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FFMPEG-DEVICES(1) FFMPEG-DEVICES(1) |
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NAME |
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ffmpeg-devices - FFmpeg devices |
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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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DEVICE OPTIONS |
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The libavdevice library provides the same interface as libavformat. |
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Namely, an input device is considered like a demuxer, and an output |
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device like a muxer, and the interface and generic device options are |
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the same provided by libavformat (see the ffmpeg-formats 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 -option value in the FFmpeg tools, or |
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by setting the value explicitly in the device "AVFormatContext" options |
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or using the libavutil/opt.h API for programmatic use. |
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INPUT DEVICES |
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Input devices are configured elements in FFmpeg which enable accessing |
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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=INDEV", or you can disable a particular input |
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device using the option "--disable-indev=INDEV". |
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The option "-devices" of the ff* tools will display the list of |
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supported input devices. |
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A description of the currently available input devices follows. |
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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 DEV and SUBDEV components are optional. |
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The three arguments (in order: CARD,DEV,SUBDEV) specify card number or |
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identifier, device number and subdevice number (-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 /proc/asound/cards and /proc/asound/devices. |
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For example to capture with ffmpeg from an ALSA device with card id 0, |
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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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<http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html> |
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Options |
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sample_rate |
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Set the sample rate in Hz. Default is 48000. |
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channels |
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Set the number of channels. Default is 2. |
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android_camera |
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Android camera input device. |
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This input devices uses the Android Camera2 NDK API which is available |
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on devices with API level 24+. The availability of android_camera is |
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autodetected during configuration. |
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This device allows capturing from all cameras on an Android device, |
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which are integrated into the Camera2 NDK API. |
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The available cameras are enumerated internally and can be selected |
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with the camera_index parameter. The input file string is discarded. |
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Generally the back facing camera has index 0 while the front facing |
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camera has index 1. |
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Options |
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video_size |
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Set the video size given as a string such as 640x480 or hd720. |
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Falls back to the first available configuration reported by Android |
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if requested video size is not available or by default. |
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framerate |
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Set the video framerate. Falls back to the first available |
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configuration reported by Android if requested framerate is not |
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available or by default (-1). |
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camera_index |
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Set the index of the camera to use. Default is 0. |
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input_queue_size |
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Set the maximum number of frames to buffer. Default is 5. |
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avfoundation |
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AVFoundation input device. |
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AVFoundation is the currently recommended framework by Apple for |
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streamgrabbing on OSX >= 10.7 as well as on iOS. |
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The input filename has to be given in the following syntax: |
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-i "[[VIDEO]:[AUDIO]]" |
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The first entry selects the video input while the latter selects the |
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audio input. The stream has to be specified by the device name or the |
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device index as shown by the device list. Alternatively, the video |
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and/or audio input device can be chosen by index using the |
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B<-video_device_index E<lt>INDEXE<gt>> |
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and/or |
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B<-audio_device_index E<lt>INDEXE<gt>> |
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, overriding any device name or index given in the input filename. |
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All available devices can be enumerated by using -list_devices true, |
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listing all device names and corresponding indices. |
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There are two device name aliases: |
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"default" |
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Select the AVFoundation default device of the corresponding type. |
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"none" |
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Do not record the corresponding media type. This is equivalent to |
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specifying an empty device name or index. |
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Options |
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AVFoundation supports the following options: |
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-list_devices <TRUE|FALSE> |
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If set to true, a list of all available input devices is given |
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showing all device names and indices. |
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-video_device_index <INDEX> |
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Specify the video device by its index. Overrides anything given in |
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the input filename. |
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-audio_device_index <INDEX> |
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Specify the audio device by its index. Overrides anything given in |
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the input filename. |
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-pixel_format <FORMAT> |
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Request the video device to use a specific pixel format. If the |
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specified format is not supported, a list of available formats is |
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given and the first one in this list is used instead. Available |
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pixel formats are: "monob, rgb555be, rgb555le, rgb565be, rgb565le, |
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rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0, |
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bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, |
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yuv422p10, yuv444p10, |
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yuv420p, nv12, yuyv422, gray" |
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-framerate |
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Set the grabbing frame rate. Default is "ntsc", corresponding to a |
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frame rate of "30000/1001". |
