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 @file{ffmpeg} from an ALSA device with
+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
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 same name (starts at 0,
+defaults to 0).
+
+@item audio_device_number
+Set audio device number for devices with same name (starts at 0,
+defaults to 0).
+
@end table
@subsection Examples
$ 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
Documentation/fb/framebuffer.txt included in the Linux source tree.
To record from the framebuffer device @file{/dev/fb0} with
-@file{ffmpeg}:
+@command{ffmpeg}:
@example
ffmpeg -f fbdev -r 10 -i /dev/fb0 out.avi
@end example
You can take a single screenshot image with the command:
@example
-ffmpeg -f fbdev -vframes 1 -r 1 -i /dev/fb0 screenshot.jpeg
+ffmpeg -f fbdev -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg
@end example
See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1).
@file{jack_lsp}.
Follows an example which shows how to capture a JACK readable client
-with @file{ffmpeg}.
+with @command{ffmpeg}.
@example
# Create a JACK writable client with name "ffmpeg".
$ ffmpeg -f jack -i ffmpeg -y out.wav
only video data is supported. The filtergraph is specified through the
option @option{graph}.
-To enable this input device, you need to configure your build with
-@code{--enable-libavfilter}.
-
@subsection Options
@table @option
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 explicitely.
+label, but all the others need to be specified explicitly.
If not specified defaults to the filename specified for the input
device.
representing the OSS input device, and is usually set to
@file{/dev/dsp}.
-For example to grab from @file{/dev/dsp} using @file{ffmpeg} use the
+For example to grab from @file{/dev/dsp} using @command{ffmpeg} use the
command:
@example
ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
For more information about OSS see:
@url{http://manuals.opensound.com/usersguide/dsp.html}
+@section pulse
+
+pulseaudio input device.
+
+To enable this input device during configuration you need libpulse-simple
+installed in your system.
+
+The filename to provide to the input device is a source device or the
+string "default"
+
+To list the pulse source devices and their properties you can invoke
+the command @file{pactl list sources}.
+
+@example
+ffmpeg -f pulse -i default /tmp/pulse.wav
+@end example
+
+@subsection @var{server} AVOption
+
+The syntax is:
+@example
+-server @var{server name}
+@end example
+
+Connects to a specific server.
+
+@subsection @var{name} AVOption
+
+The syntax is:
+@example
+-name @var{application name}
+@end example
+
+Specify the application name pulse will use when showing active clients,
+by default it is the LIBAVFORMAT_IDENT string
+
+@subsection @var{stream_name} AVOption
+
+The syntax is:
+@example
+-stream_name @var{stream name}
+@end example
+
+Specify the stream name pulse will use when showing active streams,
+by default it is "record"
+
+@subsection @var{sample_rate} AVOption
+
+The syntax is:
+@example
+-sample_rate @var{samplerate}
+@end example
+
+Specify the samplerate in Hz, by default 48kHz is used.
+
+@subsection @var{channels} AVOption
+
+The syntax is:
+@example
+-channels @var{N}
+@end example
+
+Specify the channels in use, by default 2 (stereo) is set.
+
+@subsection @var{frame_size} AVOption
+
+The syntax is:
+@example
+-frame_size @var{bytes}
+@end example
+
+Specify the number of byte per frame, by default it is set to 1024.
+
+@subsection @var{fragment_size} AVOption
+
+The syntax is:
+@example
+-fragment_size @var{bytes}
+@end example
+
+Specify the minimal buffering fragment in pulseaudio, it will affect the
+audio latency. By default it is unset.
+
@section sndio
sndio input device.
representing the sndio input device, and is usually set to
@file{/dev/audio0}.
-For example to grab from @file{/dev/audio0} using @file{ffmpeg} use the
+For example to grab from @file{/dev/audio0} using @command{ffmpeg} use the
command:
@example
ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
the device.
Video4Linux and Video4Linux2 devices only support a limited set of
-@var{width}x@var{height} sizes and framerates. You can check which are
+@var{width}x@var{height} sizes and frame rates. You can check which are
supported for example with the command @file{dov4l} for Video4Linux
devices and the command @file{v4l-info} for Video4Linux2 devices.
If the size for the device is set to 0x0, the input device will
-try to autodetect the size to use.
+try to auto-detect the size to use.
Only for the video4linux2 device, if the frame rate is set to 0/0 the
input device will use the frame rate value already set in the driver.
Video4Linux support is deprecated since Linux 2.6.30, and will be
dropped in later versions.
+Note that if FFmpeg is build with v4l-utils support ("--enable-libv4l2"
+option), it will always be used.
+
Follow some usage examples of the video4linux devices with the ff*
tools.
@example
# to the default of 25/1.
ffplay -s 320x240 -f video4linux /dev/video0
-# Grab and show the input of a video4linux2 device, autoadjust size.
+# Grab and show the input of a video4linux2 device, auto-adjust size.
ffplay -f video4linux2 /dev/video0
-# Grab and record the input of a video4linux2 device, autoadjust size,
+# Grab and record the input of a video4linux2 device, auto-adjust size,
# frame rate value defaults to 0/0 so it is read from the video4linux2
# driver.
ffmpeg -f video4linux2 -i /dev/video0 out.mpeg
@end example
+"v4l" and "v4l2" can be used as aliases for the respective "video4linux" and
+"video4linux2".
+
@section vfwcap
VfW (Video for Windows) capture input device.
@var{hostname}:@var{display_number}.@var{screen_number} specifies the
X11 display name of the screen to grab from. @var{hostname} can be
-ommitted, and defaults to "localhost". The environment variable
+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
Use the @file{dpyinfo} 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 @file{ffmpeg}:
+For example to grab from @file{:0.0} using @command{ffmpeg}:
@example
ffmpeg -f x11grab -r 25 -s cif -i :0.0 out.mpg
projects / ffmpeg / blobdiff