+
+/**
+ * Bitrate targets for different resolutions and frame rates, in bytes per second.
+ * 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
+ */
+export function getTargetBitrate (resolution: VideoResolution, fps: number,
+ fpsTranscodingConstants: VideoTranscodingFPS) {
+ 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
+ } else {
+ // 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) {
+ // quality according to Google Live Encoder: 3000 - 6000 Kbps
+ // Quality according to YouTube Video Info: 4387 Kbps
+ return 4400 * 1000
+ } else {
+ // quality according to Google Live Encoder: 3000 - 6000 Kbps
+ // Quality according to YouTube Video Info: 3277 Kbps
+ return 3300 * 1000
+ }
+ }
+}
+
+/**
+ * The maximum bitrate we expect to see on a transcoded video in bytes per second.
+ */
+export function getMaxBitrate (resolution: VideoResolution, fps: number,
+ fpsTranscodingConstants: VideoTranscodingFPS) {
+ return getTargetBitrate(resolution, fps, fpsTranscodingConstants) * 2
+}