Add 30 fps limit in transcoding

server/helpers/ffmpeg-utils.ts

@@ -1,16 +1,27 @@
 import * as ffmpeg from 'fluent-ffmpeg'
 import { VideoResolution } from '../../shared/models/videos'
-import { CONFIG } from '../initializers'
+import { CONFIG, MAX_VIDEO_TRANSCODING_FPS } from '../initializers'
 
-function getVideoFileHeight (path: string) {
-  return new Promise<number>((res, rej) => {
-    ffmpeg.ffprobe(path, (err, metadata) => {
-      if (err) return rej(err)
+async function getVideoFileHeight (path: string) {
+  const videoStream = await getVideoFileStream(path)
+  return videoStream.height
+}
 
-      const videoStream = metadata.streams.find(s => s.codec_type === 'video')
-      return res(videoStream.height)
-    })
-  })
+async function getVideoFileFPS (path: string) {
+  const videoStream = await getVideoFileStream(path)
+
+  for (const key of [ 'r_frame_rate' , 'avg_frame_rate' ]) {
+    const valuesText: string = videoStream[key]
+    if (!valuesText) continue
+
+    const [ frames, seconds ] = valuesText.split('/')
+    if (!frames || !seconds) continue
+
+    const result = parseInt(frames, 10) / parseInt(seconds, 10)
+    if (result > 0) return result
+  }
+
+  return 0
 }
 
 function getDurationFromVideoFile (path: string) {
@@ -49,7 +60,9 @@ type TranscodeOptions = {
 }
 
 function transcode (options: TranscodeOptions) {
-  return new Promise<void>((res, rej) => {
+  return new Promise<void>(async (res, rej) => {
+    const fps = await getVideoFileFPS(options.inputPath)
+
     let command = ffmpeg(options.inputPath)
                     .output(options.outputPath)
                     .videoCodec('libx264')
@@ -57,6 +70,8 @@ function transcode (options: TranscodeOptions) {
                     .outputOption('-movflags faststart')
                     // .outputOption('-crf 18')
 
+    if (fps > MAX_VIDEO_TRANSCODING_FPS) command = command.withFPS(MAX_VIDEO_TRANSCODING_FPS)
+
     if (options.resolution !== undefined) {
       const size = `?x${options.resolution}` // '?x720' for example
       command = command.size(size)
@@ -74,5 +89,21 @@ export {
   getVideoFileHeight,
   getDurationFromVideoFile,
   generateImageFromVideoFile,
-  transcode
+  transcode,
+  getVideoFileFPS
+}
+
+// ---------------------------------------------------------------------------
+
+function getVideoFileStream (path: string) {
+  return new Promise<any>((res, rej) => {
+    ffmpeg.ffprobe(path, (err, metadata) => {
+      if (err) return rej(err)
+
+      const videoStream = metadata.streams.find(s => s.codec_type === 'video')
+      if (!videoStream) throw new Error('Cannot find video stream of ' + path)
+
+      return res(videoStream)
+    })
+  })
 }