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1import { logger } from '@server/helpers/logger'
2import { AvailableEncoders, EncoderOptionsBuilder, getTargetBitrate, VideoResolution } from '../../../shared/models/videos'
3import { buildStreamSuffix, resetSupportedEncoders } from '../../helpers/ffmpeg-utils'
4import {
5 canDoQuickAudioTranscode,
6 ffprobePromise,
7 getAudioStream,
8 getMaxAudioBitrate,
9 getVideoFileBitrate,
10 getVideoStreamFromFile
11} from '../../helpers/ffprobe-utils'
12import { VIDEO_TRANSCODING_FPS } from '../../initializers/constants'
13
14/**
15 *
16 * Available encoders and profiles for the transcoding jobs
17 * These functions are used by ffmpeg-utils that will get the encoders and options depending on the chosen profile
18 *
19 */
20
21// Resources:
22// * https://slhck.info/video/2017/03/01/rate-control.html
23// * https://trac.ffmpeg.org/wiki/Limiting%20the%20output%20bitrate
24
25const defaultX264VODOptionsBuilder: EncoderOptionsBuilder = async ({ input, resolution, fps }) => {
26 const targetBitrate = await buildTargetBitrate({ input, resolution, fps })
27 if (!targetBitrate) return { outputOptions: [ ] }
28
29 return {
30 outputOptions: [
31 `-preset veryfast`,
32 `-r ${fps}`,
33 `-maxrate ${targetBitrate}`,
34 `-bufsize ${targetBitrate * 2}`
35 ]
36 }
37}
38
39const defaultX264LiveOptionsBuilder: EncoderOptionsBuilder = async ({ resolution, fps, streamNum }) => {
40 const targetBitrate = getTargetBitrate(resolution, fps, VIDEO_TRANSCODING_FPS)
41
42 return {
43 outputOptions: [
44 `-preset veryfast`,
45 `${buildStreamSuffix('-r:v', streamNum)} ${fps}`,
46 `${buildStreamSuffix('-b:v', streamNum)} ${targetBitrate}`,
47 `-maxrate ${targetBitrate}`,
48 `-bufsize ${targetBitrate * 2}`
49 ]
50 }
51}
52
53const defaultAACOptionsBuilder: EncoderOptionsBuilder = async ({ input, streamNum }) => {
54 const probe = await ffprobePromise(input)
55
56 if (await canDoQuickAudioTranscode(input, probe)) {
57 logger.debug('Copy audio stream %s by AAC encoder.', input)
58 return { copy: true, outputOptions: [ ] }
59 }
60
61 const parsedAudio = await getAudioStream(input, probe)
62
63 // We try to reduce the ceiling bitrate by making rough matches of bitrates
64 // Of course this is far from perfect, but it might save some space in the end
65
66 const audioCodecName = parsedAudio.audioStream['codec_name']
67
68 const bitrate = getMaxAudioBitrate(audioCodecName, parsedAudio.bitrate)
69
70 logger.debug('Calculating audio bitrate of %s by AAC encoder.', input, { bitrate: parsedAudio.bitrate, audioCodecName })
71
72 if (bitrate !== undefined && bitrate !== -1) {
73 return { outputOptions: [ buildStreamSuffix('-b:a', streamNum), bitrate + 'k' ] }
74 }
75
76 return { outputOptions: [ ] }
77}
78
79const defaultLibFDKAACVODOptionsBuilder: EncoderOptionsBuilder = ({ streamNum }) => {
80 return { outputOptions: [ buildStreamSuffix('-q:a', streamNum), '5' ] }
81}
82
83// Used to get and update available encoders
84class VideoTranscodingProfilesManager {
85 private static instance: VideoTranscodingProfilesManager
86
87 // 1 === less priority
88 private readonly encodersPriorities = {
89 vod: this.buildDefaultEncodersPriorities(),
90 live: this.buildDefaultEncodersPriorities()
91 }
92
93 private readonly availableEncoders = {
94 vod: {
95 libx264: {
96 default: defaultX264VODOptionsBuilder
97 },
98 aac: {
99 default: defaultAACOptionsBuilder
100 },
101 libfdk_aac: {
102 default: defaultLibFDKAACVODOptionsBuilder
103 }
104 },
105 live: {
106 libx264: {
107 default: defaultX264LiveOptionsBuilder
108 },
109 aac: {
110 default: defaultAACOptionsBuilder
111 }
112 }
113 }
114
115 private availableProfiles = {
116 vod: [] as string[],
117 live: [] as string[]
118 }
119
120 private constructor () {
121 this.buildAvailableProfiles()
122 }
123
