ffmpeg-devices.txt

FFMPEG-DEVICES(1)					     FFMPEG-DEVICES(1)

NAME
       ffmpeg-devices - FFmpeg devices

DESCRIPTION
       This document describes the input and output devices provided by the
       libavdevice library.

DEVICE OPTIONS
       The libavdevice library provides the same interface as libavformat.
       Namely, an input device is considered like a demuxer, and an output
       device like a muxer, and the interface and generic device options are
       the same provided by libavformat (see the ffmpeg-formats manual).

       In addition each input or output device may support so-called private
       options, which are specific for that component.

       Options may be set by specifying -option value in the FFmpeg tools, or
       by setting the value explicitly in the device "AVFormatContext" options
       or using the libavutil/opt.h API for programmatic use.

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=INDEV", or you can disable a particular input
       device using the option "--disable-indev=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.

   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:

	       hw:<CARD>[,<DEV>[,<SUBDEV>]]

       where the DEV and SUBDEV components are optional.

       The three arguments (in order: CARD,DEV,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 /proc/asound/cards and /proc/asound/devices.

       For example to capture with ffmpeg from an ALSA device with card id 0,
       you may run the command:

	       ffmpeg -f alsa -i hw:0 alsaout.wav

       For more information see:
       <http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html>

       Options

       sample_rate
	   Set the sample rate in Hz. Default is 48000.

       channels
	   Set the number of channels. Default is 2.

   android_camera
       Android camera input device.

       This input devices uses the Android Camera2 NDK API which is available
       on devices with API level 24+. The availability of android_camera is
       autodetected during configuration.

       This device allows capturing from all cameras on an Android device,
       which are integrated into the Camera2 NDK API.

       The available cameras are enumerated internally and can be selected
       with the camera_index parameter. The input file string is discarded.

       Generally the back facing camera has index 0 while the front facing
       camera has index 1.

       Options

       video_size
	   Set the video size given as a string such as 640x480 or hd720.
	   Falls back to the first available configuration reported by Android
	   if requested video size is not available or by default.

       framerate
	   Set the video framerate.  Falls back to the first available
	   configuration reported by Android if requested framerate is not
	   available or by default (-1).

       camera_index
	   Set the index of the camera to use. Default is 0.

       input_queue_size
	   Set the maximum number of frames to buffer. Default is 5.

   avfoundation
       AVFoundation input device.

       AVFoundation is the currently recommended framework by Apple for
       streamgrabbing on OSX >= 10.7 as well as on iOS.

       The input filename has to be given in the following syntax:

	       -i "[[VIDEO]:[AUDIO]]"

       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

	   B<-video_device_index E<lt>INDEXE<gt>>

       and/or

	   B<-audio_device_index E<lt>INDEXE<gt>>

       , overriding any device name or index given in the input filename.

       All available devices can be enumerated by using -list_devices true,
       listing all device names and corresponding indices.

       There are two device name aliases:

       "default"
	   Select the AVFoundation default device of the corresponding type.

       "none"
	   Do not record the corresponding media type.	This is equivalent to
	   specifying an empty device name or index.

       Options

       AVFoundation supports the following options:

       -list_devices <TRUE|FALSE>
	   If set to true, a list of all available input devices is given
	   showing all device names and indices.

       -video_device_index <INDEX>
	   Specify the video device by its index. Overrides anything given in
	   the input filename.

       -audio_device_index <INDEX>
	   Specify the audio device by its index. Overrides anything given in
	   the input filename.

       -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 and the first one in this list is used instead. Available
	   pixel formats are: "monob, rgb555be, rgb555le, rgb565be, rgb565le,
	   rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,
	    bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16,
	   yuv422p10, yuv444p10,
	    yuv420p, nv12, yuyv422, gray"

       -framerate
	   Set the grabbing frame rate. Default is "ntsc", corresponding to a
	   frame rate of "30000/1001".

       -video_size
	   Set the video frame size.

       -capture_cursor
	   Capture the mouse pointer. Default is 0.

       -capture_mouse_clicks
	   Capture the screen mouse clicks. Default is 0.

       -capture_raw_data
	   Capture the raw device data. Default is 0.  Using this option may
	   result in receiving the underlying data delivered to the
	   AVFoundation framework. E.g. for muxed devices that sends raw DV
	   data to the framework (like tape-based camcorders), setting this
	   option to false results in extracted video frames captured in the
	   designated pixel format only. Setting this option to true results
	   in receiving the raw DV stream untouched.

       Examples

       o   Print the list of AVFoundation supported devices and exit:

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

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

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

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

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

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

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

       o   Record raw DV data from a suitable input device and write the
	   output into out.dv:

		   $ ffmpeg -f avfoundation -capture_raw_data true -i "zr100:none" out.dv

   bktr
       BSD video input device. Deprecated and will be removed - please contact
       the developers if you are interested in maintaining it.

       Options

       framerate
	   Set the frame rate.

       video_size
	   Set the video frame size. Default is "vga".

       standard
	   Available values are:

	   pal
	   ntsc
	   secam
	   paln
	   palm
	   ntscj

   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 "--extra-cflags" and
       "--extra-ldflags".  On Windows, you need to run the IDL files through
       widl.

       DeckLink is very picky about the formats it supports. Pixel format of
       the input can be set with raw_format.  Framerate and video size must be
       determined for your device with -list_formats 1. Audio sample rate is
       always 48 kHz and the number of channels can be 2, 8 or 16. Note that
       all audio channels are bundled in one single audio track.

