Incorrect application of analysis fps when extracting frame image from video.mp4

[wdeninger]

When "Analysis FPS" is less than the capture FPS in buffer pass through mode, images retrieved (from thumbnail for instance) are found to be at time earlier in time than expected.

The DUT was capturing a mp4 video pass through at 12 fps with the analysis set at 4 fps. When a time segment was closed after 600 seconds, the number of analysis frames was found to be approximately 4*600=2400 (2533) as expected. Verification of the first and last frame time stamps within the stored video.mp4 file playback showed the correct time aligned within one second of the 10 minute interval.

However, when the last frame (2533) was selected from the frame view (above), the returned image did not correspond to the 600th second time frame... but corresponded to a time of 212 seconds...1/3 of the expected 600 second time.

This occurs because the system is not aware of the 12fps rate being stored to the video.mp4 file via pass through. The system appears to be using the analysis 4 fps to calculate seek location within the video record. This problem also applies when clicking on thumbnail views of alarm events..

(From thumbnail)

(result after clicking on thumbnail)

I have not been able to identify the correct place within the code where modifications could be made.

-W

Want to back this issue? Post a bounty on it! We accept bounties via Bountysource.