65 lines
1.5 KiB
Markdown
65 lines
1.5 KiB
Markdown
# Video4Linux
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On Linux, it is possible to send the video stream to a [v4l2] loopback device,
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so that the Android device can be opened like a webcam by any v4l2-capable tool.
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[v4l2]: https://en.wikipedia.org/wiki/Video4Linux
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The module `v4l2loopback` must be installed:
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```bash
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sudo apt install v4l2loopback-dkms
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```
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To create a v4l2 device:
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```bash
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sudo modprobe v4l2loopback
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```
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This will create a new video device in `/dev/videoN`, where `N` is an integer
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(more [options](https://github.com/umlaeute/v4l2loopback#options) are available
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to create several devices or devices with specific IDs).
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To list the enabled devices:
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```bash
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# requires v4l-utils package
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v4l2-ctl --list-devices
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# simple but might be sufficient
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ls /dev/video*
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```
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To start `scrcpy` using a v4l2 sink:
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```bash
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scrcpy --v4l2-sink=/dev/videoN
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scrcpy --v4l2-sink=/dev/videoN --no-video-playback # disable playback window
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```
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(replace `N` with the device ID, check with `ls /dev/video*`)
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Once enabled, you can open your video stream with a v4l2-capable tool:
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```bash
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ffplay -i /dev/videoN
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vlc v4l2:///dev/videoN # VLC might add some buffering delay
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```
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For example, you could capture the video within [OBS] or within your video
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conference tool.
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[OBS]: https://obsproject.com/
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## Buffering
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By default, there is no video buffering, to get the lowest possible latency.
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As for the [video display](video.md#buffering), it is possible to add
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buffering to delay the v4l2 stream:
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```bash
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scrcpy --v4l2-buffer=300 # add 300ms buffering for v4l2 sink
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```
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