@item list_devices
If set to @option{true}, print a list of devices and exit.
-Defaults to @option{false}.
+Defaults to @option{false}. Alternatively you can use the @code{-sources}
+option of ffmpeg to list the available input devices.
@item list_formats
If set to @option{true}, print a list of supported formats and exit.
the initial offset.
Defaults to @option{false}.
+@item 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
+@option{timestamp_align} seconds.
+Defaults to @samp{0}.
+
@end table
@subsection Examples
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
+ffmpeg -f iec61883 -i auto -dvbuffer 100000 out.mpg
@end example
@end itemize
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
@end example
+@item
+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:
+@example
+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
+@end example
+
@end itemize
@section lavfi
Requires the configure option @code{--enable-libdc1394}.
-@section libndi_newtek
-
-The libndi_newtek input device provides capture capabilities for using NDI (Network
-Device Interface, standard created by NewTek).
-
-Input filename is a NDI source name that could be found by sending -find_sources 1
-to command line - it has no specific syntax but human-readable formatted.
-
-To enable this input device, you need the NDI SDK and you
-need to configure with the appropriate @code{--extra-cflags}
-and @code{--extra-ldflags}.
-
@subsection Options
-
@table @option
-@item find_sources
-If set to @option{true}, print a list of found/available NDI sources and exit.
-Defaults to @option{false}.
-
-@item wait_sources
-Override time to wait until the number of online sources have changed.
-Defaults to @option{0.5}.
+@item framerate
+Set the frame rate. Default is @code{ntsc}, corresponding to a frame
+rate of @code{30000/1001}.
-@item allow_video_fields
-When this flag is @option{false}, all video that you receive will be progressive.
-Defaults to @option{true}.
+@item pixel_format
+Select the pixel format. Default is @code{uyvy422}.
+@item video_size
+Set the video size given as a string such as @code{640x480} or @code{hd720}.
+Default is @code{qvga}.
@end table
-@subsection Examples
-
-@itemize
-
-@item
-List input devices:
-@example
-ffmpeg -f libndi_newtek -find_sources 1 -i dummy
-@end example
-
-@item
-Restream to NDI:
-@example
-ffmpeg -f libndi_newtek -i "DEV-5.INTERNAL.M1STEREO.TV (NDI_SOURCE_NAME_1)" -f libndi_newtek -y NDI_SOURCE_NAME_2
-@end example
-
-@end itemize
-
@section openal
The OpenAL input device provides audio capture on all systems with a
projects / ffmpeg / blobdiff