set to @option{true}, print a list of devices and exit.
 Defaults to @option{false}.
 
 @item list_formats
 If set to @option{true}, print a list of supported formats and exit.
 Defaults to @option{false}.
 
 @item bm_v210
 If set to @samp{1}, video is captured in 10 bit v210 instead
 of uyvy422. Not all Blackmagic devices support this option.
 
 @end table
 
 @subsection Examples
 
 @itemize
 
 @item
 List input devices:
 @example
 ffmpeg -f decklink -list_devices 1 -i dummy
 @end example
 
 @item
 List supported formats:
 @example
 ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
 @end example
 
 @item
 Capture video clip at 1080i50 (format 11):
 @example
 ffmpeg -f decklink -i 'Intensity Pro@@11' -acodec copy -vcodec copy output.avi
 @end example
 
 @item
 Capture video clip at 1080i50 10 bit:
 @example
 ffmpeg -bm_v210 1 -f decklink -i 'UltraStudio Mini Recorder@@11' -acodec copy -vcodec copy output.avi
 @end example
 
 @end itemize
 

 @section dshow
 
 Windows DirectShow input device.
 

 DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.

 Currently only audio and video devices are supported.
 
 Multiple devices may be opened as separate inputs, but they may also be
 opened on the same input, which should improve synchronism between them.
 
 The input name should be in the format:
 
 @example
 @var{TYPE}=@var{NAME}[:@var{TYPE}=@var{NAME}]
 @end example
 
 where @var{TYPE} can be either @var{audio} or @var{video},

 and @var{NAME} is the device's name or alternative name..

 
 @subsection Options
 
 If no options are specified, the device's defaults are used.
 If the device does not support the requested options, it will
 fail to open.
 
 @table @option
 
 @item video_size
 Set the video size in the captured video.
 
 @item framerate

 Set the frame rate in the captured video.

 
 @item sample_rate
 Set the sample rate (in Hz) of the captured audio.
 
 @item sample_size
 Set the sample size (in bits) of the captured audio.
 
 @item channels
 Set the number of channels in the captured audio.
 
 @item list_devices
 If set to @option{true}, print a list of devices and exit.
 
 @item list_options
 If set to @option{true}, print a list of selected device's options
 and exit.
 

 @item video_device_number

 Set video device number for devices with the same name (starts at 0,

 defaults to 0).
 
 @item audio_device_number

 Set audio device number for devices with the same name (starts at 0,

 defaults to 0).
 

 @item pixel_format
 Select pixel format to be used by DirectShow. This may only be set when
 the video codec is not set or set to rawvideo.
 

 @item audio_buffer_size
 Set audio device buffer size in milliseconds (which can directly
 impact latency, depending on the device).
 Defaults to using the audio device's
 default buffer size (typically some multiple of 500ms).
 Setting this value too low can degrade performance.
 See also
 @url{http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx}
 

 @item video_pin_name
 Select video capture pin to use by name or alternative name.
 
 @item audio_pin_name
 Select audio capture pin to use by name or alternative name.
 

 @item crossbar_video_input_pin_number
 Select video input pin number for crossbar device. This will be
 routed to the crossbar device's Video Decoder output pin.

 Note that changing this value can affect future invocations
 (sets a new default) until system reboot occurs.

 
 @item crossbar_audio_input_pin_number
 Select audio input pin number for crossbar device. This will be
 routed to the crossbar device's Audio Decoder output pin.

 Note that changing this value can affect future invocations
 (sets a new default) until system reboot occurs.

 @item show_video_device_dialog
 If set to @option{true}, before capture starts, popup a display dialog
 to the end user, allowing them to change video filter properties
 and configurations manually.

 Note that for crossbar devices, adjusting values in this dialog
 may be needed at times to toggle between PAL (25 fps) and NTSC (29.97)
 input frame rates, sizes, interlacing, etc.  Changing these values can
 enable different scan rates/frame rates and avoiding green bars at
 the bottom, flickering scan lines, etc.
 Note that with some devices, changing these properties can also affect future
 invocations (sets new defaults) until system reboot occurs.

 
 @item show_audio_device_dialog
 If set to @option{true}, before capture starts, popup a display dialog
 to the end user, allowing them to change audio filter properties
 and configurations manually.
 

 @item show_video_crossbar_connection_dialog

 If set to @option{true}, before capture starts, popup a display
 dialog to the end user, allowing them to manually

 modify crossbar pin routings, when it opens a video device.
 
