[FFmpeg-user] Change of frame quality with different framerate setting

Yanhao LI yanhao.li at outlook.com
Tue Aug 17 12:41:04 EEST 2021


I would like to ask a question about framerate setting in FFmpeg. I wanted to convert a sequence of images into a video, using the following the command:

  *   ffmpeg -r 10 -f image2 -start_number 1 -i img%04d.png -vcodec libx264 -pix_fmt yuv420p out_video.mp4

to set the framerate to 10. The size of output video is 1.4MB. I also converted using the same command with framerate equal to 5, and found that the video size is bigger, which is 34MB. I reextracted the frames from both videos to compare the image quality, and found that the frames with framerate equal to 10 are blurrier. From what I can see, the framerate only changes the duration of each frame, but why the quality of frame is also changed? Can anyone give an explanation of this?


More information about the ffmpeg-user mailing list