PeerTube/server/lib/transcoding/transcoding.ts

import { MutexInterface } from 'async-mutex'
import { Job } from 'bullmq'
import { copyFile, ensureDir, move, remove, stat } from 'fs-extra'
import { basename, extname as extnameUtil, join } from 'path'
import { toEven } from '@server/helpers/core-utils'
import { retryTransactionWrapper } from '@server/helpers/database-utils'
import { createTorrentAndSetInfoHash } from '@server/helpers/webtorrent'
import { sequelizeTypescript } from '@server/initializers/database'
import { MVideo, MVideoFile, MVideoFullLight } from '@server/types/models'
import { pick } from '@shared/core-utils'
import { VideoResolution, VideoStorage } from '../../../shared/models/videos'
import {
  buildFileMetadata,
  canDoQuickTranscode,
  computeResolutionsToTranscode,
  ffprobePromise,
  getVideoStreamDuration,
  getVideoStreamFPS,
  transcodeVOD,
  TranscodeVODOptions,
  TranscodeVODOptionsType
} from '../../helpers/ffmpeg'
import { CONFIG } from '../../initializers/config'
import { VideoFileModel } from '../../models/video/video-file'
import { VideoStreamingPlaylistModel } from '../../models/video/video-streaming-playlist'
import { updatePlaylistAfterFileChange } from '../hls'
import { generateHLSVideoFilename, generateWebTorrentVideoFilename, getHlsResolutionPlaylistFilename } from '../paths'
import { VideoPathManager } from '../video-path-manager'
import { VideoTranscodingProfilesManager } from './default-transcoding-profiles'

/**
 *
 * Functions that run transcoding functions, update the database, cleanup files, create torrent files...
 * Mainly called by the job queue
 *
 */

// Optimize the original video file and replace it. The resolution is not changed.
async function optimizeOriginalVideofile (options: {
  video: MVideoFullLight
  inputVideoFile: MVideoFile
  job: Job
}) {
  const { video, inputVideoFile, job } = options

  const transcodeDirectory = CONFIG.STORAGE.TMP_DIR
  const newExtname = '.mp4'

  // Will be released by our transcodeVOD function once ffmpeg is ran
  const inputFileMutexReleaser = await VideoPathManager.Instance.lockFiles(video.uuid)

  try {
    await video.reload()

    const fileWithVideoOrPlaylist = inputVideoFile.withVideoOrPlaylist(video)

    const result = await VideoPathManager.Instance.makeAvailableVideoFile(fileWithVideoOrPlaylist, async videoInputPath => {
      const videoTranscodedPath = join(transcodeDirectory, video.id + '-transcoded' + newExtname)

      const transcodeType: TranscodeVODOptionsType = await canDoQuickTranscode(videoInputPath)
        ? 'quick-transcode'
        : 'video'

      const resolution = buildOriginalFileResolution(inputVideoFile.resolution)

      const transcodeOptions: TranscodeVODOptions = {
        type: transcodeType,

        inputPath: videoInputPath,
        outputPath: videoTranscodedPath,

        inputFileMutexReleaser,

        availableEncoders: VideoTranscodingProfilesManager.Instance.getAvailableEncoders(),
        profile: CONFIG.TRANSCODING.PROFILE,

        resolution,

        job
      }

      // Could be very long!
      await transcodeVOD(transcodeOptions)

      // Important to do this before getVideoFilename() to take in account the new filename
      inputVideoFile.resolution = resolution
      inputVideoFile.extname = newExtname
      inputVideoFile.filename = generateWebTorrentVideoFilename(resolution, newExtname)
      inputVideoFile.storage = VideoStorage.FILE_SYSTEM

      const { videoFile } = await onWebTorrentVideoFileTranscoding(video, inputVideoFile, videoTranscodedPath, inputVideoFile)
      await remove(videoInputPath)

      return { transcodeType, videoFile }
    })

    return result
  } finally {
    inputFileMutexReleaser()
  }
}

// Transcode the original video file to a lower resolution compatible with WebTorrent
async function transcodeNewWebTorrentResolution (options: {
  video: MVideoFullLight
  resolution: VideoResolution
  job: Job
}) {
  const { video, resolution, job } = options

  const transcodeDirectory = CONFIG.STORAGE.TMP_DIR
  const newExtname = '.mp4'

  const inputFileMutexReleaser = await VideoPathManager.Instance.lockFiles(video.uuid)

  try {
    await video.reload()

    const file = video.getMaxQualityFile().withVideoOrPlaylist(video)

    const result = await VideoPathManager.Instance.makeAvailableVideoFile(file, async videoInputPath => {
      const newVideoFile = new VideoFileModel({
        resolution,
        extname: newExtname,
        filename: generateWebTorrentVideoFilename(resolution, newExtname),
        size: 0,
        videoId: video.id
      })

      const videoTranscodedPath = join(transcodeDirectory, newVideoFile.filename)

      const transcodeOptions = resolution === VideoResolution.H_NOVIDEO
        ? {
          type: 'only-audio' as 'only-audio',