 @item show_audio_crossbar_connection_dialog
 If set to @option{true}, before capture starts, popup a display
 dialog to the end user, allowing them to manually
 modify crossbar pin routings, when it opens an audio device.

 @item show_analog_tv_tuner_dialog
 If set to @option{true}, before capture starts, popup a display
 dialog to the end user, allowing them to manually
 modify TV channels and frequencies.
 
 @item show_analog_tv_tuner_audio_dialog
 If set to @option{true}, before capture starts, popup a display
 dialog to the end user, allowing them to manually
 modify TV audio (like mono vs. stereo, Language A,B or C).
 

 @item audio_device_load
 Load an audio capture filter device from file instead of searching
 it by name. It may load additional parameters too, if the filter
 supports the serialization of its properties to.
 To use this an audio capture source has to be specified, but it can
 be anything even fake one.
 
 @item audio_device_save
 Save the currently used audio capture filter device and its
 parameters (if the filter supports it) to a file.
 If a file with the same name exists it will be overwritten.
 
 @item video_device_load
 Load a video capture filter device from file instead of searching
 it by name. It may load additional parameters too, if the filter
 supports the serialization of its properties to.
 To use this a video capture source has to be specified, but it can
 be anything even fake one.
 
 @item video_device_save
 Save the currently used video capture filter device and its
 parameters (if the filter supports it) to a file.
 If a file with the same name exists it will be overwritten.
 

 @end table
 
 @subsection Examples
 
 @itemize
 
 @item
 Print the list of DirectShow supported devices and exit:
 @example
 $ ffmpeg -list_devices true -f dshow -i dummy
 @end example
 
 @item
 Open video device @var{Camera}:
 @example
 $ ffmpeg -f dshow -i video="Camera"
 @end example
 
 @item

 Open second video device with name @var{Camera}:
 @example
 $ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
 @end example
 
 @item

 Open video device @var{Camera} and audio device @var{Microphone}:
 @example
 $ ffmpeg -f dshow -i video="Camera":audio="Microphone"
 @end example
 
 @item
 Print the list of supported options in selected device and exit:
 @example
 $ ffmpeg -list_options true -f dshow -i video="Camera"
 @end example
 

 @item
 Specify pin names to capture by name or alternative name, specify alternative device name:
 @example

 $ 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"

 @end example
 

 @item
 Configure a crossbar device, specifying crossbar pins, allow user to adjust video capture properties at startup:
 @example
 $ ffmpeg -f dshow -show_video_device_dialog true -crossbar_video_input_pin_number 0
      -crossbar_audio_input_pin_number 3 -i video="AVerMedia BDA Analog Capture":audio="AVerMedia BDA Analog Capture"
 @end example
 

 @end itemize
 

 @section dv1394
 
 Linux DV 1394 input device.
 

 @subsection Options
 
 @table @option
 
 @item framerate
 Set the frame rate. Default is 25.
 
 @item standard
 
 Available values are:
 @table @samp
 @item pal
 
 @item ntsc
 
 @end table
 
 Default value is @code{ntsc}.
 
 @end table
 

 @section fbdev
 
 Linux framebuffer input device.
 
 The Linux framebuffer is a graphic hardware-independent abstraction
 layer to show graphics on a computer monitor, typically on the
 console. It is accessed through a file device node, usually
 @file{/dev/fb0}.
 
 For more detailed information read the file
 Documentation/fb/framebuffer.txt included in the Linux source tree.
 

 See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1).
 

 To record from the framebuffer device @file{/dev/fb0} with

 @command{ffmpeg}:

 @example

 ffmpeg -f fbdev -framerate 10 -i /dev/fb0 out.avi

 @end example
 
 You can take a single screenshot image with the command:
 @example

 ffmpeg -f fbdev -framerate 1 -i /dev/fb0 -frames:v 1 screenshot.jpeg

 @end example
 

 @subsection Options
 
 @table @option
 
 @item framerate
 Set the frame rate. Default is 25.
 
 @end table

 @section gdigrab
 
 Win32 GDI-based screen capture device.
 
 This device allows you to capture a region of the display on Windows.
 
 There are two options for the input filename:
 @example
 desktop
 @end example
 or
 @example
 title=@var{window_title}
 @end example
 
 The first option will capture the entire desktop, or a fixed region of the
 desktop. The second option will instead capture the contents of a single
 window, regardless of its position on the screen.
 
