Implement remote runner jobs in server

Move ffmpeg functions to @shared

server/lib/transcoding/transcoding-resolutions.ts

@@ -0,0 +1,52 @@
+import { CONFIG } from '@server/initializers/config'
+import { toEven } from '@shared/core-utils'
+import { VideoResolution } from '@shared/models'
+
+export function computeResolutionsToTranscode (options: {
+  input: number
+  type: 'vod' | 'live'
+  includeInput: boolean
+  strictLower: boolean
+  hasAudio: boolean
+}) {
+  const { input, type, includeInput, strictLower, hasAudio } = options
+
+  const configResolutions = type === 'vod'
+    ? CONFIG.TRANSCODING.RESOLUTIONS
+    : CONFIG.LIVE.TRANSCODING.RESOLUTIONS
+
+  const resolutionsEnabled = new Set<number>()
+
+  // Put in the order we want to proceed jobs
+  const availableResolutions: 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 availableResolutions) {
+    // Resolution not enabled
+    if (configResolutions[resolution + 'p'] !== true) continue
+    // Too big resolution for input file
+    if (input < resolution) continue
+    // We only want lower resolutions than input file
+    if (strictLower && input === resolution) continue
+    // Audio resolutio but no audio in the video
+    if (resolution === VideoResolution.H_NOVIDEO && !hasAudio) continue
+
+    resolutionsEnabled.add(resolution)
+  }
+
+  if (includeInput) {
+    // Always use an even resolution to avoid issues with ffmpeg
+    resolutionsEnabled.add(toEven(input))
+  }
+
+  return Array.from(resolutionsEnabled)
+}