In FFmpeg, if you need to reduce the number of video frames using blending, you can achieve this by combining video frames through various methods. This is typically done by averaging consecutive frames or other blending operations. This process is sometimes referred to as frame rate conversion or motion interpolation.
To reduce the frame rate in FFmpeg, the common approach is to use the fps filter, which discards frames to reach the target frame rate instead of blending them. However, if you want to create a "motion blur" effect by blending adjacent frames, you can use the minterpolate filter.
Here is an example FFmpeg command that uses the minterpolate filter to reduce the frame rate and creates motion blur through frame blending:
ffmpeg -i input.mp4 -filter:v "minterpolate='fps=30'" output.mp4
This command reduces the frame rate of the video to 30fps. The minterpolate filter attempts to blend frames through smooth motion to reduce the frame count while maintaining natural fluidity of motion.
Please note that depending on your specific requirements, the command parameters may need adjustment. Additionally, blending frames may introduce unrealistic blurring, so it's important to weigh the pros and cons based on the intended use of the final video and the expectations of the audience.