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import { VideoTranscodingFPS } from './video-transcoding-fps.model'
export enum VideoResolution {
H_240P = 240,
H_360P = 360,
H_480P = 480,
H_720P = 720,
H_1080P = 1080
}
/**
* Bitrate targets for different resolutions and frame rates, in bytes per second.
* Sources for individual quality levels:
* Google Live Encoder: https://support.google.com/youtube/answer/2853702?hl=en
* YouTube Video Info (tested with random music video): https://www.h3xed.com/blogmedia/youtube-info.php
*/
export function getTargetBitrate (resolution: VideoResolution, fps: number,
fpsTranscodingConstants: VideoTranscodingFPS) {
switch (resolution) {
case VideoResolution.H_240P:
// quality according to Google Live Encoder: 300 - 700 Kbps
// Quality according to YouTube Video Info: 186 Kbps
return 250 * 1000
case VideoResolution.H_360P:
// quality according to Google Live Encoder: 400 - 1,000 Kbps
// Quality according to YouTube Video Info: 480 Kbps
return 500 * 1000
case VideoResolution.H_480P:
// quality according to Google Live Encoder: 500 - 2,000 Kbps
// Quality according to YouTube Video Info: 879 Kbps
return 900 * 1000
case VideoResolution.H_720P:
if (fps === fpsTranscodingConstants.MAX) {
// quality according to Google Live Encoder: 2,250 - 6,000 Kbps
// Quality according to YouTube Video Info: 2634 Kbps
return 2600 * 1000
} else {
// quality according to Google Live Encoder: 1,500 - 4,000 Kbps
// Quality according to YouTube Video Info: 1752 Kbps
return 1750 * 1000
}
case VideoResolution.H_1080P: // fallthrough
default:
if (fps === fpsTranscodingConstants.MAX) {
// quality according to Google Live Encoder: 3000 - 6000 Kbps
// Quality according to YouTube Video Info: 4387 Kbps
return 4400 * 1000
} else {
// quality according to Google Live Encoder: 3000 - 6000 Kbps
// Quality according to YouTube Video Info: 3277 Kbps
return 3300 * 1000
}
}
}
/**
* The maximum bitrate we expect to see on a transcoded video in bytes per second.
*/
export function getMaxBitrate (resolution: VideoResolution, fps: number,
fpsTranscodingConstants: VideoTranscodingFPS) {
return getTargetBitrate(resolution, fps, fpsTranscodingConstants) * 2
}
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