+/**
+ * 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)
+}
+