1 files changed, 86 insertions, 68 deletions

diff --git a/server/helpers/ffmpeg-utils.ts b/server/helpers/ffmpeg-utils.ts
index 2fdf34cb7..c180da832 100644
--- a/server/helpers/ffmpeg-utils.ts
+++ b/server/helpers/ffmpeg-utils.ts
@@ -117,37 +117,50 @@ async function generateImageFromVideoFile (fromPath: string, folder: string, ima
   }
 }
 
-type TranscodeOptions = {
+type TranscodeOptionsType = 'hls' | 'quick-transcode' | 'video' | 'merge-audio'
+
+interface BaseTranscodeOptions {
+  type: TranscodeOptionsType
   inputPath: string
   outputPath: string
   resolution: VideoResolution
   isPortraitMode?: boolean
-  doQuickTranscode?: Boolean
+}
 
-  hlsPlaylist?: {
+interface HLSTranscodeOptions extends BaseTranscodeOptions {
+  type: 'hls'
+  hlsPlaylist: {
     videoFilename: string
   }
 }
 
+interface QuickTranscodeOptions extends BaseTranscodeOptions {
+  type: 'quick-transcode'
+}
+
+interface VideoTranscodeOptions extends BaseTranscodeOptions {
+  type: 'video'
+}
+
+interface MergeAudioTranscodeOptions extends BaseTranscodeOptions {
+  type: 'merge-audio'
+  audioPath: string
+}
+
+type TranscodeOptions = HLSTranscodeOptions | VideoTranscodeOptions | MergeAudioTranscodeOptions | QuickTranscodeOptions
+
 function transcode (options: TranscodeOptions) {
   return new Promise<void>(async (res, rej) => {
     try {
       let command = ffmpeg(options.inputPath, { niceness: FFMPEG_NICE.TRANSCODING })
         .output(options.outputPath)
 
-      if (options.doQuickTranscode) {
-        if (options.hlsPlaylist) {
-          throw(Error("Quick transcode and HLS can't be used at the same time"))
-        }
-
-        command
-          .format('mp4')
-          .addOption('-c:v copy')
-          .addOption('-c:a copy')
-          .outputOption('-map_metadata -1') // strip all metadata
-          .outputOption('-movflags faststart')
-      } else if (options.hlsPlaylist) {
+      if (options.type === 'quick-transcode') {
+        command = await buildQuickTranscodeCommand(command)
+      } else if (options.type === 'hls') {
         command = await buildHLSCommand(command, options)
+      } else if (options.type === 'merge-audio') {
+        command = await buildAudioMergeCommand(command, options)
       } else {
         command = await buildx264Command(command, options)
       }
@@ -163,7 +176,7 @@ function transcode (options: TranscodeOptions) {
           return rej(err)
         })
         .on('end', () => {
-          return onTranscodingSuccess(options)
+          return fixHLSPlaylistIfNeeded(options)
             .then(() => res())
             .catch(err => rej(err))
         })
@@ -205,6 +218,8 @@ export {
   getVideoFileResolution,
   getDurationFromVideoFile,
   generateImageFromVideoFile,
+  TranscodeOptions,
+  TranscodeOptionsType,
   transcode,
   getVideoFileFPS,
   computeResolutionsToTranscode,
@@ -215,7 +230,7 @@ export {
 
 // ---------------------------------------------------------------------------
 
-async function buildx264Command (command: ffmpeg.FfmpegCommand, options: TranscodeOptions) {
+async function buildx264Command (command: ffmpeg.FfmpegCommand, options: VideoTranscodeOptions) {
   let fps = await getVideoFileFPS(options.inputPath)
   // On small/medium resolutions, limit FPS
   if (
@@ -226,7 +241,7 @@ async function buildx264Command (command: ffmpeg.FfmpegCommand, options: Transco
     fps = VIDEO_TRANSCODING_FPS.AVERAGE
   }
 
-  command = await presetH264(command, options.resolution, fps)
+  command = await presetH264(command, options.inputPath, options.resolution, fps)
 
   if (options.resolution !== undefined) {
     // '?x720' or '720x?' for example
@@ -245,7 +260,29 @@ async function buildx264Command (command: ffmpeg.FfmpegCommand, options: Transco
   return command
 }
 