       Options

       list_devices
	   If set to true, print a list of devices and exit.  Defaults to
	   false. This option is deprecated, please use the "-sources" option
	   of ffmpeg to list the available input devices.

       list_formats
	   If set to true, print a list of supported formats and exit.
	   Defaults to false.

       format_code <FourCC>
	   This sets the input video format to the format given by the FourCC.
	   To see the supported values of your device(s) use list_formats.
	   Note that there is a FourCC 'pal ' that can also be used as pal (3
	   letters).  Default behavior is autodetection of the input video
	   format, if the hardware supports it.

       raw_format
	   Set the pixel format of the captured video.	Available values are:

	   auto
	       This is the default which means 8-bit YUV 422 or 8-bit ARGB if
	       format autodetection is used, 8-bit YUV 422 otherwise.

	   uyvy422
	       8-bit YUV 422.

	   yuv422p10
	       10-bit YUV 422.

	   argb
	       8-bit RGB.

	   bgra
	       8-bit RGB.

	   rgb10
	       10-bit RGB.

       teletext_lines
	   If set to nonzero, an additional teletext stream will be captured
	   from the vertical ancillary data. Both SD PAL (576i) and HD (1080i
	   or 1080p) sources are supported. In case of HD sources, OP47
	   packets are decoded.

	   This option is a bitmask of the SD PAL VBI lines captured,
	   specifically lines 6 to 22, and lines 318 to 335. Line 6 is the LSB
	   in the mask. Selected lines which do not contain teletext
	   information will be ignored. You can use the special all constant
	   to select all possible lines, or standard to skip lines 6, 318 and
	   319, which are not compatible with all receivers.

	   For SD sources, ffmpeg needs to be compiled with
	   "--enable-libzvbi". For HD sources, on older (pre-4K) DeckLink card
	   models you have to capture in 10 bit mode.

       channels
	   Defines number of audio channels to capture. Must be 2, 8 or 16.
	   Defaults to 2.

       duplex_mode
	   Sets the decklink device duplex/profile mode. Must be unset, half,
	   full, one_sub_device_full, one_sub_device_half,
	   two_sub_device_full, four_sub_device_half Defaults to unset.

	   Note: DeckLink SDK 11.0 have replaced the duplex property by a
	   profile property.  For the DeckLink Duo 2 and DeckLink Quad 2, a
	   profile is shared between any 2 sub-devices that utilize the same
	   connectors. For the DeckLink 8K Pro, a profile is shared between
	   all 4 sub-devices. So DeckLink 8K Pro support four profiles.

	   Valid profile modes for DeckLink 8K Pro(with DeckLink SDK >= 11.0):
	   one_sub_device_full, one_sub_device_half, two_sub_device_full,
	   four_sub_device_half

	   Valid profile modes for DeckLink Quad 2 and DeckLink Duo 2: half,
	   full

       timecode_format
	   Timecode type to include in the frame and video stream metadata.
	   Must be none, rp188vitc, rp188vitc2, rp188ltc, rp188hfr, rp188any,
	   vitc, vitc2, or serial.  Defaults to none (not included).

	   In order to properly support 50/60 fps timecodes, the ordering of
	   the queried timecode types for rp188any is HFR, VITC1, VITC2 and
	   LTC for >30 fps content. Note that this is slightly different to
	   the ordering used by the DeckLink API, which is HFR, VITC1, LTC,
	   VITC2.

       video_input
	   Sets the video input source. Must be unset, sdi, hdmi, optical_sdi,
	   component, composite or s_video.  Defaults to unset.

       audio_input
	   Sets the audio input source. Must be unset, embedded, aes_ebu,
	   analog, analog_xlr, analog_rca or microphone. Defaults to unset.

       video_pts
	   Sets the video packet timestamp source. Must be video, audio,
	   reference, wallclock or abs_wallclock.  Defaults to video.

       audio_pts
	   Sets the audio packet timestamp source. Must be video, audio,
	   reference, wallclock or abs_wallclock.  Defaults to audio.

       draw_bars
	   If set to true, color bars are drawn in the event of a signal loss.
	   Defaults to true.

       queue_size
	   Sets maximum input buffer size in bytes. If the buffering reaches
	   this value, incoming frames will be dropped.  Defaults to
	   1073741824.

       audio_depth
	   Sets the audio sample bit depth. Must be 16 or 32.  Defaults to 16.

       decklink_copyts
	   If set to true, timestamps are forwarded as they are without
	   removing the initial offset.  Defaults to false.

       timestamp_align
	   Capture start time alignment in seconds. If set to nonzero, input
	   frames are dropped till the system timestamp aligns with configured
	   value.  Alignment difference of up to one frame duration is
	   tolerated.  This is useful for maintaining input synchronization
	   across N different hardware devices deployed for 'N-way'
	   redundancy. The system time of different hardware devices should be
	   synchronized with protocols such as NTP or PTP, before using this
	   option.  Note that this method is not foolproof. In some border
	   cases input synchronization may not happen due to thread scheduling
	   jitters in the OS.  Either sync could go wrong by 1 frame or in a
	   rarer case timestamp_align seconds.	Defaults to 0.

       wait_for_tc (bool)
	   Drop frames till a frame with timecode is received. Sometimes
	   serial timecode isn't received with the first input frame. If that
	   happens, the stored stream timecode will be inaccurate. If this
	   option is set to true, input frames are dropped till a frame with
	   timecode is received.  Option timecode_format must be specified.
	   Defaults to false.

       enable_klv(bool)
	   If set to true, extracts KLV data from VANC and outputs KLV
	   packets.  KLV VANC packets are joined based on MID and PSC fields
	   and aggregated into one KLV packet.	Defaults to false.

