X-Git-Url: https://git.immae.eu/?a=blobdiff_plain;f=shared%2Fmodels%2Fvideos%2Fvideo-resolution.enum.ts;h=06e0779617f908386d839c6c8b9e7ed2246fc651;hb=7cd1b12c19d0589d1d692ed0571ca0800f028aea;hp=e40e5b58bcce45b000e3e2df79b50d1508f7067a;hpb=c1c86c1599acf8aad71fb7d7f312c43d6d1fa5ac;p=github%2FChocobozzz%2FPeerTube.git

diff --git a/shared/models/videos/video-resolution.enum.ts b/shared/models/videos/video-resolution.enum.ts
index e40e5b58b..06e077961 100644
--- a/shared/models/videos/video-resolution.enum.ts
+++ b/shared/models/videos/video-resolution.enum.ts
@@ -1,62 +1,89 @@
 import { VideoTranscodingFPS } from './video-transcoding-fps.model'
 
 export enum VideoResolution {
+  H_NOVIDEO = 0,
   H_240P = 240,
   H_360P = 360,
   H_480P = 480,
   H_720P = 720,
-  H_1080P = 1080
+  H_1080P = 1080,
+  H_4K = 2160
 }
 
 /**
- * Bitrate targets for different resolutions and frame rates, in bytes per second.
+ * Bitrate targets for different resolutions, at VideoTranscodingFPS.AVERAGE.
+ *
  * Sources for individual quality levels:
  * Google Live Encoder: https://support.google.com/youtube/answer/2853702?hl=en
- * YouTube Video Info (tested with random music video): https://www.h3xed.com/blogmedia/youtube-info.php
+ * YouTube Video Info: youtube-dl --list-formats, with sample videos
  */
-export function getTargetBitrate (resolution: VideoResolution, fps: number,
-    fpsTranscodingConstants: VideoTranscodingFPS) {
+function getBaseBitrate (resolution: VideoResolution) {
   switch (resolution) {
-  case VideoResolution.H_240P:
-    // quality according to Google Live Encoder: 300 - 700 Kbps
-    // Quality according to YouTube Video Info: 186 Kbps
-    return 250 * 1000
-  case VideoResolution.H_360P:
-    // quality according to Google Live Encoder: 400 - 1,000 Kbps
-    // Quality according to YouTube Video Info: 480 Kbps
-    return 500 * 1000
-  case VideoResolution.H_480P:
-    // quality according to Google Live Encoder: 500 - 2,000 Kbps
-    // Quality according to YouTube Video Info: 879 Kbps
-    return 900 * 1000
-  case VideoResolution.H_720P:
-    if (fps === fpsTranscodingConstants.MAX) {
-      // quality according to Google Live Encoder: 2,250 - 6,000 Kbps
-      // Quality according to YouTube Video Info: 2634 Kbps
-      return 2600 * 1000
-    }
-
-    // quality according to Google Live Encoder: 1,500 - 4,000 Kbps
-    // Quality according to YouTube Video Info: 1752 Kbps
-    return 1750 * 1000
-  case VideoResolution.H_1080P: // fallthrough
-  default:
-    if (fps === fpsTranscodingConstants.MAX) {
+    case VideoResolution.H_NOVIDEO:
+      // audio-only
+      return 64 * 1000
+
+    case VideoResolution.H_240P:
+      // quality according to Google Live Encoder: 300 - 700 Kbps
+      // Quality according to YouTube Video Info: 285 Kbps
+      return 320 * 1000
+
+    case VideoResolution.H_360P:
+      // quality according to Google Live Encoder: 400 - 1,000 Kbps
+      // Quality according to YouTube Video Info: 700 Kbps
+      return 780 * 1000
+
+    case VideoResolution.H_480P:
+      // quality according to Google Live Encoder: 500 - 2,000 Kbps
+      // Quality according to YouTube Video Info: 1300 Kbps
+      return 1500 * 1000
+
+    case VideoResolution.H_720P:
+      // quality according to Google Live Encoder: 1,500 - 4,000 Kbps
+      // Quality according to YouTube Video Info: 2680 Kbps
+      return 2800 * 1000
+
+    case VideoResolution.H_1080P:
       // quality according to Google Live Encoder: 3000 - 6000 Kbps
-      // Quality according to YouTube Video Info: 4387 Kbps
-      return 4400 * 1000
-    }
+      // Quality according to YouTube Video Info: 5081 Kbps
+      return 5200 * 1000
 
-    // quality according to Google Live Encoder: 3000 - 6000 Kbps
-    // Quality according to YouTube Video Info: 3277 Kbps
-    return 3300 * 1000
+    case VideoResolution.H_4K: // fallthrough
+    default:
+      // quality according to Google Live Encoder: 13000 - 34000 Kbps
+      return 22000 * 1000
   }
 }
 
+/**
+ * Calculate the target bitrate based on video resolution and FPS.
+ *
+ * The calculation is based on two values:
+ * Bitrate at VideoTranscodingFPS.AVERAGE is always the same as
+ * getBaseBitrate(). Bitrate at VideoTranscodingFPS.MAX is always
+ * getBaseBitrate() * 1.4. All other values are calculated linearly
+ * between these two points.
+ */
+export function getTargetBitrate (resolution: VideoResolution, fps: number, fpsTranscodingConstants: VideoTranscodingFPS) {
+  const baseBitrate = getBaseBitrate(resolution)
+  // The maximum bitrate, used when fps === VideoTranscodingFPS.MAX
+  // Based on numbers from Youtube, 60 fps bitrate divided by 30 fps bitrate:
+  //  720p: 2600 / 1750 = 1.49
+  // 1080p: 4400 / 3300 = 1.33
+  const maxBitrate = baseBitrate * 1.4
+  const maxBitrateDifference = maxBitrate - baseBitrate
+  const maxFpsDifference = fpsTranscodingConstants.MAX - fpsTranscodingConstants.AVERAGE
+  // For 1080p video with default settings, this results in the following formula:
+  // 3300 + (x - 30) * (1320/30)
+  // Example outputs:
+  // 1080p10: 2420 kbps, 1080p30: 3300 kbps, 1080p60: 4620 kbps
+  //  720p10: 1283 kbps,  720p30: 1750 kbps,  720p60: 2450 kbps
+  return baseBitrate + (fps - fpsTranscodingConstants.AVERAGE) * (maxBitrateDifference / maxFpsDifference)
+}
+
 /**
  * The maximum bitrate we expect to see on a transcoded video in bytes per second.
  */
-export function getMaxBitrate (resolution: VideoResolution, fps: number,
-    fpsTranscodingConstants: VideoTranscodingFPS) {
+export function getMaxBitrate (resolution: VideoResolution, fps: number, fpsTranscodingConstants: VideoTranscodingFPS) {
   return getTargetBitrate(resolution, fps, fpsTranscodingConstants) * 2
 }