 For example, to grab the entire desktop using @command{ffmpeg}:
 @example
 ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
 @end example
 
 Grab a 640x480 region at position @code{10,20}:
 @example
 ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
 @end example
 
 Grab the contents of the window named "Calculator"
 @example
 ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
 @end example
 
 @subsection Options
 
 @table @option
 @item draw_mouse
 Specify whether to draw the mouse pointer. Use the value @code{0} to
 not draw the pointer. Default value is @code{1}.
 
 @item framerate
 Set the grabbing frame rate. Default value is @code{ntsc},
 corresponding to a frame rate of @code{30000/1001}.
 
 @item show_region
 Show grabbed region on screen.
 
 If @var{show_region} is specified with @code{1}, then the grabbing
 region will be indicated on screen. With this option, it is easy to
 know what is being grabbed if only a portion of the screen is grabbed.
 
 Note that @var{show_region} is incompatible with grabbing the contents
 of a single window.
 
 For example:
 @example
 ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
 @end example
 
 @item video_size
 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.
 
 @item offset_x
 When capturing a region with @var{video_size}, set the distance from the left edge of the screen or desktop.
 
 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.
 
 @item offset_y
 When capturing a region with @var{video_size}, set the distance from the top edge of the screen or desktop.
 
 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.
 
 @end table
 

 @section iec61883
 
 FireWire DV/HDV input device using libiec61883.
 

 To enable this input device, you need libiec61883, libraw1394 and
 libavc1394 installed on your system. Use the configure option
 @code{--enable-libiec61883} to compile with the device enabled.
 

 The iec61883 capture device supports capturing from a video device
 connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
 FireWire stack (juju). This is the default DV/HDV input method in Linux
 Kernel 2.6.37 and later, since the old FireWire stack was removed.
 
 Specify the FireWire port to be used as input file, or "auto"
 to choose the first port connected.
 
 @subsection Options
 
 @table @option
 
 @item dvtype
 Override autodetection of DV/HDV. This should only be used if auto
 detection does not work, or if usage of a different device type
 should be prohibited. Treating a DV device as HDV (or vice versa) will
 not work and result in undefined behavior.
 The values @option{auto}, @option{dv} and @option{hdv} are supported.
 
 @item dvbuffer

 Set maximum size of buffer for incoming data, in frames. For DV, this

 is an exact value. For HDV, it is not frame exact, since HDV does
 not have a fixed frame size.
 

 @item dvguid
 Select the capture device by specifying it's GUID. Capturing will only
 be performed from the specified device and fails if no device with the
 given GUID is found. This is useful to select the input if multiple
 devices are connected at the same time.
 Look at /sys/bus/firewire/devices to find out the GUIDs.
 

 @end table
 
 @subsection Examples
 
 @itemize
 
 @item
 Grab and show the input of a FireWire DV/HDV device.
 @example
 ffplay -f iec61883 -i auto
 @end example
 
 @item
 Grab and record the input of a FireWire DV/HDV device,
 using a packet buffer of 100000 packets if the source is HDV.
 @example
 ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg
 @end example
 
 @end itemize
 

 @section jack
 

 JACK input device.

 
 To enable this input device during configuration you need libjack
 installed on your system.
 

 A JACK input device creates one or more JACK writable clients, one for

 each audio channel, with name @var{client_name}:input_@var{N}, where
 @var{client_name} is the name provided by the application, and @var{N}
 is a number which identifies the channel.

 Each writable client will send the acquired data to the FFmpeg input

 device.
 

 Once you have created one or more JACK readable clients, you need to
 connect them to one or more JACK writable clients.

 To connect or disconnect JACK clients you can use the @command{jack_connect}
 and @command{jack_disconnect} programs, or do it through a graphical interface,
 for example with @command{qjackctl}.

 To list the JACK clients and their properties you can invoke the command

 @command{jack_lsp}.

 Follows an example which shows how to capture a JACK readable client

 with @command{ffmpeg}.