       Examples

       o   List input devices:

		   ffmpeg -sources decklink

       o   List supported formats:

		   ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'

       o   Capture video clip at 1080i50:

		   ffmpeg -format_code Hi50 -f decklink -i 'Intensity Pro' -c:a copy -c:v copy output.avi

       o   Capture video clip at 1080i50 10 bit:

		   ffmpeg -raw_format yuv422p10 -format_code Hi50 -f decklink -i 'UltraStudio Mini Recorder' -c:a copy -c:v copy output.avi

       o   Capture video clip at 1080i50 with 16 audio channels:

		   ffmpeg -channels 16 -format_code Hi50 -f decklink -i 'UltraStudio Mini Recorder' -c:a copy -c:v copy output.avi

   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:

	       <TYPE>=<NAME>[:<TYPE>=<NAME>]

       where TYPE can be either audio or video, and NAME is the device's name
       or alternative name..

       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.

       video_size
	   Set the video size in the captured video.

       framerate
	   Set the frame rate in the captured video.

       sample_rate
	   Set the sample rate (in Hz) of the captured audio.

       sample_size
	   Set the sample size (in bits) of the captured audio.

       channels
	   Set the number of channels in the captured audio.

       list_devices
	   If set to true, print a list of devices and exit.

       list_options
	   If set to true, print a list of selected device's options and exit.

       video_device_number
	   Set video device number for devices with the same name (starts at
	   0, defaults to 0).

       audio_device_number
	   Set audio device number for devices with the same name (starts at
	   0, defaults to 0).

       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.

       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
	   <http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx>

       video_pin_name
	   Select video capture pin to use by name or alternative name.

       audio_pin_name
	   Select audio capture pin to use by name or alternative name.

       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.

       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.

       show_video_device_dialog
	   If set to 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.

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

       show_video_crossbar_connection_dialog
	   If set to 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.

       show_audio_crossbar_connection_dialog
	   If set to 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.

       show_analog_tv_tuner_dialog
	   If set to true, before capture starts, popup a display dialog to
	   the end user, allowing them to manually modify TV channels and
	   frequencies.

       show_analog_tv_tuner_audio_dialog
	   If set to 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).

       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.

       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.

       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.

       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.

       use_video_device_timestamps
	   If set to false, the timestamp for video frames will be derived
	   from the wallclock instead of the timestamp provided by the capture
	   device. This allows working around devices that provide unreliable
	   timestamps.

       Examples

       o   Print the list of DirectShow supported devices and exit:

		   $ ffmpeg -list_devices true -f dshow -i dummy

       o   Open video device Camera:

		   $ ffmpeg -f dshow -i video="Camera"

       o   Open second video device with name Camera:

		   $ ffmpeg -f dshow -video_device_number 1 -i video="Camera"

       o   Open video device Camera and audio device Microphone:

		   $ ffmpeg -f dshow -i video="Camera":audio="Microphone"

       o   Print the list of supported options in selected device and exit:

		   $ ffmpeg -list_options true -f dshow -i video="Camera"

       o   Specify pin names to capture by name or alternative name, specify
	   alternative device name:

		   $ 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"

       o   Configure a crossbar device, specifying crossbar pins, allow user
	   to adjust video capture properties at startup:

		   $ 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"

   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 /dev/fb0.

       For more detailed information read the file
       Documentation/fb/framebuffer.txt included in the Linux source tree.

       See also <http://linux-fbdev.sourceforge.net/>, and fbset(1).

       To record from the framebuffer device /dev/fb0 with ffmpeg:

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

       You can take a single screenshot image with the command:

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

       Options

       framerate
	   Set the frame rate. Default is 25.

   gdigrab
       Win32 GDI-based screen capture device.

       This device allows you to capture a region of the display on Windows.

       Amongst options for the imput filenames are such elements as:

	       desktop

       or

	       title=<window_title>

       or

	       hwnd=<window_hwnd>

       The first option will capture the entire desktop, or a fixed region of
       the desktop. The second and third options will instead capture the
       contents of a single window, regardless of its position on the screen.

       For example, to grab the entire desktop using ffmpeg:

	       ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg

       Grab a 640x480 region at position "10,20":

	       ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg

       Grab the contents of the window named "Calculator"

	       ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg

       Options

       draw_mouse
	   Specify whether to draw the mouse pointer. Use the value 0 to not
	   draw the pointer. Default value is 1.

       framerate
	   Set the grabbing frame rate. Default value is "ntsc", corresponding
	   to a frame rate of "30000/1001".

       show_region
	   Show grabbed region on screen.

	   If show_region is specified with 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 show_region is incompatible with grabbing the contents of
	   a single window.

	   For example:

		   ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg

       video_size
	   Set the video frame size. The default is to capture the full screen
	   if desktop is selected, or the full window size if
	   title=window_title is selected.

       offset_x
	   When capturing a region with 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
	   offset_x value to move the region to that monitor.

       offset_y
	   When capturing a region with 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 offset_y
	   value to move the region to that monitor.

