Ffmpeg streaming fails to update header with correct duration

[flv @ 0x21d6a00] Failed to update header with correct duration.
[flv @ 0x21d6a00] Failed to update header with correct filesize.

The streaming commands are as follows ：
ffmpeg -i test_video.mp4 -c copy -f flv rtmp://127.0.0.1/live/livestream
Need to add -re
fmpeg -re -i test_video.mp4 -c copy -f flv rtmp://127.0.0.1/live/livestream
bring ffmpeg Streaming is performed according to the frame rate of the original video , If it is not set, the above error will be reported , Because it will push the flow at full speed .