server/helpers/ffmpeg/ffmpeg-vod.ts

   1 import { Job } from 'bullmq'
   2 import { FfmpegCommand } from 'fluent-ffmpeg'
   3 import { readFile, writeFile } from 'fs-extra'
   4 import { dirname } from 'path'
   5 import { pick } from '@shared/core-utils'
   6 import { AvailableEncoders, VideoResolution } from '@shared/models'
   7 import { logger, loggerTagsFactory } from '../logger'
   8 import { getFFmpeg, runCommand } from './ffmpeg-commons'
   9 import { presetCopy, presetOnlyAudio, presetVOD } from './ffmpeg-presets'
  10 import { computeFPS, ffprobePromise, getVideoStreamDimensionsInfo, getVideoStreamFPS } from './ffprobe-utils'
  11 import { VIDEO_TRANSCODING_FPS } from '@server/initializers/constants'
  12
  13 const lTags = loggerTagsFactory('ffmpeg')
  14
  15 // ---------------------------------------------------------------------------
  16
  17 type TranscodeVODOptionsType = 'hls' | 'hls-from-ts' | 'quick-transcode' | 'video' | 'merge-audio' | 'only-audio'
  18
  19 interface BaseTranscodeVODOptions {
  20   type: TranscodeVODOptionsType
  21
  22   inputPath: string
  23   outputPath: string
  24
  25   availableEncoders: AvailableEncoders
  26   profile: string
  27
  28   resolution: number
  29
  30   job?: Job
  31 }
  32
  33 interface HLSTranscodeOptions extends BaseTranscodeVODOptions {
  34   type: 'hls'
  35   copyCodecs: boolean
  36   hlsPlaylist: {
  37     videoFilename: string
  38   }
  39 }
  40
  41 interface HLSFromTSTranscodeOptions extends BaseTranscodeVODOptions {
  42   type: 'hls-from-ts'
  43
  44   isAAC: boolean
  45
  46   hlsPlaylist: {
  47     videoFilename: string
  48   }
  49 }
  50
  51 interface QuickTranscodeOptions extends BaseTranscodeVODOptions {
  52   type: 'quick-transcode'
  53 }
  54
  55 interface VideoTranscodeOptions extends BaseTranscodeVODOptions {
  56   type: 'video'
  57 }
  58
  59 interface MergeAudioTranscodeOptions extends BaseTranscodeVODOptions {
  60   type: 'merge-audio'
  61   audioPath: string
  62 }
  63
  64 interface OnlyAudioTranscodeOptions extends BaseTranscodeVODOptions {
  65   type: 'only-audio'
  66 }
  67
  68 type TranscodeVODOptions =
  69   HLSTranscodeOptions
  70   | HLSFromTSTranscodeOptions
  71   | VideoTranscodeOptions
  72   | MergeAudioTranscodeOptions
  73   | OnlyAudioTranscodeOptions
  74   | QuickTranscodeOptions
  75
  76 // ---------------------------------------------------------------------------
  77
  78 const builders: {
  79   [ type in TranscodeVODOptionsType ]: (c: FfmpegCommand, o?: TranscodeVODOptions) => Promise<FfmpegCommand> | FfmpegCommand
  80 } = {
  81   'quick-transcode': buildQuickTranscodeCommand,
  82   'hls': buildHLSVODCommand,
  83   'hls-from-ts': buildHLSVODFromTSCommand,
  84   'merge-audio': buildAudioMergeCommand,
  85   'only-audio': buildOnlyAudioCommand,
  86   'video': buildVODCommand
  87 }
  88
  89 async function transcodeVOD (options: TranscodeVODOptions) {
  90   logger.debug('Will run transcode.', { options, ...lTags() })
  91
  92   let command = getFFmpeg(options.inputPath, 'vod')
  93     .output(options.outputPath)
  94
  95   command = await builders[options.type](command, options)
  96
  97   await runCommand({ command, job: options.job })
  98
  99   await fixHLSPlaylistIfNeeded(options)
 100 }
 101
 102 // ---------------------------------------------------------------------------
 103
 104 export {
 105   transcodeVOD,
 106
 107   buildVODCommand,
 108
 109   TranscodeVODOptions,
 110   TranscodeVODOptionsType
 111 }
 112
 113 // ---------------------------------------------------------------------------
 114
 115 async function buildVODCommand (command: FfmpegCommand, options: TranscodeVODOptions) {
 116   const probe = await ffprobePromise(options.inputPath)
 117
 118   let fps = await getVideoStreamFPS(options.inputPath, probe)
 119   fps = computeFPS(fps, options.resolution)
 120
 121   let scaleFilterValue: string
 122
 123   if (options.resolution !== undefined) {
 124     const videoStreamInfo = await getVideoStreamDimensionsInfo(options.inputPath, probe)
 125
 126     scaleFilterValue = videoStreamInfo?.isPortraitMode === true
 127       ? `w=${options.resolution}:h=-2`
 128       : `w=-2:h=${options.resolution}`
 129   }
 130
 131   command = await presetVOD({
 132     ...pick(options, [ 'resolution', 'availableEncoders', 'profile' ]),
 133
 134     command,
 135     input: options.inputPath,
 136     canCopyAudio: true,
