server/helpers/ffmpeg-utils.ts

   1 import { Job } from 'bull'
   2 import ffmpeg, { FfmpegCommand, FilterSpecification, getAvailableEncoders } 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 { pick } from '@shared/core-utils'
   7 import {
   8   AvailableEncoders,
   9   EncoderOptions,
  10   EncoderOptionsBuilder,
  11   EncoderOptionsBuilderParams,
  12   EncoderProfile,
  13   VideoResolution
  14 } from '../../shared/models/videos'
  15 import { CONFIG } from '../initializers/config'
  16 import { execPromise, promisify0 } from './core-utils'
  17 import { computeFPS, ffprobePromise, getAudioStream, getVideoFileBitrate, getVideoFileFPS, getVideoFileResolution } from './ffprobe-utils'
  18 import { processImage } from './image-utils'
  19 import { logger, loggerTagsFactory } from './logger'
  20
  21 const lTags = loggerTagsFactory('ffmpeg')
  22
  23 /**
  24  *
  25  * Functions that run transcoding/muxing ffmpeg processes
  26  * Mainly called by lib/video-transcoding.ts and lib/live-manager.ts
  27  *
  28  */
  29
  30 // ---------------------------------------------------------------------------
  31 // Encoder options
  32 // ---------------------------------------------------------------------------
  33
  34 type StreamType = 'audio' | 'video'
  35
  36 // ---------------------------------------------------------------------------
  37 // Encoders support
  38 // ---------------------------------------------------------------------------
  39
  40 // Detect supported encoders by ffmpeg
  41 let supportedEncoders: Map<string, boolean>
  42 async function checkFFmpegEncoders (peertubeAvailableEncoders: AvailableEncoders): Promise<Map<string, boolean>> {
  43   if (supportedEncoders !== undefined) {
  44     return supportedEncoders
  45   }
  46
  47   const getAvailableEncodersPromise = promisify0(getAvailableEncoders)
  48   const availableFFmpegEncoders = await getAvailableEncodersPromise()
  49
  50   const searchEncoders = new Set<string>()
  51   for (const type of [ 'live', 'vod' ]) {
  52     for (const streamType of [ 'audio', 'video' ]) {
  53       for (const encoder of peertubeAvailableEncoders.encodersToTry[type][streamType]) {
  54         searchEncoders.add(encoder)
  55       }
  56     }
  57   }
  58
  59   supportedEncoders = new Map<string, boolean>()
  60
  61   for (const searchEncoder of searchEncoders) {
  62     supportedEncoders.set(searchEncoder, availableFFmpegEncoders[searchEncoder] !== undefined)
  63   }
  64
  65   logger.info('Built supported ffmpeg encoders.', { supportedEncoders, searchEncoders, ...lTags() })
  66
  67   return supportedEncoders
  68 }
  69
  70 function resetSupportedEncoders () {
  71   supportedEncoders = undefined
  72 }
  73
  74 // ---------------------------------------------------------------------------
  75 // Image manipulation
  76 // ---------------------------------------------------------------------------
  77
  78 function convertWebPToJPG (path: string, destination: string): Promise<void> {
  79   const command = ffmpeg(path, { niceness: FFMPEG_NICE.THUMBNAIL })
  80     .output(destination)
  81
  82   return runCommand({ command, silent: true })
  83 }
  84
  85 function processGIF (
  86   path: string,
  87   destination: string,
  88   newSize: { width: number, height: number }
  89 ): Promise<void> {
  90   const command = ffmpeg(path, { niceness: FFMPEG_NICE.THUMBNAIL })
  91     .fps(20)
  92     .size(`${newSize.width}x${newSize.height}`)
  93     .output(destination)
  94
  95   return runCommand({ command })
  96 }
  97
  98 async function generateImageFromVideoFile (fromPath: string, folder: string, imageName: string, size: { width: number, height: number }) {
  99   const pendingImageName = 'pending-' + imageName
 100
 101   const options = {