 @example

 # Create a JACK writable client with name "ffmpeg".

 $ ffmpeg -f jack -i ffmpeg -y out.wav
 

 # Start the sample jack_metro readable client.

 $ jack_metro -b 120 -d 0.2 -f 4000
 

 # List the current JACK clients.

 $ jack_lsp -c
 system:capture_1
 system:capture_2
 system:playback_1
 system:playback_2
 ffmpeg:input_1
 metro:120_bpm
 

 # Connect metro to the ffmpeg writable client.

 $ jack_connect metro:120_bpm ffmpeg:input_1
 @end example
 
 For more information read:
 @url{http://jackaudio.org/}
 

 @subsection Options
 
 @table @option
 
 @item channels
 Set the number of channels. Default is 2.
 
 @end table
 

 @section lavfi
 
 Libavfilter input virtual device.
 
 This input device reads data from the open output pads of a libavfilter
 filtergraph.
 
 For each filtergraph open output, the input device will create a
 corresponding stream which is mapped to the generated output. Currently
 only video data is supported. The filtergraph is specified through the
 option @option{graph}.
 
 @subsection Options
 
 @table @option
 
 @item graph
 Specify the filtergraph to use as input. Each video open output must be
 labelled by a unique string of the form "out@var{N}", where @var{N} is a
 number starting from 0 corresponding to the mapped input stream
 generated by the device.
 The first unlabelled output is automatically assigned to the "out0"

 label, but all the others need to be specified explicitly.

 The suffix "+subcc" can be appended to the output label to create an extra
 stream with the closed captions packets attached to that output
 (experimental; only for EIA-608 / CEA-708 for now).
 The subcc streams are created after all the normal streams, in the order of
 the corresponding stream.
 For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
 stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
 

 If not specified defaults to the filename specified for the input
 device.

 
 @item graph_file
 Set the filename of the filtergraph to be read and sent to the other
 filters. Syntax of the filtergraph is the same as the one specified by
 the option @var{graph}.
 

 @item dumpgraph
 Dump graph to stderr.
 

 @end table
 
 @subsection Examples
 
 @itemize
 @item

 Create a color video stream and play it back with @command{ffplay}:

 @example

 ffplay -f lavfi -graph "color=c=pink [out0]" dummy

 @end example
 
 @item
 As the previous example, but use filename for specifying the graph
 description, and omit the "out0" label:
 @example

 ffplay -f lavfi color=c=pink

 @end example
 
 @item
 Create three different video test filtered sources and play them:
 @example
 ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
 @end example

 
 @item
 Read an audio stream from a file using the amovie source and play it

 back with @command{ffplay}:

 @example
 ffplay -f lavfi "amovie=test.wav"
 @end example
 
 @item
 Read an audio stream and a video stream and play it back with

 @command{ffplay}:

 @example
 ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
 @end example
 

 @item
 Dump decoded frames to images and closed captions to a file (experimental):
 @example
 ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
 @end example
 

 @end itemize
 

 @section libcdio
 

 Audio-CD input device based on libcdio.

 
 To enable this input device during configuration you need libcdio

 installed on your system. It requires the configure option

 @code{--enable-libcdio}.

 
 This device allows playing and grabbing from an Audio-CD.
 

 For example to copy with @command{ffmpeg} the entire Audio-CD in @file{/dev/sr0},

 you may run the command:
 @example
 ffmpeg -f libcdio -i /dev/sr0 cd.wav
 @end example
 

 @subsection Options
 @table @option
 @item speed
 Set drive reading speed. Default value is 0.
 
 The speed is specified CD-ROM speed units. The speed is set through
 the libcdio @code{cdio_cddap_speed_set} function. On many CD-ROM
 drives, specifying a value too large will result in using the fastest
 speed.
 
 @item paranoia_mode
 Set paranoia recovery mode flags. It accepts one of the following values:
 
 @table @samp
 @item disable
 @item verify
 @item overlap
 @item neverskip
 @item full
 @end table
 
 Default value is @samp{disable}.
 
 For more information about the available recovery modes, consult the
 paranoia project documentation.
 @end table
 

 @section libdc1394
 
 IIDC1394 input device, based on libdc1394 and libraw1394.
 

 Requires the configure option @code{--enable-libdc1394}.
 

 @section openal
 
 The OpenAL input device provides audio capture on all systems with a
 working OpenAL 1.1 implementation.
 
 To enable this input device during configuration, you need OpenAL
 headers and libraries installed on your system, and need to configure
 FFmpeg with @code{--enable-openal}.
 
 OpenAL headers and libraries should be provided as part of your OpenAL
 implementation, or as an additional download (an SDK). Depending on your
 installation you may need to specify additional flags via the
 @code{--extra-cflags} and @code{--extra-ldflags} for allowing the build
 system to locate the OpenAL headers and libraries.
 
