]>
Commit | Line | Data |
---|---|---|
1 | import { VideoResolution } from "@shared/models" | |
2 | ||
3 | type BitPerPixel = { [ id in VideoResolution ]: number } | |
4 | ||
5 | // https://bitmovin.com/video-bitrate-streaming-hls-dash/ | |
6 | ||
7 | const averageBitPerPixel: BitPerPixel = { | |
8 | [VideoResolution.H_NOVIDEO]: 0, | |
9 | [VideoResolution.H_240P]: 0.17, | |
10 | [VideoResolution.H_360P]: 0.15, | |
11 | [VideoResolution.H_480P]: 0.12, | |
12 | [VideoResolution.H_720P]: 0.11, | |
13 | [VideoResolution.H_1080P]: 0.10, | |
14 | [VideoResolution.H_1440P]: 0.09, | |
15 | [VideoResolution.H_4K]: 0.08 | |
16 | } | |
17 | ||
18 | const maxBitPerPixel: BitPerPixel = { | |
19 | [VideoResolution.H_NOVIDEO]: 0, | |
20 | [VideoResolution.H_240P]: 0.29, | |
21 | [VideoResolution.H_360P]: 0.26, | |
22 | [VideoResolution.H_480P]: 0.22, | |
23 | [VideoResolution.H_720P]: 0.19, | |
24 | [VideoResolution.H_1080P]: 0.17, | |
25 | [VideoResolution.H_1440P]: 0.16, | |
26 | [VideoResolution.H_4K]: 0.14 | |
27 | } | |
28 | ||
29 | function getAverageBitrate (options: { | |
30 | resolution: VideoResolution | |
31 | ratio: number | |
32 | fps: number | |
33 | }) { | |
34 | const targetBitrate = calculateBitrate({ ...options, bitPerPixel: averageBitPerPixel }) | |
35 | if (!targetBitrate) return 192 * 1000 | |
36 | ||
37 | return targetBitrate | |
38 | } | |
39 | ||
40 | function getMaxBitrate (options: { | |
41 | resolution: VideoResolution | |
42 | ratio: number | |
43 | fps: number | |
44 | }) { | |
45 | const targetBitrate = calculateBitrate({ ...options, bitPerPixel: maxBitPerPixel }) | |
46 | if (!targetBitrate) return 256 * 1000 | |
47 | ||
48 | return targetBitrate | |
49 | } | |
50 | ||
51 | // --------------------------------------------------------------------------- | |
52 | ||
53 | export { | |
54 | getAverageBitrate, | |
55 | getMaxBitrate | |
56 | } | |
57 | ||
58 | // --------------------------------------------------------------------------- | |
59 | ||
60 | function calculateBitrate (options: { | |
61 | bitPerPixel: BitPerPixel | |
62 | resolution: VideoResolution | |
63 | ratio: number | |
64 | fps: number | |
65 | }) { | |
66 | const { bitPerPixel, resolution, ratio, fps } = options | |
67 | ||
68 | const resolutionsOrder = [ | |
69 | VideoResolution.H_4K, | |
70 | VideoResolution.H_1440P, | |
71 | VideoResolution.H_1080P, | |
72 | VideoResolution.H_720P, | |
73 | VideoResolution.H_480P, | |
74 | VideoResolution.H_360P, | |
75 | VideoResolution.H_240P, | |
76 | VideoResolution.H_NOVIDEO | |
77 | ] | |
78 | ||
79 | for (const toTestResolution of resolutionsOrder) { | |
80 | if (toTestResolution <= resolution) { | |
81 | return resolution * resolution * ratio * fps * bitPerPixel[toTestResolution] | |
82 | } | |
83 | } | |
84 | ||
85 | throw new Error('Unknown resolution ' + resolution) | |
86 | } |