forked from KolibriOS/kolibrios
1475 lines
30 KiB
Plaintext
1475 lines
30 KiB
Plaintext
=head1 NAME
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ffmpeg-devices - FFmpeg devices
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=head1 DESCRIPTION
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This document describes the input and output devices provided by the
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libavdevice library.
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=head1 DEVICE OPTIONS
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The libavdevice library provides the same interface as
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libavformat. Namely, an input device is considered like a demuxer, and
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an output device like a muxer, and the interface and generic device
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options are the same provided by libavformat (see the ffmpeg-formats
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manual).
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In addition each input or output device may support so-called private
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options, which are specific for that component.
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Options may be set by specifying -I<option> I<value> in the
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FFmpeg tools, or by setting the value explicitly in the device
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C<AVFormatContext> options or using the F<libavutil/opt.h> API
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for programmatic use.
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=head1 INPUT DEVICES
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Input devices are configured elements in FFmpeg which allow to access
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the data coming from a multimedia device attached to your system.
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When you configure your FFmpeg build, all the supported input devices
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are enabled by default. You can list all available ones using the
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configure option "--list-indevs".
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You can disable all the input devices using the configure option
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"--disable-indevs", and selectively enable an input device using the
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option "--enable-indev=I<INDEV>", or you can disable a particular
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input device using the option "--disable-indev=I<INDEV>".
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The option "-formats" of the ff* tools will display the list of
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supported input devices (amongst the demuxers).
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A description of the currently available input devices follows.
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=head2 alsa
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ALSA (Advanced Linux Sound Architecture) input device.
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To enable this input device during configuration you need libasound
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installed on your system.
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This device allows capturing from an ALSA device. The name of the
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device to capture has to be an ALSA card identifier.
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An ALSA identifier has the syntax:
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hw:<CARD>[,<DEV>[,<SUBDEV>]]
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where the I<DEV> and I<SUBDEV> components are optional.
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The three arguments (in order: I<CARD>,I<DEV>,I<SUBDEV>)
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specify card number or identifier, device number and subdevice number
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(-1 means any).
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To see the list of cards currently recognized by your system check the
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files F</proc/asound/cards> and F</proc/asound/devices>.
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For example to capture with B<ffmpeg> from an ALSA device with
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card id 0, you may run the command:
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ffmpeg -f alsa -i hw:0 alsaout.wav
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For more information see:
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E<lt>B<http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html>E<gt>
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=head2 bktr
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BSD video input device.
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=head2 dshow
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Windows DirectShow input device.
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DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
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Currently only audio and video devices are supported.
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Multiple devices may be opened as separate inputs, but they may also be
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opened on the same input, which should improve synchronism between them.
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The input name should be in the format:
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<TYPE>=<NAME>[:<TYPE>=<NAME>]
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where I<TYPE> can be either I<audio> or I<video>,
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and I<NAME> is the device's name.
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=head3 Options
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If no options are specified, the device's defaults are used.
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If the device does not support the requested options, it will
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fail to open.
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=over 4
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=item B<video_size>
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Set the video size in the captured video.
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=item B<framerate>
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Set the frame rate in the captured video.
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=item B<sample_rate>
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Set the sample rate (in Hz) of the captured audio.
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=item B<sample_size>
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Set the sample size (in bits) of the captured audio.
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=item B<channels>
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Set the number of channels in the captured audio.
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=item B<list_devices>
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If set to B<true>, print a list of devices and exit.
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=item B<list_options>
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If set to B<true>, print a list of selected device's options
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and exit.
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=item B<video_device_number>
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Set video device number for devices with same name (starts at 0,
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defaults to 0).
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=item B<audio_device_number>
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Set audio device number for devices with same name (starts at 0,
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defaults to 0).
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=item B<pixel_format>
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Select pixel format to be used by DirectShow. This may only be set when
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the video codec is not set or set to rawvideo.
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=item B<audio_buffer_size>
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Set audio device buffer size in milliseconds (which can directly
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impact latency, depending on the device).
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Defaults to using the audio device's
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default buffer size (typically some multiple of 500ms).
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Setting this value too low can degrade performance.