-async function buildHLSCommand (command: ffmpeg.FfmpegCommand, options: TranscodeOptions) {
+async function buildAudioMergeCommand (command: ffmpeg.FfmpegCommand, options: MergeAudioTranscodeOptions) {
+  command = command.loop(undefined)
+
+  command = await presetH264VeryFast(command, options.audioPath, options.resolution)
+
+  command = command.input(options.audioPath)
+                   .videoFilter('scale=trunc(iw/2)*2:trunc(ih/2)*2') // Avoid "height not divisible by 2" error
+                   .outputOption('-tune stillimage')
+                   .outputOption('-shortest')
+
+  return command
+}
+
+async function buildQuickTranscodeCommand (command: ffmpeg.FfmpegCommand) {
+  command = await presetCopy(command)
+
+  command = command.outputOption('-map_metadata -1') // strip all metadata
+                   .outputOption('-movflags faststart')
+
+  return command
+}
+
+async function buildHLSCommand (command: ffmpeg.FfmpegCommand, options: HLSTranscodeOptions) {
   const videoPath = getHLSVideoPath(options)
 
   command = await presetCopy(command)
@@ -261,19 +298,19 @@ async function buildHLSCommand (command: ffmpeg.FfmpegCommand, options: Transcod
   return command
 }
 
-function getHLSVideoPath (options: TranscodeOptions) {
+function getHLSVideoPath (options: HLSTranscodeOptions) {
   return `${dirname(options.outputPath)}/${options.hlsPlaylist.videoFilename}`
 }
 
-async function onTranscodingSuccess (options: TranscodeOptions) {
-  if (!options.hlsPlaylist) return
+async function fixHLSPlaylistIfNeeded (options: TranscodeOptions) {
+  if (options.type !== 'hls') return
 
-  // Fix wrong mapping with some ffmpeg versions
   const fileContent = await readFile(options.outputPath)
 
   const videoFileName = options.hlsPlaylist.videoFilename
   const videoFilePath = getHLSVideoPath(options)
 
+  // Fix wrong mapping with some ffmpeg versions
   const newContent = fileContent.toString()
                                 .replace(`#EXT-X-MAP:URI="${videoFilePath}",`, `#EXT-X-MAP:URI="${videoFileName}",`)
 
@@ -300,44 +337,27 @@ function getVideoStreamFromFile (path: string) {
  * and quality. Superfast and ultrafast will give you better
  * performance, but then quality is noticeably worse.
  */
-async function presetH264VeryFast (command: ffmpeg.FfmpegCommand, resolution: VideoResolution, fps: number): Promise<ffmpeg.FfmpegCommand> {
-  let localCommand = await presetH264(command, resolution, fps)
+async function presetH264VeryFast (command: ffmpeg.FfmpegCommand, input: string, resolution: VideoResolution, fps?: number) {
+  let localCommand = await presetH264(command, input, resolution, fps)
+
   localCommand = localCommand.outputOption('-preset:v veryfast')
-             .outputOption([ '--aq-mode=2', '--aq-strength=1.3' ])
+
   /*
   MAIN reference: https://slhck.info/video/2017/03/01/rate-control.html
   Our target situation is closer to a livestream than a stream,
   since we want to reduce as much a possible the encoding burden,
-  altough not to the point of a livestream where there is a hard
+  although not to the point of a livestream where there is a hard
   constraint on the frames per second to be encoded.
-
-  why '--aq-mode=2 --aq-strength=1.3' instead of '-profile:v main'?
-    Make up for most of the loss of grain and macroblocking
-    with less computing power.
   */
 
   return localCommand
 }
 
 /**
- * A preset optimised for a stillimage audio video
- */
-async function presetStillImageWithAudio (
-  command: ffmpeg.FfmpegCommand,
-  resolution: VideoResolution,
-  fps: number
-): Promise<ffmpeg.FfmpegCommand> {
-  let localCommand = await presetH264VeryFast(command, resolution, fps)
-  localCommand = localCommand.outputOption('-tune stillimage')
-
-  return localCommand
-}
-
-/**
  * A toolbox to play with audio
  */
 namespace audio {
-  export const get = (option: ffmpeg.FfmpegCommand | string) => {
+  export const get = (option: string) => {
     // 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
@@ -359,11 +379,7 @@ namespace audio {
         return res({ absolutePath: data.format.filename })
       }
 
