1 files changed, 231 insertions, 0 deletions

diff --git a/server/helpers/ffmpeg/ffprobe-utils.ts b/server/helpers/ffmpeg/ffprobe-utils.ts
new file mode 100644
index 000000000..07bcf01f4
--- /dev/null
+++ b/server/helpers/ffmpeg/ffprobe-utils.ts
@@ -0,0 +1,231 @@
+import { FfprobeData } from 'fluent-ffmpeg'
+import { getMaxBitrate } from '@shared/core-utils'
+import {
+  ffprobePromise,
+  getAudioStream,
+  getVideoStreamDuration,
+  getMaxAudioBitrate,
+  buildFileMetadata,
+  getVideoStreamBitrate,
+  getVideoStreamFPS,
+  getVideoStream,
+  getVideoStreamDimensionsInfo,
+  hasAudioStream
+} from '@shared/extra-utils/ffprobe'
+import { VideoResolution, VideoTranscodingFPS } from '@shared/models'
+import { CONFIG } from '../../initializers/config'
+import { VIDEO_TRANSCODING_FPS } from '../../initializers/constants'
+import { logger } from '../logger'
+
+/**
+ *
+ * Helpers to run ffprobe and extract data from the JSON output
+ *
+ */
+
+// ---------------------------------------------------------------------------
+// Codecs
+// ---------------------------------------------------------------------------
+
+async function getVideoStreamCodec (path: string) {
+  const videoStream = await getVideoStream(path)
+  if (!videoStream) return ''
+
+  const videoCodec = videoStream.codec_tag_string
+
+  if (videoCodec === 'vp09') return 'vp09.00.50.08'
+  if (videoCodec === 'hev1') return 'hev1.1.6.L93.B0'
+
+  const baseProfileMatrix = {
+    avc1: {
+      High: '6400',
+      Main: '4D40',
+      Baseline: '42E0'
+    },
+    av01: {
+      High: '1',
+      Main: '0',
+      Professional: '2'
+    }
+  }
+
+  let baseProfile = baseProfileMatrix[videoCodec][videoStream.profile]
+  if (!baseProfile) {
+    logger.warn('Cannot get video profile codec of %s.', path, { videoStream })
+    baseProfile = baseProfileMatrix[videoCodec]['High'] // Fallback
+  }
+
+  if (videoCodec === 'av01') {
+    const level = videoStream.level
+
+    // Guess the tier indicator and bit depth
+    return `${videoCodec}.${baseProfile}.${level}M.08`
+  }
+
+  // Default, h264 codec
+  let level = videoStream.level.toString(16)
+  if (level.length === 1) level = `0${level}`
+
+  return `${videoCodec}.${baseProfile}${level}`
+}
+
+async function getAudioStreamCodec (path: string, existingProbe?: FfprobeData) {
+  const { audioStream } = await getAudioStream(path, existingProbe)
+
+  if (!audioStream) return ''
+
+  const audioCodecName = audioStream.codec_name
+
+  if (audioCodecName === 'opus') return 'opus'
+  if (audioCodecName === 'vorbis') return 'vorbis'
+  if (audioCodecName === 'aac') return 'mp4a.40.2'
+
+  logger.warn('Cannot get audio codec of %s.', path, { audioStream })
+
+  return 'mp4a.40.2' // Fallback
+}
+
+// ---------------------------------------------------------------------------
+// Resolutions
+// ---------------------------------------------------------------------------
+
+function computeLowerResolutionsToTranscode (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[] = [
+    VideoResolution.H_NOVIDEO,
+    VideoResolution.H_480P,
+    VideoResolution.H_360P,
+    VideoResolution.H_720P,
+    VideoResolution.H_240P,
+    VideoResolution.H_144P,
+    VideoResolution.H_1080P,
+    VideoResolution.H_1440P,
+    VideoResolution.H_4K
+  ]
+
+  for (const resolution of resolutions) {
+    if (configResolutions[resolution + 'p'] === true && videoFileResolution > resolution) {
+      resolutionsEnabled.push(resolution)
+    }
+  }
+
+  return resolutionsEnabled
+}
+