          inputPath: videoInputPath,
          outputPath: videoTranscodedPath,

          inputFileMutexReleaser,

          availableEncoders: VideoTranscodingProfilesManager.Instance.getAvailableEncoders(),
          profile: CONFIG.TRANSCODING.PROFILE,

          resolution,

          job
        }
        : {
          type: 'video' as 'video',
          inputPath: videoInputPath,
          outputPath: videoTranscodedPath,

          inputFileMutexReleaser,

          availableEncoders: VideoTranscodingProfilesManager.Instance.getAvailableEncoders(),
          profile: CONFIG.TRANSCODING.PROFILE,

          resolution,

          job
        }

      await transcodeVOD(transcodeOptions)

      return onWebTorrentVideoFileTranscoding(video, newVideoFile, videoTranscodedPath, newVideoFile)
    })

    return result
  } finally {
    inputFileMutexReleaser()
  }
}

// Merge an image with an audio file to create a video
async function mergeAudioVideofile (options: {
  video: MVideoFullLight
  resolution: VideoResolution
  job: Job
}) {
  const { video, resolution, job } = options

  const transcodeDirectory = CONFIG.STORAGE.TMP_DIR
  const newExtname = '.mp4'

  const inputFileMutexReleaser = await VideoPathManager.Instance.lockFiles(video.uuid)

  try {
    await video.reload()

    const inputVideoFile = video.getMinQualityFile()

    const fileWithVideoOrPlaylist = inputVideoFile.withVideoOrPlaylist(video)

    const result = await VideoPathManager.Instance.makeAvailableVideoFile(fileWithVideoOrPlaylist, async audioInputPath => {
      const videoTranscodedPath = join(transcodeDirectory, video.id + '-transcoded' + newExtname)

      // If the user updates the video preview during transcoding
      const previewPath = video.getPreview().getPath()
      const tmpPreviewPath = join(CONFIG.STORAGE.TMP_DIR, basename(previewPath))
      await copyFile(previewPath, tmpPreviewPath)

      const transcodeOptions = {
        type: 'merge-audio' as 'merge-audio',

        inputPath: tmpPreviewPath,
        outputPath: videoTranscodedPath,

        inputFileMutexReleaser,

        availableEncoders: VideoTranscodingProfilesManager.Instance.getAvailableEncoders(),
        profile: CONFIG.TRANSCODING.PROFILE,

        audioPath: audioInputPath,
        resolution,

        job
      }

      try {
        await transcodeVOD(transcodeOptions)

        await remove(audioInputPath)
        await remove(tmpPreviewPath)
      } catch (err) {
        await remove(tmpPreviewPath)
        throw err
      }

      // Important to do this before getVideoFilename() to take in account the new file extension
      inputVideoFile.extname = newExtname
      inputVideoFile.resolution = resolution
      inputVideoFile.filename = generateWebTorrentVideoFilename(inputVideoFile.resolution, newExtname)

      // ffmpeg generated a new video file, so update the video duration
      // See https://trac.ffmpeg.org/ticket/5456
      video.duration = await getVideoStreamDuration(videoTranscodedPath)
      await video.save()

      return onWebTorrentVideoFileTranscoding(video, inputVideoFile, videoTranscodedPath, inputVideoFile)
    })

    return result
  } finally {
    inputFileMutexReleaser()
  }
}

// Concat TS segments from a live video to a fragmented mp4 HLS playlist
async function generateHlsPlaylistResolutionFromTS (options: {
  video: MVideo
  concatenatedTsFilePath: string
  resolution: VideoResolution
  isAAC: boolean
  inputFileMutexReleaser: MutexInterface.Releaser
}) {
  return generateHlsPlaylistCommon({
    type: 'hls-from-ts' as 'hls-from-ts',
    inputPath: options.concatenatedTsFilePath,

    ...pick(options, [ 'video', 'resolution', 'inputFileMutexReleaser', 'isAAC' ])
  })
}

// Generate an HLS playlist from an input file, and update the master playlist
function generateHlsPlaylistResolution (options: {
  video: MVideo
  videoInputPath: string
  resolution: VideoResolution
  copyCodecs: boolean
  inputFileMutexReleaser: MutexInterface.Releaser
  job?: Job
}) {
  return generateHlsPlaylistCommon({
    type: 'hls' as 'hls',
    inputPath: options.videoInputPath,

    ...pick(options, [ 'video', 'resolution', 'copyCodecs', 'inputFileMutexReleaser', 'job' ])
  })
}

// ---------------------------------------------------------------------------

export {
  generateHlsPlaylistResolution,
  generateHlsPlaylistResolutionFromTS,
  optimizeOriginalVideofile,
  transcodeNewWebTorrentResolution,
  mergeAudioVideofile
}

