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, getAudioStream, 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
 222   availableEncoders: AvailableEncoders
 223   profile: string
 224 }) {
 225   const { rtmpUrl, outPath, resolutions, fps, availableEncoders, profile, masterPlaylistName } = options
 226   const input = rtmpUrl
 227
 228   const command = getFFmpeg(input, 'live')
 229
 230   const varStreamMap: string[] = []
 231
 232   const complexFilter: ffmpeg.FilterSpecification[] = [
 233     {
 234       inputs: '[v:0]',
 235       filter: 'split',
 236       options: resolutions.length,
 237       outputs: resolutions.map(r => `vtemp${r}`)
 238     }
 239   ]
 240
 241   command.outputOption('-sc_threshold 0')
 242
 243   addDefaultEncoderGlobalParams({ command })
 244
 245   for (let i = 0; i < resolutions.length; i++) {
 246     const resolution = resolutions[i]
 247     const resolutionFPS = computeFPS(fps, resolution)
 248
 249     const baseEncoderBuilderParams = {
 250       input,
 251
 252       availableEncoders,
 253       profile,
 254
 255       fps: resolutionFPS,
 256       resolution,
 257       streamNum: i,
 258       videoType: 'live' as 'live'
 259     }
 260
 261     {
 262       const streamType: StreamType = 'video'
 263       const builderResult = await getEncoderBuilderResult(Object.assign({}, baseEncoderBuilderParams, { streamType }))
 264       if (!builderResult) {
 265         throw new Error('No available live video encoder found')
 266       }
 267
 268       command.outputOption(`-map [vout${resolution}]`)
 269
 270       addDefaultEncoderParams({ command, encoder: builderResult.encoder, fps: resolutionFPS, streamNum: i })
 271
 272       logger.debug('Apply ffmpeg live video params from %s using %s profile.', builderResult.encoder, profile, builderResult)
 273
 274       command.outputOption(`${buildStreamSuffix('-c:v', i)} ${builderResult.encoder}`)
 275       applyEncoderOptions(command, builderResult.result)
 276
 277       complexFilter.push({
 278         inputs: `vtemp${resolution}`,
 279         filter: getScaleFilter(builderResult.result),
 280         options: `w=-2:h=${resolution}`,
 281         outputs: `vout${resolution}`
 282       })
 283     }
 284
 285     {
 286       const streamType: StreamType = 'audio'
 287       const builderResult = await getEncoderBuilderResult(Object.assign({}, baseEncoderBuilderParams, { streamType }))
 288       if (!builderResult) {
 289         throw new Error('No available live audio encoder found')
 290       }
 291
 292       command.outputOption('-map a:0')
 293
 294       addDefaultEncoderParams({ command, encoder: builderResult.encoder, fps: resolutionFPS, streamNum: i })
 295
 296       logger.debug('Apply ffmpeg live audio params from %s using %s profile.', builderResult.encoder, profile, builderResult)
 297
 298       command.outputOption(`${buildStreamSuffix('-c:a', i)} ${builderResult.encoder}`)
 299       applyEncoderOptions(command, builderResult.result)
 300     }
 301
 302     varStreamMap.push(`v:${i},a:${i}`)
 303   }
 304
 305   command.complexFilter(complexFilter)
 306
 307   addDefaultLiveHLSParams(command, outPath, masterPlaylistName)
 308
 309   command.outputOption('-var_stream_map', varStreamMap.join(' '))
 310
 311   return command
 312 }
 313
 314 function getLiveMuxingCommand (rtmpUrl: string, outPath: string, masterPlaylistName: string) {
 315   const command = getFFmpeg(rtmpUrl, 'live')
 316
 317   command.outputOption('-c:v copy')
 318   command.outputOption('-c:a copy')
 319   command.outputOption('-map 0:a?')
 320   command.outputOption('-map 0:v?')
