Server can skip frames when output video stream

[shanyu-sys]

Description

The output video stream may not be consecutive. Since we always process the latest item in tracking stream, instead of the next item of the last processed one.

Corresponding code with the behavior.

Expected Behavior

I am not sure whether the behavior is as expected, or it's better that we always try to output consecutive frames.

Actual Behavior

Output videos can skip frames. The case is more severe when the server is at remote (low network bandwidth).

Screen.Recording.2023-09-11.at.6.25.33.PM.mov

Affected Version

main branch

Steps to Reproduce

run on remote server.

Checklist

• I have read the contributing guidelines
• I have verified this does not duplicate an existing issue