1 import * as ffmpeg from 'fluent-ffmpeg'
2 import { join } from 'path'
3 import { VideoResolution } from '../../shared/models/videos'
4 import { CONFIG, VIDEO_TRANSCODING_FPS, FFMPEG_NICE } from '../initializers'
5 import { unlinkPromise } from './core-utils'
6 import { processImage } from './image-utils'
7 import { logger } from './logger'
8 import { checkFFmpegEncoders } from '../initializers/checker'
10 async function getVideoFileResolution (path: string) {
11 const videoStream = await getVideoFileStream(path)
14 videoFileResolution: Math.min(videoStream.height, videoStream.width),
15 isPortraitMode: videoStream.height > videoStream.width
19 async function getVideoFileFPS (path: string) {
20 const videoStream = await getVideoFileStream(path)
22 for (const key of [ 'r_frame_rate' , 'avg_frame_rate' ]) {
23 const valuesText: string = videoStream[key]
24 if (!valuesText) continue
26 const [ frames, seconds ] = valuesText.split('/')
27 if (!frames || !seconds) continue
29 const result = parseInt(frames, 10) / parseInt(seconds, 10)
30 if (result > 0) return Math.round(result)
36 function getDurationFromVideoFile (path: string) {
37 return new Promise<number>((res, rej) => {
38 ffmpeg.ffprobe(path, (err, metadata) => {
39 if (err) return rej(err)
41 return res(Math.floor(metadata.format.duration))
46 async function generateImageFromVideoFile (fromPath: string, folder: string, imageName: string, size: { width: number, height: number }) {
47 const pendingImageName = 'pending-' + imageName
50 filename: pendingImageName,
55 const pendingImagePath = join(folder, pendingImageName)
58 await new Promise<string>((res, rej) => {
59 ffmpeg(fromPath, { 'niceness': FFMPEG_NICE.THUMBNAIL })
61 .on('end', () => res(imageName))
65 const destination = join(folder, imageName)
66 await processImage({ path: pendingImagePath }, destination, size)
68 logger.error('Cannot generate image from video %s.', fromPath, { err })
71 await unlinkPromise(pendingImagePath)
73 logger.debug('Cannot remove pending image path after generation error.', { err })
78 type TranscodeOptions = {
81 resolution?: VideoResolution
82 isPortraitMode?: boolean
85 function transcode (options: TranscodeOptions) {
86 return new Promise<void>(async (res, rej) => {
87 let command = ffmpeg(options.inputPath, { 'niceness': FFMPEG_NICE.TRANSCODING })
88 .output(options.outputPath)
90 if (CONFIG.TRANSCODING.THREADS > 0) {
91 command.outputOption('-threads ' + CONFIG.TRANSCODING.THREADS) // if we don't set any threads ffmpeg will chose automatically
94 let fps = await getVideoFileFPS(options.inputPath)
95 if (options.resolution !== undefined) {
96 // '?x720' or '720x?' for example
97 const size = options.isPortraitMode === true ? `${options.resolution}x?` : `?x${options.resolution}`
98 command = command.size(size)
100 // On small/medium resolutions, limit FPS
102 options.resolution < VIDEO_TRANSCODING_FPS.KEEP_ORIGIN_FPS_RESOLUTION_MIN &&
103 fps > VIDEO_TRANSCODING_FPS.AVERAGE
105 fps = VIDEO_TRANSCODING_FPS.AVERAGE
111 if (fps > VIDEO_TRANSCODING_FPS.MAX) fps = VIDEO_TRANSCODING_FPS.MAX
112 else if (fps < VIDEO_TRANSCODING_FPS.MIN) fps = VIDEO_TRANSCODING_FPS.MIN
114 command = command.withFPS(fps)
118 .on('error', (err, stdout, stderr) => {
119 logger.error('Error in transcoding job.', { stdout, stderr })
127 // ---------------------------------------------------------------------------
130 getVideoFileResolution,
131 getDurationFromVideoFile,
132 generateImageFromVideoFile,
137 // ---------------------------------------------------------------------------
139 function getVideoFileStream (path: string) {
140 return new Promise<any>((res, rej) => {
141 ffmpeg.ffprobe(path, (err, metadata) => {
142 if (err) return rej(err)
144 const videoStream = metadata.streams.find(s => s.codec_type === 'video')
145 if (!videoStream) throw new Error('Cannot find video stream of ' + path)
147 return res(videoStream)
153 * A slightly customised version of the 'veryfast' x264 preset
155 * The veryfast preset is right in the sweet spot of performance
156 * and quality. Superfast and ultrafast will give you better
157 * performance, but then quality is noticeably worse.
