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diff --git a/ffmpeg/doc/indevs.texi b/ffmpeg/doc/indevs.texi new file mode 100644 index 0000000..cc5d666 --- /dev/null +++ b/ffmpeg/doc/indevs.texi @@ -0,0 +1,797 @@ +@chapter Input Devices +@c man begin INPUT DEVICES + +Input devices are configured elements in FFmpeg which allow to access +the data coming from a multimedia device attached to your system. + +When you configure your FFmpeg build, all the supported input devices +are enabled by default. You can list all available ones using the +configure option "--list-indevs". + +You can disable all the input devices using the configure option +"--disable-indevs", and selectively enable an input device using the +option "--enable-indev=@var{INDEV}", or you can disable a particular +input device using the option "--disable-indev=@var{INDEV}". + +The option "-formats" of the ff* tools will display the list of +supported input devices (amongst the demuxers). + +A description of the currently available input devices follows. + +@section alsa + +ALSA (Advanced Linux Sound Architecture) input device. + +To enable this input device during configuration you need libasound +installed on your system. + +This device allows capturing from an ALSA device. The name of the +device to capture has to be an ALSA card identifier. + +An ALSA identifier has the syntax: +@example +hw:@var{CARD}[,@var{DEV}[,@var{SUBDEV}]] +@end example + +where the @var{DEV} and @var{SUBDEV} components are optional. + +The three arguments (in order: @var{CARD},@var{DEV},@var{SUBDEV}) +specify card number or identifier, device number and subdevice number +(-1 means any). + +To see the list of cards currently recognized by your system check the +files @file{/proc/asound/cards} and @file{/proc/asound/devices}. + +For example to capture with @command{ffmpeg} from an ALSA device with +card id 0, you may run the command: +@example +ffmpeg -f alsa -i hw:0 alsaout.wav +@end example + +For more information see: +@url{http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html} + +@section bktr + +BSD video input device. + +@section dshow + +Windows DirectShow input device. + +DirectShow support is enabled when FFmpeg is built with the mingw-w64 project. +Currently only audio and video devices are supported. + +Multiple devices may be opened as separate inputs, but they may also be +opened on the same input, which should improve synchronism between them. + +The input name should be in the format: + +@example +@var{TYPE}=@var{NAME}[:@var{TYPE}=@var{NAME}] +@end example + +where @var{TYPE} can be either @var{audio} or @var{video}, +and @var{NAME} is the device's name. + +@subsection Options + +If no options are specified, the device's defaults are used. +If the device does not support the requested options, it will +fail to open. + +@table @option + +@item video_size +Set the video size in the captured video. + +@item framerate +Set the framerate in the captured video. + +@item sample_rate +Set the sample rate (in Hz) of the captured audio. + +@item sample_size +Set the sample size (in bits) of the captured audio. + +@item channels +Set the number of channels in the captured audio. + +@item list_devices +If set to @option{true}, print a list of devices and exit. + +@item list_options +If set to @option{true}, print a list of selected device's options +and exit. + +@item video_device_number +Set video device number for devices with 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). + +@item pixel_format +Select pixel format to be used by DirectShow. This may only be set when +the video codec is not set or set to rawvideo. + +@item audio_buffer_size +Set audio device buffer size in milliseconds (which can directly +impact latency, depending on the device). +Defaults to using the audio device's +default buffer size (typically some multiple of 500ms). +Setting this value too low can degrade performance. +See also +@url{http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx} + +@end table + +@subsection Examples + +@itemize + +@item +Print the list of DirectShow supported devices and exit: +@example +$ ffmpeg -list_devices true -f dshow -i dummy +@end example + +@item +Open video device @var{Camera}: +@example +$ ffmpeg -f dshow -i video="Camera" +@end example + +@item +Open second video device with name @var{Camera}: +@example +$ ffmpeg -f dshow -video_device_number 1 -i video="Camera" +@end example + +@item +Open video device @var{Camera} and audio device @var{Microphone}: +@example +$ ffmpeg -f dshow -i video="Camera":audio="Microphone" +@end example + +@item +Print the list of supported options in selected device and exit: +@example +$ ffmpeg -list_options true -f dshow -i video="Camera" +@end example + +@end itemize + +@section dv1394 + +Linux DV 1394 input device. + +@section fbdev + +Linux framebuffer input device. + +The Linux framebuffer is a graphic hardware-independent abstraction +layer to show graphics on a computer monitor, typically on the +console. It is accessed through a file device node, usually +@file{/dev/fb0}. + +For more detailed information read the file +Documentation/fb/framebuffer.txt included in the Linux source tree. + +To record from the framebuffer device @file{/dev/fb0} with +@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 -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg +@end example + +See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1). + +@section iec61883 + +FireWire DV/HDV input device using libiec61883. + +To enable this input device, you need libiec61883, libraw1394 and +libavc1394 installed on your system. Use the configure option +@code{--enable-libiec61883} to compile with the device enabled. + +The iec61883 capture device supports capturing from a video device +connected via IEEE1394 (FireWire), using libiec61883 and the new Linux +FireWire stack (juju). This is the default DV/HDV input method in Linux +Kernel 2.6.37 and later, since the old FireWire stack was removed. + +Specify the FireWire port to be used as input file, or "auto" +to choose the first port connected. + +@subsection Options + +@table @option + +@item dvtype +Override autodetection of DV/HDV. This should only be used if auto +detection does not work, or if usage of a different device type +should be prohibited. Treating a DV device as HDV (or vice versa) will +not work and result in undefined behavior. +The values @option{auto}, @option{dv} and @option{hdv} are supported. + +@item dvbuffer +Set maxiumum size of buffer for incoming data, in frames. For DV, this +is an exact value. For HDV, it is not frame exact, since HDV does +not have a fixed frame size. + +@item dvguid +Select the capture device by specifying it's GUID. Capturing will only +be performed from the specified device and fails if no device with the +given GUID is found. This is useful to select the input if multiple +devices are connected at the same time. +Look at /sys/bus/firewire/devices to find out the GUIDs. + +@end table + +@subsection Examples + +@itemize + +@item +Grab and show the input of a FireWire DV/HDV device. +@example +ffplay -f iec61883 -i auto +@end example + +@item +Grab and record the input of a FireWire DV/HDV device, +using a packet buffer of 100000 packets if the source is HDV. +@example +ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg +@end example + +@end itemize + +@section jack + +JACK input device. + +To enable this input device during configuration you need libjack +installed on your system. + +A JACK input device creates one or more JACK writable clients, one for +each audio channel, with name @var{client_name}:input_@var{N}, where +@var{client_name} is the name provided by the application, and @var{N} +is a number which identifies the channel. +Each writable client will send the acquired data to the FFmpeg input +device. + +Once you have created one or more JACK readable clients, you need to +connect them to one or more JACK writable clients. + +To connect or disconnect JACK clients you can use the @command{jack_connect} +and @command{jack_disconnect} programs, or do it through a graphical interface, +for example with @command{qjackctl}. + +To list the JACK clients and their properties you can invoke the command +@command{jack_lsp}. + +Follows an example which shows how to capture a JACK readable client +with @command{ffmpeg}. +@example +# Create a JACK writable client with name "ffmpeg". +$ ffmpeg -f jack -i ffmpeg -y out.wav + +# Start the sample jack_metro readable client. +$ jack_metro -b 120 -d 0.2 -f 4000 + +# List the current JACK clients. +$ jack_lsp -c +system:capture_1 +system:capture_2 +system:playback_1 +system:playback_2 +ffmpeg:input_1 +metro:120_bpm + +# Connect metro to the ffmpeg writable client. +$ jack_connect metro:120_bpm ffmpeg:input_1 +@end example + +For more information read: +@url{http://jackaudio.org/} + +@section lavfi + +Libavfilter input virtual device. + +This input device reads data from the open output pads of a libavfilter +filtergraph. + +For each filtergraph open output, the input device will create a +corresponding stream which is mapped to the generated output. Currently +only video data is supported. The filtergraph is specified through the +option @option{graph}. + +@subsection Options + +@table @option + +@item graph +Specify the filtergraph to use as input. Each video open output must be +labelled by a unique string of the form "out@var{N}", where @var{N} is a +number starting from 0 corresponding to the mapped input stream +generated by the device. +The first unlabelled output is automatically assigned to the "out0" +label, but all the others need to be specified explicitly. + +If not specified defaults to the filename specified for the input +device. + +@item graph_file +Set the filename of the filtergraph to be read and sent to the other +filters. Syntax of the filtergraph is the same as the one specified by +the option @var{graph}. + +@end table + +@subsection Examples + +@itemize +@item +Create a color video stream and play it back with @command{ffplay}: +@example +ffplay -f lavfi -graph "color=c=pink [out0]" dummy +@end example + +@item +As the previous example, but use filename for specifying the graph +description, and omit the "out0" label: +@example +ffplay -f lavfi color=c=pink +@end example + +@item +Create three different video test filtered sources and play them: +@example +ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3 +@end example + +@item +Read an audio stream from a file using the amovie source and play it +back with @command{ffplay}: +@example +ffplay -f