 An incomplete list of OpenAL implementations follows:
 
 @table @strong
 @item Creative
 The official Windows implementation, providing hardware acceleration
 with supported devices and software fallback.
 See @url{http://openal.org/}.
 @item OpenAL Soft
 Portable, open source (LGPL) software implementation. Includes
 backends for the most common sound APIs on the Windows, Linux,
 Solaris, and BSD operating systems.
 See @url{http://kcat.strangesoft.net/openal.html}.
 @item Apple
 OpenAL is part of Core Audio, the official Mac OS X Audio interface.
 See @url{http://developer.apple.com/technologies/mac/audio-and-video.html}
 @end table
 

 This device allows one to capture from an audio input device handled

 through OpenAL.
 
 You need to specify the name of the device to capture in the provided
 filename. If the empty string is provided, the device will
 automatically select the default device. You can get the list of the
 supported devices by using the option @var{list_devices}.
 
 @subsection Options
 
 @table @option
 
 @item channels
 Set the number of channels in the captured audio. Only the values
 @option{1} (monaural) and @option{2} (stereo) are currently supported.
 Defaults to @option{2}.
 
 @item sample_size
 Set the sample size (in bits) of the captured audio. Only the values
 @option{8} and @option{16} are currently supported. Defaults to
 @option{16}.
 
 @item sample_rate
 Set the sample rate (in Hz) of the captured audio.
 Defaults to @option{44.1k}.
 
 @item list_devices
 If set to @option{true}, print a list of devices and exit.
 Defaults to @option{false}.
 
 @end table
 
 @subsection Examples
 
 Print the list of OpenAL supported devices and exit:
 @example
 $ ffmpeg -list_devices true -f openal -i dummy out.ogg
 @end example
 
 Capture from the OpenAL device @file{DR-BT101 via PulseAudio}:
 @example
 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
 @end example
 
 Capture from the default device (note the empty string '' as filename):
 @example
 $ ffmpeg -f openal -i '' out.ogg
 @end example
 
 Capture from two devices simultaneously, writing to two different files,

 within the same @command{ffmpeg} command:

 @example
 $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
 @end example
 Note: not all OpenAL implementations support multiple simultaneous capture -
 try the latest OpenAL Soft if the above does not work.
 

 @section oss
 
 Open Sound System input device.
 
 The filename to provide to the input device is the device node
 representing the OSS input device, and is usually set to

 @file{/dev/dsp}.

 For example to grab from @file{/dev/dsp} using @command{ffmpeg} use the

 command:
 @example
 ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
 @end example
 
 For more information about OSS see:
 @url{http://manuals.opensound.com/usersguide/dsp.html}
 

 @subsection Options
 
 @table @option
 
 @item sample_rate
 Set the sample rate in Hz. Default is 48000.
 
 @item channels
 Set the number of channels. Default is 2.
 
 @end table
 
 

 @section pulse
 

 PulseAudio input device.

 To enable this output device you need to configure FFmpeg with @code{--enable-libpulse}.

 
 The filename to provide to the input device is a source device or the
 string "default"
 

 To list the PulseAudio source devices and their properties you can invoke

 the command @command{pactl list sources}.

 More information about PulseAudio can be found on @url{http://www.pulseaudio.org}.
 

 @subsection Options
 @table @option
 @item server

 Connect to a specific PulseAudio server, specified by an IP address.
 Default server is used when not provided.

 @item name
 Specify the application name PulseAudio will use when showing active clients,
 by default it is the @code{LIBAVFORMAT_IDENT} string.

 @item stream_name
 Specify the stream name PulseAudio will use when showing active streams,
 by default it is "record".

 @item sample_rate

 Specify the samplerate in Hz, by default 48kHz is used.
 

 @item channels

 Specify the channels in use, by default 2 (stereo) is set.
 

 @item frame_size
 Specify the number of bytes per frame, by default it is set to 1024.

 @item fragment_size
 Specify the minimal buffering fragment in PulseAudio, it will affect the
 audio latency. By default it is unset.

 
 @item wallclock
 Set the initial PTS using the current time. Default is 1.
 

 @end table

 @subsection Examples
 Record a stream from default device:

 @example

 ffmpeg -f pulse -i default /tmp/pulse.wav

 @end example
 

 @section qtkit
 
 QTKit input device.
 