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See also
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E<lt>B<http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx>E<gt>
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=back
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=head3 Examples
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=over 4
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=item *
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Print the list of DirectShow supported devices and exit:
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$ ffmpeg -list_devices true -f dshow -i dummy
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=item *
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Open video device I<Camera>:
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$ ffmpeg -f dshow -i video="Camera"
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=item *
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Open second video device with name I<Camera>:
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$ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
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=item *
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Open video device I<Camera> and audio device I<Microphone>:
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$ ffmpeg -f dshow -i video="Camera":audio="Microphone"
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=item *
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Print the list of supported options in selected device and exit:
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$ ffmpeg -list_options true -f dshow -i video="Camera"
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=back
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=head2 dv1394
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Linux DV 1394 input device.
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=head2 fbdev
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Linux framebuffer input device.
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The Linux framebuffer is a graphic hardware-independent abstraction
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layer to show graphics on a computer monitor, typically on the
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console. It is accessed through a file device node, usually
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F</dev/fb0>.
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For more detailed information read the file
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Documentation/fb/framebuffer.txt included in the Linux source tree.
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To record from the framebuffer device F</dev/fb0> with
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B<ffmpeg>:
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ffmpeg -f fbdev -r 10 -i /dev/fb0 out.avi
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You can take a single screenshot image with the command:
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ffmpeg -f fbdev -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg
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See also E<lt>B<http://linux-fbdev.sourceforge.net/>E<gt>, and fbset(1).
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=head2 iec61883
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FireWire DV/HDV input device using libiec61883.
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To enable this input device, you need libiec61883, libraw1394 and
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libavc1394 installed on your system. Use the configure option
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C<--enable-libiec61883> to compile with the device enabled.
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The iec61883 capture device supports capturing from a video device
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connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
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FireWire stack (juju). This is the default DV/HDV input method in Linux
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Kernel 2.6.37 and later, since the old FireWire stack was removed.
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Specify the FireWire port to be used as input file, or "auto"
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to choose the first port connected.
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=head3 Options
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=over 4
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=item B<dvtype>
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Override autodetection of DV/HDV. This should only be used if auto
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detection does not work, or if usage of a different device type
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should be prohibited. Treating a DV device as HDV (or vice versa) will
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not work and result in undefined behavior.
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The values B<auto>, B<dv> and B<hdv> are supported.
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=item B<dvbuffer>
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Set maxiumum size of buffer for incoming data, in frames. For DV, this
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is an exact value. For HDV, it is not frame exact, since HDV does
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not have a fixed frame size.
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=item B<dvguid>
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Select the capture device by specifying it's GUID. Capturing will only
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be performed from the specified device and fails if no device with the
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given GUID is found. This is useful to select the input if multiple
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devices are connected at the same time.
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Look at /sys/bus/firewire/devices to find out the GUIDs.
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=back
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=head3 Examples
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=over 4
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=item *
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Grab and show the input of a FireWire DV/HDV device.
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ffplay -f iec61883 -i auto
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=item *
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Grab and record the input of a FireWire DV/HDV device,
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using a packet buffer of 100000 packets if the source is HDV.
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ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg
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=back
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=head2 jack
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JACK input device.
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To enable this input device during configuration you need libjack
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installed on your system.
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A JACK input device creates one or more JACK writable clients, one for
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each audio channel, with name I<client_name>:input_I<N>, where
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I<client_name> is the name provided by the application, and I<N>
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is a number which identifies the channel.
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Each writable client will send the acquired data to the FFmpeg input
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device.
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Once you have created one or more JACK readable clients, you need to
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connect them to one or more JACK writable clients.
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To connect or disconnect JACK clients you can use the B<jack_connect>
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and B<jack_disconnect> programs, or do it through a graphical interface,
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for example with B<qjackctl>.
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To list the JACK clients and their properties you can invoke the command
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B<jack_lsp>.
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Follows an example which shows how to capture a JACK readable client
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with B<ffmpeg>.
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# Create a JACK writable client with name "ffmpeg".
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$ ffmpeg -f jack -i ffmpeg -y out.wav
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# Start the sample jack_metro readable client.
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$ jack_metro -b 120 -d 0.2 -f 4000
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# List the current JACK clients.
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$ jack_lsp -c
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system:capture_1
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system:capture_2
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system:playback_1
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system:playback_2
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ffmpeg:input_1
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metro:120_bpm
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# Connect metro to the ffmpeg writable client.
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$ jack_connect metro:120_bpm ffmpeg:input_1
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For more information read:
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E<lt>B<http://jackaudio.org/>E<gt>
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=head2 lavfi
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Libavfilter input virtual device.
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This input device reads data from the open output pads of a libavfilter
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filtergraph.