 102     filename: pendingImageName,
 103     count: 1,
 104     folder
 105   }
 106
 107   const pendingImagePath = join(folder, pendingImageName)
 108
 109   try {
 110     await new Promise<string>((res, rej) => {
 111       ffmpeg(fromPath, { niceness: FFMPEG_NICE.THUMBNAIL })
 112         .on('error', rej)
 113         .on('end', () => res(imageName))
 114         .thumbnail(options)
 115     })
 116
 117     const destination = join(folder, imageName)
 118     await processImage(pendingImagePath, destination, size)
 119   } catch (err) {
 120     logger.error('Cannot generate image from video %s.', fromPath, { err, ...lTags() })
 121
 122     try {
 123       await remove(pendingImagePath)
 124     } catch (err) {
 125       logger.debug('Cannot remove pending image path after generation error.', { err, ...lTags() })
 126     }
 127   }
 128 }
 129
 130 // ---------------------------------------------------------------------------
 131 // Transcode meta function
 132 // ---------------------------------------------------------------------------
 133
 134 type TranscodeOptionsType = 'hls' | 'hls-from-ts' | 'quick-transcode' | 'video' | 'merge-audio' | 'only-audio'
 135
 136 interface BaseTranscodeOptions {
 137   type: TranscodeOptionsType
 138
 139   inputPath: string
 140   outputPath: string
 141
 142   availableEncoders: AvailableEncoders
 143   profile: string
 144
 145   resolution: number
 146
 147   isPortraitMode?: boolean
 148
 149   job?: Job
 150 }
 151
 152 interface HLSTranscodeOptions extends BaseTranscodeOptions {
 153   type: 'hls'
 154   copyCodecs: boolean
 155   hlsPlaylist: {
 156     videoFilename: string
 157   }
 158 }
 159
 160 interface HLSFromTSTranscodeOptions extends BaseTranscodeOptions {
 161   type: 'hls-from-ts'
 162
 163   isAAC: boolean
 164
 165   hlsPlaylist: {
 166     videoFilename: string
 167   }
 168 }
 169
 170 interface QuickTranscodeOptions extends BaseTranscodeOptions {
 171   type: 'quick-transcode'
 172 }
 173
 174 interface VideoTranscodeOptions extends BaseTranscodeOptions {
 175   type: 'video'
 176 }
 177
 178 interface MergeAudioTranscodeOptions extends BaseTranscodeOptions {
 179   type: 'merge-audio'
 180   audioPath: string
 181 }
 182
 183 interface OnlyAudioTranscodeOptions extends BaseTranscodeOptions {
 184   type: 'only-audio'
 185 }
 186
 187 type TranscodeOptions =
 188   HLSTranscodeOptions
 189   | HLSFromTSTranscodeOptions
 190   | VideoTranscodeOptions
 191   | MergeAudioTranscodeOptions
 192   | OnlyAudioTranscodeOptions
 193   | QuickTranscodeOptions
 194
 195 const builders: {
 196   [ type in TranscodeOptionsType ]: (c: FfmpegCommand, o?: TranscodeOptions) => Promise<FfmpegCommand> | FfmpegCommand
 197 } = {
 198   'quick-transcode': buildQuickTranscodeCommand,
 199   'hls': buildHLSVODCommand,
 200   'hls-from-ts': buildHLSVODFromTSCommand,
 201   'merge-audio': buildAudioMergeCommand,
 202   'only-audio': buildOnlyAudioCommand,
 203   'video': buildx264VODCommand
 204 }
 205
 206 async function transcode (options: TranscodeOptions) {
 207   logger.debug('Will run transcode.', { options, ...lTags() })
 208
 209   let command = getFFmpeg(options.inputPath, 'vod')
 210     .output(options.outputPath)
 211
 212   command = await builders[options.type](command, options)
 213
 214   await runCommand({ command, job: options.job })
 215
 216   await fixHLSPlaylistIfNeeded(options)
 217 }
 218
 219 // ---------------------------------------------------------------------------
 220 // Live muxing/transcoding functions
 221 // ---------------------------------------------------------------------------
 222
 223 async function getLiveTranscodingCommand (options: {
 224   inputUrl: string
 225
 226   outPath: string
 227   masterPlaylistName: string
 228
 229   resolutions: number[]
 230