lavfi "amovie=test.wav" +@end example + +@item +Read an audio stream and a video stream and play it back with +@command{ffplay}: +@example +ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]" +@end example + +@end itemize + +@section libdc1394 + +IIDC1394 input device, based on libdc1394 and libraw1394. + +@section openal + +The OpenAL input device provides audio capture on all systems with a +working OpenAL 1.1 implementation. + +To enable this input device during configuration, you need OpenAL +headers and libraries installed on your system, and need to configure +FFmpeg with @code{--enable-openal}. + +OpenAL headers and libraries should be provided as part of your OpenAL +implementation, or as an additional download (an SDK). Depending on your +installation you may need to specify additional flags via the +@code{--extra-cflags} and @code{--extra-ldflags} for allowing the build +system to locate the OpenAL headers and libraries. + +An incomplete list of OpenAL implementations follows: + +@table @strong +@item Creative +The official Windows implementation, providing hardware acceleration +with supported devices and software fallback. +See @url{http://openal.org/}. +@item OpenAL Soft +Portable, open source (LGPL) software implementation. Includes +backends for the most common sound APIs on the Windows, Linux, +Solaris, and BSD operating systems. +See @url{http://kcat.strangesoft.net/openal.html}. +@item Apple +OpenAL is part of Core Audio, the official Mac OS X Audio interface. +See @url{http://developer.apple.com/technologies/mac/audio-and-video.html} +@end table + +This device allows to capture from an audio input device handled +through OpenAL. + +You need to specify the name of the device to capture in the provided +filename. If the empty string is provided, the device will +automatically select the default device. You can get the list of the +supported devices by using the option @var{list_devices}. + +@subsection Options + +@table @option + +@item channels +Set the number of channels in the captured audio. Only the values +@option{1} (monaural) and @option{2} (stereo) are currently supported. +Defaults to @option{2}. + +@item sample_size +Set the sample size (in bits) of the captured audio. Only the values +@option{8} and @option{16} are currently supported. Defaults to +@option{16}. + +@item sample_rate +Set the sample rate (in Hz) of the captured audio. +Defaults to @option{44.1k}. + +@item list_devices +If set to @option{true}, print a list of devices and exit. +Defaults to @option{false}. + +@end table + +@subsection Examples + +Print the list of OpenAL supported devices and exit: +@example +$ ffmpeg -list_devices true -f openal -i dummy out.ogg +@end example + +Capture from the OpenAL device @file{DR-BT101 via PulseAudio}: +@example +$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg +@end example + +Capture from the default device (note the empty string '' as filename): +@example +$ ffmpeg -f openal -i '' out.ogg +@end example + +Capture from two devices simultaneously, writing to two different files, +within the same @command{ffmpeg} command: +@example +$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg +@end example +Note: not all OpenAL implementations support multiple simultaneous capture - +try the latest OpenAL Soft if the above does not work. + +@section oss + +Open Sound System input device. + +The filename to provide to the input device is the device node +representing the OSS input device, and is usually set to +@file{/dev/dsp}. + +For example to grab from @file{/dev/dsp} using @command{ffmpeg} use the +command: +@example +ffmpeg -f oss -i /dev/dsp /tmp/oss.wav +@end example + +For more information about OSS see: +@url{http://manuals.opensound.com/usersguide/dsp.html} + +@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 @command{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. + +To enable this input device during configuration you need libsndio +installed on your system. + +The filename to provide to the input device is the device node +representing the sndio input device, and is usually set to +@file{/dev/audio0}. + +For example to grab from @file{/dev/audio0} using @command{ffmpeg} use the +command: +@example +ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav +@end example + +@section video4linux2, v4l2 + +Video4Linux2 input video device. + +"v4l2" can be used as alias for "video4linux2". + +If FFmpeg is built with v4l-utils support (by using the +@code{--enable-libv4l2} configure option), the device will always rely +on libv4l2. + +The name of the device to grab is a file device node, usually Linux +systems tend to automatically create such nodes when the device +(e.g. an USB webcam) is plugged into the system, and has a name of the +kind @file{/dev/video@var{N}}, where @var{N} is a number associated to +the device. + +Video4Linux2 devices usually support a limited set of +@var{width}x@var{height} sizes and framerates. You can check which are +supported using @command{-list_formats all} for Video4Linux2 devices. +Some devices, like TV cards, support one or more standards. It is possible +to list all the supported standards using @command{-list_standards all}. + +The time base for the timestamps is 1 microsecond. Depending on the kernel +version and