1 files changed, 156 insertions, 0 deletions

diff --git a/server/helpers/ffmpeg/ffmpeg-presets.ts b/server/helpers/ffmpeg/ffmpeg-presets.ts
new file mode 100644
index 000000000..99b39f79a
--- /dev/null
+++ b/server/helpers/ffmpeg/ffmpeg-presets.ts
@@ -0,0 +1,156 @@
+import { FfmpegCommand } from 'fluent-ffmpeg'
+import { pick } from 'lodash'
+import { logger, loggerTagsFactory } from '@server/helpers/logger'
+import { AvailableEncoders, EncoderOptions } from '@shared/models'
+import { buildStreamSuffix, getScaleFilter, StreamType } from './ffmpeg-commons'
+import { getEncoderBuilderResult } from './ffmpeg-encoders'
+import { ffprobePromise, getVideoStreamBitrate, getVideoStreamDimensionsInfo, hasAudioStream } from './ffprobe-utils'
+
+const lTags = loggerTagsFactory('ffmpeg')
+
+// ---------------------------------------------------------------------------
+
+function addDefaultEncoderGlobalParams (command: FfmpegCommand) {
+  // avoid issues when transcoding some files: https://trac.ffmpeg.org/ticket/6375
+  command.outputOption('-max_muxing_queue_size 1024')
+         // strip all metadata
+         .outputOption('-map_metadata -1')
+         // allows import of source material with incompatible pixel formats (e.g. MJPEG video)
+         .outputOption('-pix_fmt yuv420p')
+}
+
+function addDefaultEncoderParams (options: {
+  command: FfmpegCommand
+  encoder: 'libx264' | string
+  fps: number
+
+  streamNum?: number
+}) {
+  const { command, encoder, fps, streamNum } = options
+
+  if (encoder === 'libx264') {
+    // 3.1 is the minimal resource allocation for our highest supported resolution
+    command.outputOption(buildStreamSuffix('-level:v', streamNum) + ' 3.1')
+
+    if (fps) {
+      // Keyframe interval of 2 seconds for faster seeking and resolution switching.
+      // https://streaminglearningcenter.com/blogs/whats-the-right-keyframe-interval.html
+      // https://superuser.com/a/908325
+      command.outputOption(buildStreamSuffix('-g:v', streamNum) + ' ' + (fps * 2))
+    }
+  }
+}
+
+// ---------------------------------------------------------------------------
+
+async function presetVOD (options: {
+  command: FfmpegCommand
+  input: string
+
+  availableEncoders: AvailableEncoders
+  profile: string
+
+  canCopyAudio: boolean
+  canCopyVideo: boolean
+
+  resolution: number
+  fps: number
+
+  scaleFilterValue?: string
+}) {
+  const { command, input, profile, resolution, fps, scaleFilterValue } = options
+
+  let localCommand = command
+    .format('mp4')
+    .outputOption('-movflags faststart')
+
+  addDefaultEncoderGlobalParams(command)
+
+  const probe = await ffprobePromise(input)
+
+  // Audio encoder
+  const bitrate = await getVideoStreamBitrate(input, probe)
+  const videoStreamDimensions = await getVideoStreamDimensionsInfo(input, probe)
+
+  let streamsToProcess: StreamType[] = [ 'audio', 'video' ]
+
+  if (!await hasAudioStream(input, probe)) {
+    localCommand = localCommand.noAudio()
+    streamsToProcess = [ 'video' ]
+  }
+
+  for (const streamType of streamsToProcess) {
+    const builderResult = await getEncoderBuilderResult({
+      ...pick(options, [ 'availableEncoders', 'canCopyAudio', 'canCopyVideo' ]),
+
+      input,
+      inputBitrate: bitrate,
+      inputRatio: videoStreamDimensions?.ratio || 0,
+
+      profile,
+      resolution,
+      fps,
+      streamType,
+
+      videoType: 'vod' as 'vod'
+    })
+
+    if (!builderResult) {
+      throw new Error('No available encoder found for stream ' + streamType)
+    }
+
+    logger.debug(
+      'Apply ffmpeg params from %s for %s stream of input %s using %s profile.',
+      builderResult.encoder, streamType, input, profile,
+      { builderResult, resolution, fps, ...lTags() }
+    )
+
+    if (streamType === 'video') {
+      localCommand.videoCodec(builderResult.encoder)
+
+      if (scaleFilterValue) {
+        localCommand.outputOption(`-vf ${getScaleFilter(builderResult.result)}=${scaleFilterValue}`)
+      }
+    } else if (streamType === 'audio') {
+      localCommand.audioCodec(builderResult.encoder)
+    }
+
+    applyEncoderOptions(localCommand, builderResult.result)
+    addDefaultEncoderParams({ command: localCommand, encoder: builderResult.encoder, fps })
+  }
+
+  return localCommand
+}
+
+function presetCopy (command: FfmpegCommand): FfmpegCommand {
+  return command
+    .format('mp4')
+    .videoCodec('copy')
+    .audioCodec('copy')
+}
+
+function presetOnlyAudio (command: FfmpegCommand): FfmpegCommand {
+  return command
+    .format('mp4')
+    .audioCodec('copy')
+    .noVideo()
+}
+
+function applyEncoderOptions (command: FfmpegCommand, options: EncoderOptions): FfmpegCommand {
+  return command
+    .inputOptions(options.inputOptions ?? [])
+    .outputOptions(options.outputOptions ?? [])
+}
+
+// ---------------------------------------------------------------------------
+
+export {
+  presetVOD,
+  presetCopy,
+  presetOnlyAudio,
+
+  addDefaultEncoderGlobalParams,
+  addDefaultEncoderParams,
+
+  applyEncoderOptions
+}