server/helpers/ffmpeg-utils.ts

   1 import * as ffmpeg from 'fluent-ffmpeg'
   2 import { join } from 'path'
   3 import { VideoResolution } from '../../shared/models/videos'
   4 import { CONFIG, VIDEO_TRANSCODING_FPS } from '../initializers'
   5 import { unlinkPromise } from './core-utils'
   6 import { processImage } from './image-utils'
   7 import { logger } from './logger'
   8
   9 async function getVideoFileResolution (path: string) {
  10   const videoStream = await getVideoFileStream(path)
  11
  12   return {
  13     videoFileResolution: Math.min(videoStream.height, videoStream.width),
  14     isPortraitMode: videoStream.height > videoStream.width
  15   }
  16 }
  17
  18 async function getVideoFileFPS (path: string) {
  19   const videoStream = await getVideoFileStream(path)
  20
  21   for (const key of [ 'r_frame_rate' , 'avg_frame_rate' ]) {
  22     const valuesText: string = videoStream[key]
  23     if (!valuesText) continue
  24
  25     const [ frames, seconds ] = valuesText.split('/')
  26     if (!frames || !seconds) continue
  27
  28     const result = parseInt(frames, 10) / parseInt(seconds, 10)
  29     if (result > 0) return Math.round(result)
  30   }
  31
  32   return 0
  33 }
  34
  35 function getDurationFromVideoFile (path: string) {
  36   return new Promise<number>((res, rej) => {
  37     ffmpeg.ffprobe(path, (err, metadata) => {
  38       if (err) return rej(err)
  39
  40       return res(Math.floor(metadata.format.duration))
  41     })
  42   })
  43 }
  44
  45 async function generateImageFromVideoFile (fromPath: string, folder: string, imageName: string, size: { width: number, height: number }) {
  46   const pendingImageName = 'pending-' + imageName
  47
  48   const options = {
  49     filename: pendingImageName,
  50     count: 1,
  51     folder
  52   }
  53
  54   const pendingImagePath = join(folder, pendingImageName)
  55
  56   try {
  57     await new Promise<string>((res, rej) => {
  58       ffmpeg(fromPath)
  59         .on('error', rej)
  60         .on('end', () => res(imageName))
  61         .thumbnail(options)
  62     })
  63
  64     const destination = join(folder, imageName)
  65     await processImage({ path: pendingImagePath }, destination, size)
  66   } catch (err) {
  67     logger.error('Cannot generate image from video %s.', fromPath, { err })
  68
  69     try {
  70       await unlinkPromise(pendingImagePath)
  71     } catch (err) {
  72       logger.debug('Cannot remove pending image path after generation error.', { err })
  73     }
  74   }
  75 }
  76
  77 type TranscodeOptions = {
  78   inputPath: string
  79   outputPath: string
  80   resolution?: VideoResolution
  81   isPortraitMode?: boolean
  82 }
  83
  84 function transcode (options: TranscodeOptions) {
  85   return new Promise<void>(async (res, rej) => {
  86     let command = ffmpeg(options.inputPath)
  87                     .output(options.outputPath)
  88                     .videoCodec('libx264')
  89                     .outputOption('-threads ' + CONFIG.TRANSCODING.THREADS)
  90                     .outputOption('-movflags faststart')
  91                     // .outputOption('-crf 18')
  92
  93     let fps = await getVideoFileFPS(options.inputPath)
  94     if (options.resolution !== undefined) {
  95       // '?x720' or '720x?' for example
  96       const size = options.isPortraitMode === true ? `${options.resolution}x?` : `?x${options.resolution}`
  97       command = command.size(size)
  98
  99       // On small/medium resolutions, limit FPS
 100       if (
 101         options.resolution < VIDEO_TRANSCODING_FPS.KEEP_ORIGIN_FPS_RESOLUTION_MIN &&
 102         fps > VIDEO_TRANSCODING_FPS.AVERAGE
 103       ) {
 104         fps = VIDEO_TRANSCODING_FPS.AVERAGE
 105       }
 106     }
 107
 108     if (fps) {
 109       // Hard FPS limits
 110       if (fps > VIDEO_TRANSCODING_FPS.MAX) fps = VIDEO_TRANSCODING_FPS.MAX
 111       else if (fps < VIDEO_TRANSCODING_FPS.MIN) fps = VIDEO_TRANSCODING_FPS.MIN
 112
 113       command = command.withFPS(fps)
 114     }
 115
 116     command
 117       .on('error', (err, stdout, stderr) => {
 118         logger.error('Error in transcoding job.', { stdout, stderr })
 119         return rej(err)
 120       })
 121       .on('end', res)
 122       .run()
 123   })
 124 }
 125
 126 // ---------------------------------------------------------------------------
 127
 128 export {
 129   getVideoFileResolution,
 130   getDurationFromVideoFile,
 131   generateImageFromVideoFile,
 132   transcode,
 133   getVideoFileFPS
 134 }
 135
 136 // ---------------------------------------------------------------------------
 137
 138 function getVideoFileStream (path: string) {
 139   return new Promise<any>((res, rej) => {
 140     ffmpeg.ffprobe(path, (err, metadata) => {
 141       if (err) return rej(err)
 142
 143       const videoStream = metadata.streams.find(s => s.codec_type === 'video')
 144       if (!videoStream) throw new Error('Cannot find video stream of ' + path)
 145
 146       return res(videoStream)
 147     })
 148   })
 149 }