// ---------------------------------------------------------------------------

async function onWebTorrentVideoFileTranscoding (
  video: MVideoFullLight,
  videoFile: MVideoFile,
  transcodingPath: string,
  newVideoFile: MVideoFile
) {
  const mutexReleaser = await VideoPathManager.Instance.lockFiles(video.uuid)

  try {
    await video.reload()

    const outputPath = VideoPathManager.Instance.getFSVideoFileOutputPath(video, newVideoFile)

    const stats = await stat(transcodingPath)

    const probe = await ffprobePromise(transcodingPath)
    const fps = await getVideoStreamFPS(transcodingPath, probe)
    const metadata = await buildFileMetadata(transcodingPath, probe)

    await move(transcodingPath, outputPath, { overwrite: true })

    videoFile.size = stats.size
    videoFile.fps = fps
    videoFile.metadata = metadata

    await createTorrentAndSetInfoHash(video, videoFile)

    const oldFile = await VideoFileModel.loadWebTorrentFile({ videoId: video.id, fps: videoFile.fps, resolution: videoFile.resolution })
    if (oldFile) await video.removeWebTorrentFile(oldFile)

    await VideoFileModel.customUpsert(videoFile, 'video', undefined)
    video.VideoFiles = await video.$get('VideoFiles')

    return { video, videoFile }
  } finally {
    mutexReleaser()
  }
}

async function generateHlsPlaylistCommon (options: {
  type: 'hls' | 'hls-from-ts'
  video: MVideo
  inputPath: string
  resolution: VideoResolution

  inputFileMutexReleaser: MutexInterface.Releaser

  copyCodecs?: boolean
  isAAC?: boolean

  job?: Job
}) {
  const { type, video, inputPath, resolution, copyCodecs, isAAC, job, inputFileMutexReleaser } = options
  const transcodeDirectory = CONFIG.STORAGE.TMP_DIR

  const videoTranscodedBasePath = join(transcodeDirectory, type)
  await ensureDir(videoTranscodedBasePath)

  const videoFilename = generateHLSVideoFilename(resolution)
  const resolutionPlaylistFilename = getHlsResolutionPlaylistFilename(videoFilename)
  const resolutionPlaylistFileTranscodePath = join(videoTranscodedBasePath, resolutionPlaylistFilename)

  const transcodeOptions = {
    type,

    inputPath,
    outputPath: resolutionPlaylistFileTranscodePath,

    availableEncoders: VideoTranscodingProfilesManager.Instance.getAvailableEncoders(),
    profile: CONFIG.TRANSCODING.PROFILE,

    resolution,
    copyCodecs,

    isAAC,

    inputFileMutexReleaser,

    hlsPlaylist: {
      videoFilename
    },

    job
  }

  await transcodeVOD(transcodeOptions)

  // Create or update the playlist
  const playlist = await retryTransactionWrapper(() => {
    return sequelizeTypescript.transaction(async transaction => {
      return VideoStreamingPlaylistModel.loadOrGenerate(video, transaction)
    })
  })

  const newVideoFile = new VideoFileModel({
    resolution,
    extname: extnameUtil(videoFilename),
    size: 0,
    filename: videoFilename,
    fps: -1,
    videoStreamingPlaylistId: playlist.id
  })

  const mutexReleaser = await VideoPathManager.Instance.lockFiles(video.uuid)

  try {
    // VOD transcoding is a long task, refresh video attributes
    await video.reload()

    const videoFilePath = VideoPathManager.Instance.getFSVideoFileOutputPath(playlist, newVideoFile)
    await ensureDir(VideoPathManager.Instance.getFSHLSOutputPath(video))

    // Move playlist file
    const resolutionPlaylistPath = VideoPathManager.Instance.getFSHLSOutputPath(video, resolutionPlaylistFilename)
    await move(resolutionPlaylistFileTranscodePath, resolutionPlaylistPath, { overwrite: true })
    // Move video file
    await move(join(videoTranscodedBasePath, videoFilename), videoFilePath, { overwrite: true })

    // Update video duration if it was not set (in case of a live for example)
    if (!video.duration) {
      video.duration = await getVideoStreamDuration(videoFilePath)
      await video.save()
    }

    const stats = await stat(videoFilePath)

    newVideoFile.size = stats.size
    newVideoFile.fps = await getVideoStreamFPS(videoFilePath)
    newVideoFile.metadata = await buildFileMetadata(videoFilePath)

    await createTorrentAndSetInfoHash(playlist, newVideoFile)

    const oldFile = await VideoFileModel.loadHLSFile({
      playlistId: playlist.id,
      fps: newVideoFile.fps,
      resolution: newVideoFile.resolution
    })

    if (oldFile) {
      await video.removeStreamingPlaylistVideoFile(playlist, oldFile)
      await oldFile.destroy()
    }

    const savedVideoFile = await VideoFileModel.customUpsert(newVideoFile, 'streaming-playlist', undefined)

    await updatePlaylistAfterFileChange(video, playlist)

    return { resolutionPlaylistPath, videoFile: savedVideoFile }
  } finally {
    mutexReleaser()
  }
}

function buildOriginalFileResolution (inputResolution: number) {
  if (CONFIG.TRANSCODING.ALWAYS_TRANSCODE_ORIGINAL_RESOLUTION === true) return toEven(inputResolution)

  const resolutions = computeResolutionsToTranscode({
    input: inputResolution,
    type: 'vod',
    includeInput: false,
    strictLower: false,
    // We don't really care about the audio resolution in this context
    hasAudio: true
  })

  if (resolutions.length === 0) return toEven(inputResolution)

  return Math.max(...resolutions)
}