 137     canCopyVideo: true,
 138     fps,
 139     scaleFilterValue
 140   })
 141
 142   return command
 143 }
 144
 145 function buildQuickTranscodeCommand (command: FfmpegCommand) {
 146   command = presetCopy(command)
 147
 148   command = command.outputOption('-map_metadata -1') // strip all metadata
 149                    .outputOption('-movflags faststart')
 150
 151   return command
 152 }
 153
 154 // ---------------------------------------------------------------------------
 155 // Audio transcoding
 156 // ---------------------------------------------------------------------------
 157
 158 async function buildAudioMergeCommand (command: FfmpegCommand, options: MergeAudioTranscodeOptions) {
 159   command = command.loop(undefined)
 160
 161   const scaleFilterValue = getMergeAudioScaleFilterValue()
 162   command = await presetVOD({
 163     ...pick(options, [ 'resolution', 'availableEncoders', 'profile' ]),
 164
 165     command,
 166     input: options.audioPath,
 167     canCopyAudio: true,
 168     canCopyVideo: true,
 169     fps: VIDEO_TRANSCODING_FPS.AUDIO_MERGE,
 170     scaleFilterValue
 171   })
 172
 173   command.outputOption('-preset:v veryfast')
 174
 175   command = command.input(options.audioPath)
 176                    .outputOption('-tune stillimage')
 177                    .outputOption('-shortest')
 178
 179   return command
 180 }
 181
 182 function buildOnlyAudioCommand (command: FfmpegCommand, _options: OnlyAudioTranscodeOptions) {
 183   command = presetOnlyAudio(command)
 184
 185   return command
 186 }
 187
 188 // ---------------------------------------------------------------------------
 189 // HLS transcoding
 190 // ---------------------------------------------------------------------------
 191
 192 async function buildHLSVODCommand (command: FfmpegCommand, options: HLSTranscodeOptions) {
 193   const videoPath = getHLSVideoPath(options)
 194
 195   if (options.copyCodecs) command = presetCopy(command)
 196   else if (options.resolution === VideoResolution.H_NOVIDEO) command = presetOnlyAudio(command)
 197   else command = await buildVODCommand(command, options)
 198
 199   addCommonHLSVODCommandOptions(command, videoPath)
 200
 201   return command
 202 }
 203
 204 function buildHLSVODFromTSCommand (command: FfmpegCommand, options: HLSFromTSTranscodeOptions) {
 205   const videoPath = getHLSVideoPath(options)
 206
 207   command.outputOption('-c copy')
 208
 209   if (options.isAAC) {
 210     // Required for example when copying an AAC stream from an MPEG-TS
 211     // Since it's a bitstream filter, we don't need to reencode the audio
 212     command.outputOption('-bsf:a aac_adtstoasc')
 213   }
 214
 215   addCommonHLSVODCommandOptions(command, videoPath)
 216
 217   return command
 218 }
 219
 220 function addCommonHLSVODCommandOptions (command: FfmpegCommand, outputPath: string) {
 221   return command.outputOption('-hls_time 4')
 222                 .outputOption('-hls_list_size 0')
 223                 .outputOption('-hls_playlist_type vod')
 224                 .outputOption('-hls_segment_filename ' + outputPath)
 225                 .outputOption('-hls_segment_type fmp4')
 226                 .outputOption('-f hls')
 227                 .outputOption('-hls_flags single_file')
 228 }
 229
 230 async function fixHLSPlaylistIfNeeded (options: TranscodeVODOptions) {
 231   if (options.type !== 'hls' && options.type !== 'hls-from-ts') return
 232
 233   const fileContent = await readFile(options.outputPath)
 234
 235   const videoFileName = options.hlsPlaylist.videoFilename
 236   const videoFilePath = getHLSVideoPath(options)
 237
 238   // Fix wrong mapping with some ffmpeg versions
 239   const newContent = fileContent.toString()
 240                                 .replace(`#EXT-X-MAP:URI="${videoFilePath}",`, `#EXT-X-MAP:URI="${videoFileName}",`)
 241
 242   await writeFile(options.outputPath, newContent)
 243 }
 244
 245 // ---------------------------------------------------------------------------
 246 // Helpers
 247 // ---------------------------------------------------------------------------
 248
 249 function getHLSVideoPath (options: HLSTranscodeOptions | HLSFromTSTranscodeOptions) {
 250   return `${dirname(options.outputPath)}/${options.hlsPlaylist.videoFilename}`
 251 }
 252
 253 // Avoid "height not divisible by 2" error
 254 function getMergeAudioScaleFilterValue () {
 255   return 'trunc(iw/2)*2:trunc(ih/2)*2'
 256 }