server/helpers/ffmpeg-utils.ts

   1 import { Job } from 'bull'
   2 import * as ffmpeg from 'fluent-ffmpeg'
   3 import { readFile, remove, writeFile } from 'fs-extra'
   4 import { dirname, join } from 'path'
   5 import { FFMPEG_NICE, VIDEO_LIVE } from '@server/initializers/constants'
   6 import { AvailableEncoders, EncoderOptions, EncoderOptionsBuilder, EncoderProfile, VideoResolution } from '../../shared/models/videos'
   7 import { CONFIG } from '../initializers/config'
   8 import { execPromise, promisify0 } from './core-utils'
   9 import { computeFPS, ffprobePromise, getAudioStream, getVideoFileBitrate, getVideoFileFPS } from './ffprobe-utils'
  10 import { processImage } from './image-utils'
  11 import { logger } from './logger'
  12
  13 /**
  14  *
  15  * Functions that run transcoding/muxing ffmpeg processes
  16  * Mainly called by lib/video-transcoding.ts and lib/live-manager.ts
  17  *
  18  */
  19
  20 // ---------------------------------------------------------------------------
  21 // Encoder options
  22 // ---------------------------------------------------------------------------
  23
  24 type StreamType = 'audio' | 'video'
  25
  26 // ---------------------------------------------------------------------------
  27 // Encoders support
  28 // ---------------------------------------------------------------------------
  29
  30 // Detect supported encoders by ffmpeg
  31 let supportedEncoders: Map<string, boolean>
  32 async function checkFFmpegEncoders (peertubeAvailableEncoders: AvailableEncoders): Promise<Map<string, boolean>> {
  33   if (supportedEncoders !== undefined) {
  34     return supportedEncoders
  35   }
  36
  37   const getAvailableEncodersPromise = promisify0(ffmpeg.getAvailableEncoders)
  38   const availableFFmpegEncoders = await getAvailableEncodersPromise()
  39
  40   const searchEncoders = new Set<string>()
  41   for (const type of [ 'live', 'vod' ]) {
  42     for (const streamType of [ 'audio', 'video' ]) {
  43       for (const encoder of peertubeAvailableEncoders.encodersToTry[type][streamType]) {
  44         searchEncoders.add(encoder)
  45       }
  46     }
  47   }
  48
  49   supportedEncoders = new Map<string, boolean>()
  50
  51   for (const searchEncoder of searchEncoders) {
  52     supportedEncoders.set(searchEncoder, availableFFmpegEncoders[searchEncoder] !== undefined)
  53   }
  54
  55   logger.info('Built supported ffmpeg encoders.', { supportedEncoders, searchEncoders })
  56
  57   return supportedEncoders
  58 }
  59
  60 function resetSupportedEncoders () {
  61   supportedEncoders = undefined
  62 }
  63
  64 // ---------------------------------------------------------------------------
  65 // Image manipulation
  66 // ---------------------------------------------------------------------------
  67
  68 function convertWebPToJPG (path: string, destination: string): Promise<void> {
  69   const command = ffmpeg(path, { niceness: FFMPEG_NICE.THUMBNAIL })
  70     .output(destination)
  71
  72   return runCommand({ command, silent: true })
  73 }
  74
  75 function processGIF (
  76   path: string,
  77   destination: string,
  78   newSize: { width: number, height: number }
  79 ): Promise<void> {
  80   const command = ffmpeg(path, { niceness: FFMPEG_NICE.THUMBNAIL })
  81     .fps(20)
  82     .size(`${newSize.width}x${newSize.height}`)
  83     .output(destination)
  84
  85   return runCommand({ command })
  86 }
  87
  88 async function generateImageFromVideoFile (fromPath: string, folder: string, imageName: string, size: { width: number, height: number }) {
  89   const pendingImageName = 'pending-' + imageName
  90
  91   const options = {