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-video_size |
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Set the video frame size. |
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-capture_cursor |
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Capture the mouse pointer. Default is 0. |
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-capture_mouse_clicks |
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Capture the screen mouse clicks. Default is 0. |
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-capture_raw_data |
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Capture the raw device data. Default is 0. Using this option may |
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result in receiving the underlying data delivered to the |
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AVFoundation framework. E.g. for muxed devices that sends raw DV |
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data to the framework (like tape-based camcorders), setting this |
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option to false results in extracted video frames captured in the |
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designated pixel format only. Setting this option to true results |
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in receiving the raw DV stream untouched. |
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Examples |
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o Print the list of AVFoundation supported devices and exit: |
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$ ffmpeg -f avfoundation -list_devices true -i "" |
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o Record video from video device 0 and audio from audio device 0 into |
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out.avi: |
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$ ffmpeg -f avfoundation -i "0:0" out.avi |
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o Record video from video device 2 and audio from audio device 1 into |
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out.avi: |
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$ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi |
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o Record video from the system default video device using the pixel |
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format bgr0 and do not record any audio into out.avi: |
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$ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi |
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o Record raw DV data from a suitable input device and write the |
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output into out.dv: |
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$ ffmpeg -f avfoundation -capture_raw_data true -i "zr100:none" out.dv |
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bktr |
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BSD video input device. |
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Options |
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framerate |
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Set the frame rate. |
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video_size |
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Set the video frame size. Default is "vga". |
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standard |
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Available values are: |
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pal |
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ntsc |
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secam |
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paln |
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palm |
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ntscj |
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decklink |
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The decklink input device provides capture capabilities for Blackmagic |
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DeckLink devices. |
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To enable this input device, you need the Blackmagic DeckLink SDK and |
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you need to configure with the appropriate "--extra-cflags" and |
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"--extra-ldflags". On Windows, you need to run the IDL files through |
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widl. |
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DeckLink is very picky about the formats it supports. Pixel format of |
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the input can be set with raw_format. Framerate and video size must be |
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determined for your device with -list_formats 1. Audio sample rate is |
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always 48 kHz and the number of channels can be 2, 8 or 16. Note that |
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all audio channels are bundled in one single audio track. |
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Options |
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list_devices |
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If set to true, print a list of devices and exit. Defaults to |
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false. This option is deprecated, please use the "-sources" option |
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of ffmpeg to list the available input devices. |
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list_formats |
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If set to true, print a list of supported formats and exit. |
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Defaults to false. |
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format_code <FourCC> |
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This sets the input video format to the format given by the FourCC. |
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To see the supported values of your device(s) use list_formats. |
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Note that there is a FourCC 'pal ' that can also be used as pal (3 |
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letters). Default behavior is autodetection of the input video |
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format, if the hardware supports it. |
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raw_format |
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Set the pixel format of the captured video. Available values are: |
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auto |
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This is the default which means 8-bit YUV 422 or 8-bit ARGB if |
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format autodetection is used, 8-bit YUV 422 otherwise. |
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uyvy422 |
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8-bit YUV 422. |
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yuv422p10 |
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10-bit YUV 422. |
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argb |
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8-bit RGB. |
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bgra |
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8-bit RGB. |
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rgb10 |
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10-bit RGB. |
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teletext_lines |
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If set to nonzero, an additional teletext stream will be captured |
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from the vertical ancillary data. Both SD PAL (576i) and HD (1080i |
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or 1080p) sources are supported. In case of HD sources, OP47 |
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packets are decoded. |
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This option is a bitmask of the SD PAL VBI lines captured, |
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specifically lines 6 to 22, and lines 318 to 335. Line 6 is the LSB |
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in the mask. Selected lines which do not contain teletext |
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information will be ignored. You can use the special all constant |
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to select all possible lines, or standard to skip lines 6, 318 and |
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319, which are not compatible with all receivers. |
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For SD sources, ffmpeg needs to be compiled with |
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"--enable-libzvbi". For HD sources, on older (pre-4K) DeckLink card |
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models you have to capture in 10 bit mode. |
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channels |
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Defines number of audio channels to capture. Must be 2, 8 or 16. |
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Defaults to 2. |
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duplex_mode |
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Sets the decklink device duplex/profile mode. Must be unset, half, |
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full, one_sub_device_full, one_sub_device_half, |
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two_sub_device_full, four_sub_device_half Defaults to unset. |
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Note: DeckLink SDK 11.0 have replaced the duplex property by a |
