server/helpers/ffmpeg-utils.ts

   1 import * as ffmpeg from 'fluent-ffmpeg'
   2 import { readFile, remove, writeFile } from 'fs-extra'
   3 import { dirname, join } from 'path'
   4 import { FFMPEG_NICE, VIDEO_LIVE, VIDEO_TRANSCODING_ENCODERS, VIDEO_TRANSCODING_FPS } from '@server/initializers/constants'
   5 import { VideoResolution } from '../../shared/models/videos'
   6 import { checkFFmpegEncoders } from '../initializers/checker-before-init'
   7 import { CONFIG } from '../initializers/config'
   8 import { getAudioStream, getClosestFramerateStandard, getVideoFileFPS } from './ffprobe-utils'
   9 import { processImage } from './image-utils'
  10 import { logger } from './logger'
  11
  12 /**
  13  *
  14  * Functions that run transcoding/muxing ffmpeg processes
  15  * Mainly called by lib/video-transcoding.ts and lib/live-manager.ts
  16  *
  17  */
  18
  19 // ---------------------------------------------------------------------------
  20 // Encoder options
  21 // ---------------------------------------------------------------------------
  22
  23 // Options builders
  24
  25 export type EncoderOptionsBuilder = (params: {
  26   input: string
  27   resolution: VideoResolution
  28   fps?: number
  29   streamNum?: number
  30 }) => Promise<EncoderOptions> | EncoderOptions
  31
  32 // Options types
  33
  34 export interface EncoderOptions {
  35   copy?: boolean
  36   outputOptions: string[]
  37 }
  38
  39 // All our encoders
  40
  41 export interface EncoderProfile <T> {
  42   [ profile: string ]: T
  43
  44   default: T
  45 }
  46
  47 export type AvailableEncoders = {
  48   [ id in 'live' | 'vod' ]: {
  49     [ encoder in 'libx264' | 'aac' | 'libfdk_aac' ]?: EncoderProfile<EncoderOptionsBuilder>
  50   }
  51 }
  52
  53 // ---------------------------------------------------------------------------
  54 // Image manipulation
  55 // ---------------------------------------------------------------------------
  56
  57 function convertWebPToJPG (path: string, destination: string): Promise<void> {
  58   const command = ffmpeg(path)
  59     .output(destination)
  60
  61   return runCommand(command)
  62 }
  63
  64 function processGIF (
  65   path: string,
  66   destination: string,
  67   newSize: { width: number, height: number }
  68 ): Promise<void> {
  69   const command = ffmpeg(path)
  70     .fps(20)
  71     .size(`${newSize.width}x${newSize.height}`)
  72     .output(destination)
  73
  74   return runCommand(command)
  75 }
  76
  77 async function generateImageFromVideoFile (fromPath: string, folder: string, imageName: string, size: { width: number, height: number }) {
  78   const pendingImageName = 'pending-' + imageName
  79
  80   const options = {
  81     filename: pendingImageName,
  82     count: 1,
  83     folder
  84   }
  85
  86   const pendingImagePath = join(folder, pendingImageName)
  87
  88   try {
  89     await new Promise<string>((res, rej) => {
  90       ffmpeg(fromPath, { niceness: FFMPEG_NICE.THUMBNAIL })
  91         .on('error', rej)
  92         .on('end', () => res(imageName))
  93         .thumbnail(options)
  94     })
  95
  96     const destination = join(folder, imageName)
  97     await processImage(pendingImagePath, destination, size)
  98   } catch (err) {
  99     logger.error('Cannot generate image from video %s.', fromPath, { err })
 100
 101     try {
 102       await remove(pendingImagePath)
 103     } catch (err) {
 104       logger.debug('Cannot remove pending image path after generation error.', { err })
 105     }
 106   }
 107 }
 108
 109 // ---------------------------------------------------------------------------
 110 // Transcode meta function
 111 // ---------------------------------------------------------------------------
 112