 321
 322   addDefaultLiveHLSParams(command, outPath, masterPlaylistName)
 323
 324   return command
 325 }
 326
 327 function buildStreamSuffix (base: string, streamNum?: number) {
 328   if (streamNum !== undefined) {
 329     return `${base}:${streamNum}`
 330   }
 331
 332   return base
 333 }
 334
 335 // ---------------------------------------------------------------------------
 336 // Default options
 337 // ---------------------------------------------------------------------------
 338
 339 function addDefaultEncoderGlobalParams (options: {
 340   command: ffmpeg.FfmpegCommand
 341 }) {
 342   const { command } = options
 343
 344   // avoid issues when transcoding some files: https://trac.ffmpeg.org/ticket/6375
 345   command.outputOption('-max_muxing_queue_size 1024')
 346          // strip all metadata
 347          .outputOption('-map_metadata -1')
 348          // NOTE: b-strategy 1 - heuristic algorithm, 16 is optimal B-frames for it
 349          .outputOption('-b_strategy 1')
 350          // NOTE: Why 16: https://github.com/Chocobozzz/PeerTube/pull/774. b-strategy 2 -> B-frames<16
 351          .outputOption('-bf 16')
 352          // allows import of source material with incompatible pixel formats (e.g. MJPEG video)
 353          .outputOption('-pix_fmt yuv420p')
 354 }
 355
 356 function addDefaultEncoderParams (options: {
 357   command: ffmpeg.FfmpegCommand
 358   encoder: 'libx264' | string
 359   streamNum?: number
 360   fps?: number
 361 }) {
 362   const { command, encoder, fps, streamNum } = options
 363
 364   if (encoder === 'libx264') {
 365     // 3.1 is the minimal resource allocation for our highest supported resolution
 366     command.outputOption(buildStreamSuffix('-level:v', streamNum) + ' 3.1')
 367
 368     if (fps) {
 369       // Keyframe interval of 2 seconds for faster seeking and resolution switching.
 370       // https://streaminglearningcenter.com/blogs/whats-the-right-keyframe-interval.html
 371       // https://superuser.com/a/908325
 372       command.outputOption(buildStreamSuffix('-g:v', streamNum) + ' ' + (fps * 2))
 373     }
 374   }
 375 }
 376
 377 function addDefaultLiveHLSParams (command: ffmpeg.FfmpegCommand, outPath: string, masterPlaylistName: string) {
 378   command.outputOption('-hls_time ' + VIDEO_LIVE.SEGMENT_TIME_SECONDS)
 379   command.outputOption('-hls_list_size ' + VIDEO_LIVE.SEGMENTS_LIST_SIZE)
 380   command.outputOption('-hls_flags delete_segments+independent_segments')
 381   command.outputOption(`-hls_segment_filename ${join(outPath, '%v-%06d.ts')}`)
 382   command.outputOption('-master_pl_name ' + masterPlaylistName)
 383   command.outputOption(`-f hls`)
 384
 385   command.output(join(outPath, '%v.m3u8'))
 386 }
 387
 388 // ---------------------------------------------------------------------------
 389 // Transcode VOD command builders
 390 // ---------------------------------------------------------------------------
 391
 392 async function buildx264VODCommand (command: ffmpeg.FfmpegCommand, options: TranscodeOptions) {
 393   let fps = await getVideoFileFPS(options.inputPath)
 394   fps = computeFPS(fps, options.resolution)
 395
 396   let scaleFilterValue: string
 397
 398   if (options.resolution !== undefined) {
 399     scaleFilterValue = options.isPortraitMode === true
 400       ? `w=${options.resolution}:h=-2`
 401       : `w=-2:h=${options.resolution}`
 402   }
 403
 404   command = await presetVideo({ command, input: options.inputPath, transcodeOptions: options, fps, scaleFilterValue })
 405
 406   return command
 407 }
 408
 409 async function buildAudioMergeCommand (command: ffmpeg.FfmpegCommand, options: MergeAudioTranscodeOptions) {
 410   command = command.loop(undefined)
 411
 412   const scaleFilterValue = getScaleCleanerValue()
 413   command = await presetVideo({ command, input: options.audioPath, transcodeOptions: options, scaleFilterValue })