   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
       "--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.

       Options

       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 auto,
	   dv and hdv are supported.

       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.

       dvguid
	   Select the capture device by specifying its 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.

       Examples

       o   Grab and show the input of a FireWire DV/HDV device.

		   ffplay -f iec61883 -i auto

       o   Grab and record the input of a FireWire DV/HDV device, using a
	   packet buffer of 100000 packets if the source is HDV.

		   ffmpeg -f iec61883 -i auto -dvbuffer 100000 out.mpg

   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 client_name:input_N, where client_name is
       the name provided by the application, and 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 jack_connect and
       jack_disconnect programs, or do it through a graphical interface, for
       example with qjackctl.

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

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

	       # 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

       For more information read: <http://jackaudio.org/>

       Options

       channels
	   Set the number of channels. Default is 2.

   kmsgrab
       KMS video input device.

       Captures the KMS scanout framebuffer associated with a specified CRTC
       or plane as a DRM object that can be passed to other hardware
       functions.

       Requires either DRM master or CAP_SYS_ADMIN to run.

       If you don't understand what all of that means, you probably don't want
       this.  Look at x11grab instead.

       Options

       device
	   DRM device to capture on.  Defaults to /dev/dri/card0.

       format
	   Pixel format of the framebuffer.  This can be autodetected if you
	   are running Linux 5.7 or later, but needs to be provided for
	   earlier versions.  Defaults to bgr0, which is the most common
	   format used by the Linux console and Xorg X server.

       format_modifier
	   Format modifier to signal on output frames.	This is necessary to
	   import correctly into some APIs.  It can be autodetected if you are
	   running Linux 5.7 or later, but will need to be provided explicitly
	   when needed in earlier versions.  See the libdrm documentation for
	   possible values.

       crtc_id
	   KMS CRTC ID to define the capture source.  The first active plane
	   on the given CRTC will be used.

       plane_id
	   KMS plane ID to define the capture source.  Defaults to the first
	   active plane found if neither crtc_id nor plane_id are specified.

       framerate
	   Framerate to capture at.  This is not synchronised to any page
	   flipping or framebuffer changes - it just defines the interval at
	   which the framebuffer is sampled.  Sampling faster than the
	   framebuffer update rate will generate independent frames with the
	   same content.  Defaults to 30.

       Examples

       o   Capture from the first active plane, download the result to normal
	   frames and encode.  This will only work if the framebuffer is both
	   linear and mappable - if not, the result may be scrambled or fail
	   to download.

		   ffmpeg -f kmsgrab -i - -vf 'hwdownload,format=bgr0' output.mp4

       o   Capture from CRTC ID 42 at 60fps, map the result to VAAPI, convert
	   to NV12 and encode as H.264.

		   ffmpeg -crtc_id 42 -framerate 60 -f kmsgrab -i - -vf 'hwmap=derive_device=vaapi,scale_vaapi=w=1920:h=1080:format=nv12' -c:v h264_vaapi output.mp4

       o   To capture only part of a plane the output can be cropped - this
	   can be used to capture a single window, as long as it has a known
	   absolute position and size.	For example, to capture and encode the
	   middle quarter of a 1920x1080 plane:

		   ffmpeg -f kmsgrab -i - -vf 'hwmap=derive_device=vaapi,crop=960:540:480:270,scale_vaapi=960:540:nv12' -c:v h264_vaapi output.mp4

   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.  The
       filtergraph is specified through the option graph.

       Options

       graph
	   Specify the filtergraph to use as input. Each video open output
	   must be labelled by a unique string of the form "outN", where 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.

       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 graph.

       dumpgraph
	   Dump graph to stderr.

       Examples

       o   Create a color video stream and play it back with ffplay:

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

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

		   ffplay -f lavfi color=c=pink

       o   Create three different video test filtered sources and play them:

		   ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3

       o   Read an audio stream from a file using the amovie source and play
	   it back with ffplay:

		   ffplay -f lavfi "amovie=test.wav"

       o   Read an audio stream and a video stream and play it back with
	   ffplay:

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

       o   Dump decoded frames to images and closed captions to a file
	   (experimental):

		   ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin

   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
       "--enable-libcdio".

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

       For example to copy with ffmpeg the entire Audio-CD in /dev/sr0, you
       may run the command:

	       ffmpeg -f libcdio -i /dev/sr0 cd.wav

       Options

       speed
	   Set drive reading speed. Default value is 0.

	   The speed is specified CD-ROM speed units. The speed is set through
	   the libcdio "cdio_cddap_speed_set" function. On many CD-ROM drives,
	   specifying a value too large will result in using the fastest
	   speed.

       paranoia_mode
	   Set paranoia recovery mode flags. It accepts one of the following
	   values:

	   disable
	   verify
	   overlap
	   neverskip
	   full

	   Default value is disable.

	   For more information about the available recovery modes, consult
	   the paranoia project documentation.

   libdc1394
       IIDC1394 input device, based on libdc1394 and libraw1394.

       Requires the configure option "--enable-libdc1394".

       Options

       framerate
	   Set the frame rate. Default is "ntsc", corresponding to a frame
	   rate of "30000/1001".

       pixel_format
	   Select the pixel format. Default is "uyvy422".

       video_size
	   Set the video size given as a string such as "640x480" or "hd720".
	   Default is "qvga".

   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 "--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
       "--extra-cflags" and "--extra-ldflags" for allowing the build system to
       locate the OpenAL headers and libraries.

