Egress refers to the use of xvfb and chrome to complete room composite flow recording

Yes, Egress in LiveKit uses a headless Chrome instance to render and capture the output for room composite recordings. This process involves creating a composited view of a room, which includes all participants and interactions, and is rendered using a web app. The output is captured using headless Chromium, which is often run with Xvfb (X virtual framebuffer) to simulate a display environment for Chrome to operate in a headless mode. This setup allows for the recording of the room's video and audio in a format that closely resembles the actual application experience. Would you like more details on how to set up or customize this process? Sources: - Egress Overview - RoomComposite Egress 👍 0 button 👎 0 button 💡 Hint: Mention @runllm in the thread for followups.

@millions-hair-24956 Why is the image quality of the rendering stream relatively low

The image quality of the rendering stream in a RoomComposite Egress can be affected by several factors. According to LiveKit documentation, the RoomComposite Egress uses a headless Chrome instance to render the output, and the quality can be influenced by the encoding settings, such as bitrate and codec choice. If the bitrate is too low, it can result in lower image quality. Additionally, the use of certain codecs, like VP9, might initially produce lower quality due to bandwidth estimation and adaptation processes inherent in WebRTC. To improve image quality, consider increasing the video bitrate and using a more efficient codec like H.264, which is known for smoother initial quality. You can also customize the encoding options to better suit your needs. If you need further assistance with specific settings or configurations, let me know. Sources: - LiveKit documentation 👍 0 button 👎 0 button 💡 Hint: Mention @runllm in the thread for followups.

@millions-hair-24956 In the scenario of sharing desktop PPT, using H264 encoding, please provide an example of custom encoding parameter settings

To customize encoding parameters for sharing a desktop presentation using H.264 encoding in LiveKit, you can adjust the

VideoEncoding

settings to optimize for quality and performance. Here's an example of how you might configure these parameters:

const room = new Room({
  videoCaptureDefaults: {
    resolution: { width: 1920, height: 1080, frameRate: 30 },
  },
  publishDefaults: {
    videoEncoding: {
      maxBitrate: 5000 * 1000, // 5000 kbps for high quality
      maxFramerate: 30,
    },
    videoCodec: 'h264',
  },
});

// Example of publishing a screen share track
async function publishScreenShare() {
  const screenShareTrack = await createLocalScreenShareTrack();
  await room.localParticipant.publishTrack(screenShareTrack, {
    videoEncoding: {
      maxBitrate: 5000 * 1000, // Adjust bitrate as needed
      maxFramerate: 30,
    },
  });
}

This example sets a high bitrate and frame rate to ensure good quality for a desktop presentation. Would you like more details on any specific part of this setup? Sources: - https://docs.livekit.io/client-sdk-flutter/livekit_client/VideoParametersPresets/screenShareH2160FPS30-constant.html - https://docs.livekit.io/client-sdk-flutter/livekit_client/VideoParametersPresets/screenShareH720FPS15-constant.html 👍 0 button 👎 0 button 💡 Hint: Mention @runllm in the thread for followups.

@millions-hair-24956 Is the image quality of the room composite stream exported by egress equivalent to the original image quality, achieving lossless output

The image quality of the room composite stream exported by Egress is not typically equivalent to the original image quality, and achieving lossless output is generally not feasible. According to LiveKit documentation, the RoomComposite Egress involves re-encoding the video stream, which can introduce some quality loss. The extent of this loss depends on the encoding settings, such as bitrate and codec choice. By default, the encoding is optimized for a balance between quality and bandwidth efficiency, rather than lossless quality. If you require higher quality, you can increase the video bitrate and choose a codec that better preserves quality, such as H.264. However, keep in mind that higher bitrates will increase bandwidth usage and may not completely eliminate quality loss due to the nature of video compression. Would you like more information on how to adjust these settings for better quality? Sources: - LiveKit documentation 👍 0 button 👎 0 button 💡 Hint: Mention @runllm in the thread for followups.