 113 type TranscodeOptionsType = 'hls' | 'quick-transcode' | 'video' | 'merge-audio' | 'only-audio'
 114
 115 interface BaseTranscodeOptions {
 116   type: TranscodeOptionsType
 117
 118   inputPath: string
 119   outputPath: string
 120
 121   availableEncoders: AvailableEncoders
 122   profile: string
 123
 124   resolution: VideoResolution
 125
 126   isPortraitMode?: boolean
 127 }
 128
 129 interface HLSTranscodeOptions extends BaseTranscodeOptions {
 130   type: 'hls'
 131   copyCodecs: boolean
 132   hlsPlaylist: {
 133     videoFilename: string
 134   }
 135 }
 136
 137 interface QuickTranscodeOptions extends BaseTranscodeOptions {
 138   type: 'quick-transcode'
 139 }
 140
 141 interface VideoTranscodeOptions extends BaseTranscodeOptions {
 142   type: 'video'
 143 }
 144
 145 interface MergeAudioTranscodeOptions extends BaseTranscodeOptions {
 146   type: 'merge-audio'
 147   audioPath: string
 148 }
 149
 150 interface OnlyAudioTranscodeOptions extends BaseTranscodeOptions {
 151   type: 'only-audio'
 152 }
 153
 154 type TranscodeOptions =
 155   HLSTranscodeOptions
 156   | VideoTranscodeOptions
 157   | MergeAudioTranscodeOptions
 158   | OnlyAudioTranscodeOptions
 159   | QuickTranscodeOptions
 160
 161 const builders: {
 162   [ type in TranscodeOptionsType ]: (c: ffmpeg.FfmpegCommand, o?: TranscodeOptions) => Promise<ffmpeg.FfmpegCommand> | ffmpeg.FfmpegCommand
 163 } = {
 164   'quick-transcode': buildQuickTranscodeCommand,
 165   'hls': buildHLSVODCommand,
 166   'merge-audio': buildAudioMergeCommand,
 167   'only-audio': buildOnlyAudioCommand,
 168   'video': buildx264VODCommand
 169 }
 170
 171 async function transcode (options: TranscodeOptions) {
 172   logger.debug('Will run transcode.', { options })
 173
 174   let command = getFFmpeg(options.inputPath)
 175     .output(options.outputPath)
 176
 177   command = await builders[options.type](command, options)
 178
 179   await runCommand(command)
 180
 181   await fixHLSPlaylistIfNeeded(options)
 182 }
 183
 184 // ---------------------------------------------------------------------------
 185 // Live muxing/transcoding functions
 186 // ---------------------------------------------------------------------------
 187
 188 async function getLiveTranscodingCommand (options: {
 189   rtmpUrl: string
 190   outPath: string
 191   resolutions: number[]
 192   fps: number
 193   deleteSegments: boolean
 194
 195   availableEncoders: AvailableEncoders
 196   profile: string
 197 }) {
 198   const { rtmpUrl, outPath, resolutions, fps, deleteSegments, availableEncoders, profile } = options
 199   const input = rtmpUrl
 200
 201   const command = getFFmpeg(input)
 202   command.inputOption('-fflags nobuffer')
 203
 204   const varStreamMap: string[] = []
 205
 206   command.complexFilter([
 207     {
 208       inputs: '[v:0]',
 209       filter: 'split',
 210       options: resolutions.length,
 211       outputs: resolutions.map(r => `vtemp${r}`)
 212     },
 213
 214     ...resolutions.map(r => ({
 215       inputs: `vtemp${r}`,
 216       filter: 'scale',
 217       options: `w=-2:h=${r}`,
 218       outputs: `vout${r}`
 219     }))
 220   ])
 221
 222   command.outputOption('-preset superfast')
 223
 224   for (let i = 0; i < resolutions.length; i++) {
 225     const resolution = resolutions[i]
 226     const baseEncoderBuilderParams = { input, availableEncoders, profile, fps, resolution, streamNum: i, videoType: 'live' as 'live' }
 227
 228     {
 229       const builderResult = await getEncoderBuilderResult(Object.assign({}, baseEncoderBuilderParams, { streamType: 'VIDEO' }))
 230       if (!builderResult) {
 231         throw new Error('No available live video encoder found')
 232       }
 233
 234       command.outputOption(`-map [vout${resolution}]`)
 235
 236       addDefaultEncoderParams({ command, encoder: builderResult.encoder, fps, streamNum: i })