       An incomplete list of OpenAL implementations follows:

       Creative
	   The official Windows implementation, providing hardware
	   acceleration with supported devices and software fallback.  See
	   <http://openal.org/>.

       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
	   <http://kcat.strangesoft.net/openal.html>.

       Apple
	   OpenAL is part of Core Audio, the official Mac OS X Audio
	   interface.  See
	   <http://developer.apple.com/technologies/mac/audio-and-video.html>

       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 list_devices.

       Options

       channels
	   Set the number of channels in the captured audio. Only the values 1
	   (monaural) and 2 (stereo) are currently supported.  Defaults to 2.

       sample_size
	   Set the sample size (in bits) of the captured audio. Only the
	   values 8 and 16 are currently supported. Defaults to 16.

       sample_rate
	   Set the sample rate (in Hz) of the captured audio.  Defaults to
	   44.1k.

       list_devices
	   If set to true, print a list of devices and exit.  Defaults to
	   false.

       Examples

       Print the list of OpenAL supported devices and exit:

	       $ ffmpeg -list_devices true -f openal -i dummy out.ogg

       Capture from the OpenAL device DR-BT101 via PulseAudio:

	       $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg

       Capture from the default device (note the empty string '' as filename):

	       $ ffmpeg -f openal -i '' out.ogg

       Capture from two devices simultaneously, writing to two different
       files, within the same ffmpeg command:

	       $ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg

       Note: not all OpenAL implementations support multiple simultaneous
       capture - try the latest OpenAL Soft if the above does not work.

   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 /dev/dsp.

       For example to grab from /dev/dsp using ffmpeg use the command:

	       ffmpeg -f oss -i /dev/dsp /tmp/oss.wav

       For more information about OSS see:
       <http://manuals.opensound.com/usersguide/dsp.html>

       Options

       sample_rate
	   Set the sample rate in Hz. Default is 48000.

       channels
	   Set the number of channels. Default is 2.

   pulse
       PulseAudio input device.

       To enable this output device you need to configure FFmpeg with
       "--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 pactl list sources.

       More information about PulseAudio can be found on
       <http://www.pulseaudio.org>.

       Options

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

       name
	   Specify the application name PulseAudio will use when showing
	   active clients, by default it is the "LIBAVFORMAT_IDENT" string.

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

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

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

       frame_size
	   This option does nothing and is deprecated.

       fragment_size
	   Specify the size in bytes of the minimal buffering fragment in
	   PulseAudio, it will affect the audio latency. By default it is set
	   to 50 ms amount of data.

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

       Examples

       Record a stream from default device:

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

   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 /dev/audio0.

       For example to grab from /dev/audio0 using ffmpeg use the command:

	       ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav

       Options

       sample_rate
	   Set the sample rate in Hz. Default is 48000.

       channels
	   Set the number of channels. Default is 2.

   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
       "--enable-libv4l2" configure option), it is possible to use it with the
       "-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
       /dev/videoN, where N is a number associated to the device.

       Video4Linux2 devices usually support a limited set of widthxheight
       sizes and frame rates. You can check which are supported using
       -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 -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 -timestamps abs or -ts abs option can be used to force
       conversion into the real time clock.

       Some usage examples of the video4linux2 device with ffmpeg and ffplay:

       o   List supported formats for a video4linux2 device:

		   ffplay -f video4linux2 -list_formats all /dev/video0

       o   Grab and show the input of a video4linux2 device:

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

       o   Grab and record the input of a video4linux2 device, leave the frame
	   rate and size as previously set:

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

       For more information about Video4Linux, check <http://linuxtv.org/>.

       Options

       standard
	   Set the standard. Must be the name of a supported standard. To get
	   a list of the supported standards, use the list_standards option.

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

       video_size
	   Set the video frame size. The argument must be a string in the form
	   WIDTHxHEIGHT or a valid size abbreviation.

       pixel_format
	   Select the pixel format (only valid for raw video input).

       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.

       framerate
	   Set the preferred video frame rate.

       list_formats
	   List available formats (supported pixel formats, codecs, and frame
	   sizes) and exit.

	   Available values are:

	   all Show all available (compressed and non-compressed) formats.

	   raw Show only raw video (non-compressed) formats.

	   compressed
	       Show only compressed formats.

       list_standards
	   List supported standards and exit.

	   Available values are:

	   all Show all supported standards.

       timestamps, ts
	   Set type of timestamps for grabbed frames.

	   Available values are:

	   default
	       Use timestamps from the kernel.

	   abs Use absolute timestamps (wall clock).

	   mono2abs
	       Force conversion from monotonic to absolute timestamps.

	   Default value is "default".

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

   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.

       Options

       video_size
	   Set the video frame size.

       framerate
	   Set the grabbing frame rate. Default value is "ntsc", corresponding
	   to a frame rate of "30000/1001".

   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.

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

       The filename passed as input has the syntax:

	       [<hostname>]:<display_number>.<screen_number>[+<x_offset>,<y_offset>]

       hostname:display_number.screen_number specifies the X11 display name of
       the screen to grab from. hostname can be omitted, and defaults to
       "localhost". The environment variable DISPLAY contains the default
       display name.

       x_offset and 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. man X) for more detailed information.

