63 lines
2.3 KiB
TypeScript
63 lines
2.3 KiB
TypeScript
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
|
|
}
|