android – a little bit slow when playback h264 raw video with ffmpeg

I have running scrcpy to record a h264 raw video from android device, but when I playback it in linux with ffmpeg, the video looks like a little bit slow.

The video encoder in android device should be variable fps since video frame update actually depends on screen content change or not.

Does h264 raw video has frame rate information or only PTS values,, if playback use PTS, it should be the same speed as original frames.

What’s the reason maybe cause such slow playback effect?