This is excellent thread with solid information regarding frame rates.
I have anomaly on my system that I'm trying to understand. It's not causing issues but it bothers me to see it.
I have Epson project 5030UB connected to RPi2 and recently testing RPi3.
What I see is that refresh rate reported by the projector is not in sync with what Pi is displaying.
My settings are:
Adjust display refresh rate - Always
Sync playback to display OFF
Half the time I see projector showing 24.00Hz while RPi is set for and reports 23.98Hz.
The randomness is based on Kodi player initializing the screen. By starting the system projector may boot into 24.00Hz or 23.98Hz even if Kodi is set and displaying 23.98Hz. If I change refresh rate from Kodi to 24 and back to 23.98 or even cancel half way through projector may jump into 23.98Hz. Changes to audio mode, restart player "Y" key and anything else that makes the screen black can cause projector to jump into 24Hz or 23.98 rather random at 50% chance.
RPi SSH tvservice -s reports in both cases 24.00 and 23.98 the same message:
"state 0x12000a [HDMI CEA (32) RGB lim 16:9], 1920x1080 @ 23.98Hz, progressive"
Monitoring HDMI status with tvservice -M when changing frame rates:
"[I] HDMI in HDMI mode"
When playing true 24.00 fps movie I get automatic refresh rate change to 24 and tvservice -s reports:
"state 0x12000a [HDMI CEA (32) RGB lim 16:9], 1920x1080 @ 24.00Hz, progressive"
I didn't notice this issue with PS3. It shows 23.98Hz on the projector always.
I'm not quite sure about the mechanism behind this. I don't really see dropping frames every 20s when projector is in 24Hz rather then 23.98. My settings for frame interpolation is set to low on scale 0 to 3. I know you guys are against this feature but the low setting helps to sharpen the image with panning scenes and it does not eliminate true 24 frames experience. Any missing frames are clearly visible on my 150" wall with or without frame interpolation.
Projector is showing Sync Info SSNN 02700 during 24.00Hz and SSNN 02696 when it is set for 23.98Hz. I don't have any information regarding this.
3D packed frames. Projector shows 24.00Hz at 90% at the time with RPi showing 23.98Hz always. On rare occasion I can see 23.98 on the projector info screen with 3D packed frames. PS3 is always showing 24Hz on 3D blu-rays.
My preferred mode for 3D on this projector with active glasses is high (max) for frame interpolation. I can't find any information and I don't have any equipment to measure this but it looks like the glasses are working at 120Hz fixed speed independent from the source material and projector frame rate. At 24 fps it looks like the 3D glasses are out of sync to video frame rate. With frame interpolation to the max. glasses will pick any high speed interpolated frames without noticeable pulsing and skips.
Pictures below are from latest Tarzan trailer from apple.com to illustrate the 32.98 to 24.00Hz issue. The issue is consistent on any 23.98 fps video material with RPi2 and 3 independent from source material or compression type.
watch gallery
watch gallery