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For each filtergraph open output, the input device will create a
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corresponding stream which is mapped to the generated output. Currently
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only video data is supported. The filtergraph is specified through the
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option B<graph>.
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=head3 Options
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=over 4
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=item B<graph>
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Specify the filtergraph to use as input. Each video open output must be
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labelled by a unique string of the form "outI<N>", where I<N> is a
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number starting from 0 corresponding to the mapped input stream
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generated by the device.
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The first unlabelled output is automatically assigned to the "out0"
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label, but all the others need to be specified explicitly.
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If not specified defaults to the filename specified for the input
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device.
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=item B<graph_file>
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Set the filename of the filtergraph to be read and sent to the other
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filters. Syntax of the filtergraph is the same as the one specified by
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the option I<graph>.
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=back
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=head3 Examples
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=over 4
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=item *
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Create a color video stream and play it back with B<ffplay>:
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ffplay -f lavfi -graph "color=c=pink [out0]" dummy
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=item *
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As the previous example, but use filename for specifying the graph
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description, and omit the "out0" label:
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ffplay -f lavfi color=c=pink
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=item *
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Create three different video test filtered sources and play them:
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ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
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=item *
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Read an audio stream from a file using the amovie source and play it
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back with B<ffplay>:
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ffplay -f lavfi "amovie=test.wav"
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=item *
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Read an audio stream and a video stream and play it back with
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B<ffplay>:
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ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
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=back
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=head2 libdc1394
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IIDC1394 input device, based on libdc1394 and libraw1394.
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=head2 openal
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The OpenAL input device provides audio capture on all systems with a
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working OpenAL 1.1 implementation.
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To enable this input device during configuration, you need OpenAL
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headers and libraries installed on your system, and need to configure
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FFmpeg with C<--enable-openal>.
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OpenAL headers and libraries should be provided as part of your OpenAL
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implementation, or as an additional download (an SDK). Depending on your
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installation you may need to specify additional flags via the
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C<--extra-cflags> and C<--extra-ldflags> for allowing the build
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system to locate the OpenAL headers and libraries.
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An incomplete list of OpenAL implementations follows:
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=over 4
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=item B<Creative>
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The official Windows implementation, providing hardware acceleration
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with supported devices and software fallback.
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See E<lt>B<http://openal.org/>E<gt>.
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=item B<OpenAL Soft>
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Portable, open source (LGPL) software implementation. Includes
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backends for the most common sound APIs on the Windows, Linux,
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Solaris, and BSD operating systems.
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See E<lt>B<http://kcat.strangesoft.net/openal.html>E<gt>.
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=item B<Apple>
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OpenAL is part of Core Audio, the official Mac OS X Audio interface.
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See E<lt>B<http://developer.apple.com/technologies/mac/audio-and-video.html>E<gt>
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=back
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This device allows to capture from an audio input device handled
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through OpenAL.
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You need to specify the name of the device to capture in the provided
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filename. If the empty string is provided, the device will
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automatically select the default device. You can get the list of the
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supported devices by using the option I<list_devices>.
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=head3 Options
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=over 4
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=item B<channels>
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Set the number of channels in the captured audio. Only the values
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B<1> (monaural) and B<2> (stereo) are currently supported.
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Defaults to B<2>.
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=item B<sample_size>
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Set the sample size (in bits) of the captured audio. Only the values
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B<8> and B<16> are currently supported. Defaults to
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B<16>.
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=item B<sample_rate>
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Set the sample rate (in Hz) of the captured audio.
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Defaults to B<44.1k>.
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=item B<list_devices>
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If set to B<true>, print a list of devices and exit.
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Defaults to B<false>.
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=back
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=head3 Examples
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Print the list of OpenAL supported devices and exit:
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$ ffmpeg -list_devices true -f openal -i dummy out.ogg
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Capture from the OpenAL device F<DR-BT101 via PulseAudio>:
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$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
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Capture from the default device (note the empty string '' as filename):
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$ ffmpeg -f openal -i '' out.ogg
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Capture from two devices simultaneously, writing to two different files,
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within the same B<ffmpeg> command:
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$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
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Note: not all OpenAL implementations support multiple simultaneous capture -
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try the latest OpenAL Soft if the above does not work.
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=head2 oss
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Open Sound System input device.
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The filename to provide to the input device is the device node
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representing the OSS input device, and is usually set to
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F</dev/dsp>.