 The filename passed as input is parsed to contain either a device name or index.
 The device index can also be given by using -video_device_index.
 A given device index will override any given device name.
 If the desired device consists of numbers only, use -video_device_index to identify it.
 The default device will be chosen if an empty string  or the device name "default" is given.
 The available devices can be enumerated by using -list_devices.

 
 @example

 ffmpeg -f qtkit -i "0" out.mpg

 @end example
 

 @example
 ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg
 @end example
 
 @example
 ffmpeg -f qtkit -i "default" out.mpg
 @end example
 
 @example
 ffmpeg -f qtkit -list_devices true -i ""
 @end example
 

 @subsection Options
 
 @table @option
 
 @item frame_rate
 Set frame rate. Default is 30.
 
 @item list_devices
 If set to @code{true}, print a list of devices and exit. Default is
 @code{false}.
 
 @item video_device_index
 Select the video device by index for devices with the same name (starts at 0).
 
 @end table
 

 @section sndio
 
 sndio input device.
 
 To enable this input device during configuration you need libsndio
 installed on your system.
 
 The filename to provide to the input device is the device node
 representing the sndio input device, and is usually set to
 @file{/dev/audio0}.
 

 For example to grab from @file{/dev/audio0} using @command{ffmpeg} use the

 command:
 @example
 ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
 @end example
 

 @subsection Options
 
 @table @option
 
 @item sample_rate
 Set the sample rate in Hz. Default is 48000.
 
 @item channels
 Set the number of channels. Default is 2.
 
 @end table
 

 @section video4linux2, v4l2

 Video4Linux2 input video device.

 "v4l2" can be used as alias for "video4linux2".
 
 If FFmpeg is built with v4l-utils support (by using the

 @code{--enable-libv4l2} configure option), it is possible to use it with the
 @code{-use_libv4l2} input device option.

 The name of the device to grab is a file device node, usually Linux
 systems tend to automatically create such nodes when the device

 (e.g. an USB webcam) is plugged into the system, and has a name of the

 kind @file{/dev/video@var{N}}, where @var{N} is a number associated to
 the device.
 

 Video4Linux2 devices usually support a limited set of

 @var{width}x@var{height} sizes and frame rates. You can check which are

 supported using @command{-list_formats all} for Video4Linux2 devices.

 Some devices, like TV cards, support one or more standards. It is possible
 to list all the supported standards using @command{-list_standards all}.

 The time base for the timestamps is 1 microsecond. Depending on the kernel
 version and configuration, the timestamps may be derived from the real time
 clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
 boot time, unaffected by NTP or manual changes to the clock). The
 @option{-timestamps abs} or @option{-ts abs} option can be used to force
 conversion into the real time clock.
 

 Some usage examples of the video4linux2 device with @command{ffmpeg}

 and @command{ffplay}:

 @itemize
 @item

 List supported formats for a video4linux2 device:
 @example
 ffplay -f video4linux2 -list_formats all /dev/video0
 @end example

 @item

 Grab and show the input of a video4linux2 device:

 @example

 ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0

 @end example

 @item
 Grab and record the input of a video4linux2 device, leave the

 frame rate and size as previously set:

 @example

 ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg

 @end example

 @end itemize

 For more information about Video4Linux, check @url{http://linuxtv.org/}.

 @subsection Options
 
 @table @option
 @item standard
 Set the standard. Must be the name of a supported standard. To get a
 list of the supported standards, use the @option{list_standards}
 option.
 
 @item channel

 Set the input channel number. Default to -1, which means using the
 previously selected channel.

 
 @item video_size
 Set the video frame size. The argument must be a string in the form
 @var{WIDTH}x@var{HEIGHT} or a valid size abbreviation.
 
 @item pixel_format
 Select the pixel format (only valid for raw video input).
 
 @item input_format
 Set the preferred pixel format (for raw video) or a codec name.

 This option allows one to select the input format, when several are

 available.
 
 @item framerate

 Set the preferred video frame rate.

 
 @item list_formats
 List available formats (supported pixel formats, codecs, and frame
 sizes) and exit.
 
 Available values are:
 @table @samp
 @item all
 Show all available (compressed and non-compressed) formats.
 
 @item raw
 Show only raw video (non-compressed) formats.
 
 @item compressed
 Show only compressed formats.
 @end table
 
 @item list_standards
 List supported standards and exit.
 