+// ---------------------------------------------------------------------------
+// Can quick transcode
+// ---------------------------------------------------------------------------
+
+async function canDoQuickTranscode (path: string): Promise<boolean> {
+  if (CONFIG.TRANSCODING.PROFILE !== 'default') return false
+
+  const probe = await ffprobePromise(path)
+
+  return await canDoQuickVideoTranscode(path, probe) &&
+         await canDoQuickAudioTranscode(path, probe)
+}
+
+async function canDoQuickAudioTranscode (path: string, probe?: FfprobeData): Promise<boolean> {
+  const parsedAudio = await getAudioStream(path, probe)
+
+  if (!parsedAudio.audioStream) return true
+
+  if (parsedAudio.audioStream['codec_name'] !== 'aac') return false
+
+  const audioBitrate = parsedAudio.bitrate
+  if (!audioBitrate) return false
+
+  const maxAudioBitrate = getMaxAudioBitrate('aac', audioBitrate)
+  if (maxAudioBitrate !== -1 && audioBitrate > maxAudioBitrate) return false
+
+  const channelLayout = parsedAudio.audioStream['channel_layout']
+  // Causes playback issues with Chrome
+  if (!channelLayout || channelLayout === 'unknown') return false
+
+  return true
+}
+
+async function canDoQuickVideoTranscode (path: string, probe?: FfprobeData): Promise<boolean> {
+  const videoStream = await getVideoStream(path, probe)
+  const fps = await getVideoStreamFPS(path, probe)
+  const bitRate = await getVideoStreamBitrate(path, probe)
+  const resolutionData = await getVideoStreamDimensionsInfo(path, probe)
+
+  // If ffprobe did not manage to guess the bitrate
+  if (!bitRate) return false
+
+  // check video params
+  if (!videoStream) 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({ ...resolutionData, fps })) return false
+
+  return true
+}
+
+// ---------------------------------------------------------------------------
+// Framerate
+// ---------------------------------------------------------------------------
+
+function getClosestFramerateStandard <K extends keyof Pick<VideoTranscodingFPS, 'HD_STANDARD' | 'STANDARD'>> (fps: number, type: K) {
+  return VIDEO_TRANSCODING_FPS[type].slice(0)
+                                    .sort((a, b) => fps % a - fps % b)[0]
+}
+
+function computeFPS (fpsArg: number, resolution: VideoResolution) {
+  let fps = fpsArg
+
+  if (
+    // On small/medium resolutions, limit FPS
+    resolution !== undefined &&
+    resolution < VIDEO_TRANSCODING_FPS.KEEP_ORIGIN_FPS_RESOLUTION_MIN &&
+    fps > VIDEO_TRANSCODING_FPS.AVERAGE
+  ) {
+    // Get closest standard framerate by modulo: downsampling has to be done to a divisor of the nominal fps value
+    fps = getClosestFramerateStandard(fps, 'STANDARD')
+  }
+
+  // Hard FPS limits
+  if (fps > VIDEO_TRANSCODING_FPS.MAX) fps = getClosestFramerateStandard(fps, 'HD_STANDARD')
+
+  if (fps < VIDEO_TRANSCODING_FPS.MIN) {
+    throw new Error(`Cannot compute FPS because ${fps} is lower than our minimum value ${VIDEO_TRANSCODING_FPS.MIN}`)
+  }
+
+  return fps
+}
+
+// ---------------------------------------------------------------------------
+
+export {
+  // Re export ffprobe utils
+  getVideoStreamDimensionsInfo,
+  buildFileMetadata,
+  getMaxAudioBitrate,
+  getVideoStream,
+  getVideoStreamDuration,
+  getAudioStream,
+  hasAudioStream,
+  getVideoStreamFPS,
+  ffprobePromise,
+  getVideoStreamBitrate,
+
+  getVideoStreamCodec,
+  getAudioStreamCodec,
+
+  computeFPS,
+  getClosestFramerateStandard,
+
+  computeLowerResolutionsToTranscode,
+
+  canDoQuickTranscode,
+  canDoQuickVideoTranscode,
+  canDoQuickAudioTranscode
+}