Split ffmpeg utils with ffprobe utils

1 files changed, 249 insertions, 0 deletions

diff --git a/server/helpers/ffprobe-utils.ts b/server/helpers/ffprobe-utils.ts
new file mode 100644
index 000000000..6159d3963
--- /dev/null
+++ b/server/helpers/ffprobe-utils.ts
@@ -0,0 +1,249 @@
+import * as ffmpeg from 'fluent-ffmpeg'
+import { VideoFileMetadata } from '@shared/models/videos/video-file-metadata'
+import { getMaxBitrate, VideoResolution } from '../../shared/models/videos'
+import { CONFIG } from '../initializers/config'
+import { VIDEO_TRANSCODING_FPS } from '../initializers/constants'
+import { logger } from './logger'
+
+function ffprobePromise (path: string) {
+  return new Promise<ffmpeg.FfprobeData>((res, rej) => {
+    ffmpeg.ffprobe(path, (err, data) => {
+      if (err) return rej(err)
+
+      return res(data)
+    })
+  })
+}
+
+async function getAudioStream (videoPath: string, existingProbe?: ffmpeg.FfprobeData) {
+  // without position, ffprobe considers the last input only
+  // we make it consider the first input only
+  // if you pass a file path to pos, then ffprobe acts on that file directly
+  const data = existingProbe || await ffprobePromise(videoPath)
+
+  if (Array.isArray(data.streams)) {
+    const audioStream = data.streams.find(stream => stream['codec_type'] === 'audio')
+
+    if (audioStream) {
+      return {
+        absolutePath: data.format.filename,
+        audioStream,
+        bitrate: parseInt(audioStream['bit_rate'] + '', 10)
+      }
+    }
+  }
+
+  return { absolutePath: data.format.filename }
+}
+
+function getMaxAudioBitrate (type: 'aac' | 'mp3' | string, bitrate: number) {
+  const baseKbitrate = 384
+  const toBits = (kbits: number) => kbits * 8000
+
+  if (type === 'aac') {
+    switch (true) {
+      case bitrate > toBits(baseKbitrate):
+        return baseKbitrate
+
+      default:
+        return -1 // we interpret it as a signal to copy the audio stream as is
+    }
+  }
+
+  if (type === 'mp3') {
+    /*
+      a 192kbit/sec mp3 doesn't hold as much information as a 192kbit/sec aac.
+      That's why, when using aac, we can go to lower kbit/sec. The equivalences
+      made here are not made to be accurate, especially with good mp3 encoders.
+      */
+    switch (true) {
+      case bitrate <= toBits(192):
+        return 128
+
+      case bitrate <= toBits(384):
+        return 256
+
+      default:
+        return baseKbitrate
+    }
+  }
+
+  return undefined
+}
+
+async function getVideoStreamSize (path: string, existingProbe?: ffmpeg.FfprobeData) {
+  const videoStream = await getVideoStreamFromFile(path, existingProbe)
+
+  return videoStream === null
+    ? { width: 0, height: 0 }
+    : { width: videoStream.width, height: videoStream.height }
+}
+
+async function getVideoStreamCodec (path: string) {
+  const videoStream = await getVideoStreamFromFile(path)
+
+  if (!videoStream) return ''
+
+  const videoCodec = videoStream.codec_tag_string
+
+  const baseProfileMatrix = {
+    High: '6400',
+    Main: '4D40',
+    Baseline: '42E0'
+  }
+
+  let baseProfile = baseProfileMatrix[videoStream.profile]
+  if (!baseProfile) {
+    logger.warn('Cannot get video profile codec of %s.', path, { videoStream })
+    baseProfile = baseProfileMatrix['High'] // Fallback
+  }
+
+  let level = videoStream.level.toString(16)
+  if (level.length === 1) level = `0${level}`
+
+  return `${videoCodec}.${baseProfile}${level}`
+}
+
+async function getAudioStreamCodec (path: string, existingProbe?: ffmpeg.FfprobeData) {
+  const { audioStream } = await getAudioStream(path, existingProbe)
+
+  if (!audioStream) return ''
+
+  const audioCodec = audioStream.codec_name
+  if (audioCodec === 'aac') return 'mp4a.40.2'
+
+  logger.warn('Cannot get audio codec of %s.', path, { audioStream })
+
+  return 'mp4a.40.2' // Fallback
+}
+
+async function getVideoFileResolution (path: string, existingProbe?: ffmpeg.FfprobeData) {
+  const size = await getVideoStreamSize(path, existingProbe)
+
+  return {
