Trying to build an interface for Python doing similar things as OBS Studio
LiveKit for Windows x64 is available as a conda package:
conda install -c fyplus livekit
LiveKit currently can be built for Windows x64 platforms.
Building for Windows x86 is possible if dependecies are available.
- Clone the repository (including submodules):
git clone --recursive https://github.com/fynv/LiveKit.git
- Download a FFMpeg prebuilt package
For Windows x64, a prebuilt package can be found at https://www.gyan.dev/ffmpeg/builds/.
- Create a "build" folder and build with CMake
- Select "Visual Studio 16 2019" or "Visual Studio 15 2017".
- Select "x64"
- Click "Configure"
- Set "FFMPEG_ROOT" to where you extracted FFMpeg.
- Click "Generate"
- Build with Visual Studio
- Build the "INSTALL" project
The 'VirtualCamera' sub-project can be built separately using the provided visual-studio project files. (Binaries are already provided under the VirtualCamera/bin folder)
The system works by compositing the following kinds of objects:
- VideoSource objects
Video frames (images) can be retrieved from these objects.
- VideoTarget objects
Video frames (images) can be written to these objects.
- Objects that operates on VideoSources and VideoTargets
This includes:
* Objects that read frames
* Objects that write frames
- VideoPort
A VideoPort object is a VideoSource and a VideoTarget at the same time. Frames written to a video-port are cached shortly and can be retrieved by other objects. This can be used to connect an object that read frames to an object that write frames.
For example, there is a class WindowCapture, which is a VideoSource class. A WindowCapture object can be directly connected to objects that read frames, like a Viewer or a Recorder. And there is a class Camera. A camera object writes frames, therefore it can be connected to objects that read frames with the help of a VideoPort.
You can connect these objects in different ways to accomplish different tasks.
Here is an incomplete list of what can be done at the moment.
ImageFile => Viewer
A Player object is capable of playback of a media file containing both video and audio streams. It has its own worker threads. Video frames can be written to one or more VideoTargets.
For a straight playback:
Player => VideoPort => Viewer
A LazyPlayer object playback only the video part of a media file. It works in lazy-mode, and is a VideoSource itself.
LazyPlayer => Viewer
Camera => VideoPort => Viewer
Camera => VideoPort => Recorder
WindowCapture => Viewer
WindowCapture => Recorder
A Compositor object is one that actually works like OBS Studio. It can take in multiple VideoSources and put them at difference places to form a scene.
ImageFile => Compositor
Player => VideoPort => Compositor
LazyPlayer => Compositor
Camera => VideoPort =>Compositor
WindowCapture => Compositor
Like a Viewer, a compositor maintains its own window which shows the composited result.
Optionally, it writes to one or more VideoTargets. You can use it to record the composited video.
Compsitor => VideoPort => Recorder
Interprocess video transmission can be done by a pair of IPCTarget and IPCSource objects, which uses named file-mapping to efficiently share the frames.
The 'VirtualCamera' sub-project provides a dshow virtual-camera which is compatible with IPCTarget.
Registering the virtual camera:
VirtualCamera\bin> register.cmd
Mapping-name and virtual resolution must be set before using the virtual camera from the host process, whcih can be done by setting a couple of registry values. See VirtualCamera/bin/reg_config.py for details.
A IPCTarget object can be used to feed content into the virtual camera.
import LiveKit as lk
target = lk.IPCTarget("LiveKitVCam", width, height, False)The "filename" parameter used when creating a Player object or a Recorder object can be a url of one of the protocols supported by ffmpeg. (See https://www.ffmpeg.org/ffmpeg-protocols.html). Now the Recorder becomes a Sender and the Player becomes a Reciever. The 'mp4' parameter of Recorder should be set to 'False', so that flv stream will be used.
A Copier object simply copies one file to another (in its own process). The filenames used here can also be network urls. This can be useful, for example, if you want to build a conference server.
Audio Device IDs are used in Player, Recorder and AudioRepeater objects. When an Audio Device ID >=0, it is corresponding to a system audio device. When it is negative, the audio stream will be wired to an (in-proess) virtual audio channel. For interprocess virtual-wiring, VB-CABLE would be very helpful.
This source code is provided to you by Vulcan Eon (北京鲜衣怒马文化传媒有限公司) and is licensed under GPL 2.0.