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profile property. For the DeckLink Duo 2 and DeckLink Quad 2, a |
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profile is shared between any 2 sub-devices that utilize the same |
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connectors. For the DeckLink 8K Pro, a profile is shared between |
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all 4 sub-devices. So DeckLink 8K Pro support four profiles. |
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Valid profile modes for DeckLink 8K Pro(with DeckLink SDK >= 11.0): |
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one_sub_device_full, one_sub_device_half, two_sub_device_full, |
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four_sub_device_half |
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Valid profile modes for DeckLink Quad 2 and DeckLink Duo 2: half, |
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full |
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timecode_format |
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Timecode type to include in the frame and video stream metadata. |
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Must be none, rp188vitc, rp188vitc2, rp188ltc, rp188hfr, rp188any, |
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vitc, vitc2, or serial. Defaults to none (not included). |
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In order to properly support 50/60 fps timecodes, the ordering of |
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the queried timecode types for rp188any is HFR, VITC1, VITC2 and |
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LTC for >30 fps content. Note that this is slightly different to |
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the ordering used by the DeckLink API, which is HFR, VITC1, LTC, |
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VITC2. |
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video_input |
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Sets the video input source. Must be unset, sdi, hdmi, optical_sdi, |
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component, composite or s_video. Defaults to unset. |
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audio_input |
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Sets the audio input source. Must be unset, embedded, aes_ebu, |
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analog, analog_xlr, analog_rca or microphone. Defaults to unset. |
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video_pts |
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Sets the video packet timestamp source. Must be video, audio, |
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reference, wallclock or abs_wallclock. Defaults to video. |
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audio_pts |
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Sets the audio packet timestamp source. Must be video, audio, |
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reference, wallclock or abs_wallclock. Defaults to audio. |
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draw_bars |
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If set to true, color bars are drawn in the event of a signal loss. |
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Defaults to true. |
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queue_size |
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Sets maximum input buffer size in bytes. If the buffering reaches |
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this value, incoming frames will be dropped. Defaults to |
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1073741824. |
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audio_depth |
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Sets the audio sample bit depth. Must be 16 or 32. Defaults to 16. |
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decklink_copyts |
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If set to true, timestamps are forwarded as they are without |
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removing the initial offset. Defaults to false. |
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timestamp_align |
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Capture start time alignment in seconds. If set to nonzero, input |
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frames are dropped till the system timestamp aligns with configured |
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value. Alignment difference of up to one frame duration is |
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tolerated. This is useful for maintaining input synchronization |
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across N different hardware devices deployed for 'N-way' |
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redundancy. The system time of different hardware devices should be |
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synchronized with protocols such as NTP or PTP, before using this |
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option. Note that this method is not foolproof. In some border |
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cases input synchronization may not happen due to thread scheduling |
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jitters in the OS. Either sync could go wrong by 1 frame or in a |
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rarer case timestamp_align seconds. Defaults to 0. |
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wait_for_tc (bool) |
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Drop frames till a frame with timecode is received. Sometimes |
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serial timecode isn't received with the first input frame. If that |
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happens, the stored stream timecode will be inaccurate. If this |
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option is set to true, input frames are dropped till a frame with |
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timecode is received. Option timecode_format must be specified. |
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Defaults to false. |
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enable_klv(bool) |
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If set to true, extracts KLV data from VANC and outputs KLV |
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packets. KLV VANC packets are joined based on MID and PSC fields |
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and aggregated into one KLV packet. Defaults to false. |
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Examples |
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o List input devices: |
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ffmpeg -sources decklink |
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o List supported formats: |
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ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro' |
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o Capture video clip at 1080i50: |
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ffmpeg -format_code Hi50 -f decklink -i 'Intensity Pro' -c:a copy -c:v copy output.avi |
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o Capture video clip at 1080i50 10 bit: |
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ffmpeg -raw_format yuv422p10 -format_code Hi50 -f decklink -i 'UltraStudio Mini Recorder' -c:a copy -c:v copy output.avi |
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o Capture video clip at 1080i50 with 16 audio channels: |
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ffmpeg -channels 16 -format_code Hi50 -f decklink -i 'UltraStudio Mini Recorder' -c:a copy -c:v copy output.avi |
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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 |
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project. 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 |
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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 TYPE can be either audio or video, and NAME is the device's name |
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or alternative name.. |
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Options |
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If no options are specified, the device's defaults are used. If the |
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device does not support the requested options, it will fail to open. |
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video_size |
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Set the video size in the captured video. |
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framerate |
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Set the frame rate in the captured video. |
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sample_rate |
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Set the sample rate (in Hz) of the captured audio. |
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sample_size |
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Set the sample size (in bits) of the captured audio. |
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channels |
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Set the number of channels in the captured audio. |
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list_devices |
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If set to true, print a list of devices and exit. |
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list_options |
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If set to true, print a list of selected device's options and exit. |