 414
 415   command.outputOption('-preset:v veryfast')
 416
 417   command = command.input(options.audioPath)
 418                    .outputOption('-tune stillimage')
 419                    .outputOption('-shortest')
 420
 421   return command
 422 }
 423
 424 function buildOnlyAudioCommand (command: ffmpeg.FfmpegCommand, _options: OnlyAudioTranscodeOptions) {
 425   command = presetOnlyAudio(command)
 426
 427   return command
 428 }
 429
 430 function buildQuickTranscodeCommand (command: ffmpeg.FfmpegCommand) {
 431   command = presetCopy(command)
 432
 433   command = command.outputOption('-map_metadata -1') // strip all metadata
 434                    .outputOption('-movflags faststart')
 435
 436   return command
 437 }
 438
 439 function addCommonHLSVODCommandOptions (command: ffmpeg.FfmpegCommand, outputPath: string) {
 440   return command.outputOption('-hls_time 4')
 441                 .outputOption('-hls_list_size 0')
 442                 .outputOption('-hls_playlist_type vod')
 443                 .outputOption('-hls_segment_filename ' + outputPath)
 444                 .outputOption('-hls_segment_type fmp4')
 445                 .outputOption('-f hls')
 446                 .outputOption('-hls_flags single_file')
 447 }
 448
 449 async function buildHLSVODCommand (command: ffmpeg.FfmpegCommand, options: HLSTranscodeOptions) {
 450   const videoPath = getHLSVideoPath(options)
 451
 452   if (options.copyCodecs) command = presetCopy(command)
 453   else if (options.resolution === VideoResolution.H_NOVIDEO) command = presetOnlyAudio(command)
 454   else command = await buildx264VODCommand(command, options)
 455
 456   addCommonHLSVODCommandOptions(command, videoPath)
 457
 458   return command
 459 }
 460
 461 async function buildHLSVODFromTSCommand (command: ffmpeg.FfmpegCommand, options: HLSFromTSTranscodeOptions) {
 462   const videoPath = getHLSVideoPath(options)
 463
 464   command.outputOption('-c copy')
 465
 466   if (options.isAAC) {
 467     // Required for example when copying an AAC stream from an MPEG-TS
 468     // Since it's a bitstream filter, we don't need to reencode the audio
 469     command.outputOption('-bsf:a aac_adtstoasc')
 470   }
 471
 472   addCommonHLSVODCommandOptions(command, videoPath)
 473
 474   return command
 475 }
 476
 477 async function fixHLSPlaylistIfNeeded (options: TranscodeOptions) {
 478   if (options.type !== 'hls' && options.type !== 'hls-from-ts') return
 479
 480   const fileContent = await readFile(options.outputPath)
 481
 482   const videoFileName = options.hlsPlaylist.videoFilename
 483   const videoFilePath = getHLSVideoPath(options)
 484
 485   // Fix wrong mapping with some ffmpeg versions
 486   const newContent = fileContent.toString()
 487                                 .replace(`#EXT-X-MAP:URI="${videoFilePath}",`, `#EXT-X-MAP:URI="${videoFileName}",`)
 488
 489   await writeFile(options.outputPath, newContent)
 490 }
 491
 492 function getHLSVideoPath (options: HLSTranscodeOptions | HLSFromTSTranscodeOptions) {
 493   return `${dirname(options.outputPath)}/${options.hlsPlaylist.videoFilename}`
 494 }
 495
 496 // ---------------------------------------------------------------------------
 497 // Transcoding presets
 498 // ---------------------------------------------------------------------------
 499
 500 // Run encoder builder depending on available encoders
 501 // Try encoders by priority: if the encoder is available, run the chosen profile or fallback to the default one
 502 // If the default one does not exist, check the next encoder
 503 async function getEncoderBuilderResult (options: {
 504   streamType: 'video' | 'audio'
 505   input: string
 506
 507   availableEncoders: AvailableEncoders
 508   profile: string
 509
 510   videoType: 'vod' | 'live'
 511
 512   resolution: number
 513   fps?: number
 514   streamNum?: number