+    videoFileResolution: Math.min(size.height, size.width),
+    isPortraitMode: size.height > size.width
+  }
+}
+
+async function getVideoFileFPS (path: string, existingProbe?: ffmpeg.FfprobeData) {
+  const videoStream = await getVideoStreamFromFile(path, existingProbe)
+  if (videoStream === null) return 0
+
+  for (const key of [ 'avg_frame_rate', 'r_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 Math.round(result)
+  }
+
+  return 0
+}
+
+async function getMetadataFromFile (path: string, existingProbe?: ffmpeg.FfprobeData) {
+  const metadata = existingProbe || await ffprobePromise(path)
+
+  return new VideoFileMetadata(metadata)
+}
+
+async function getVideoFileBitrate (path: string, existingProbe?: ffmpeg.FfprobeData) {
+  const metadata = await getMetadataFromFile(path, existingProbe)
+
+  return metadata.format.bit_rate as number
+}
+
+async function getDurationFromVideoFile (path: string, existingProbe?: ffmpeg.FfprobeData) {
+  const metadata = await getMetadataFromFile(path, existingProbe)
+
+  return Math.floor(metadata.format.duration)
+}
+
+async function getVideoStreamFromFile (path: string, existingProbe?: ffmpeg.FfprobeData) {
+  const metadata = await getMetadataFromFile(path, existingProbe)
+
+  return metadata.streams.find(s => s.codec_type === 'video') || null
+}
+
+function computeResolutionsToTranscode (videoFileResolution: number, type: 'vod' | 'live') {
+  const configResolutions = type === 'vod'
+    ? CONFIG.TRANSCODING.RESOLUTIONS
+    : CONFIG.LIVE.TRANSCODING.RESOLUTIONS
+
+  const resolutionsEnabled: number[] = []
+
+  // Put in the order we want to proceed jobs
+  const resolutions = [
+    VideoResolution.H_NOVIDEO,
+    VideoResolution.H_480P,
+    VideoResolution.H_360P,
+    VideoResolution.H_720P,
+    VideoResolution.H_240P,
+    VideoResolution.H_1080P,
+    VideoResolution.H_4K
+  ]
+
+  for (const resolution of resolutions) {
+    if (configResolutions[resolution + 'p'] === true && videoFileResolution > resolution) {
+      resolutionsEnabled.push(resolution)
+    }
+  }
+
+  return resolutionsEnabled
+}
+
+async function canDoQuickTranscode (path: string): Promise<boolean> {
+  const probe = await ffprobePromise(path)
+
+  // NOTE: This could be optimized by running ffprobe only once (but it runs fast anyway)
+  const videoStream = await getVideoStreamFromFile(path, probe)
+  const parsedAudio = await getAudioStream(path, probe)
+  const fps = await getVideoFileFPS(path, probe)
+  const bitRate = await getVideoFileBitrate(path, probe)
+  const resolution = await getVideoFileResolution(path, probe)
+
+  // check video params
+  if (videoStream == null) return false
+  if (videoStream['codec_name'] !== 'h264') return false
+  if (videoStream['pix_fmt'] !== 'yuv420p') return false
+  if (fps < VIDEO_TRANSCODING_FPS.MIN || fps > VIDEO_TRANSCODING_FPS.MAX) return false
+  if (bitRate > getMaxBitrate(resolution.videoFileResolution, fps, VIDEO_TRANSCODING_FPS)) return false
+
+  // check audio params (if audio stream exists)
+  if (parsedAudio.audioStream) {
+    if (parsedAudio.audioStream['codec_name'] !== 'aac') return false
+
+    const audioBitrate = parsedAudio.bitrate
+
+    const maxAudioBitrate = getMaxAudioBitrate('aac', audioBitrate)
+    if (maxAudioBitrate !== -1 && audioBitrate > maxAudioBitrate) return false
+  }
+
+  return true
+}
+
+function getClosestFramerateStandard (fps: number, type: 'HD_STANDARD' | 'STANDARD'): number {
+  return VIDEO_TRANSCODING_FPS[type].slice(0)
+                                    .sort((a, b) => fps % a - fps % b)[0]
+}
+
+// ---------------------------------------------------------------------------
+
+export {
+  getVideoStreamCodec,
+  getAudioStreamCodec,
+  getVideoStreamSize,
+  getVideoFileResolution,
+  getMetadataFromFile,
+  getMaxAudioBitrate,
+  getDurationFromVideoFile,
+  getAudioStream,
+  getVideoFileFPS,
+  getClosestFramerateStandard,
+  computeResolutionsToTranscode,
+  getVideoFileBitrate,
+  canDoQuickTranscode
+}