 237
 238       logger.debug('Apply ffmpeg live video params from %s.', builderResult.encoder, builderResult)
 239
 240       command.outputOption(`${buildStreamSuffix('-c:v', i)} ${builderResult.encoder}`)
 241       command.addOutputOptions(builderResult.result.outputOptions)
 242     }
 243
 244     {
 245       const builderResult = await getEncoderBuilderResult(Object.assign({}, baseEncoderBuilderParams, { streamType: 'AUDIO' }))
 246       if (!builderResult) {
 247         throw new Error('No available live audio encoder found')
 248       }
 249
 250       command.outputOption('-map a:0')
 251
 252       addDefaultEncoderParams({ command, encoder: builderResult.encoder, fps, streamNum: i })
 253
 254       logger.debug('Apply ffmpeg live audio params from %s.', builderResult.encoder, builderResult)
 255
 256       command.outputOption(`${buildStreamSuffix('-c:a', i)} ${builderResult.encoder}`)
 257       command.addOutputOptions(builderResult.result.outputOptions)
 258     }
 259
 260     varStreamMap.push(`v:${i},a:${i}`)
 261   }
 262
 263   addDefaultLiveHLSParams(command, outPath, deleteSegments)
 264
 265   command.outputOption('-var_stream_map', varStreamMap.join(' '))
 266
 267   return command
 268 }
 269
 270 function getLiveMuxingCommand (rtmpUrl: string, outPath: string, deleteSegments: boolean) {
 271   const command = getFFmpeg(rtmpUrl)
 272   command.inputOption('-fflags nobuffer')
 273
 274   command.outputOption('-c:v copy')
 275   command.outputOption('-c:a copy')
 276   command.outputOption('-map 0:a?')
 277   command.outputOption('-map 0:v?')
 278
 279   addDefaultLiveHLSParams(command, outPath, deleteSegments)
 280
 281   return command
 282 }
 283
 284 async function hlsPlaylistToFragmentedMP4 (hlsDirectory: string, segmentFiles: string[], outputPath: string) {
 285   const concatFilePath = join(hlsDirectory, 'concat.txt')
 286
 287   function cleaner () {
 288     remove(concatFilePath)
 289       .catch(err => logger.error('Cannot remove concat file in %s.', hlsDirectory, { err }))
 290   }
 291
 292   // First concat the ts files to a mp4 file
 293   const content = segmentFiles.map(f => 'file ' + f)
 294                               .join('\n')
 295
 296   await writeFile(concatFilePath, content + '\n')
 297
 298   const command = getFFmpeg(concatFilePath)
 299   command.inputOption('-safe 0')
 300   command.inputOption('-f concat')
 301
 302   command.outputOption('-c:v copy')
 303   command.audioFilter('aresample=async=1:first_pts=0')
 304   command.output(outputPath)
 305
 306   return runCommand(command, cleaner)
 307 }
 308
 309 function buildStreamSuffix (base: string, streamNum?: number) {
 310   if (streamNum !== undefined) {
 311     return `${base}:${streamNum}`
 312   }
 313
 314   return base
 315 }
 316
 317 // ---------------------------------------------------------------------------
 318
 319 export {
 320   getLiveTranscodingCommand,
 321   getLiveMuxingCommand,
 322   buildStreamSuffix,
 323   convertWebPToJPG,
 324   processGIF,
 325   generateImageFromVideoFile,
 326   TranscodeOptions,
 327   TranscodeOptionsType,
 328   transcode,
 329   hlsPlaylistToFragmentedMP4
 330 }
 331
 332 // ---------------------------------------------------------------------------
 333
 334 // ---------------------------------------------------------------------------
 335 // Default options
 336 // ---------------------------------------------------------------------------
 337
 338 function addDefaultEncoderParams (options: {
 339   command: ffmpeg.FfmpegCommand
 340   encoder: 'libx264' | string
 341   streamNum?: number
 342   fps?: number
 343 }) {
 344   const { command, encoder, fps, streamNum } = options
 345
 346   if (encoder === 'libx264') {
 347     // 3.1 is the minimal resource allocation for our highest supported resolution