 515 }) {
 516   const { availableEncoders, input, profile, resolution, streamType, fps, streamNum, videoType } = options
 517
 518   const encodersToTry = availableEncoders.encodersToTry[videoType][streamType]
 519   const encoders = availableEncoders.available[videoType]
 520
 521   for (const encoder of encodersToTry) {
 522     if (!(await checkFFmpegEncoders(availableEncoders)).get(encoder)) {
 523       logger.debug('Encoder %s not available in ffmpeg, skipping.', encoder)
 524       continue
 525     }
 526
 527     if (!encoders[encoder]) {
 528       logger.debug('Encoder %s not available in peertube encoders, skipping.', encoder)
 529       continue
 530     }
 531
 532     // An object containing available profiles for this encoder
 533     const builderProfiles: EncoderProfile<EncoderOptionsBuilder> = encoders[encoder]
 534     let builder = builderProfiles[profile]
 535
 536     if (!builder) {
 537       logger.debug('Profile %s for encoder %s not available. Fallback to default.', profile, encoder)
 538       builder = builderProfiles.default
 539
 540       if (!builder) {
 541         logger.debug('Default profile for encoder %s not available. Try next available encoder.', encoder)
 542         continue
 543       }
 544     }
 545
 546     const result = await builder({ input, resolution, fps, streamNum })
 547
 548     return {
 549       result,
 550
 551       // If we don't have output options, then copy the input stream
 552       encoder: result.copy === true
 553         ? 'copy'
 554         : encoder
 555     }
 556   }
 557
 558   return null
 559 }
 560
 561 async function presetVideo (options: {
 562   command: ffmpeg.FfmpegCommand
 563   input: string
 564   transcodeOptions: TranscodeOptions
 565   fps?: number
 566   scaleFilterValue?: string
 567 }) {
 568   const { command, input, transcodeOptions, fps, scaleFilterValue } = options
 569
 570   let localCommand = command
 571     .format('mp4')
 572     .outputOption('-movflags faststart')
 573
 574   addDefaultEncoderGlobalParams({ command })
 575
 576   // Audio encoder
 577   const parsedAudio = await getAudioStream(input)
 578
 579   let streamsToProcess: StreamType[] = [ 'audio', 'video' ]
 580
 581   if (!parsedAudio.audioStream) {
 582     localCommand = localCommand.noAudio()
 583     streamsToProcess = [ 'video' ]
 584   }
 585
 586   for (const streamType of streamsToProcess) {
 587     const { profile, resolution, availableEncoders } = transcodeOptions
 588
 589     const builderResult = await getEncoderBuilderResult({
 590       streamType,
 591       input,
 592       resolution,
 593       availableEncoders,
 594       profile,
 595       fps,
 596       videoType: 'vod' as 'vod'
 597     })
 598
 599     if (!builderResult) {
 600       throw new Error('No available encoder found for stream ' + streamType)
 601     }
 602
 603     logger.debug(
 604       'Apply ffmpeg params from %s for %s stream of input %s using %s profile.',
 605       builderResult.encoder, streamType, input, profile, builderResult
 606     )
 607
 608     if (streamType === 'video') {
 609       localCommand.videoCodec(builderResult.encoder)
 610
 611       if (scaleFilterValue) {
 612         localCommand.outputOption(`-vf ${getScaleFilter(builderResult.result)}=${scaleFilterValue}`)
 613       }
 614     } else if (streamType === 'audio') {
 615       localCommand.audioCodec(builderResult.encoder)
 616     }
 617
 618     applyEncoderOptions(localCommand, builderResult.result)
 619     addDefaultEncoderParams({ command: localCommand, encoder: builderResult.encoder, fps })
 620   }
 621
 622   return localCommand
 623 }
 624
 625 function presetCopy (command: ffmpeg.FfmpegCommand): ffmpeg.FfmpegCommand {
 626   return command
 627     .format('mp4')
 628     .videoCodec('copy')
 629     .audioCodec('copy')
 630 }
 631
 632 function presetOnlyAudio (command: ffmpeg.FfmpegCommand): ffmpeg.FfmpegCommand {