-      if (typeof option === 'string') {
-        return ffmpeg.ffprobe(option, parseFfprobe)
-      }
-
-      return option.ffprobe(parseFfprobe)
+      return ffmpeg.ffprobe(option, parseFfprobe)
     })
   }
 
@@ -405,7 +421,7 @@ namespace audio {
  * As for the audio, quality '5' is the highest and ensures 96-112kbps/channel
  * See https://trac.ffmpeg.org/wiki/Encode/AAC#fdk_vbr
  */
-async function presetH264 (command: ffmpeg.FfmpegCommand, resolution: VideoResolution, fps: number): Promise<ffmpeg.FfmpegCommand> {
+async function presetH264 (command: ffmpeg.FfmpegCommand, input: string, resolution: VideoResolution, fps?: number) {
   let localCommand = command
     .format('mp4')
     .videoCodec('libx264')
@@ -416,7 +432,7 @@ async function presetH264 (command: ffmpeg.FfmpegCommand, resolution: VideoResol
     .outputOption('-map_metadata -1') // strip all metadata
     .outputOption('-movflags faststart')
 
-  const parsedAudio = await audio.get(localCommand)
+  const parsedAudio = await audio.get(input)
 
   if (!parsedAudio.audioStream) {
     localCommand = localCommand.noAudio()
@@ -425,28 +441,30 @@ async function presetH264 (command: ffmpeg.FfmpegCommand, resolution: VideoResol
       .audioCodec('libfdk_aac')
       .audioQuality(5)
   } else {
-    // we try to reduce the ceiling bitrate by making rough correspondances of bitrates
+    // we try to reduce the ceiling bitrate by making rough matches of bitrates
     // of course this is far from perfect, but it might save some space in the end
+    localCommand = localCommand.audioCodec('aac')
+
     const audioCodecName = parsedAudio.audioStream[ 'codec_name' ]
-    let bitrate: number
-    if (audio.bitrate[ audioCodecName ]) {
-      localCommand = localCommand.audioCodec('aac')
 
-      bitrate = audio.bitrate[ audioCodecName ](parsedAudio.audioStream[ 'bit_rate' ])
+    if (audio.bitrate[ audioCodecName ]) {
+      const bitrate = audio.bitrate[ audioCodecName ](parsedAudio.audioStream[ 'bit_rate' ])
       if (bitrate !== undefined && bitrate !== -1) localCommand = localCommand.audioBitrate(bitrate)
     }
   }
 
-  // Constrained Encoding (VBV)
-  // https://slhck.info/video/2017/03/01/rate-control.html
-  // https://trac.ffmpeg.org/wiki/Limiting%20the%20output%20bitrate
-  const targetBitrate = getTargetBitrate(resolution, fps, VIDEO_TRANSCODING_FPS)
-  localCommand = localCommand.outputOptions([`-maxrate ${ targetBitrate }`, `-bufsize ${ targetBitrate * 2 }`])
-
-  // 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
-  localCommand = localCommand.outputOption(`-g ${ fps * 2 }`)
+  if (fps) {
+    // Constrained Encoding (VBV)
+    // https://slhck.info/video/2017/03/01/rate-control.html
+    // https://trac.ffmpeg.org/wiki/Limiting%20the%20output%20bitrate
+    const targetBitrate = getTargetBitrate(resolution, fps, VIDEO_TRANSCODING_FPS)
+    localCommand = localCommand.outputOptions([ `-maxrate ${targetBitrate}`, `-bufsize ${targetBitrate * 2}` ])
+
+    // 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
+    localCommand = localCommand.outputOption(`-g ${fps * 2}`)
+  }
 
   return localCommand
 }