 231   // Input information
 232   fps: number
 233   bitrate: number
 234   ratio: number
 235
 236   availableEncoders: AvailableEncoders
 237   profile: string
 238 }) {
 239   const { inputUrl, outPath, resolutions, fps, bitrate, availableEncoders, profile, masterPlaylistName, ratio } = options
 240
 241   const command = getFFmpeg(inputUrl, 'live')
 242
 243   const varStreamMap: string[] = []
 244
 245   const complexFilter: FilterSpecification[] = [
 246     {
 247       inputs: '[v:0]',
 248       filter: 'split',
 249       options: resolutions.length,
 250       outputs: resolutions.map(r => `vtemp${r}`)
 251     }
 252   ]
 253
 254   command.outputOption('-sc_threshold 0')
 255
 256   addDefaultEncoderGlobalParams({ command })
 257
 258   for (let i = 0; i < resolutions.length; i++) {
 259     const resolution = resolutions[i]
 260     const resolutionFPS = computeFPS(fps, resolution)
 261
 262     const baseEncoderBuilderParams = {
 263       input: inputUrl,
 264
 265       availableEncoders,
 266       profile,
 267
 268       inputBitrate: bitrate,
 269       inputRatio: ratio,
 270
 271       resolution,
 272       fps: resolutionFPS,
 273
 274       streamNum: i,
 275       videoType: 'live' as 'live'
 276     }
 277
 278     {
 279       const streamType: StreamType = 'video'
 280       const builderResult = await getEncoderBuilderResult({ ...baseEncoderBuilderParams, streamType })
 281       if (!builderResult) {
 282         throw new Error('No available live video encoder found')
 283       }
 284
 285       command.outputOption(`-map [vout${resolution}]`)
 286
 287       addDefaultEncoderParams({ command, encoder: builderResult.encoder, fps: resolutionFPS, streamNum: i })
 288
 289       logger.debug(
 290         'Apply ffmpeg live video params from %s using %s profile.', builderResult.encoder, profile,
 291         { builderResult, fps: resolutionFPS, resolution, ...lTags() }
 292       )
 293
 294       command.outputOption(`${buildStreamSuffix('-c:v', i)} ${builderResult.encoder}`)
 295       applyEncoderOptions(command, builderResult.result)
 296
 297       complexFilter.push({
 298         inputs: `vtemp${resolution}`,
 299         filter: getScaleFilter(builderResult.result),
 300         options: `w=-2:h=${resolution}`,
 301         outputs: `vout${resolution}`
 302       })
 303     }
 304
 305     {
 306       const streamType: StreamType = 'audio'
 307       const builderResult = await getEncoderBuilderResult({ ...baseEncoderBuilderParams, streamType })
 308       if (!builderResult) {
 309         throw new Error('No available live audio encoder found')
 310       }
 311
 312       command.outputOption('-map a:0')
 313
 314       addDefaultEncoderParams({ command, encoder: builderResult.encoder, fps: resolutionFPS, streamNum: i })
 315
 316       logger.debug(
 317         'Apply ffmpeg live audio params from %s using %s profile.', builderResult.encoder, profile,
 318         { builderResult, fps: resolutionFPS, resolution, ...lTags() }
 319       )
 320
 321       command.outputOption(`${buildStreamSuffix('-c:a', i)} ${builderResult.encoder}`)
 322       applyEncoderOptions(command, builderResult.result)
 323     }
 324
 325     varStreamMap.push(`v:${i},a:${i}`)
 326   }
 327
 328   command.complexFilter(complexFilter)
 329
 330   addDefaultLiveHLSParams(command, outPath, masterPlaylistName)
 331
 332   command.outputOption('-var_stream_map', varStreamMap.join(' '))
 333
 334   return command
 335 }
 336
 337 function getLiveMuxingCommand (inputUrl: string, outPath: string, masterPlaylistName: string) {
 338   const command = getFFmpeg(inputUrl, 'live')
 339
 340   command.outputOption('-c:v copy')
 341   command.outputOption('-c:a copy')
 342   command.outputOption('-map 0:a?')
 343   command.outputOption('-map 0:v?')