  92     filename: pendingImageName,
  93     count: 1,
  94     folder
  95   }
  96
  97   const pendingImagePath = join(folder, pendingImageName)
  98
  99   try {
 100     await new Promise<string>((res, rej) => {
 101       ffmpeg(fromPath, { niceness: FFMPEG_NICE.THUMBNAIL })
 102         .on('error', rej)
 103         .on('end', () => res(imageName))
 104         .thumbnail(options)
 105     })
 106
 107     const destination = join(folder, imageName)
 108     await processImage(pendingImagePath, destination, size)
 109   } catch (err) {
 110     logger.error('Cannot generate image from video %s.', fromPath, { err })
 111
 112     try {
 113       await remove(pendingImagePath)
 114     } catch (err) {
 115       logger.debug('Cannot remove pending image path after generation error.', { err })
 116     }
 117   }
 118 }
 119
 120 // ---------------------------------------------------------------------------
 121 // Transcode meta function
 122 // ---------------------------------------------------------------------------
 123
 124 type TranscodeOptionsType = 'hls' | 'hls-from-ts' | 'quick-transcode' | 'video' | 'merge-audio' | 'only-audio'
 125
 126 interface BaseTranscodeOptions {
 127   type: TranscodeOptionsType
 128
 129   inputPath: string
 130   outputPath: string
 131
 132   availableEncoders: AvailableEncoders
 133   profile: string
 134
 135   resolution: number
 136
 137   isPortraitMode?: boolean
 138
 139   job?: Job
 140 }
 141
 142 interface HLSTranscodeOptions extends BaseTranscodeOptions {
 143   type: 'hls'
 144   copyCodecs: boolean
 145   hlsPlaylist: {
 146     videoFilename: string
 147   }
 148 }
 149
 150 interface HLSFromTSTranscodeOptions extends BaseTranscodeOptions {
 151   type: 'hls-from-ts'
 152
 153   isAAC: boolean
 154
 155   hlsPlaylist: {
 156     videoFilename: string
 157   }
 158 }
 159
 160 interface QuickTranscodeOptions extends BaseTranscodeOptions {
 161   type: 'quick-transcode'
 162 }
 163
 164 interface VideoTranscodeOptions extends BaseTranscodeOptions {
 165   type: 'video'
 166 }
 167
 168 interface MergeAudioTranscodeOptions extends BaseTranscodeOptions {
 169   type: 'merge-audio'
 170   audioPath: string
 171 }
 172
 173 interface OnlyAudioTranscodeOptions extends BaseTranscodeOptions {
 174   type: 'only-audio'
 175 }
 176
 177 type TranscodeOptions =
 178   HLSTranscodeOptions
 179   | HLSFromTSTranscodeOptions
 180   | VideoTranscodeOptions
 181   | MergeAudioTranscodeOptions
 182   | OnlyAudioTranscodeOptions
 183   | QuickTranscodeOptions
 184
 185 const builders: {
 186   [ type in TranscodeOptionsType ]: (c: ffmpeg.FfmpegCommand, o?: TranscodeOptions) => Promise<ffmpeg.FfmpegCommand> | ffmpeg.FfmpegCommand
 187 } = {
 188   'quick-transcode': buildQuickTranscodeCommand,
 189   'hls': buildHLSVODCommand,
 190   'hls-from-ts': buildHLSVODFromTSCommand,
 191   'merge-audio': buildAudioMergeCommand,
 192   'only-audio': buildOnlyAudioCommand,
 193   'video': buildx264VODCommand
 194 }
 195
 196 async function transcode (options: TranscodeOptions) {
 197   logger.debug('Will run transcode.', { options })
 198
 199   let command = getFFmpeg(options.inputPath, 'vod')
 200     .output(options.outputPath)
 201
 202   command = await builders[options.type](command, options)
 203
 204   await runCommand({ command, job: options.job })
 205
 206   await fixHLSPlaylistIfNeeded(options)
 207 }
 208
 209 // ---------------------------------------------------------------------------
 210 // Live muxing/transcoding functions
 211 // ---------------------------------------------------------------------------
 212
 213 async function getLiveTranscodingCommand (options: {