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For example to grab from F</dev/dsp> using B<ffmpeg> use the
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command:
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|
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ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
|
|
|
|
|
|
For more information about OSS see:
|
|
E<lt>B<http://manuals.opensound.com/usersguide/dsp.html>E<gt>
|
|
|
|
|
|
=head2 pulse
|
|
|
|
|
|
PulseAudio input device.
|
|
|
|
To enable this output device you need to configure FFmpeg with C<--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 B<pactl list sources>.
|
|
|
|
More information about PulseAudio can be found on E<lt>B<http://www.pulseaudio.org>E<gt>.
|
|
|
|
|
|
=head3 Options
|
|
|
|
|
|
=over 4
|
|
|
|
|
|
=item B<server>
|
|
|
|
Connect to a specific PulseAudio server, specified by an IP address.
|
|
Default server is used when not provided.
|
|
|
|
|
|
=item B<name>
|
|
|
|
Specify the application name PulseAudio will use when showing active clients,
|
|
by default it is the C<LIBAVFORMAT_IDENT> string.
|
|
|
|
|
|
=item B<stream_name>
|
|
|
|
Specify the stream name PulseAudio will use when showing active streams,
|
|
by default it is "record".
|
|
|
|
|
|
=item B<sample_rate>
|
|
|
|
Specify the samplerate in Hz, by default 48kHz is used.
|
|
|
|
|
|
=item B<channels>
|
|
|
|
Specify the channels in use, by default 2 (stereo) is set.
|
|
|
|
|
|
=item B<frame_size>
|
|
|
|
Specify the number of bytes per frame, by default it is set to 1024.
|
|
|
|
|
|
=item B<fragment_size>
|
|
|
|
Specify the minimal buffering fragment in PulseAudio, it will affect the
|
|
audio latency. By default it is unset.
|
|
|
|
=back
|
|
|
|
|
|
|
|
=head3 Examples
|
|
|
|
Record a stream from default device:
|
|
|
|
ffmpeg -f pulse -i default /tmp/pulse.wav
|
|
|
|
|
|
|
|
=head2 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
|
|
F</dev/audio0>.
|
|
|
|
For example to grab from F</dev/audio0> using B<ffmpeg> use the
|
|
command:
|
|
|
|
ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
|
|
|
|
|
|
|
|
=head2 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
|
|
C<--enable-libv4l2> configure option), it is possible to use it with the
|
|
C<-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 F</dev/videoI<N>>, where I<N> is a number associated to
|
|
the device.
|
|
|
|
Video4Linux2 devices usually support a limited set of
|
|
I<width>xI<height> sizes and frame rates. You can check which are
|
|
supported using B<-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 B<-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
|
|
B<-timestamps abs> or B<-ts abs> option can be used to force
|
|
conversion into the real time clock.
|
|
|
|
Some usage examples of the video4linux2 device with B<ffmpeg>
|
|
and B<ffplay>:
|
|
|
|
=over 4
|
|
|
|
|
|
=item *
|
|
|
|
Grab and show the input of a video4linux2 device:
|
|
|
|
ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
|
|
|
|
|
|
|
|
=item *
|
|
|
|
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
|
|
|
|
|
|
=back
|
|
|
|
|
|
For more information about Video4Linux, check E<lt>B<http://linuxtv.org/>E<gt>.
|
|
|
|
|
|
=head3 Options
|
|
|
|
|
|
|
|
=over 4
|
|
|
|
|
|
=item B<standard>
|
|
|
|
Set the standard. Must be the name of a supported standard. To get a
|
|
list of the supported standards, use the B<list_standards>
|
|
option.
|
|
|
|
|
|
=item B<channel>
|
|
|
|
Set the input channel number. Default to -1, which means using the
|
|
previously selected channel.
|
|
|
|
|
|
=item B<video_size>
|
|
|
|
Set the video frame size. The argument must be a string in the form
|
|
I<WIDTH>xI<HEIGHT> or a valid size abbreviation.
|
|
|
|
|
|
=item B<pixel_format>
|
|
|
|
Select the pixel format (only valid for raw video input).
|
|
|
|
|
|
=item B<input_format>
|
|
|
|
Set the preferred pixel format (for raw video) or a codec name.
|
|
This option allows to select the input format, when several are
|
|
available.
|
|
|
|
|
|
=item B<framerate>
|
|
|
|
Set the preferred video frame rate.