 344
 345   addDefaultLiveHLSParams(command, outPath, masterPlaylistName)
 346
 347   return command
 348 }
 349
 350 function buildStreamSuffix (base: string, streamNum?: number) {
 351   if (streamNum !== undefined) {
 352     return `${base}:${streamNum}`
 353   }
 354
 355   return base
 356 }
 357
 358 // ---------------------------------------------------------------------------
 359 // Default options
 360 // ---------------------------------------------------------------------------
 361
 362 function addDefaultEncoderGlobalParams (options: {
 363   command: FfmpegCommand
 364 }) {
 365   const { command } = options
 366
 367   // avoid issues when transcoding some files: https://trac.ffmpeg.org/ticket/6375
 368   command.outputOption('-max_muxing_queue_size 1024')
 369          // strip all metadata
 370          .outputOption('-map_metadata -1')
 371          // allows import of source material with incompatible pixel formats (e.g. MJPEG video)
 372          .outputOption('-pix_fmt yuv420p')
 373 }
 374
 375 function addDefaultEncoderParams (options: {
 376   command: FfmpegCommand
 377   encoder: 'libx264' | string
 378   streamNum?: number
 379   fps?: number
 380 }) {
 381   const { command, encoder, fps, streamNum } = options
 382
 383   if (encoder === 'libx264') {
 384     // 3.1 is the minimal resource allocation for our highest supported resolution
 385     command.outputOption(buildStreamSuffix('-level:v', streamNum) + ' 3.1')
 386
 387     if (fps) {
 388       // Keyframe interval of 2 seconds for faster seeking and resolution switching.
 389       // https://streaminglearningcenter.com/blogs/whats-the-right-keyframe-interval.html
 390       // https://superuser.com/a/908325
 391       command.outputOption(buildStreamSuffix('-g:v', streamNum) + ' ' + (fps * 2))
 392     }
 393   }
 394 }
 395
 396 function addDefaultLiveHLSParams (command: FfmpegCommand, outPath: string, masterPlaylistName: string) {
 397   command.outputOption('-hls_time ' + VIDEO_LIVE.SEGMENT_TIME_SECONDS)
 398   command.outputOption('-hls_list_size ' + VIDEO_LIVE.SEGMENTS_LIST_SIZE)
 399   command.outputOption('-hls_flags delete_segments+independent_segments')
 400   command.outputOption(`-hls_segment_filename ${join(outPath, '%v-%06d.ts')}`)
 401   command.outputOption('-master_pl_name ' + masterPlaylistName)
 402   command.outputOption(`-f hls`)
 403
 404   command.output(join(outPath, '%v.m3u8'))
 405 }
 406
 407 // ---------------------------------------------------------------------------
 408 // Transcode VOD command builders
 409 // ---------------------------------------------------------------------------
 410
 411 async function buildx264VODCommand (command: FfmpegCommand, options: TranscodeOptions) {
 412   let fps = await getVideoFileFPS(options.inputPath)
 413   fps = computeFPS(fps, options.resolution)
 414
 415   let scaleFilterValue: string
 416
 417   if (options.resolution !== undefined) {
 418     scaleFilterValue = options.isPortraitMode === true
 419       ? `w=${options.resolution}:h=-2`
 420       : `w=-2:h=${options.resolution}`
 421   }
 422
 423   command = await presetVideo({ command, input: options.inputPath, transcodeOptions: options, fps, scaleFilterValue })
 424
 425   return command
 426 }
 427
 428 async function buildAudioMergeCommand (command: FfmpegCommand, options: MergeAudioTranscodeOptions) {
 429   command = command.loop(undefined)
 430
 431   const scaleFilterValue = getScaleCleanerValue()
 432   command = await presetVideo({ command, input: options.audioPath, transcodeOptions: options, scaleFilterValue })
 433
 434   command.outputOption('-preset:v veryfast')
 435
 436   command = command.input(options.audioPath)
 437                    .outputOption('-tune stillimage')
 438                    .outputOption('-shortest')
 439
 440   return command
 441 }
 442
 443 function buildOnlyAudioCommand (command: FfmpegCommand, _options: OnlyAudioTranscodeOptions) {