 214   rtmpUrl: string
 215
 216   outPath: string
 217   masterPlaylistName: string
 218
 219   resolutions: number[]
 220   fps: number
 221   bitrate: number
 222
 223   availableEncoders: AvailableEncoders
 224   profile: string
 225 }) {
 226   const { rtmpUrl, outPath, resolutions, fps, bitrate, availableEncoders, profile, masterPlaylistName } = options
 227   const input = rtmpUrl
 228
 229   const command = getFFmpeg(input, 'live')
 230
 231   const varStreamMap: string[] = []
 232
 233   const complexFilter: ffmpeg.FilterSpecification[] = [
 234     {
 235       inputs: '[v:0]',
 236       filter: 'split',
 237       options: resolutions.length,
 238       outputs: resolutions.map(r => `vtemp${r}`)
 239     }
 240   ]
 241
 242   command.outputOption('-sc_threshold 0')
 243
 244   addDefaultEncoderGlobalParams({ command })
 245
 246   for (let i = 0; i < resolutions.length; i++) {
 247     const resolution = resolutions[i]
 248     const resolutionFPS = computeFPS(fps, resolution)
 249
 250     const baseEncoderBuilderParams = {
 251       input,
 252
 253       availableEncoders,
 254       profile,
 255
 256       fps: resolutionFPS,
 257       inputBitrate: bitrate,
 258       resolution,
 259       streamNum: i,
 260       videoType: 'live' as 'live'
 261     }
 262
 263     {
 264       const streamType: StreamType = 'video'
 265       const builderResult = await getEncoderBuilderResult({ ...baseEncoderBuilderParams, streamType })
 266       if (!builderResult) {
 267         throw new Error('No available live video encoder found')
 268       }
 269
 270       command.outputOption(`-map [vout${resolution}]`)
 271
 272       addDefaultEncoderParams({ command, encoder: builderResult.encoder, fps: resolutionFPS, streamNum: i })
 273
 274       logger.debug('Apply ffmpeg live video params from %s using %s profile.', builderResult.encoder, profile, builderResult)
 275
 276       command.outputOption(`${buildStreamSuffix('-c:v', i)} ${builderResult.encoder}`)
 277       applyEncoderOptions(command, builderResult.result)
 278
 279       complexFilter.push({
 280         inputs: `vtemp${resolution}`,
 281         filter: getScaleFilter(builderResult.result),
 282         options: `w=-2:h=${resolution}`,
 283         outputs: `vout${resolution}`
 284       })
 285     }
 286
 287     {
 288       const streamType: StreamType = 'audio'
 289       const builderResult = await getEncoderBuilderResult({ ...baseEncoderBuilderParams, streamType })
 290       if (!builderResult) {
 291         throw new Error('No available live audio encoder found')
 292       }
 293
 294       command.outputOption('-map a:0')
 295
 296       addDefaultEncoderParams({ command, encoder: builderResult.encoder, fps: resolutionFPS, streamNum: i })
 297
 298       logger.debug('Apply ffmpeg live audio params from %s using %s profile.', builderResult.encoder, profile, builderResult)
 299
 300       command.outputOption(`${buildStreamSuffix('-c:a', i)} ${builderResult.encoder}`)
 301       applyEncoderOptions(command, builderResult.result)
 302     }
 303
 304     varStreamMap.push(`v:${i},a:${i}`)
 305   }
 306
 307   command.complexFilter(complexFilter)
 308
 309   addDefaultLiveHLSParams(command, outPath, masterPlaylistName)
 310
 311   command.outputOption('-var_stream_map', varStreamMap.join(' '))
 312
 313   return command
 314 }
 315
 316 function getLiveMuxingCommand (rtmpUrl: string, outPath: string, masterPlaylistName: string) {
 317   const command = getFFmpeg(rtmpUrl, 'live')
 318
 319   command.outputOption('-c:v copy')
 320   command.outputOption('-c:a copy')
 321   command.outputOption('-map 0:a?')
 322   command.outputOption('-map 0:v?')