159 function veryfast (_ffmpeg) {
162 .outputOption('-preset:v veryfast')
163 .outputOption(['--aq-mode=2', '--aq-strength=1.3'])
165 MAIN reference: https://slhck.info/video/2017/03/01/rate-control.html
166 Our target situation is closer to a livestream than a stream,
167 since we want to reduce as much a possible the encoding burden,
168 altough not to the point of a livestream where there is a hard
169 constraint on the frames per second to be encoded.
171 why '--aq-mode=2 --aq-strength=1.3' instead of '-profile:v main'?
172 Make up for most of the loss of grain and macroblocking
173 with less computing power.
178 * A preset optimised for a stillimage audio video
180 function audio (_ffmpeg) {
183 .outputOption('-tune stillimage')
187 * A toolbox to play with audio
190 export const get = (_ffmpeg, pos: number | string = 0) => {
191 // without position, ffprobe considers the last input only
192 // we make it consider the first input only
193 // if you pass a file path to pos, then ffprobe acts on that file directly
194 return new Promise<any>((res, rej) => {
196 .ffprobe(pos, (err,data) => {
197 if (err) return rej(err)
199 if ('streams' in data) {
200 return res(data['streams'].find(stream => stream['codec_type'] === 'audio'))
208 export namespace bitrate {
209 export const baseKbitrate = 384
211 const toBits = (kbits: number): number => { return kbits * 8000 }
213 export const aac = (bitrate: number): number => {
215 case bitrate > toBits(384):
218 return -1 // we interpret it as a signal to copy the audio stream as is
222 export const mp3 = (bitrate: number): number => {
224 case bitrate <= toBits(192):
226 case bitrate <= toBits(384):
236 * Standard profile, with variable bitrate audio and faststart.
238 * As for the audio, quality '5' is the highest and ensures 96-112kbps/channel
239 * See https://trac.ffmpeg.org/wiki/Encode/AAC#fdk_vbr
241 async function standard (_ffmpeg) {
242 let _bitrate = audio.bitrate.baseKbitrate
243 let localFfmpeg = _ffmpeg
245 .videoCodec('libx264')
246 .outputOption('-level 3.1') // 3.1 is the minimal ressource allocation for our highest supported resolution
247 .outputOption('-b_strategy 1') // NOTE: b-strategy 1 - heuristic algorythm, 16 is optimal B-frames for it
248 .outputOption('-bf 16') // NOTE: Why 16: https://github.com/Chocobozzz/PeerTube/pull/774. b-strategy 2 -> B-frames<16
249 .outputOption('-map_metadata -1') // strip all metadata
250 .outputOption('-movflags faststart')
251 let _audio = audio.get(localFfmpeg)
253 .catch(_ => undefined)
255 if (!_audio) return localFfmpeg.noAudio()
257 // we try to reduce the ceiling bitrate by making rough correspondances of bitrates
258 // of course this is far from perfect, but it might save some space in the end
259 if (audio.bitrate[_audio['codec_name']]) {
260 _bitrate = audio.bitrate[_audio['codec_name']](_audio['bit_rate'])
261 if (_bitrate === -1) {
262 return localFfmpeg.audioCodec('copy')
266 // we favor VBR, if a good AAC encoder is available
267 if ((await checkFFmpegEncoders()).get('libfdk_aac')) {
269 .audioCodec('libfdk_aac')
273 return localFfmpeg.audioBitrate(_bitrate)