[FFmpeg-user] Why does changing Y4M frame rate cause a 4x larger encoded H264 size?

[Moses DeJong]

> 
>> What might be going on here and how could I get ffmpeg or x264 to get the higher compression results seen with 30 or 60 FPS in the Y4m header but with the low frame rate settings in the header? The frame rate defined in the M4V output header controls playback rate and I am not able to say encode a 30 FPS video and then play it back at 1 FPS on the client side.
> 
> x264 modulates rate control, taking into account, frame duration, which is much larger for a 1 FPS video than 30 FPS.
> 
> See https://stackoverflow.com/a/49623331/5726027
> 

Thanks so much for the info Gyan,

Mo