 323
 324   addDefaultLiveHLSParams(command, outPath, masterPlaylistName)
 325
 326   return command
 327 }
 328
 329 function buildStreamSuffix (base: string, streamNum?: number) {
 330   if (streamNum !== undefined) {
 331     return `${base}:${streamNum}`
 332   }
 333
 334   return base
 335 }
 336
 337 // ---------------------------------------------------------------------------
 338 // Default options
 339 // ---------------------------------------------------------------------------
 340
 341 function addDefaultEncoderGlobalParams (options: {
 342   command: ffmpeg.FfmpegCommand
 343 }) {
 344   const { command } = options
 345
 346   // avoid issues when transcoding some files: https://trac.ffmpeg.org/ticket/6375
 347   command.outputOption('-max_muxing_queue_size 1024')
 348          // strip all metadata
 349          .outputOption('-map_metadata -1')
 350          // NOTE: b-strategy 1 - heuristic algorithm, 16 is optimal B-frames for it
 351          .outputOption('-b_strategy 1')
 352          // NOTE: Why 16: https://github.com/Chocobozzz/PeerTube/pull/774. b-strategy 2 -> B-frames<16
 353          .outputOption('-bf 16')
 354          // allows import of source material with incompatible pixel formats (e.g. MJPEG video)
 355          .outputOption('-pix_fmt yuv420p')
 356 }
 357
 358 function addDefaultEncoderParams (options: {
 359   command: ffmpeg.FfmpegCommand
 360   encoder: 'libx264' | string
 361   streamNum?: number
 362   fps?: number
 363 }) {
 364   const { command, encoder, fps, streamNum } = options
 365
 366   if (encoder === 'libx264') {
 367     // 3.1 is the minimal resource allocation for our highest supported resolution
 368     command.outputOption(buildStreamSuffix('-level:v', streamNum) + ' 3.1')
 369
 370     if (fps) {
 371       // Keyframe interval of 2 seconds for faster seeking and resolution switching.
 372       // https://streaminglearningcenter.com/blogs/whats-the-right-keyframe-interval.html
 373       // https://superuser.com/a/908325
 374       command.outputOption(buildStreamSuffix('-g:v', streamNum) + ' ' + (fps * 2))
 375     }
 376   }
 377 }
 378
 379 function addDefaultLiveHLSParams (command: ffmpeg.FfmpegCommand, outPath: string, masterPlaylistName: string) {
 380   command.outputOption('-hls_time ' + VIDEO_LIVE.SEGMENT_TIME_SECONDS)
 381   command.outputOption('-hls_list_size ' + VIDEO_LIVE.SEGMENTS_LIST_SIZE)
 382   command.outputOption('-hls_flags delete_segments+independent_segments')
 383   command.outputOption(`-hls_segment_filename ${join(outPath, '%v-%06d.ts')}`)
 384   command.outputOption('-master_pl_name ' + masterPlaylistName)
 385   command.outputOption(`-f hls`)
 386
 387   command.output(join(outPath, '%v.m3u8'))
 388 }
 389
 390 // ---------------------------------------------------------------------------
 391 // Transcode VOD command builders
 392 // ---------------------------------------------------------------------------
 393
 394 async function buildx264VODCommand (command: ffmpeg.FfmpegCommand, options: TranscodeOptions) {
 395   let fps = await getVideoFileFPS(options.inputPath)
 396   fps = computeFPS(fps, options.resolution)
 397
 398   let scaleFilterValue: string
 399
 400   if (options.resolution !== undefined) {
 401     scaleFilterValue = options.isPortraitMode === true
 402       ? `w=${options.resolution}:h=-2`
 403       : `w=-2:h=${options.resolution}`
 404   }
 405
 406   command = await presetVideo({ command, input: options.inputPath, transcodeOptions: options, fps, scaleFilterValue })
 407
 408   return command
 409 }
 410
 411 async function buildAudioMergeCommand (command: ffmpeg.FfmpegCommand, options: MergeAudioTranscodeOptions) {
 412   command = command.loop(undefined)
 413
 414   const scaleFilterValue = getScaleCleanerValue()
 415   command = await presetVideo({ command, input: options.audioPath, transcodeOptions: options, scaleFilterValue })
 416
 417   command.outputOption('-preset:v veryfast')
 418