       Use the 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 :0.0 using ffmpeg:

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

       Grab at position "10,20":

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

       Options

       select_region
	   Specify whether to select the grabbing area graphically using the
	   pointer.  A value of 1 prompts the user to select the grabbing area
	   graphically by clicking and dragging. A single click with no
	   dragging will select the whole screen. A region with zero width or
	   height will also select the whole screen. This option overwrites
	   the video_size, grab_x, and grab_y options. Default value is 0.

       draw_mouse
	   Specify whether to draw the mouse pointer. A value of 0 specifies
	   not to draw the pointer. Default value is 1.

       follow_mouse
	   Make the grabbed area follow the mouse. The argument can be
	   "centered" or a number of pixels 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 PIXELS (greater than zero) to the edge of region.

	   For example:

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

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

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

       framerate
	   Set the grabbing frame rate. Default value is "ntsc", corresponding
	   to a frame rate of "30000/1001".

       show_region
	   Show grabbed region on screen.

	   If show_region is specified with 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.

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

	   For example:

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

	   With follow_mouse:

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

       window_id
	   Grab this window, instead of the whole screen. Default value is 0,
	   which maps to the whole screen (root window).

	   The id of a window can be found using the xwininfo program,
	   possibly with options -tree and -root.

	   If the window is later enlarged, the new area is not recorded.
	   Video ends when the window is closed, unmapped (i.e., iconified) or
	   shrunk beyond the video size (which defaults to the initial window
	   size).

	   This option disables options follow_mouse and select_region.

       video_size
	   Set the video frame size. Default is the full desktop or window.

       grab_x
       grab_y
	   Set the grabbing region coordinates. They are expressed as offset
	   from the top left corner of the X11 window and correspond to the
	   x_offset and y_offset parameters in the device name. The default
	   value for both options is 0.

OUTPUT DEVICES
       Output devices are configured elements in FFmpeg that can write
       multimedia data to an output device attached to your system.

       When you configure your FFmpeg build, all the supported output devices
       are enabled by default. You can list all available ones using the
       configure option "--list-outdevs".

       You can disable all the output devices using the configure option
       "--disable-outdevs", and selectively enable an output device using the
       option "--enable-outdev=OUTDEV", or you can disable a particular input
       device using the option "--disable-outdev=OUTDEV".

       The option "-devices" of the ff* tools will display the list of enabled
       output devices.

       A description of the currently available output devices follows.

   alsa
       ALSA (Advanced Linux Sound Architecture) output device.

       Examples

       o   Play a file on default ALSA device:

		   ffmpeg -i INPUT -f alsa default

       o   Play a file on soundcard 1, audio device 7:

		   ffmpeg -i INPUT -f alsa hw:1,7

   AudioToolbox
       AudioToolbox output device.

       Allows native output to CoreAudio devices on OSX.

       The output filename can be empty (or "-") to refer to the default
       system output device or a number that refers to the device index as
       shown using: "-list_devices true".

       Alternatively, the audio input device can be chosen by index using the

	   B<-audio_device_index E<lt>INDEXE<gt>>

       , overriding any device name or index given in the input filename.

       All available devices can be enumerated by using -list_devices true,
       listing all device names, UIDs and corresponding indices.

       Options

       AudioToolbox supports the following options:

       -audio_device_index <INDEX>
	   Specify the audio device by its index. Overrides anything given in
	   the output filename.

       Examples

       o   Print the list of supported devices and output a sine wave to the
	   default device:

		   $ ffmpeg -f lavfi -i sine=r=44100 -f audiotoolbox -list_devices true -

       o   Output a sine wave to the device with the index 2, overriding any
	   output filename:

		   $ ffmpeg -f lavfi -i sine=r=44100 -f audiotoolbox -audio_device_index 2 -

   caca
       CACA output device.

       This output device allows one to show a video stream in CACA window.
       Only one CACA window is allowed per application, so you can have only
       one instance of this output device in an application.

       To enable this output device you need to configure FFmpeg with
       "--enable-libcaca".  libcaca is a graphics library that outputs text
       instead of pixels.

       For more information about libcaca, check:
       <http://caca.zoy.org/wiki/libcaca>

       Options

       window_title
	   Set the CACA window title, if not specified default to the filename
	   specified for the output device.

       window_size
	   Set the CACA window size, can be a string of the form widthxheight
	   or a video size abbreviation.  If not specified it defaults to the
	   size of the input video.

       driver
	   Set display driver.

       algorithm
	   Set dithering algorithm. Dithering is necessary because the picture
	   being rendered has usually far more colours than the available
	   palette.  The accepted values are listed with "-list_dither
	   algorithms".

       antialias
	   Set antialias method. Antialiasing smoothens the rendered image and
	   avoids the commonly seen staircase effect.  The accepted values are
	   listed with "-list_dither antialiases".

       charset
	   Set which characters are going to be used when rendering text.  The
	   accepted values are listed with "-list_dither charsets".

       color
	   Set color to be used when rendering text.  The accepted values are
	   listed with "-list_dither colors".

       list_drivers
	   If set to true, print a list of available drivers and exit.

       list_dither
	   List available dither options related to the argument.  The
	   argument must be one of "algorithms", "antialiases", "charsets",
	   "colors".

       Examples

       o   The following command shows the ffmpeg output is an CACA window,
	   forcing its size to 80x25:

		   ffmpeg -i INPUT -c:v rawvideo -pix_fmt rgb24 -window_size 80x25 -f caca -

       o   Show the list of available drivers and exit:

		   ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_drivers true -

       o   Show the list of available dither colors and exit:

		   ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_dither colors -

   decklink
       The decklink output device provides playback capabilities for
       Blackmagic DeckLink devices.