 444   command = presetOnlyAudio(command)
 445
 446   return command
 447 }
 448
 449 function buildQuickTranscodeCommand (command: FfmpegCommand) {
 450   command = presetCopy(command)
 451
 452   command = command.outputOption('-map_metadata -1') // strip all metadata
 453                    .outputOption('-movflags faststart')
 454
 455   return command
 456 }
 457
 458 function addCommonHLSVODCommandOptions (command: FfmpegCommand, outputPath: string) {
 459   return command.outputOption('-hls_time 4')
 460                 .outputOption('-hls_list_size 0')
 461                 .outputOption('-hls_playlist_type vod')
 462                 .outputOption('-hls_segment_filename ' + outputPath)
 463                 .outputOption('-hls_segment_type fmp4')
 464                 .outputOption('-f hls')
 465                 .outputOption('-hls_flags single_file')
 466 }
 467
 468 async function buildHLSVODCommand (command: FfmpegCommand, options: HLSTranscodeOptions) {
 469   const videoPath = getHLSVideoPath(options)
 470
 471   if (options.copyCodecs) command = presetCopy(command)
 472   else if (options.resolution === VideoResolution.H_NOVIDEO) command = presetOnlyAudio(command)
 473   else command = await buildx264VODCommand(command, options)
 474
 475   addCommonHLSVODCommandOptions(command, videoPath)
 476
 477   return command
 478 }
 479
 480 function buildHLSVODFromTSCommand (command: FfmpegCommand, options: HLSFromTSTranscodeOptions) {
 481   const videoPath = getHLSVideoPath(options)
 482
 483   command.outputOption('-c copy')
 484
 485   if (options.isAAC) {
 486     // Required for example when copying an AAC stream from an MPEG-TS
 487     // Since it's a bitstream filter, we don't need to reencode the audio
 488     command.outputOption('-bsf:a aac_adtstoasc')
 489   }
 490
 491   addCommonHLSVODCommandOptions(command, videoPath)
 492
 493   return command
 494 }
 495
 496 async function fixHLSPlaylistIfNeeded (options: TranscodeOptions) {
 497   if (options.type !== 'hls' && options.type !== 'hls-from-ts') return
 498
 499   const fileContent = await readFile(options.outputPath)
 500
 501   const videoFileName = options.hlsPlaylist.videoFilename
 502   const videoFilePath = getHLSVideoPath(options)
 503
 504   // Fix wrong mapping with some ffmpeg versions
 505   const newContent = fileContent.toString()
 506                                 .replace(`#EXT-X-MAP:URI="${videoFilePath}",`, `#EXT-X-MAP:URI="${videoFileName}",`)
 507
 508   await writeFile(options.outputPath, newContent)
 509 }
 510
 511 function getHLSVideoPath (options: HLSTranscodeOptions | HLSFromTSTranscodeOptions) {
 512   return `${dirname(options.outputPath)}/${options.hlsPlaylist.videoFilename}`
 513 }
 514
 515 // ---------------------------------------------------------------------------
 516 // Transcoding presets
 517 // ---------------------------------------------------------------------------
 518
 519 // Run encoder builder depending on available encoders
 520 // Try encoders by priority: if the encoder is available, run the chosen profile or fallback to the default one
 521 // If the default one does not exist, check the next encoder
 522 async function getEncoderBuilderResult (options: EncoderOptionsBuilderParams & {
 523   streamType: 'video' | 'audio'
 524   input: string
 525
 526   availableEncoders: AvailableEncoders
 527   profile: string
 528
 529   videoType: 'vod' | 'live'
 530 }) {
 531   const { availableEncoders, profile, streamType, videoType } = options
 532
 533   const encodersToTry = availableEncoders.encodersToTry[videoType][streamType]
 534   const encoders = availableEncoders.available[videoType]
 535
 536   for (const encoder of encodersToTry) {
 537     if (!(await checkFFmpegEncoders(availableEncoders)).get(encoder)) {
 538       logger.debug('Encoder %s not available in ffmpeg, skipping.', encoder, lTags())