configuration, the timestamps may be derived from the real time +clock (origin at the Unix Epoch) or the monotonic clock (origin usually at +boot time, unaffected by NTP or manual changes to the clock). The +@option{-timestamps abs} or @option{-ts abs} option can be used to force +conversion into the real time clock. + +Some usage examples of the video4linux2 device with @command{ffmpeg} +and @command{ffplay}: +@itemize +@item +Grab and show the input of a video4linux2 device: +@example +ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0 +@end example + +@item +Grab and record the input of a video4linux2 device, leave the +framerate and size as previously set: +@example +ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg +@end example +@end itemize + +For more information about Video4Linux, check @url{http://linuxtv.org/}. + +@subsection Options + +@table @option +@item standard +Set the standard. Must be the name of a supported standard. To get a +list of the supported standards, use the @option{list_standards} +option. + +@item channel +Set the input channel number. Default to 0. + +@item video_size +Set the video frame size. The argument must be a string in the form +@var{WIDTH}x@var{HEIGHT} or a valid size abbreviation. + +@item pixel_format +Select the pixel format (only valid for raw video input). + +@item input_format +Set the preferred pixel format (for raw video) or a codec name. +This option allows to select the input format, when several are +available. + +@item framerate +Set the preferred video framerate. + +@item list_formats +List available formats (supported pixel formats, codecs, and frame +sizes) and exit. + +Available values are: +@table @samp +@item all +Show all available (compressed and non-compressed) formats. + +@item raw +Show only raw video (non-compressed) formats. + +@item compressed +Show only compressed formats. +@end table + +@item list_standards +List supported standards and exit. + +Available values are: +@table @samp +@item all +Show all supported standards. +@end table + +@item timestamps, ts +Set type of timestamps for grabbed frames. + +Available values are: +@table @samp +@item default +Use timestamps from the kernel. + +@item abs +Use absolute timestamps (wall clock). + +@item mono2abs +Force conversion from monotonic to absolute timestamps. +@end table + +Default value is @code{default}. +@end table + +@section vfwcap + +VfW (Video for Windows) capture input device. + +The filename passed as input is the capture driver number, ranging from +0 to 9. You may use "list" as filename to print a list of drivers. Any +other filename will be interpreted as device number 0. + +@section x11grab + +X11 video input device. + +This device allows to capture a region of an X11 display. + +The filename passed as input has the syntax: +@example +[@var{hostname}]:@var{display_number}.@var{screen_number}[+@var{x_offset},@var{y_offset}] +@end example + +@var{hostname}:@var{display_number}.@var{screen_number} specifies the +X11 display name of the screen to grab from. @var{hostname} can be +omitted, and defaults to "localhost". The environment variable +@env{DISPLAY} contains the default display name. + +@var{x_offset} and @var{y_offset} specify the offsets of the grabbed +area with respect to the top-left border of the X11 screen. They +default to 0. + +Check the X11 documentation (e.g. man X) for more detailed information. + +Use the @command{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 @command{ffmpeg}: +@example +ffmpeg -f x11grab -r 25 -s cif -i :0.0 out.mpg +@end example + +Grab at position @code{10,20}: +@example +ffmpeg -f x11grab -r 25 -s cif -i :0.0+10,20 out.mpg +@end example + +@subsection Options + +@table @option +@item draw_mouse +Specify whether to draw the mouse pointer. A value of @code{0} specify +not to draw the pointer. Default value is @code{1}. + +@item follow_mouse +Make the grabbed area follow the mouse. The argument can be +@code{centered} or a number of pixels @var{PIXELS}. + +When it is specified with "centered", the grabbing region follows the mouse +pointer and keeps the pointer at the center of region; otherwise, the region +follows only when the mouse pointer reaches within @var{PIXELS} (greater than +zero) to the edge of region. + +For example: +@example +ffmpeg -f x11grab -follow_mouse centered -r 25 -s cif -i :0.0 out.mpg +@end example + +To follow only when the mouse pointer reaches within 100 pixels to edge: +@example +ffmpeg -f x11grab -follow_mouse 100 -r 25 -s cif -i :0.0 out.mpg +@end example + +@item framerate +Set the grabbing frame rate. Default value is @code{ntsc}, +corresponding to a framerate of @code{30000/1001}. + +@item show_region +Show grabbed region on screen. + +If @var{show_region} is specified with @code{1}, then the grabbing +region will be indicated on screen. With this option, it is easy to +know what is being grabbed if only a portion of the screen is grabbed. + +For example: +@example +ffmpeg -f x11grab -show_region 1 -r 25 -s cif -i :0.0+10,20 out.mpg +@end example + +With @var{follow_mouse}: +@example +ffmpeg -f x11grab -follow_mouse centered -show_region 1 -r 25 -s cif -i :0.0 out.mpg +@end example + +@item video_size +Set the video frame size. Default value is @code{vga}. +@end table + +@c man end INPUT DEVICES |