 348     command.outputOption('-level 3.1')
 349         // NOTE: b-strategy 1 - heuristic algorithm, 16 is optimal B-frames for it
 350         .outputOption('-b_strategy 1')
 351         // NOTE: Why 16: https://github.com/Chocobozzz/PeerTube/pull/774. b-strategy 2 -> B-frames<16
 352         .outputOption('-bf 16')
 353         // allows import of source material with incompatible pixel formats (e.g. MJPEG video)
 354         .outputOption(buildStreamSuffix('-pix_fmt', streamNum) + ' yuv420p')
 355         // strip all metadata
 356         .outputOption('-map_metadata -1')
 357         // avoid issues when transcoding some files: https://trac.ffmpeg.org/ticket/6375
 358         .outputOption(buildStreamSuffix('-max_muxing_queue_size', streamNum) + ' 1024')
 359
 360     if (fps) {
 361       // Keyframe interval of 2 seconds for faster seeking and resolution switching.
 362       // https://streaminglearningcenter.com/blogs/whats-the-right-keyframe-interval.html
 363       // https://superuser.com/a/908325
 364       command.outputOption('-g ' + (fps * 2))
 365     }
 366   }
 367 }
 368
 369 function addDefaultLiveHLSParams (command: ffmpeg.FfmpegCommand, outPath: string, deleteSegments: boolean) {
 370   command.outputOption('-hls_time ' + VIDEO_LIVE.SEGMENT_TIME_SECONDS)
 371   command.outputOption('-hls_list_size ' + VIDEO_LIVE.SEGMENTS_LIST_SIZE)
 372
 373   if (deleteSegments === true) {
 374     command.outputOption('-hls_flags delete_segments')
 375   }
 376
 377   command.outputOption(`-hls_segment_filename ${join(outPath, '%v-%06d.ts')}`)
 378   command.outputOption('-master_pl_name master.m3u8')
 379   command.outputOption(`-f hls`)
 380
 381   command.output(join(outPath, '%v.m3u8'))
 382 }
 383
 384 // ---------------------------------------------------------------------------
 385 // Transcode VOD command builders
 386 // ---------------------------------------------------------------------------
 387
 388 async function buildx264VODCommand (command: ffmpeg.FfmpegCommand, options: TranscodeOptions) {
 389   let fps = await getVideoFileFPS(options.inputPath)
 390   if (
 391     // On small/medium resolutions, limit FPS
 392     options.resolution !== undefined &&
 393     options.resolution < VIDEO_TRANSCODING_FPS.KEEP_ORIGIN_FPS_RESOLUTION_MIN &&
 394     fps > VIDEO_TRANSCODING_FPS.AVERAGE
 395   ) {
 396     // Get closest standard framerate by modulo: downsampling has to be done to a divisor of the nominal fps value
 397     fps = getClosestFramerateStandard(fps, 'STANDARD')
 398   }
 399
 400   command = await presetVideo(command, options.inputPath, options, fps)
 401
 402   if (options.resolution !== undefined) {
 403     // '?x720' or '720x?' for example
 404     const size = options.isPortraitMode === true
 405       ? `${options.resolution}x?`
 406       : `?x${options.resolution}`
 407
 408     command = command.size(size)
 409   }
 410
 411   // Hard FPS limits
 412   if (fps > VIDEO_TRANSCODING_FPS.MAX) fps = getClosestFramerateStandard(fps, 'HD_STANDARD')
 413   else if (fps < VIDEO_TRANSCODING_FPS.MIN) fps = VIDEO_TRANSCODING_FPS.MIN
 414
 415   command = command.withFPS(fps)
 416
 417   return command
 418 }
 419
 420 async function buildAudioMergeCommand (command: ffmpeg.FfmpegCommand, options: MergeAudioTranscodeOptions) {
 421   command = command.loop(undefined)
 422
 423   command = await presetVideo(command, options.audioPath, options)
 424
 425   /*
 426   MAIN reference: https://slhck.info/video/2017/03/01/rate-control.html
 427   Our target situation is closer to a livestream than a stream,
 428   since we want to reduce as much a possible the encoding burden,
 429   although not to the point of a livestream where there is a hard
 430   constraint on the frames per second to be encoded.