 Available values are:
 @table @samp
 @item all
 Show all supported standards.
 @end table
 
 @item timestamps, ts
 Set type of timestamps for grabbed frames.
 
 Available values are:
 @table @samp
 @item default
 Use timestamps from the kernel.
 
 @item abs
 Use absolute timestamps (wall clock).
 
 @item mono2abs

 Force conversion from monotonic to absolute timestamps.

 @end table
 
 Default value is @code{default}.

 
 @item use_libv4l2
 Use libv4l2 (v4l-utils) conversion functions. Default is 0.
 

 @end table
 

 @section vfwcap
 

 VfW (Video for Windows) capture input device.

 The filename passed as input is the capture driver number, ranging from
 0 to 9. You may use "list" as filename to print a list of drivers. Any
 other filename will be interpreted as device number 0.
 

 @subsection Options
 
 @table @option
 
 @item video_size
 Set the video frame size.
 
 @item framerate
 Set the grabbing frame rate. Default value is @code{ntsc},
 corresponding to a frame rate of @code{30000/1001}.
 
 @end table
 

 @section x11grab
 
 X11 video input device.
 

 To enable this input device during configuration you need libxcb
 installed on your system. It will be automatically detected during
 configuration.
 
 Alternatively, the configure option @option{--enable-x11grab} exists
 for legacy Xlib users.

 This device allows one to capture a region of an X11 display.

 The filename passed as input has the syntax:

 @example
 [@var{hostname}]:@var{display_number}.@var{screen_number}[+@var{x_offset},@var{y_offset}]
 @end example
 
 @var{hostname}:@var{display_number}.@var{screen_number} specifies the

 X11 display name of the screen to grab from. @var{hostname} can be

 omitted, and defaults to "localhost". The environment variable

 @env{DISPLAY} contains the default display name.
 
 @var{x_offset} and @var{y_offset} specify the offsets of the grabbed

 area with respect to the top-left border of the X11 screen. They

 default to 0.
 

 Check the X11 documentation (e.g. @command{man X}) for more detailed
 information.

 Use the @command{xdpyinfo} program for getting basic information about
 the properties of your X11 display (e.g. grep for "name" or
 "dimensions").

 For example to grab from @file{:0.0} using @command{ffmpeg}:

 @example

 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg

 @end example

 Grab at position @code{10,20}:
 @example

 ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg

 @end example
 

 @subsection Options

 @table @option

 @item draw_mouse
 Specify whether to draw the mouse pointer. A value of @code{0} specify
 not to draw the pointer. Default value is @code{1}.
 

 @item follow_mouse
 Make the grabbed area follow the mouse. The argument can be
 @code{centered} or a number of pixels @var{PIXELS}.

 
 When it is specified with "centered", the grabbing region follows the mouse
 pointer and keeps the pointer at the center of region; otherwise, the region
 follows only when the mouse pointer reaches within @var{PIXELS} (greater than
 zero) to the edge of region.
 
 For example:
 @example

 ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg

 @end example
 

 To follow only when the mouse pointer reaches within 100 pixels to edge:

 @example

 ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg

 @end example
 

 @item framerate
 Set the grabbing frame rate. Default value is @code{ntsc},

 corresponding to a frame rate of @code{30000/1001}.

 @item show_region
 Show grabbed region on screen.
 
 If @var{show_region} is specified with @code{1}, then the grabbing
 region will be indicated on screen. With this option, it is easy to
 know what is being grabbed if only a portion of the screen is grabbed.

 @item region_border
 Set the region border thickness if @option{-show_region 1} is used.
 Range is 1 to 128 and default is 3 (XCB-based x11grab only).
 

 For example:
 @example

 ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg

 @end example

 With @var{follow_mouse}:
 @example

 ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg

 @end example

 
 @item video_size
 Set the video frame size. Default value is @code{vga}.

 
 @item use_shm
 Use the MIT-SHM extension for shared memory. Default value is @code{1}.

 It may be necessary to disable it for remote displays (legacy x11grab
 only).

 @end table

 @subsection @var{grab_x} @var{grab_y} AVOption
 
 The syntax is:
 @example
 -grab_x @var{x_offset} -grab_y @var{y_offset}
 @end example
 

 Set the grabbing region coordinates. They are expressed as offset from the top left

 corner of the X11 window. The default value is 0.
 

 @c man end INPUT DEVICES