Time between frames in RTSP stream

Python
1

Hi Everybody.

I’m trying to achieve stable inflow of new frames.
I’ve used threading to separate image analysis from frame reading.
Average time between frames in 50FPS stream is 20 ms…
… but when i check difference between each frame i got time between 1 ms and 50 ms:

[37.878662109375, 1.48046875, 2.094482421875, 46.072509765625, 1.70361328125, 49.056396484375, 1.463134765625, 1.626953125, 55.8798828125, 1.5107421875, 38.955810546875, 1.45166015625, 8.177978515625, 40.328369140625, 1.58447265625, 48.63623046875, 1.72119140625, 1.703369140625, 46.313720703125, 1.509033203125, 48.306640625, 1.595458984375, 8.275634765625, 50.98974609375, 2.272705078125, 46.52392578125, 1.497802734375, 2.11669921875, 37.48388671875, 2.898681640625]

are the frames that I’m getting really 20 ms apart but the transfer is “messing it up” ?
cap.get(cv2.CAP_PROP_POS_MSEC) returns constant 20 ms.

Thanks in advance for answer :slight_smile:
Piotr

2

it makes no sense to desire that.

the processing gives you data as it becomes available. this is desirable.

YOU are responsible for timing its presentation correctly using Presentation Timestamps. PTSes are fundamental to all video.

3

Thanks for clarification!