What is the Appropriate Bitrate Setting for H.264 Output
What is Video Bitrate
Video bitrate is the number of bits per second output from video data (video color quantity, brightness measurement, pixel quantity), and the usual unit of video bitrate is kbps.
The Necessity of Setting Appropriate Video Bitrate
In the application of video conference, the quality of video and the network bandwidth occupation are contradictory. Normally, the video streaming occupying more bandwidth gets higher quality. Therefore, the high quality of video requires high network bandwidth. The way to solve the contradiction is video coding technology. To judge the advantages and disadvantages of a video coding-decoding technology, on one hand, we can compare which video's quality is better based on the same network; on the other hand, we can compare which video occupies less room on the basis of the same quality.
However, do videos with higher bitrate get high quality? In theory, it's true. Yet in the range of visual resolution, when the bit rate is high enough, it doesn't seem to make a difference. Therefore, the bitrate does have its optimal value. In the documentation of h.264 (also known as AVC or x.264), the recommended bitrate of H.264 video is as follows:
Suggested bitrates for different video resolutions with H.264 Encoding
|480P||720 x 480||1800Kbps|
|720P||1280 x 720||3500Kbps|
|1080P||1920 x 1080||8500Kbps|
Suggested bitrate settings for mobile phones with different resolution
|192 x 144||320 x 240||480 x 360||640 x 480||1280 x 720||1920 x 1080|
|Ultra low bitrate||30kbps||60kbps||120kbps||250kbps||500kbps||1mbps|
|Ultra high bitrate||500kbps||1mbps||2mbps||4mbps||8mbps||16mbps|