       To enable this output device, you need the Blackmagic DeckLink SDK and
       you need to configure with the appropriate "--extra-cflags" and
       "--extra-ldflags".  On Windows, you need to run the IDL files through
       widl.

       DeckLink is very picky about the formats it supports. Pixel format is
       always uyvy422, framerate, field order and video size must be
       determined for your device with -list_formats 1. Audio sample rate is
       always 48 kHz.

       Options

       list_devices
	   If set to true, print a list of devices and exit.  Defaults to
	   false. This option is deprecated, please use the "-sinks" option of
	   ffmpeg to list the available output devices.

       list_formats
	   If set to true, print a list of supported formats and exit.
	   Defaults to false.

       preroll
	   Amount of time to preroll video in seconds.	Defaults to 0.5.

       duplex_mode
	   Sets the decklink device duplex/profile mode. Must be unset, half,
	   full, one_sub_device_full, one_sub_device_half,
	   two_sub_device_full, four_sub_device_half Defaults to unset.

	   Note: DeckLink SDK 11.0 have replaced the duplex property by a
	   profile property.  For the DeckLink Duo 2 and DeckLink Quad 2, a
	   profile is shared between any 2 sub-devices that utilize the same
	   connectors. For the DeckLink 8K Pro, a profile is shared between
	   all 4 sub-devices. So DeckLink 8K Pro support four profiles.

	   Valid profile modes for DeckLink 8K Pro(with DeckLink SDK >= 11.0):
	   one_sub_device_full, one_sub_device_half, two_sub_device_full,
	   four_sub_device_half

	   Valid profile modes for DeckLink Quad 2 and DeckLink Duo 2: half,
	   full

       timing_offset
	   Sets the genlock timing pixel offset on the used output.  Defaults
	   to unset.

       link
	   Sets the SDI video link configuration on the used output. Must be
	   unset, single link SDI, dual link SDI or quad link SDI.  Defaults
	   to unset.

       sqd Enable Square Division Quad Split mode for Quad-link SDI output.
	   Must be unset, true or false.  Defaults to unset.

       level_a
	   Enable SMPTE Level A mode on the used output.  Must be unset, true
	   or false.  Defaults to unset.

       vanc_queue_size
	   Sets maximum output buffer size in bytes for VANC data. If the
	   buffering reaches this value, outgoing VANC data will be dropped.
	   Defaults to 1048576.

       Examples

       o   List output devices:

		   ffmpeg -sinks decklink

       o   List supported formats:

		   ffmpeg -i test.avi -f decklink -list_formats 1 'DeckLink Mini Monitor'

       o   Play video clip:

		   ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 'DeckLink Mini Monitor'

       o   Play video clip with non-standard framerate or video size:

		   ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 -s 720x486 -r 24000/1001 'DeckLink Mini Monitor'

   fbdev
       Linux framebuffer output 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 /dev/fb0.

       For more detailed information read the file
       Documentation/fb/framebuffer.txt included in the Linux source tree.

       Options

       xoffset
       yoffset
	   Set x/y coordinate of top left corner. Default is 0.

       Examples

       Play a file on framebuffer device /dev/fb0.  Required pixel format
       depends on current framebuffer settings.

	       ffmpeg -re -i INPUT -c:v rawvideo -pix_fmt bgra -f fbdev /dev/fb0

       See also <http://linux-fbdev.sourceforge.net/>, and fbset(1).

   opengl
       OpenGL output device. Deprecated and will be removed.

       To enable this output device you need to configure FFmpeg with
       "--enable-opengl".

       This output device allows one to render to OpenGL context.  Context may
       be provided by application or default SDL window is created.

       When device renders to external context, application must implement
       handlers for following messages: "AV_DEV_TO_APP_CREATE_WINDOW_BUFFER" -
       create OpenGL context on current thread.
       "AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER" - make OpenGL context current.
       "AV_DEV_TO_APP_DISPLAY_WINDOW_BUFFER" - swap buffers.
       "AV_DEV_TO_APP_DESTROY_WINDOW_BUFFER" - destroy OpenGL context.
       Application is also required to inform a device about current
       resolution by sending "AV_APP_TO_DEV_WINDOW_SIZE" message.

       Options

       background
	   Set background color. Black is a default.

       no_window
	   Disables default SDL window when set to non-zero value.
	   Application must provide OpenGL context and both "window_size_cb"
	   and "window_swap_buffers_cb" callbacks when set.

       window_title
	   Set the SDL window title, if not specified default to the filename
	   specified for the output device.  Ignored when no_window is set.

       window_size
	   Set preferred window size, can be a string of the form widthxheight
	   or a video size abbreviation.  If not specified it defaults to the
	   size of the input video, downscaled according to the aspect ratio.
	   Mostly usable when no_window is not set.

       Examples

       Play a file on SDL window using OpenGL rendering:

	       ffmpeg  -i INPUT -f opengl "window title"

   oss
       OSS (Open Sound System) output device.

   pulse
       PulseAudio output device.

       To enable this output device you need to configure FFmpeg with
       "--enable-libpulse".