 431   */
 432   command.outputOption('-preset:v veryfast')
 433
 434   command = command.input(options.audioPath)
 435                    .videoFilter('scale=trunc(iw/2)*2:trunc(ih/2)*2') // Avoid "height not divisible by 2" error
 436                    .outputOption('-tune stillimage')
 437                    .outputOption('-shortest')
 438
 439   return command
 440 }
 441
 442 function buildOnlyAudioCommand (command: ffmpeg.FfmpegCommand, _options: OnlyAudioTranscodeOptions) {
 443   command = presetOnlyAudio(command)
 444
 445   return command
 446 }
 447
 448 function buildQuickTranscodeCommand (command: ffmpeg.FfmpegCommand) {
 449   command = presetCopy(command)
 450
 451   command = command.outputOption('-map_metadata -1') // strip all metadata
 452                    .outputOption('-movflags faststart')
 453
 454   return command
 455 }
 456
 457 async function buildHLSVODCommand (command: ffmpeg.FfmpegCommand, options: HLSTranscodeOptions) {
 458   const videoPath = getHLSVideoPath(options)
 459
 460   if (options.copyCodecs) command = presetCopy(command)
 461   else if (options.resolution === VideoResolution.H_NOVIDEO) command = presetOnlyAudio(command)
 462   else command = await buildx264VODCommand(command, options)
 463
 464   command = command.outputOption('-hls_time 4')
 465                    .outputOption('-hls_list_size 0')
 466                    .outputOption('-hls_playlist_type vod')
 467                    .outputOption('-hls_segment_filename ' + videoPath)
 468                    .outputOption('-hls_segment_type fmp4')
 469                    .outputOption('-f hls')
 470                    .outputOption('-hls_flags single_file')
 471
 472   return command
 473 }
 474
 475 async function fixHLSPlaylistIfNeeded (options: TranscodeOptions) {
 476   if (options.type !== 'hls') return
 477
 478   const fileContent = await readFile(options.outputPath)
 479
 480   const videoFileName = options.hlsPlaylist.videoFilename
 481   const videoFilePath = getHLSVideoPath(options)
 482
 483   // Fix wrong mapping with some ffmpeg versions
 484   const newContent = fileContent.toString()
 485                                 .replace(`#EXT-X-MAP:URI="${videoFilePath}",`, `#EXT-X-MAP:URI="${videoFileName}",`)
 486
 487   await writeFile(options.outputPath, newContent)
 488 }
 489
 490 function getHLSVideoPath (options: HLSTranscodeOptions) {
 491   return `${dirname(options.outputPath)}/${options.hlsPlaylist.videoFilename}`
 492 }
 493
 494 // ---------------------------------------------------------------------------
 495 // Transcoding presets
 496 // ---------------------------------------------------------------------------
 497
 498 async function getEncoderBuilderResult (options: {
 499   streamType: string
 500   input: string
 501
 502   availableEncoders: AvailableEncoders
 503   profile: string
 504
 505   videoType: 'vod' | 'live'
 506
 507   resolution: number
 508   fps?: number
 509   streamNum?: number
 510 }) {
 511   const { availableEncoders, input, profile, resolution, streamType, fps, streamNum, videoType } = options
 512
 513   const encodersToTry: string[] = VIDEO_TRANSCODING_ENCODERS[streamType]
 514
 515   for (const encoder of encodersToTry) {
 516     if (!(await checkFFmpegEncoders()).get(encoder) || !availableEncoders[videoType][encoder]) continue
 517
 518     const builderProfiles: EncoderProfile<EncoderOptionsBuilder> = availableEncoders[videoType][encoder]
 519     let builder = builderProfiles[profile]
 520
 521     if (!builder) {
 522       logger.debug('Profile %s for encoder %s not available. Fallback to default.', profile, encoder)
