server/helpers/ffmpeg-utils.ts

   1 import * as ffmpeg from 'fluent-ffmpeg'
   2 import { VideoResolution } from '../../shared/models/videos'
   3 import { CONFIG, MAX_VIDEO_TRANSCODING_FPS } from '../initializers'
   4 import { processImage } from './image-utils'
   5 import { join } from 'path'
   6
   7 async function getVideoFileHeight (path: string) {
   8   const videoStream = await getVideoFileStream(path)
   9   return videoStream.height
  10 }
  11
  12 async function getVideoFileFPS (path: string) {
  13   const videoStream = await getVideoFileStream(path)
  14
  15   for (const key of [ 'r_frame_rate' , 'avg_frame_rate' ]) {
  16     const valuesText: string = videoStream[key]
  17     if (!valuesText) continue
  18
  19     const [ frames, seconds ] = valuesText.split('/')
  20     if (!frames || !seconds) continue
  21
  22     const result = parseInt(frames, 10) / parseInt(seconds, 10)
  23     if (result > 0) return result
  24   }
  25
  26   return 0
  27 }
  28
  29 function getDurationFromVideoFile (path: string) {
  30   return new Promise<number>((res, rej) => {
  31     ffmpeg.ffprobe(path, (err, metadata) => {
  32       if (err) return rej(err)
  33
  34       return res(Math.floor(metadata.format.duration))
  35     })
  36   })
  37 }
  38
  39 async function generateImageFromVideoFile (fromPath: string, folder: string, imageName: string, size: { width: number, height: number }) {
  40   const pendingImageName = 'pending-' + imageName
  41
  42   const options = {
  43     filename: pendingImageName,
  44     count: 1,
  45     folder
  46   }
  47
  48   await new Promise<string>((res, rej) => {
  49     ffmpeg(fromPath)
  50       .on('error', rej)
  51       .on('end', () => res(imageName))
  52       .thumbnail(options)
  53   })
  54
  55   const pendingImagePath = join(folder, pendingImageName)
  56   const destination = join(folder, imageName)
  57   await processImage({ path: pendingImagePath }, destination, size)
  58 }
  59
  60 type TranscodeOptions = {
  61   inputPath: string
  62   outputPath: string
  63   resolution?: VideoResolution
  64 }
  65
  66 function transcode (options: TranscodeOptions) {
  67   return new Promise<void>(async (res, rej) => {
  68     const fps = await getVideoFileFPS(options.inputPath)
  69
  70     let command = ffmpeg(options.inputPath)
  71                     .output(options.outputPath)
  72                     .videoCodec('libx264')
  73                     .outputOption('-threads ' + CONFIG.TRANSCODING.THREADS)
  74                     .outputOption('-movflags faststart')
  75                     // .outputOption('-crf 18')
  76
  77     if (fps > MAX_VIDEO_TRANSCODING_FPS) command = command.withFPS(MAX_VIDEO_TRANSCODING_FPS)
  78
  79     if (options.resolution !== undefined) {
  80       const size = `?x${options.resolution}` // '?x720' for example
  81       command = command.size(size)
  82     }
  83
  84     command.on('error', rej)
  85            .on('end', res)
  86            .run()
  87   })
  88 }
  89
  90 // ---------------------------------------------------------------------------
  91
  92 export {
  93   getVideoFileHeight,
  94   getDurationFromVideoFile,
  95   generateImageFromVideoFile,
  96   transcode,
  97   getVideoFileFPS
  98 }
  99
 100 // ---------------------------------------------------------------------------
 101
 102 function getVideoFileStream (path: string) {
 103   return new Promise<any>((res, rej) => {
 104     ffmpeg.ffprobe(path, (err, metadata) => {
 105       if (err) return rej(err)
 106
 107       const videoStream = metadata.streams.find(s => s.codec_type === 'video')
 108       if (!videoStream) throw new Error('Cannot find video stream of ' + path)
 109
 110       return res(videoStream)
 111     })
 112   })
 113 }