|
|
|
|
|
|
=item B<list_formats>
|
|
|
|
List available formats (supported pixel formats, codecs, and frame
|
|
sizes) and exit.
|
|
|
|
Available values are:
|
|
|
|
=over 4
|
|
|
|
|
|
=item B<all>
|
|
|
|
Show all available (compressed and non-compressed) formats.
|
|
|
|
|
|
=item B<raw>
|
|
|
|
Show only raw video (non-compressed) formats.
|
|
|
|
|
|
=item B<compressed>
|
|
|
|
Show only compressed formats.
|
|
|
|
=back
|
|
|
|
|
|
|
|
=item B<list_standards>
|
|
|
|
List supported standards and exit.
|
|
|
|
Available values are:
|
|
|
|
=over 4
|
|
|
|
|
|
=item B<all>
|
|
|
|
Show all supported standards.
|
|
|
|
=back
|
|
|
|
|
|
|
|
=item B<timestamps, ts>
|
|
|
|
Set type of timestamps for grabbed frames.
|
|
|
|
Available values are:
|
|
|
|
=over 4
|
|
|
|
|
|
=item B<default>
|
|
|
|
Use timestamps from the kernel.
|
|
|
|
|
|
=item B<abs>
|
|
|
|
Use absolute timestamps (wall clock).
|
|
|
|
|
|
=item B<mono2abs>
|
|
|
|
Force conversion from monotonic to absolute timestamps.
|
|
|
|
=back
|
|
|
|
|
|
Default value is C<default>.
|
|
|
|
=back
|
|
|
|
|
|
|
|
=head2 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.
|
|
|
|
|
|
=head2 x11grab
|
|
|
|
|
|
X11 video input device.
|
|
|
|
This device allows 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>]
|
|
|
|
|
|
I<hostname>:I<display_number>.I<screen_number> specifies the
|
|
X11 display name of the screen to grab from. I<hostname> can be
|
|
omitted, and defaults to "localhost". The environment variable
|
|
B<DISPLAY> contains the default display name.
|
|
|
|
I<x_offset> and I<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 B<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 F<:0.0> using B<ffmpeg>:
|
|
|
|
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
|
|
|
|
|
|
Grab at position C<10,20>:
|
|
|
|
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
|
|
|
|
|
|
|
|
=head3 Options
|
|
|
|
|
|
|
|
=over 4
|
|
|
|
|
|
=item B<draw_mouse>
|
|
|
|
Specify whether to draw the mouse pointer. A value of C<0> specify
|
|
not to draw the pointer. Default value is C<1>.
|
|
|
|
|
|
=item B<follow_mouse>
|
|
|
|
Make the grabbed area follow the mouse. The argument can be
|
|
C<centered> or a number of pixels I<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 I<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
|
|
|
|
|
|
|
|
=item B<framerate>
|
|
|
|
Set the grabbing frame rate. Default value is C<ntsc>,
|
|
corresponding to a frame rate of C<30000/1001>.
|
|
|
|
|
|
=item B<show_region>
|
|
|
|
Show grabbed region on screen.
|
|
|
|
If I<show_region> is specified with C<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.
|
|
|
|
For example:
|
|
|
|
ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
|
|
|
|
|
|
With I<follow_mouse>:
|
|
|
|
ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
|
|
|
|
|
|
|
|
=item B<video_size>
|
|
|
|
Set the video frame size. Default value is C<vga>.
|
|
|
|
=back
|
|
|
|
|
|
|
|
=head1 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=I<OUTDEV>", or you can disable a particular
|
|
input device using the option "--disable-outdev=I<OUTDEV>".
|
|
|
|
The option "-formats" of the ff* tools will display the list of
|
|
enabled output devices (amongst the muxers).
|
|
|
|
A description of the currently available output devices follows.
|
|
|
|
|
|
=head2 alsa
|
|
|
|
|
|
ALSA (Advanced Linux Sound Architecture) output device.
|
|
|
|
|
|
=head2 caca
|
|
|
|
|
|
CACA output device.
|
|
|
|
This output device allows 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
|
|
C<--enable-libcaca>.
|
|
libcaca is a graphics library that outputs text instead of pixels.
|
|
|
|
For more information about libcaca, check:
|
|
E<lt>B<http://caca.zoy.org/wiki/libcaca>E<gt>
|
|
|
|
|
|
=head3 Options
|
|
|
|
|
|
|
|
=over 4
|
|
|
|
|
|
|
|
=item B<window_title>
|
|
|
|
Set the CACA window title, if not specified default to the filename
|
|
specified for the output device.