124 getAvailableEncoders (): AvailableEncoders {
125 return {
126 available: this.availableEncoders,
127 encodersToTry: {
128 vod: {
129 video: this.getEncodersByPriority('vod', 'video'),
130 audio: this.getEncodersByPriority('vod', 'audio')
131 },
132 live: {
133 video: this.getEncodersByPriority('live', 'video'),
134 audio: this.getEncodersByPriority('live', 'audio')
135 }
136 }
137 }
138 }
139
140 getAvailableProfiles (type: 'vod' | 'live') {
141 return this.availableProfiles[type]
142 }
143
144 addProfile (options: {
145 type: 'vod' | 'live'
146 encoder: string
147 profile: string
148 builder: EncoderOptionsBuilder
149 }) {
150 const { type, encoder, profile, builder } = options
151
152 const encoders = this.availableEncoders[type]
153
154 if (!encoders[encoder]) encoders[encoder] = {}
155 encoders[encoder][profile] = builder
156
157 this.buildAvailableProfiles()
158 }
159
160 removeProfile (options: {
161 type: 'vod' | 'live'
162 encoder: string
163 profile: string
164 }) {
165 const { type, encoder, profile } = options
166
167 delete this.availableEncoders[type][encoder][profile]
168 this.buildAvailableProfiles()
169 }
170
171 addEncoderPriority (type: 'vod' | 'live', streamType: 'audio' | 'video', encoder: string, priority: number) {
172 this.encodersPriorities[type][streamType].push({ name: encoder, priority })
173
174 resetSupportedEncoders()
175 }
176
177 removeEncoderPriority (type: 'vod' | 'live', streamType: 'audio' | 'video', encoder: string, priority: number) {
178 this.encodersPriorities[type][streamType] = this.encodersPriorities[type][streamType]
179 .filter(o => o.name !== encoder && o.priority !== priority)
180
181 resetSupportedEncoders()
182 }
183
184 private getEncodersByPriority (type: 'vod' | 'live', streamType: 'audio' | 'video') {
185 return this.encodersPriorities[type][streamType]
186 .sort((e1, e2) => {
187 if (e1.priority > e2.priority) return -1
188 else if (e1.priority === e2.priority) return 0
189
190 return 1
191 })
192 .map(e => e.name)
193 }
194
195 private buildAvailableProfiles () {
196 for (const type of [ 'vod', 'live' ]) {
197 const result = new Set()
198
199 const encoders = this.availableEncoders[type]
200
201 for (const encoderName of Object.keys(encoders)) {
202 for (const profile of Object.keys(encoders[encoderName])) {
203 result.add(profile)
204 }
205 }
206
207 this.availableProfiles[type] = Array.from(result)
208 }
209
210 logger.debug('Available transcoding profiles built.', { availableProfiles: this.availableProfiles })
211 }
212
213 private buildDefaultEncodersPriorities () {
214 return {
215 video: [
216 { name: 'libx264', priority: 100 }
217 ],
218
219 // Try the first one, if not available try the second one etc
220 audio: [
221 // we favor VBR, if a good AAC encoder is available
222 { name: 'libfdk_aac', priority: 200 },
223 { name: 'aac', priority: 100 }
224 ]
225 }
226 }
227
228 static get Instance () {
229 return this.instance || (this.instance = new this())
230 }
231}
232
233// ---------------------------------------------------------------------------
234
235export {
236 VideoTranscodingProfilesManager
237}
238
239// ---------------------------------------------------------------------------
240async function buildTargetBitrate (options: {
241 input: string
242 resolution: VideoResolution
243 fps: number
244}) {
245 const { input, resolution, fps } = options
246 const probe = await ffprobePromise(input)
247
248 const videoStream = await getVideoStreamFromFile(input, probe)
249 if (!videoStream) return undefined
250
251 const targetBitrate = getTargetBitrate(resolution, fps, VIDEO_TRANSCODING_FPS)
252
253 // Don't transcode to an higher bitrate than the original file
254 const fileBitrate = await getVideoFileBitrate(input, probe)
255 return Math.min(targetBitrate, fileBitrate)
256}