       More information about PulseAudio can be found on
       <http://www.pulseaudio.org>

       Options

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

       name
	   Specify the application name PulseAudio will use when showing
	   active clients, by default it is the "LIBAVFORMAT_IDENT" string.

       stream_name
	   Specify the stream name PulseAudio will use when showing active
	   streams, by default it is set to the specified output name.

       device
	   Specify the device to use. Default device is used when not
	   provided.  List of output devices can be obtained with command
	   pactl list sinks.

       buffer_size
       buffer_duration
	   Control the size and duration of the PulseAudio buffer. A small
	   buffer gives more control, but requires more frequent updates.

	   buffer_size specifies size in bytes while buffer_duration specifies
	   duration in milliseconds.

	   When both options are provided then the highest value is used
	   (duration is recalculated to bytes using stream parameters). If
	   they are set to 0 (which is default), the device will use the
	   default PulseAudio duration value. By default PulseAudio set buffer
	   duration to around 2 seconds.

       prebuf
	   Specify pre-buffering size in bytes. The server does not start with
	   playback before at least prebuf bytes are available in the buffer.
	   By default this option is initialized to the same value as
	   buffer_size or buffer_duration (whichever is bigger).

       minreq
	   Specify minimum request size in bytes. The server does not request
	   less than minreq bytes from the client, instead waits until the
	   buffer is free enough to request more bytes at once. It is
	   recommended to not set this option, which will initialize this to a
	   value that is deemed sensible by the server.

       Examples

       Play a file on default device on default server:

	       ffmpeg  -i INPUT -f pulse "stream name"

   sdl
       SDL (Simple DirectMedia Layer) output device. Deprecated and will be
       removed.

       For monitoring purposes in FFmpeg, pipes and a video player such as
       ffplay can be used:

	       ffmpeg -i INPUT -f nut -c:v rawvideo - | ffplay -

       "sdl2" can be used as alias for "sdl".

       This output device allows one to show a video stream in an SDL window.
       Only one SDL window is allowed per application, so you can have only
       one instance of this output device in an application.

       To enable this output device you need libsdl installed on your system
       when configuring your build.

       For more information about SDL, check: <http://www.libsdl.org/>

       Options

       window_borderless
	   Set SDL window border off.  Default value is 0 (enable window
	   border).

       window_enable_quit
	   Enable quit action (using window button or keyboard key) when non-
	   zero value is provided.  Default value is 1 (enable quit action).

       window_fullscreen
	   Set fullscreen mode when non-zero value is provided.  Default value
	   is zero.

       window_size
	   Set the SDL window size, can be a string of the form widthxheight
	   or a video size abbreviation.  If not specified it defaults to the
	   size of the input video, downscaled according to the aspect ratio.

       window_title
	   Set the SDL window title, if not specified default to the filename
	   specified for the output device.

       window_x
       window_y
	   Set the position of the window on the screen.

       Interactive commands

       The window created by the device can be controlled through the
       following interactive commands.

       q, ESC
	   Quit the device immediately.

       Examples

       The following command shows the ffmpeg output is an SDL window, forcing
       its size to the qcif format:

	       ffmpeg -i INPUT -c:v rawvideo -pix_fmt yuv420p -window_size qcif -f sdl "SDL output"

   sndio
       sndio audio output device.

   v4l2
       Video4Linux2 output device.

   xv
       XV (XVideo) output device.

       This output device allows one to show a video stream in a X Window
       System window.

       Options

       display_name
	   Specify the hardware display name, which determines the display and
	   communications domain to be used.

	   The display name or DISPLAY environment variable can be a string in
	   the format hostname[:number[.screen_number]].

	   hostname specifies the name of the host machine on which the
	   display is physically attached. number specifies the number of the
	   display server on that host machine. screen_number specifies the
	   screen to be used on that server.

	   If unspecified, it defaults to the value of the DISPLAY environment
	   variable.

	   For example, "dual-headed:0.1" would specify screen 1 of display 0
	   on the machine named ``dual-headed''.

	   Check the X11 specification for more detailed information about the
	   display name format.

       window_id
	   When set to non-zero value then device doesn't create new window,
	   but uses existing one with provided window_id. By default this
	   options is set to zero and device creates its own window.

       window_size
	   Set the created window size, can be a string of the form
	   widthxheight or a video size abbreviation. If not specified it
	   defaults to the size of the input video.  Ignored when window_id is
	   set.

       window_x
       window_y
	   Set the X and Y window offsets for the created window. They are
	   both set to 0 by default. The values may be ignored by the window
	   manager.  Ignored when window_id is set.

       window_title
	   Set the window title, if not specified default to the filename
	   specified for the output device. Ignored when window_id is set.

       For more information about XVideo see <http://www.x.org/>.

       Examples

       o   Decode, display and encode video input with ffmpeg at the same
	   time:

		   ffmpeg -i INPUT OUTPUT -f xv display

       o   Decode and display the input video to multiple X11 windows:

		   ffmpeg -i INPUT -f xv normal -vf negate -f xv negated

SEE ALSO
       ffmpeg(1), ffplay(1), ffprobe(1), libavdevice(3)

AUTHORS
       The FFmpeg developers.

       For details about the authorship, see the Git history of the project
       (https://git.ffmpeg.org/ffmpeg), e.g. by typing the command git log in
       the FFmpeg source directory, or browsing the online repository at
       <https://git.ffmpeg.org/ffmpeg>.

       Maintainers for the specific components are listed in the file
       MAINTAINERS in the source code tree.

							     FFMPEG-DEVICES(1)