 633   return command
 634     .format('mp4')
 635     .audioCodec('copy')
 636     .noVideo()
 637 }
 638
 639 function applyEncoderOptions (command: ffmpeg.FfmpegCommand, options: EncoderOptions): ffmpeg.FfmpegCommand {
 640   return command
 641     .inputOptions(options.inputOptions ?? [])
 642     .outputOptions(options.outputOptions ?? [])
 643 }
 644
 645 function getScaleFilter (options: EncoderOptions): string {
 646   if (options.scaleFilter) return options.scaleFilter.name
 647
 648   return 'scale'
 649 }
 650
 651 // ---------------------------------------------------------------------------
 652 // Utils
 653 // ---------------------------------------------------------------------------
 654
 655 function getFFmpeg (input: string, type: 'live' | 'vod') {
 656   // We set cwd explicitly because ffmpeg appears to create temporary files when trancoding which fails in read-only file systems
 657   const command = ffmpeg(input, {
 658     niceness: type === 'live' ? FFMPEG_NICE.LIVE : FFMPEG_NICE.VOD,
 659     cwd: CONFIG.STORAGE.TMP_DIR
 660   })
 661
 662   const threads = type === 'live'
 663     ? CONFIG.LIVE.TRANSCODING.THREADS
 664     : CONFIG.TRANSCODING.THREADS
 665
 666   if (threads > 0) {
 667     // If we don't set any threads ffmpeg will chose automatically
 668     command.outputOption('-threads ' + threads)
 669   }
 670
 671   return command
 672 }
 673
 674 function getFFmpegVersion () {
 675   return new Promise<string>((res, rej) => {
 676     (ffmpeg() as any)._getFfmpegPath((err, ffmpegPath) => {
 677       if (err) return rej(err)
 678       if (!ffmpegPath) return rej(new Error('Could not find ffmpeg path'))
 679
 680       return execPromise(`${ffmpegPath} -version`)
 681         .then(stdout => {
 682           const parsed = stdout.match(/ffmpeg version .?(\d+\.\d+(\.\d+)?)/)
 683           if (!parsed || !parsed[1]) return rej(new Error(`Could not find ffmpeg version in ${stdout}`))
 684
 685           // Fix ffmpeg version that does not include patch version (4.4 for example)
 686           let version = parsed[1]
 687           if (version.match(/^\d+\.\d+$/)) {
 688             version += '.0'
 689           }
 690
 691           return res(version)
 692         })
 693         .catch(err => rej(err))
 694     })
 695   })
 696 }
 697
 698 async function runCommand (options: {
 699   command: ffmpeg.FfmpegCommand
 700   silent?: boolean // false
 701   job?: Job
 702 }) {
 703   const { command, silent = false, job } = options
 704
 705   return new Promise<void>((res, rej) => {
 706     command.on('error', (err, stdout, stderr) => {
 707       if (silent !== true) logger.error('Error in ffmpeg.', { stdout, stderr })
 708
 709       rej(err)
 710     })
 711
 712     command.on('end', (stdout, stderr) => {
 713       logger.debug('FFmpeg command ended.', { stdout, stderr })
 714
 715       res()
 716     })
 717
 718     if (job) {
 719       command.on('progress', progress => {
 720         if (!progress.percent) return
 721
 722         job.progress(Math.round(progress.percent))
 723           .catch(err => logger.warn('Cannot set ffmpeg job progress.', { err }))
 724       })
 725     }
 726
 727     command.run()
 728   })
 729 }
 730
 731 // Avoid "height not divisible by 2" error
 732 function getScaleCleanerValue () {
 733   return 'trunc(iw/2)*2:trunc(ih/2)*2'
 734 }
 735
 736 // ---------------------------------------------------------------------------
 737
 738 export {
 739   getLiveTranscodingCommand,
 740   getLiveMuxingCommand,
 741   buildStreamSuffix,
 742   convertWebPToJPG,
 743   processGIF,
 744   generateImageFromVideoFile,
 745   TranscodeOptions,
 746   TranscodeOptionsType,
 747   transcode,
 748   runCommand,
 749   getFFmpegVersion,
 750
 751   resetSupportedEncoders,
 752
 753   // builders
 754   buildx264VODCommand
 755 }