Tech Talk: “Observations on YouTube Bitrates”
DISCLAIMER: As with anything tech related, information in this article could change by the time you read it. So, use the advice/tips here as simply a starting off point!
Lately, I’ve been thinking a bit about how bitrates work with YouTube. A lot of people just upload videos and forget about it, but there’s a lot that goes on behind the scenes that most won’t think about. For example, even though it should be obvious that YouTube compresses videos that you upload in an effort to save data, the amount that something gets compressed varies and will depend on several things. Also, there are work-arounds for when you really think that quality matters and don’t care as much about the file size at upload.
First, let’s consider the approximate bit-rates that YouTube will re-encode your uploads to depending on the source resolution and frame-rate:
- 1280×720 (720p) @ 30 FPS: 2000 kbps
- 1280×720 (720p) @ 60 FPS: 4000 kbps
- 1920×1080 (1080p) @ 30 FPS: 4000 kbps
- 1920×1080 (1080p) @ 60 FPS: 8000 kbps
- 2560×1440 (1440p) @ 30 FPS: 8000 kbps
- 2560×1440 (1440p) @ 60 FPS: 16000 kbps
- 3840×2160 (4K) @ 30 FPS: 16000 kbps
- 3840×2160 (4K) @ 60 FPS: 32000 kbps
Now, although a bit-rate of 32,000 kbps sounds pretty high, that’s actually slightly less than what’s used on Blu-Ray discs for high-quality 1080p movies. Bit-rate is very important when it comes to fidelity of the graphics involved, so if you have a video where being able to see detail with high clarity is important, you’ll want to have a good bit-rate for the video. One “trick” that people have used with YouTube has been that if they have a 1080p video that they think needs to have a much higher viewing bit-rate than would be available at 4000 kbps, they will encode the video and scale it to 1440p or 4K, which would afford the video higher quality viewing options. Even on a standard 1920×1080 display, when the video is scaled up to 4K and then played back (downscaled), there is more data per pixel present in the video and thus it would look a bit more crisp than standard 1080p would.
Obviously, for videos that would not be compressed online, it’d be perfectly fine to just have a high-bitrate video that was 1920×1080, just as you would on a Blu-Ray disc. So, when uploading a video to YouTube, you might want to keep these limitations in mind.
Also, this doesn’t really account for the possible bitrates used for strange resolutions like 2560×1080, 3440×1440, or 5120×2160 (all of which are 21:9 ultra-wide formats).
With the video encoder I use, I take the raw footage, edit it all together, and then encode it in H.264 to an AVI format and set the “quality factor” in the encoder to 20. This seems to result in nice, crisp video and a reasonable file-size. So far, YouTube has played nice with that, and only on a couple occasions did something odd happen like a 60 FPS video only getting 30 FPS playback. Yet, there are even work-arounds to that, such as going into the YouTube editor, not changing anything, but saving the new video and forcing it to encode the video again.
Anyway, that’s my helpful little article for today! See you guys soon!