|
|
|
|
|
|
=item B<window_size>
|
|
|
|
Set the CACA window size, can be a string of the form
|
|
I<width>xI<height> or a video size abbreviation.
|
|
If not specified it defaults to the size of the input video.
|
|
|
|
|
|
=item B<driver>
|
|
|
|
Set display driver.
|
|
|
|
|
|
=item B<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 C<-list_dither algorithms>.
|
|
|
|
|
|
=item B<antialias>
|
|
|
|
Set antialias method. Antialiasing smoothens the rendered
|
|
image and avoids the commonly seen staircase effect.
|
|
The accepted values are listed with C<-list_dither antialiases>.
|
|
|
|
|
|
=item B<charset>
|
|
|
|
Set which characters are going to be used when rendering text.
|
|
The accepted values are listed with C<-list_dither charsets>.
|
|
|
|
|
|
=item B<color>
|
|
|
|
Set color to be used when rendering text.
|
|
The accepted values are listed with C<-list_dither colors>.
|
|
|
|
|
|
=item B<list_drivers>
|
|
|
|
If set to B<true>, print a list of available drivers and exit.
|
|
|
|
|
|
=item B<list_dither>
|
|
|
|
List available dither options related to the argument.
|
|
The argument must be one of C<algorithms>, C<antialiases>,
|
|
C<charsets>, C<colors>.
|
|
|
|
=back
|
|
|
|
|
|
|
|
=head3 Examples
|
|
|
|
|
|
|
|
=over 4
|
|
|
|
|
|
=item *
|
|
|
|
The following command shows the B<ffmpeg> output is an
|
|
CACA window, forcing its size to 80x25:
|
|
|
|
ffmpeg -i INPUT -vcodec rawvideo -pix_fmt rgb24 -window_size 80x25 -f caca -
|
|
|
|
|
|
|
|
=item *
|
|
|
|
Show the list of available drivers and exit:
|
|
|
|
ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_drivers true -
|
|
|
|
|
|
|
|
=item *
|
|
|
|
Show the list of available dither colors and exit:
|
|
|
|
ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_dither colors -
|
|
|
|
|
|
=back
|
|
|
|
|
|
|
|
=head2 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
|
|
F</dev/fb0>.
|
|
|
|
For more detailed information read the file
|
|
F<Documentation/fb/framebuffer.txt> included in the Linux source tree.
|
|
|
|
|
|
=head3 Options
|
|
|
|
|
|
=over 4
|
|
|
|
|
|
|
|
=item B<xoffset>
|
|
|
|
|
|
=item B<yoffset>
|
|
|
|
Set x/y coordinate of top left corner. Default is 0.
|
|
|
|
=back
|
|
|
|
|
|
|
|
=head3 Examples
|
|
|
|
Play a file on framebuffer device F</dev/fb0>.
|
|
Required pixel format depends on current framebuffer settings.
|
|
|
|
ffmpeg -re -i INPUT -vcodec rawvideo -pix_fmt bgra -f fbdev /dev/fb0
|
|
|
|
|
|
See also E<lt>B<http://linux-fbdev.sourceforge.net/>E<gt>, and fbset(1).
|
|
|
|
|
|
=head2 oss
|
|
|
|
|
|
OSS (Open Sound System) output device.
|
|
|
|
|
|
=head2 pulse
|
|
|
|
|
|
PulseAudio output device.
|
|
|
|
To enable this output device you need to configure FFmpeg with C<--enable-libpulse>.
|
|
|
|
More information about PulseAudio can be found on E<lt>B<http://www.pulseaudio.org>E<gt>
|
|
|
|
|
|
=head3 Options
|
|
|
|
|
|
=over 4
|
|
|
|
|
|
|
|
=item B<server>
|
|
|
|
Connect to a specific PulseAudio server, specified by an IP address.
|
|
Default server is used when not provided.
|
|
|
|
|
|
=item B<name>
|
|
|
|
Specify the application name PulseAudio will use when showing active clients,
|
|
by default it is the C<LIBAVFORMAT_IDENT> string.
|
|
|
|
|
|
=item B<stream_name>
|
|
|
|
Specify the stream name PulseAudio will use when showing active streams,
|
|
by default it is set to the specified output name.