 539       continue
 540     }
 541
 542     if (!encoders[encoder]) {
 543       logger.debug('Encoder %s not available in peertube encoders, skipping.', encoder, lTags())
 544       continue
 545     }
 546
 547     // An object containing available profiles for this encoder
 548     const builderProfiles: EncoderProfile<EncoderOptionsBuilder> = encoders[encoder]
 549     let builder = builderProfiles[profile]
 550
 551     if (!builder) {
 552       logger.debug('Profile %s for encoder %s not available. Fallback to default.', profile, encoder, lTags())
 553       builder = builderProfiles.default
 554
 555       if (!builder) {
 556         logger.debug('Default profile for encoder %s not available. Try next available encoder.', encoder, lTags())
 557         continue
 558       }
 559     }
 560
 561     const result = await builder(pick(options, [ 'input', 'resolution', 'inputBitrate', 'fps', 'inputRatio', 'streamNum' ]))
 562
 563     return {
 564       result,
 565
 566       // If we don't have output options, then copy the input stream
 567       encoder: result.copy === true
 568         ? 'copy'
 569         : encoder
 570     }
 571   }
 572
 573   return null
 574 }
 575
 576 async function presetVideo (options: {
 577   command: FfmpegCommand
 578   input: string
 579   transcodeOptions: TranscodeOptions
 580   fps?: number
 581   scaleFilterValue?: string
 582 }) {
 583   const { command, input, transcodeOptions, fps, scaleFilterValue } = options
 584
 585   let localCommand = command
 586     .format('mp4')
 587     .outputOption('-movflags faststart')
 588
 589   addDefaultEncoderGlobalParams({ command })
 590
 591   const probe = await ffprobePromise(input)
 592
 593   // Audio encoder
 594   const parsedAudio = await getAudioStream(input, probe)
 595   const bitrate = await getVideoFileBitrate(input, probe)
 596   const { ratio } = await getVideoFileResolution(input, probe)
 597
 598   let streamsToProcess: StreamType[] = [ 'audio', 'video' ]
 599
 600   if (!parsedAudio.audioStream) {
 601     localCommand = localCommand.noAudio()
 602     streamsToProcess = [ 'video' ]
 603   }
 604
 605   for (const streamType of streamsToProcess) {
 606     const { profile, resolution, availableEncoders } = transcodeOptions
 607
 608     const builderResult = await getEncoderBuilderResult({
 609       streamType,
 610       input,
 611       resolution,
 612       availableEncoders,
 613       profile,
 614       fps,
 615       inputBitrate: bitrate,
 616       inputRatio: ratio,
 617       videoType: 'vod' as 'vod'
 618     })
 619
 620     if (!builderResult) {
 621       throw new Error('No available encoder found for stream ' + streamType)
 622     }
 623
 624     logger.debug(
 625       'Apply ffmpeg params from %s for %s stream of input %s using %s profile.',
 626       builderResult.encoder, streamType, input, profile,
 627       { builderResult, resolution, fps, ...lTags() }
 628     )
 629
 630     if (streamType === 'video') {
 631       localCommand.videoCodec(builderResult.encoder)
 632
 633       if (scaleFilterValue) {
 634         localCommand.outputOption(`-vf ${getScaleFilter(builderResult.result)}=${scaleFilterValue}`)
 635       }
 636     } else if (streamType === 'audio') {
 637       localCommand.audioCodec(builderResult.encoder)
 638     }
 639
 640     applyEncoderOptions(localCommand, builderResult.result)
 641     addDefaultEncoderParams({ command: localCommand, encoder: builderResult.encoder, fps })
 642   }
 643
 644   return localCommand
 645 }
 646
 647 function presetCopy (command: FfmpegCommand): FfmpegCommand {
 648   return command
 649     .format('mp4')
 650     .videoCodec('copy')
 651     .audioCodec('copy')
 652 }
 653
 654 function presetOnlyAudio (command: FfmpegCommand): FfmpegCommand {
 655   return command
 656     .format('mp4')
 657     .audioCodec('copy')
 658     .noVideo()
