Frametime Analyser

Frametime Analyser is a tool that detects duplicate frames in game footage to calculate FPS and frame times

It is inspired by Digital Foundry's FPSGui tool:

Setup

Frametime Analyser requires the following prerequisites

• Python 2.7.14
• OpenCV 4.2.0
• Numpy 1.14.3
• Matplotlib 2.2.5

Usage

1. Clone this repo
2. Open Frametime Analyser.py in a text editor and set file_path to the location of your video
3. Run Frametime Analyser.py

Notes

• Input video must be encoded at 60 FPS
• OpenCV decodes video in software, so a fast CPU is recommended. i7-3770 is sufficient for H.264 @ 1080p. H.265 or higher resolutions would require a faster CPU

Technical Overview

Key processing steps

1. Calculate absolute difference of each pixel relative to previous frame
2. Calculate the average difference across the whole frame, giving the value frame_diff
3. Compare frame_diff with the exponential moving average of frame_diff. If frame_diff is significantly lower than the moving average (suggesting a duplicate frame), the frame is counted as a duplicate

Limitations

• Frametime Analyser assumes the input video is encoded at a constant frame rate of 60 FPS, with dropped frames encoded as duplicate frames
• Frametime Analyser does not account for screen tearing. V-Sync should be enabled when recording the game footage.