|
|
|
|
|
|
=item B<device>
|
|
|
|
Specify the device to use. Default device is used when not provided.
|
|
List of output devices can be obtained with command B<pactl list sinks>.
|
|
|
|
|
|
=back
|
|
|
|
|
|
|
|
=head3 Examples
|
|
|
|
Play a file on default device on default server:
|
|
|
|
ffmpeg -i INPUT -f pulse "stream name"
|
|
|
|
|
|
|
|
=head2 sdl
|
|
|
|
|
|
SDL (Simple DirectMedia Layer) output device.
|
|
|
|
This output device allows 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:
|
|
E<lt>B<http://www.libsdl.org/>E<gt>
|
|
|
|
|
|
=head3 Options
|
|
|
|
|
|
|
|
=over 4
|
|
|
|
|
|
|
|
=item B<window_title>
|
|
|
|
Set the SDL window title, if not specified default to the filename
|
|
specified for the output device.
|
|
|
|
|
|
=item B<icon_title>
|
|
|
|
Set the name of the iconified SDL window, if not specified it is set
|
|
to the same value of I<window_title>.
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|
=item B<window_size>
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|
|
|
Set the SDL window size, can be a string of the form
|
|
I<width>xI<height> or a video size abbreviation.
|
|
If not specified it defaults to the size of the input video,
|
|
downscaled according to the aspect ratio.
|
|
|
|
|
|
=item B<window_fullscreen>
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|
|
|
Set fullscreen mode when non-zero value is provided.
|
|
Zero is a default.
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|
|
=back
|
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|
=head3 Examples
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|
|
|
|
The following command shows the B<ffmpeg> output is an
|
|
SDL window, forcing its size to the qcif format:
|
|
|
|
ffmpeg -i INPUT -vcodec rawvideo -pix_fmt yuv420p -window_size qcif -f sdl "SDL output"
|
|
|
|
|
|
|
|
=head2 sndio
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|
|
|
|
|
sndio audio output device.
|
|
|
|
|
|
=head2 xv
|
|
|
|
|
|
XV (XVideo) output device.
|
|
|
|
This output device allows to show a video stream in a X Window System
|
|
window.
|
|
|
|
|
|
=head3 Options
|
|
|
|
|
|
|
|
=over 4
|
|
|
|
|
|
=item B<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 I<hostname>[:I<number>[.I<screen_number>]].
|
|
|
|
I<hostname> specifies the name of the host machine on which the
|
|
display is physically attached. I<number> specifies the number of
|
|
the display server on that host machine. I<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, C<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.
|
|
|
|
|
|
=item B<window_size>
|
|
|
|
Set the created window size, can be a string of the form
|
|
I<width>xI<height> or a video size abbreviation. If not
|
|
specified it defaults to the size of the input video.
|
|
|
|
|
|
=item B<window_x>
|
|
|
|
|
|
=item B<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.
|
|
|
|
|
|
=item B<window_title>
|
|
|
|
Set the window title, if not specified default to the filename
|
|
specified for the output device.
|
|
|
|
=back
|
|
|
|
|
|
For more information about XVideo see E<lt>B<http://www.x.org/>E<gt>.
|
|
|
|
|
|
=head3 Examples
|
|
|
|
|
|
|
|
=over 4
|
|
|
|
|
|
=item *
|
|
|
|
Decode, display and encode video input with B<ffmpeg> at the
|
|
same time:
|
|
|
|
ffmpeg -i INPUT OUTPUT -f xv display
|
|
|
|
|
|
|
|
=item *
|
|
|
|
Decode and display the input video to multiple X11 windows:
|
|
|
|
ffmpeg -i INPUT -f xv normal -vf negate -f xv negated
|
|
|
|
|
|
=back
|
|
|
|
|
|
|
|
|
|
=head1 SEE ALSO
|
|
|
|
|
|
|
|
ffmpeg(1), ffplay(1), ffprobe(1), ffserver(1), libavdevice(3)
|
|
|
|
|
|
=head1 AUTHORS
|
|
|
|
|
|
The FFmpeg developers.
|
|
|
|
For details about the authorship, see the Git history of the project
|
|
(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
|
|
B<git log> in the FFmpeg source directory, or browsing the
|
|
online repository at E<lt>B<http://source.ffmpeg.org>E<gt>.
|
|
|
|
Maintainers for the specific components are listed in the file
|
|
F<MAINTAINERS> in the source code tree.
|
|
|
|
|
|
|