 659 }
 660
 661 function applyEncoderOptions (command: FfmpegCommand, options: EncoderOptions): FfmpegCommand {
 662   return command
 663     .inputOptions(options.inputOptions ?? [])
 664     .outputOptions(options.outputOptions ?? [])
 665 }
 666
 667 function getScaleFilter (options: EncoderOptions): string {
 668   if (options.scaleFilter) return options.scaleFilter.name
 669
 670   return 'scale'
 671 }
 672
 673 // ---------------------------------------------------------------------------
 674 // Utils
 675 // ---------------------------------------------------------------------------
 676
 677 function getFFmpeg (input: string, type: 'live' | 'vod') {
 678   // We set cwd explicitly because ffmpeg appears to create temporary files when trancoding which fails in read-only file systems
 679   const command = ffmpeg(input, {
 680     niceness: type === 'live' ? FFMPEG_NICE.LIVE : FFMPEG_NICE.VOD,
 681     cwd: CONFIG.STORAGE.TMP_DIR
 682   })
 683
 684   const threads = type === 'live'
 685     ? CONFIG.LIVE.TRANSCODING.THREADS
 686     : CONFIG.TRANSCODING.THREADS
 687
 688   if (threads > 0) {
 689     // If we don't set any threads ffmpeg will chose automatically
 690     command.outputOption('-threads ' + threads)
 691   }
 692
 693   return command
 694 }
 695
 696 function getFFmpegVersion () {
 697   return new Promise<string>((res, rej) => {
 698     (ffmpeg() as any)._getFfmpegPath((err, ffmpegPath) => {
 699       if (err) return rej(err)
 700       if (!ffmpegPath) return rej(new Error('Could not find ffmpeg path'))
 701
 702       return execPromise(`${ffmpegPath} -version`)
 703         .then(stdout => {
 704           const parsed = stdout.match(/ffmpeg version .?(\d+\.\d+(\.\d+)?)/)
 705           if (!parsed || !parsed[1]) return rej(new Error(`Could not find ffmpeg version in ${stdout}`))
 706
 707           // Fix ffmpeg version that does not include patch version (4.4 for example)
 708           let version = parsed[1]
 709           if (version.match(/^\d+\.\d+$/)) {
 710             version += '.0'
 711           }
 712
 713           return res(version)
 714         })
 715         .catch(err => rej(err))
 716     })
 717   })
 718 }
 719
 720 async function runCommand (options: {
 721   command: FfmpegCommand
 722   silent?: boolean // false
 723   job?: Job
 724 }) {
 725   const { command, silent = false, job } = options
 726
 727   return new Promise<void>((res, rej) => {
 728     let shellCommand: string
 729
 730     command.on('start', cmdline => { shellCommand = cmdline })
 731
 732     command.on('error', (err, stdout, stderr) => {
 733       if (silent !== true) logger.error('Error in ffmpeg.', { stdout, stderr, shellCommand, ...lTags() })
 734
 735       rej(err)
 736     })
 737
 738     command.on('end', (stdout, stderr) => {
 739       logger.debug('FFmpeg command ended.', { stdout, stderr, shellCommand, ...lTags() })
 740
 741       res()
 742     })
 743
 744     if (job) {
 745       command.on('progress', progress => {
 746         if (!progress.percent) return
 747
 748         job.progress(Math.round(progress.percent))
 749           .catch(err => logger.warn('Cannot set ffmpeg job progress.', { err, ...lTags() }))
 750       })
 751     }
 752
 753     command.run()
 754   })
 755 }
 756
 757 // Avoid "height not divisible by 2" error
 758 function getScaleCleanerValue () {
 759   return 'trunc(iw/2)*2:trunc(ih/2)*2'
 760 }
 761
 762 // ---------------------------------------------------------------------------
 763
 764 export {
 765   getLiveTranscodingCommand,
 766   getLiveMuxingCommand,
 767   buildStreamSuffix,
 768   convertWebPToJPG,
 769   processGIF,
 770   generateImageFromVideoFile,
 771   TranscodeOptions,
 772   TranscodeOptionsType,
 773   transcode,
 774   runCommand,
 775   getFFmpegVersion,
 776
 777   resetSupportedEncoders,
 778
 779   // builders
 780   buildx264VODCommand
 781 }