stricter youtubedl format selectors (#3516)

* stricter youtubedl format selectors

make sure selectors avoid av1, and otherwise match as closely to the
maximum resolution enabled for transcoding

* add support for merge formats in youtubedl

* avoid vp9.2 in youtubedl to avoid any HDR

* move getEnabledResolutions, safer replace of imported extension

* add test for youtube-dl selectors

1 files changed, 47 insertions, 6 deletions

diff --git a/server/helpers/youtube-dl.ts b/server/helpers/youtube-dl.ts
index 74e5f896c..ebb788e8e 100644
--- a/server/helpers/youtube-dl.ts
+++ b/server/helpers/youtube-dl.ts
@@ -1,6 +1,7 @@
 import { CONSTRAINTS_FIELDS, VIDEO_CATEGORIES, VIDEO_LANGUAGES, VIDEO_LICENCES } from '../initializers/constants'
 import { logger } from './logger'
 import { generateVideoImportTmpPath } from './utils'
+import { getEnabledResolutions } from '../lib/video-transcoding'
 import { join } from 'path'
 import { peertubeTruncate, root } from './core-utils'
 import { ensureDir, remove, writeFile } from 'fs-extra'
@@ -8,6 +9,7 @@ import * as request from 'request'
 import { createWriteStream } from 'fs'
 import { CONFIG } from '@server/initializers/config'
 import { HttpStatusCode } from '../../shared/core-utils/miscs/http-error-codes'
+import { VideoResolution } from '../../shared/models/videos'
 
 export type YoutubeDLInfo = {
   name?: string
@@ -18,7 +20,8 @@ export type YoutubeDLInfo = {
   nsfw?: boolean
   tags?: string[]
   thumbnailUrl?: string
-  fileExt?: string
+  ext?: string
+  mergeExt?: string
   originallyPublishedAt?: Date
 }
 
@@ -41,12 +44,21 @@ function getYoutubeDLInfo (url: string, opts?: string[]): Promise<YoutubeDLInfo>
     }
 
     args = wrapWithProxyOptions(args)
+    args = [ '-f', getYoutubeDLVideoFormat() ].concat(args)
 
     safeGetYoutubeDL()
       .then(youtubeDL => {
         youtubeDL.getInfo(url, args, processOptions, (err, info) => {
           if (err) return rej(err)
           if (info.is_live === true) return rej(new Error('Cannot download a live streaming.'))
+          if (info.format_id?.includes('+')) {
+            // this is a merge format and its extension will be appended
+            if (info.ext === 'mp4') {
+              info.mergeExt = 'mp4'
+            } else {
+              info.mergeExt = 'mkv'
+            }
+          }
 
           const obj = buildVideoInfo(normalizeObject(info))
           if (obj.name && obj.name.length < CONSTRAINTS_FIELDS.VIDEOS.NAME.min) obj.name += ' video'
@@ -92,13 +104,40 @@ function getYoutubeDLSubs (url: string, opts?: object): Promise<YoutubeDLSubs> {
   })
 }
 
-function downloadYoutubeDLVideo (url: string, extension: string, timeout: number) {
+function getYoutubeDLVideoFormat () {
+  /**
+   * list of format selectors in order or preference
+   * see https://github.com/ytdl-org/youtube-dl#format-selection
+   *
+   * case #1 asks for a mp4 using h264 (avc1) and the exact resolution in the hope
+   * of being able to do a "quick-transcode"
+   * case #2 is the first fallback. No "quick-transcode" means we can get anything else (like vp9)
+   * case #3 is the resolution-degraded equivalent of #1, and already a pretty safe fallback
+   *
+   * in any case we avoid AV1, see https://github.com/Chocobozzz/PeerTube/issues/3499
+   **/
+  const enabledResolutions = getEnabledResolutions('vod')
+  const resolution = enabledResolutions.length === 0
+    ? VideoResolution.H_720P
+    : Math.max(...enabledResolutions)
+
+  return [
+    `bestvideo[vcodec^=avc1][height=${resolution}]+bestaudio[ext=m4a]`, // case #1
+    `bestvideo[vcodec!*=av01][vcodec!*=vp9.2][height=${resolution}]+bestaudio`, // case #2
+    `bestvideo[vcodec^=avc1][height<=${resolution}]+bestaudio[ext=m4a]`, // case #3
+    `bestvideo[vcodec!*=av01][vcodec!*=vp9.2]+bestaudio`,
+    'best[vcodec!*=av01][vcodec!*=vp9.2]' // case fallback
+  ].join('/')
+}
+
+function downloadYoutubeDLVideo (url: string, extension: string, timeout: number, mergeExtension?: string) {
   const path = generateVideoImportTmpPath(url, extension)
+  const finalPath = mergeExtension ? path.replace(new RegExp(`${extension}$`), mergeExtension) : path
   let timer
 
-  logger.info('Importing youtubeDL video %s to %s', url, path)
+  logger.info('Importing youtubeDL video %s to %s', url, finalPath)
 
-  let options = [ '-f', 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/best', '-o', path ]
+  let options = [ '-f', getYoutubeDLVideoFormat(), '-o', path ]
   options = wrapWithProxyOptions(options)
 
   if (process.env.FFMPEG_PATH) {
@@ -118,7 +157,7 @@ function downloadYoutubeDLVideo (url: string, extension: string, timeout: number
             return rej(err)
           }
 
-          return res(path)
+          return res(finalPath)
         })
 
         timer = setTimeout(() => {
@@ -236,6 +275,7 @@ function buildOriginallyPublishedAt (obj: any) {
 
 export {
   updateYoutubeDLBinary,
+  getYoutubeDLVideoFormat,
   downloadYoutubeDLVideo,
   getYoutubeDLSubs,
   getYoutubeDLInfo,
@@ -275,7 +315,8 @@ function buildVideoInfo (obj: any): YoutubeDLInfo {
     tags: getTags(obj.tags),
     thumbnailUrl: obj.thumbnail || undefined,
     originallyPublishedAt: buildOriginallyPublishedAt(obj),
-    fileExt: obj.ext
+    ext: obj.ext,
+    mergeExt: obj.mergeExt
   }
 }