About
A video bitrate is the number of bit per unit of time that a video sends to the display buffer (and sound).
It's given in:
- bps - bits per second
- kbps - kilobps
- mbps - megabps
It may be parameter that you give to your video editing software as a target to determine the file size.
The lower the bitrate is:
- the more the software has to compress the video
- which leads to loss of information
- which makes the video quality worse.
Formula
<MATH> Bitrate = \frac{fileSize}{Duration} </MATH>
Example: if the video file output of 200 MiB is desired for a movie of 10 minutes (600 seconds) long
The image bitrate is: <MATH> \frac{(200 * 8192 )}{600} =~ 2730 \text{ kBit/s total bitrate} </MATH> The video bitrate is (with a 128kb/s desired audio bitrate) <MATH> 2730 - 128 = 2602 \text{ kBit/s video bitrate } </MATH>
Streaming
The max bitrate you can set it to when streaming is limited by:
- your internet connection upload speed (If your upload speed is 12 mbps (megabits per second) then your max bitrate limited by your internet is 12,000
- the minimum and maximum of your streaming website
| Facebook Live | a max bitrate of 4,000 Kbps, plus a max audio bitrate of 128 Kbps |
| YouTube Live | a range between 1,500 and 4,000 Kbps for video, plus 128 Kbps for audio. |
| Twitch | a range between 2,500 and 4,000 Kbps for video, plus up to 160 Kbps for audio. |
Recording video locally, no limited to the bitrate
Note that because youtube is going to compress it anyway, there's no point in waiting for the big video file to upload.