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video_device_number |
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Set video device number for devices with the same name (starts at |
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0, defaults to 0). |
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audio_device_number |
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Set audio device number for devices with the same name (starts at |
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0, defaults to 0). |
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pixel_format |
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Select pixel format to be used by DirectShow. This may only be set |
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when the video codec is not set or set to rawvideo. |
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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). Defaults to using the |
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audio device's default buffer size (typically some multiple of |
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500ms). Setting this value too low can degrade performance. See |
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also |
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<http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx> |
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video_pin_name |
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Select video capture pin to use by name or alternative name. |
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audio_pin_name |
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Select audio capture pin to use by name or alternative name. |
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crossbar_video_input_pin_number |
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Select video input pin number for crossbar device. This will be |
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routed to the crossbar device's Video Decoder output pin. Note |
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that changing this value can affect future invocations (sets a new |
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default) until system reboot occurs. |
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crossbar_audio_input_pin_number |
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Select audio input pin number for crossbar device. This will be |
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routed to the crossbar device's Audio Decoder output pin. Note |
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that changing this value can affect future invocations (sets a new |
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default) until system reboot occurs. |
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show_video_device_dialog |
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If set to true, before capture starts, popup a display dialog to |
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the end user, allowing them to change video filter properties and |
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configurations manually. Note that for crossbar devices, adjusting |
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values in this dialog may be needed at times to toggle between PAL |
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(25 fps) and NTSC (29.97) input frame rates, sizes, interlacing, |
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etc. Changing these values can enable different scan rates/frame |
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rates and avoiding green bars at the bottom, flickering scan lines, |
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etc. Note that with some devices, changing these properties can |
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also affect future invocations (sets new defaults) until system |
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reboot occurs. |
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show_audio_device_dialog |
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If set to true, before capture starts, popup a display dialog to |
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the end user, allowing them to change audio filter properties and |
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configurations manually. |
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show_video_crossbar_connection_dialog |
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If set to true, before capture starts, popup a display dialog to |
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the end user, allowing them to manually modify crossbar pin |
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routings, when it opens a video device. |
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show_audio_crossbar_connection_dialog |
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If set to true, before capture starts, popup a display dialog to |
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the end user, allowing them to manually modify crossbar pin |
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routings, when it opens an audio device. |
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show_analog_tv_tuner_dialog |
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If set to true, before capture starts, popup a display dialog to |
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the end user, allowing them to manually modify TV channels and |
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frequencies. |
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show_analog_tv_tuner_audio_dialog |
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If set to true, before capture starts, popup a display dialog to |
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the end user, allowing them to manually modify TV audio (like mono |
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vs. stereo, Language A,B or C). |
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audio_device_load |
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Load an audio capture filter device from file instead of searching |
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it by name. It may load additional parameters too, if the filter |
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supports the serialization of its properties to. To use this an |
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audio capture source has to be specified, but it can be anything |
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even fake one. |
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audio_device_save |
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Save the currently used audio capture filter device and its |
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parameters (if the filter supports it) to a file. If a file with |
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the same name exists it will be overwritten. |
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video_device_load |
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Load a video capture filter device from file instead of searching |
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it by name. It may load additional parameters too, if the filter |
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supports the serialization of its properties to. To use this a |
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video capture source has to be specified, but it can be anything |
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even fake one. |
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video_device_save |
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Save the currently used video capture filter device and its |
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parameters (if the filter supports it) to a file. If a file with |
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the same name exists it will be overwritten. |
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use_video_device_timestamps |
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If set to false, the timestamp for video frames will be derived |
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from the wallclock instead of the timestamp provided by the capture |
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device. This allows working around devices that provide unreliable |
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timestamps. |
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Examples |
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o 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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o Open video device Camera: |
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$ ffmpeg -f dshow -i video="Camera" |
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o Open second video device with name Camera: |
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$ ffmpeg -f dshow -video_device_number 1 -i video="Camera" |
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o Open video device Camera and audio device Microphone: |
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|
|
$ 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. |
|
|
|
There are two options for the input filename: |
|
|
|
desktop |
|
|
|
or |
|
|
|
title=<window_title> |
|
|
|
The first option will capture the entire desktop, or a fixed region of |
|
the desktop. The second option 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. |
|
|
|
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. |
|
|
|
"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 |
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|
|
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) |
|
|