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edb4ffc7 FA |
1 | import { VideoTranscodingFPS } from './video-transcoding-fps.model' |
2 | ||
40298b02 | 3 | export enum VideoResolution { |
40298b02 C |
4 | H_240P = 240, |
5 | H_360P = 360, | |
6 | H_480P = 480, | |
7 | H_720P = 720, | |
8 | H_1080P = 1080 | |
9 | } | |
edb4ffc7 FA |
10 | |
11 | /** | |
12 | * Bitrate targets for different resolutions and frame rates, in bytes per second. | |
13 | * Sources for individual quality levels: | |
14 | * Google Live Encoder: https://support.google.com/youtube/answer/2853702?hl=en | |
15 | * YouTube Video Info (tested with random music video): https://www.h3xed.com/blogmedia/youtube-info.php | |
16 | */ | |
17 | export function getTargetBitrate (resolution: VideoResolution, fps: number, | |
18 | fpsTranscodingConstants: VideoTranscodingFPS) { | |
19 | switch (resolution) { | |
20 | case VideoResolution.H_240P: | |
21 | // quality according to Google Live Encoder: 300 - 700 Kbps | |
22 | // Quality according to YouTube Video Info: 186 Kbps | |
23 | return 250 * 1000 | |
24 | case VideoResolution.H_360P: | |
25 | // quality according to Google Live Encoder: 400 - 1,000 Kbps | |
26 | // Quality according to YouTube Video Info: 480 Kbps | |
27 | return 500 * 1000 | |
28 | case VideoResolution.H_480P: | |
29 | // quality according to Google Live Encoder: 500 - 2,000 Kbps | |
30 | // Quality according to YouTube Video Info: 879 Kbps | |
31 | return 900 * 1000 | |
32 | case VideoResolution.H_720P: | |
33 | if (fps === fpsTranscodingConstants.MAX) { | |
34 | // quality according to Google Live Encoder: 2,250 - 6,000 Kbps | |
35 | // Quality according to YouTube Video Info: 2634 Kbps | |
36 | return 2600 * 1000 | |
37 | } else { | |
38 | // quality according to Google Live Encoder: 1,500 - 4,000 Kbps | |
39 | // Quality according to YouTube Video Info: 1752 Kbps | |
40 | return 1750 * 1000 | |
41 | } | |
42 | case VideoResolution.H_1080P: // fallthrough | |
43 | default: | |
44 | if (fps === fpsTranscodingConstants.MAX) { | |
45 | // quality according to Google Live Encoder: 3000 - 6000 Kbps | |
46 | // Quality according to YouTube Video Info: 4387 Kbps | |
47 | return 4400 * 1000 | |
48 | } else { | |
49 | // quality according to Google Live Encoder: 3000 - 6000 Kbps | |
50 | // Quality according to YouTube Video Info: 3277 Kbps | |
51 | return 3300 * 1000 | |
52 | } | |
53 | } | |
54 | } | |
55 | ||
56 | /** | |
57 | * The maximum bitrate we expect to see on a transcoded video in bytes per second. | |
58 | */ | |
59 | export function getMaxBitrate (resolution: VideoResolution, fps: number, | |
60 | fpsTranscodingConstants: VideoTranscodingFPS) { | |
61 | return getTargetBitrate(resolution, fps, fpsTranscodingConstants) * 2 | |
62 | } |