 419   command = command.input(options.audioPath)
 420                    .outputOption('-tune stillimage')
 421                    .outputOption('-shortest')
 422
 423   return command
 424 }
 425
 426 function buildOnlyAudioCommand (command: ffmpeg.FfmpegCommand, _options: OnlyAudioTranscodeOptions) {
 427   command = presetOnlyAudio(command)
 428
 429   return command
 430 }
 431
 432 function buildQuickTranscodeCommand (command: ffmpeg.FfmpegCommand) {
 433   command = presetCopy(command)
 434
 435   command = command.outputOption('-map_metadata -1') // strip all metadata
 436                    .outputOption('-movflags faststart')
 437
 438   return command
 439 }
 440
 441 function addCommonHLSVODCommandOptions (command: ffmpeg.FfmpegCommand, outputPath: string) {
 442   return command.outputOption('-hls_time 4')
 443                 .outputOption('-hls_list_size 0')
 444                 .outputOption('-hls_playlist_type vod')
 445                 .outputOption('-hls_segment_filename ' + outputPath)
 446                 .outputOption('-hls_segment_type fmp4')
 447                 .outputOption('-f hls')
 448                 .outputOption('-hls_flags single_file')
 449 }
 450
 451 async function buildHLSVODCommand (command: ffmpeg.FfmpegCommand, options: HLSTranscodeOptions) {
 452   const videoPath = getHLSVideoPath(options)
 453
 454   if (options.copyCodecs) command = presetCopy(command)
 455   else if (options.resolution === VideoResolution.H_NOVIDEO) command = presetOnlyAudio(command)
 456   else command = await buildx264VODCommand(command, options)
 457
 458   addCommonHLSVODCommandOptions(command, videoPath)
 459
 460   return command
 461 }
 462
 463 async function buildHLSVODFromTSCommand (command: ffmpeg.FfmpegCommand, options: HLSFromTSTranscodeOptions) {
 464   const videoPath = getHLSVideoPath(options)
 465
 466   command.outputOption('-c copy')
 467
 468   if (options.isAAC) {
 469     // Required for example when copying an AAC stream from an MPEG-TS
 470     // Since it's a bitstream filter, we don't need to reencode the audio
 471     command.outputOption('-bsf:a aac_adtstoasc')
 472   }
 473
 474   addCommonHLSVODCommandOptions(command, videoPath)
 475
 476   return command
 477 }
 478
 479 async function fixHLSPlaylistIfNeeded (options: TranscodeOptions) {
 480   if (options.type !== 'hls' && options.type !== 'hls-from-ts') return
 481
 482   const fileContent = await readFile(options.outputPath)
 483
 484   const videoFileName = options.hlsPlaylist.videoFilename
 485   const videoFilePath = getHLSVideoPath(options)
 486
 487   // Fix wrong mapping with some ffmpeg versions
 488   const newContent = fileContent.toString()
 489                                 .replace(`#EXT-X-MAP:URI="${videoFilePath}",`, `#EXT-X-MAP:URI="${videoFileName}",`)
 490
 491   await writeFile(options.outputPath, newContent)
 492 }
 493
 494 function getHLSVideoPath (options: HLSTranscodeOptions | HLSFromTSTranscodeOptions) {
 495   return `${dirname(options.outputPath)}/${options.hlsPlaylist.videoFilename}`
 496 }
 497
 498 // ---------------------------------------------------------------------------
 499 // Transcoding presets
 500 // ---------------------------------------------------------------------------
 501
 502 // Run encoder builder depending on available encoders
 503 // Try encoders by priority: if the encoder is available, run the chosen profile or fallback to the default one
 504 // If the default one does not exist, check the next encoder
 505 async function getEncoderBuilderResult (options: {
 506   streamType: 'video' | 'audio'
 507   input: string
 508
 509   availableEncoders: AvailableEncoders
 510   profile: string
 511
 512   videoType: 'vod' | 'live'
 513
 514   resolution: number
 515   inputBitrate: number
 516   fps?: number
 517   streamNum?: number
 518 }) {
 519   const { availableEncoders, input, profile, resolution, streamType, fps, inputBitrate, streamNum, videoType } = options
 520
