1 import { logger } from '@server/helpers/logger'
2 import { getAverageBitrate } from '@shared/core-utils'
3 import { AvailableEncoders, EncoderOptionsBuilder, EncoderOptionsBuilderParams } from '../../../shared/models/videos'
4 import { buildStreamSuffix, resetSupportedEncoders } from '../../helpers/ffmpeg-utils'
5 import { canDoQuickAudioTranscode, ffprobePromise, getAudioStream, getMaxAudioBitrate } from '../../helpers/ffprobe-utils'
9 * Available encoders and profiles for the transcoding jobs
10 * These functions are used by ffmpeg-utils that will get the encoders and options depending on the chosen profile
13 * * https://slhck.info/video/2017/03/01/rate-control.html
14 * * https://trac.ffmpeg.org/wiki/Limiting%20the%20output%20bitrate
17 const defaultX264VODOptionsBuilder: EncoderOptionsBuilder = (options: EncoderOptionsBuilderParams) => {
18 const { fps, inputRatio, inputBitrate } = options
19 if (!fps) return { outputOptions: [ ] }
21 const targetBitrate = capBitrate(inputBitrate, getAverageBitrate({ ...options, fps, ratio: inputRatio }))
27 `-maxrate ${targetBitrate}`,
28 `-bufsize ${targetBitrate * 2}`
33 const defaultX264LiveOptionsBuilder: EncoderOptionsBuilder = (options: EncoderOptionsBuilderParams) => {
34 const { streamNum, fps, inputBitrate, inputRatio } = options
36 const targetBitrate = capBitrate(inputBitrate, getAverageBitrate({ ...options, fps, ratio: inputRatio }))
41 `${buildStreamSuffix('-r:v', streamNum)} ${fps}`,
42 `${buildStreamSuffix('-b:v', streamNum)} ${targetBitrate}`,
43 `-maxrate ${targetBitrate}`,
44 `-bufsize ${targetBitrate * 2}`
49 const defaultAACOptionsBuilder: EncoderOptionsBuilder = async ({ input, streamNum }) => {
50 const probe = await ffprobePromise(input)
52 if (await canDoQuickAudioTranscode(input, probe)) {
53 logger.debug('Copy audio stream %s by AAC encoder.', input)
54 return { copy: true, outputOptions: [ ] }
57 const parsedAudio = await getAudioStream(input, probe)
59 // We try to reduce the ceiling bitrate by making rough matches of bitrates
60 // Of course this is far from perfect, but it might save some space in the end
62 const audioCodecName = parsedAudio.audioStream['codec_name']
64 const bitrate = getMaxAudioBitrate(audioCodecName, parsedAudio.bitrate)
66 logger.debug('Calculating audio bitrate of %s by AAC encoder.', input, { bitrate: parsedAudio.bitrate, audioCodecName })
69 return { outputOptions: [ buildStreamSuffix('-b:a', streamNum), bitrate + 'k' ] }
72 return { outputOptions: [ ] }
75 const defaultLibFDKAACVODOptionsBuilder: EncoderOptionsBuilder = ({ streamNum }) => {
76 return { outputOptions: [ buildStreamSuffix('-q:a', streamNum), '5' ] }
79 // Used to get and update available encoders
80 class VideoTranscodingProfilesManager {
81 private static instance: VideoTranscodingProfilesManager
83 // 1 === less priority
84 private readonly encodersPriorities = {
85 vod: this.buildDefaultEncodersPriorities(),
86 live: this.buildDefaultEncodersPriorities()
89 private readonly availableEncoders = {
92 default: defaultX264VODOptionsBuilder
95 default: defaultAACOptionsBuilder
98 default: defaultLibFDKAACVODOptionsBuilder
103 default: defaultX264LiveOptionsBuilder
106 default: defaultAACOptionsBuilder
111 private availableProfiles = {
116 private constructor () {
117 this.buildAvailableProfiles()
120 getAvailableEncoders (): AvailableEncoders {
122 available: this.availableEncoders,
125 video: this.getEncodersByPriority('vod', 'video'),
126 audio: this.getEncodersByPriority('vod', 'audio')
129 video: this.getEncodersByPriority('live', 'video'),
130 audio: this.getEncodersByPriority('live', 'audio')
136 getAvailableProfiles (type: 'vod' | 'live') {
137 return this.availableProfiles[type]
140 addProfile (options: {
144 builder: EncoderOptionsBuilder
146 const { type, encoder, profile, builder } = options
148 const encoders = this.availableEncoders[type]
150 if (!encoders[encoder]) encoders[encoder] = {}
151 encoders[encoder][profile] = builder
153 this.buildAvailableProfiles()
156 removeProfile (options: {
161 const { type, encoder, profile } = options
163 delete this.availableEncoders[type][encoder][profile]
164 this.buildAvailableProfiles()
167 addEncoderPriority (type: 'vod' | 'live', streamType: 'audio' | 'video', encoder: string, priority: number) {
168 this.encodersPriorities[type][streamType].push({ name: encoder, priority })
170 resetSupportedEncoders()
173 removeEncoderPriority (type: 'vod' | 'live', streamType: 'audio' | 'video', encoder: string, priority: number) {
174 this.encodersPriorities[type][streamType] = this.encodersPriorities[type][streamType]
175 .filter(o => o.name !== encoder && o.priority !== priority)
177 resetSupportedEncoders()
180 private getEncodersByPriority (type: 'vod' | 'live', streamType: 'audio' | 'video') {
181 return this.encodersPriorities[type][streamType]
183 if (e1.priority > e2.priority) return -1
184 else if (e1.priority === e2.priority) return 0
191 private buildAvailableProfiles () {
192 for (const type of [ 'vod', 'live' ]) {
193 const result = new Set()
195 const encoders = this.availableEncoders[type]
197 for (const encoderName of Object.keys(encoders)) {
198 for (const profile of Object.keys(encoders[encoderName])) {
203 this.availableProfiles[type] = Array.from(result)
206 logger.debug('Available transcoding profiles built.', { availableProfiles: this.availableProfiles })
209 private buildDefaultEncodersPriorities () {
212 { name: 'libx264', priority: 100 }
215 // Try the first one, if not available try the second one etc
217 // we favor VBR, if a good AAC encoder is available
218 { name: 'libfdk_aac', priority: 200 },
219 { name: 'aac', priority: 100 }
224 static get Instance () {
225 return this.instance || (this.instance = new this())
229 // ---------------------------------------------------------------------------
232 VideoTranscodingProfilesManager
235 // ---------------------------------------------------------------------------
237 function capBitrate (inputBitrate: number, targetBitrate: number) {
238 if (!inputBitrate) return targetBitrate
240 // Add 30% margin to input bitrate
241 const inputBitrateWithMargin = inputBitrate + (inputBitrate * 0.3)
243 return Math.min(targetBitrate, inputBitrateWithMargin)