 523       builder = builderProfiles.default
 524     }
 525
 526     const result = await builder({ input, resolution: resolution, fps, streamNum })
 527
 528     return {
 529       result,
 530
 531       // If we don't have output options, then copy the input stream
 532       encoder: result.copy === true
 533         ? 'copy'
 534         : encoder
 535     }
 536   }
 537
 538   return null
 539 }
 540
 541 async function presetVideo (
 542   command: ffmpeg.FfmpegCommand,
 543   input: string,
 544   transcodeOptions: TranscodeOptions,
 545   fps?: number
 546 ) {
 547   let localCommand = command
 548     .format('mp4')
 549     .outputOption('-movflags faststart')
 550
 551   // Audio encoder
 552   const parsedAudio = await getAudioStream(input)
 553
 554   let streamsToProcess = [ 'AUDIO', 'VIDEO' ]
 555
 556   if (!parsedAudio.audioStream) {
 557     localCommand = localCommand.noAudio()
 558     streamsToProcess = [ 'VIDEO' ]
 559   }
 560
 561   for (const streamType of streamsToProcess) {
 562     const { profile, resolution, availableEncoders } = transcodeOptions
 563
 564     const builderResult = await getEncoderBuilderResult({
 565       streamType,
 566       input,
 567       resolution,
 568       availableEncoders,
 569       profile,
 570       fps,
 571       videoType: 'vod' as 'vod'
 572     })
 573
 574     if (!builderResult) {
 575       throw new Error('No available encoder found for stream ' + streamType)
 576     }
 577
 578     logger.debug('Apply ffmpeg params from %s.', builderResult.encoder, builderResult)
 579
 580     if (streamType === 'VIDEO') {
 581       localCommand.videoCodec(builderResult.encoder)
 582     } else if (streamType === 'AUDIO') {
 583       localCommand.audioCodec(builderResult.encoder)
 584     }
 585
 586     command.addOutputOptions(builderResult.result.outputOptions)
 587     addDefaultEncoderParams({ command: localCommand, encoder: builderResult.encoder, fps })
 588   }
 589
 590   return localCommand
 591 }
 592
 593 function presetCopy (command: ffmpeg.FfmpegCommand): ffmpeg.FfmpegCommand {
 594   return command
 595     .format('mp4')
 596     .videoCodec('copy')
 597     .audioCodec('copy')
 598 }
 599
 600 function presetOnlyAudio (command: ffmpeg.FfmpegCommand): ffmpeg.FfmpegCommand {
 601   return command
 602     .format('mp4')
 603     .audioCodec('copy')
 604     .noVideo()
 605 }
 606
 607 // ---------------------------------------------------------------------------
 608 // Utils
 609 // ---------------------------------------------------------------------------
 610
 611 function getFFmpeg (input: string) {
 612   // We set cwd explicitly because ffmpeg appears to create temporary files when trancoding which fails in read-only file systems
 613   const command = ffmpeg(input, { niceness: FFMPEG_NICE.TRANSCODING, cwd: CONFIG.STORAGE.TMP_DIR })
 614
 615   if (CONFIG.TRANSCODING.THREADS > 0) {
 616     // If we don't set any threads ffmpeg will chose automatically
 617     command.outputOption('-threads ' + CONFIG.TRANSCODING.THREADS)
 618   }
 619
 620   return command
 621 }
 622
 623 async function runCommand (command: ffmpeg.FfmpegCommand, onEnd?: Function) {
 624   return new Promise<void>((res, rej) => {
 625     command.on('error', (err, stdout, stderr) => {
 626       if (onEnd) onEnd()
 627
 628       logger.error('Error in transcoding job.', { stdout, stderr })
 629       rej(err)
 630     })
 631
 632     command.on('end', () => {
 633       if (onEnd) onEnd()
 634
 635       res()
 636     })
 637
 638     command.run()
 639   })
 640 }