 521   const encodersToTry = availableEncoders.encodersToTry[videoType][streamType]
 522   const encoders = availableEncoders.available[videoType]
 523
 524   for (const encoder of encodersToTry) {
 525     if (!(await checkFFmpegEncoders(availableEncoders)).get(encoder)) {
 526       logger.debug('Encoder %s not available in ffmpeg, skipping.', encoder)
 527       continue
 528     }
 529
 530     if (!encoders[encoder]) {
 531       logger.debug('Encoder %s not available in peertube encoders, skipping.', encoder)
 532       continue
 533     }
 534
 535     // An object containing available profiles for this encoder
 536     const builderProfiles: EncoderProfile<EncoderOptionsBuilder> = encoders[encoder]
 537     let builder = builderProfiles[profile]
 538
 539     if (!builder) {
 540       logger.debug('Profile %s for encoder %s not available. Fallback to default.', profile, encoder)
 541       builder = builderProfiles.default
 542
 543       if (!builder) {
 544         logger.debug('Default profile for encoder %s not available. Try next available encoder.', encoder)
 545         continue
 546       }
 547     }
 548
 549     const result = await builder({ input, resolution, inputBitrate, fps, streamNum })
 550
 551     return {
 552       result,
 553
 554       // If we don't have output options, then copy the input stream
 555       encoder: result.copy === true
 556         ? 'copy'
 557         : encoder
 558     }
 559   }
 560
 561   return null
 562 }
 563
 564 async function presetVideo (options: {
 565   command: ffmpeg.FfmpegCommand
 566   input: string
 567   transcodeOptions: TranscodeOptions
 568   fps?: number
 569   scaleFilterValue?: string
 570 }) {
 571   const { command, input, transcodeOptions, fps, scaleFilterValue } = options
 572
 573   let localCommand = command
 574     .format('mp4')
 575     .outputOption('-movflags faststart')
 576
 577   addDefaultEncoderGlobalParams({ command })
 578
 579   const probe = await ffprobePromise(input)
 580
 581   // Audio encoder
 582   const parsedAudio = await getAudioStream(input, probe)
 583   const bitrate = await getVideoFileBitrate(input, probe)
 584
 585   let streamsToProcess: StreamType[] = [ 'audio', 'video' ]
 586
 587   if (!parsedAudio.audioStream) {
 588     localCommand = localCommand.noAudio()
 589     streamsToProcess = [ 'video' ]
 590   }
 591
 592   for (const streamType of streamsToProcess) {
 593     const { profile, resolution, availableEncoders } = transcodeOptions
 594
 595     const builderResult = await getEncoderBuilderResult({
 596       streamType,
 597       input,
 598       resolution,
 599       availableEncoders,
 600       profile,
 601       fps,
 602       inputBitrate: bitrate,
 603       videoType: 'vod' as 'vod'
 604     })
 605
 606     if (!builderResult) {
 607       throw new Error('No available encoder found for stream ' + streamType)
 608     }
 609
 610     logger.debug(
 611       'Apply ffmpeg params from %s for %s stream of input %s using %s profile.',
 612       builderResult.encoder, streamType, input, profile, builderResult
 613     )
 614
 615     if (streamType === 'video') {
 616       localCommand.videoCodec(builderResult.encoder)
 617
 618       if (scaleFilterValue) {
 619         localCommand.outputOption(`-vf ${getScaleFilter(builderResult.result)}=${scaleFilterValue}`)
 620       }
 621     } else if (streamType === 'audio') {
 622       localCommand.audioCodec(builderResult.encoder)
 623     }
 624
 625     applyEncoderOptions(localCommand, builderResult.result)
 626     addDefaultEncoderParams({ command: localCommand, encoder: builderResult.encoder, fps })
 627   }
 628
 629   return localCommand
 630 }
 631
 632 function presetCopy (command: ffmpeg.FfmpegCommand): ffmpeg.FfmpegCommand {
 633   return command
 634     .format('mp4')
 635     .videoCodec('copy')
 636     .audioCodec('copy')
 637 }
 638
 639 function presetOnlyAudio (command: ffmpeg.FfmpegCommand): ffmpeg.FfmpegCommand {
