[Libav-user] frame rate and time base question

[Uğur Bozkaya]

Hi,

I am encoding a video using a specific framerate (let’s say 12 fps). When i check the rtmp stream info using ffprobe i see 
r_frame_rate = 12/1 (=144/12)
avg_frame_rate = 145/12
time_base = 1/1000

what is the reason behind this. Why avg_frame_rate has a different value. What I notice is that numerator is increased by 1 or a small value. 

When i check the rtsp info it looks 
r_frame_rate = 12/1
avg_frame_rate = 12/1
time_base = 1/90000

Also regarding the time_base, are these values standard for rtmp and rtsp, or can i specify these values?

Thanks,
Ugur