 640   return command
 641     .format('mp4')
 642     .audioCodec('copy')
 643     .noVideo()
 644 }
 645
 646 function applyEncoderOptions (command: ffmpeg.FfmpegCommand, options: EncoderOptions): ffmpeg.FfmpegCommand {
 647   return command
 648     .inputOptions(options.inputOptions ?? [])
 649     .outputOptions(options.outputOptions ?? [])
 650 }
 651
 652 function getScaleFilter (options: EncoderOptions): string {
 653   if (options.scaleFilter) return options.scaleFilter.name
 654
 655   return 'scale'
 656 }
 657
 658 // ---------------------------------------------------------------------------
 659 // Utils
 660 // ---------------------------------------------------------------------------
 661
 662 function getFFmpeg (input: string, type: 'live' | 'vod') {
 663   // We set cwd explicitly because ffmpeg appears to create temporary files when trancoding which fails in read-only file systems
 664   const command = ffmpeg(input, {
 665     niceness: type === 'live' ? FFMPEG_NICE.LIVE : FFMPEG_NICE.VOD,
 666     cwd: CONFIG.STORAGE.TMP_DIR
 667   })
 668
 669   const threads = type === 'live'
 670     ? CONFIG.LIVE.TRANSCODING.THREADS
 671     : CONFIG.TRANSCODING.THREADS
 672
 673   if (threads > 0) {
 674     // If we don't set any threads ffmpeg will chose automatically
 675     command.outputOption('-threads ' + threads)
 676   }
 677
 678   return command
 679 }
 680
 681 function getFFmpegVersion () {
 682   return new Promise<string>((res, rej) => {
 683     (ffmpeg() as any)._getFfmpegPath((err, ffmpegPath) => {
 684       if (err) return rej(err)
 685       if (!ffmpegPath) return rej(new Error('Could not find ffmpeg path'))
 686
 687       return execPromise(`${ffmpegPath} -version`)
 688         .then(stdout => {
 689           const parsed = stdout.match(/ffmpeg version .?(\d+\.\d+(\.\d+)?)/)
 690           if (!parsed || !parsed[1]) return rej(new Error(`Could not find ffmpeg version in ${stdout}`))
 691
 692           // Fix ffmpeg version that does not include patch version (4.4 for example)
 693           let version = parsed[1]
 694           if (version.match(/^\d+\.\d+$/)) {
 695             version += '.0'
 696           }
 697
 698           return res(version)
 699         })
 700         .catch(err => rej(err))
 701     })
 702   })
 703 }
 704
 705 async function runCommand (options: {
 706   command: ffmpeg.FfmpegCommand
 707   silent?: boolean // false
 708   job?: Job
 709 }) {
 710   const { command, silent = false, job } = options
 711
 712   return new Promise<void>((res, rej) => {
 713     let shellCommand: string
 714
 715     command.on('start', cmdline => { shellCommand = cmdline })
 716
 717     command.on('error', (err, stdout, stderr) => {
 718       if (silent !== true) logger.error('Error in ffmpeg.', { stdout, stderr })
 719
 720       rej(err)
 721     })
 722
 723     command.on('end', (stdout, stderr) => {
 724       logger.debug('FFmpeg command ended.', { stdout, stderr, shellCommand })
 725
 726       res()
 727     })
 728
 729     if (job) {
 730       command.on('progress', progress => {
 731         if (!progress.percent) return
 732
 733         job.progress(Math.round(progress.percent))
 734           .catch(err => logger.warn('Cannot set ffmpeg job progress.', { err }))
 735       })
 736     }
 737
 738     command.run()
 739   })
 740 }
 741
 742 // Avoid "height not divisible by 2" error
 743 function getScaleCleanerValue () {
 744   return 'trunc(iw/2)*2:trunc(ih/2)*2'
 745 }
 746
 747 // ---------------------------------------------------------------------------
 748
 749 export {
 750   getLiveTranscodingCommand,
 751   getLiveMuxingCommand,
 752   buildStreamSuffix,
 753   convertWebPToJPG,
 754   processGIF,
 755   generateImageFromVideoFile,
 756   TranscodeOptions,
 757   TranscodeOptionsType,
 758   transcode,
 759   runCommand,
 760   getFFmpegVersion,
 761
 762   resetSupportedEncoders,
 763
 764   // builders
 765   buildx264VODCommand
 766 }