FPS indicators in RV not displaying correct FPS?

[cjlee]

Hi all,

We recently received a ticket from one of our users that the FPS indicator does not change when he changes the Source FPS using “Image” > Set Source FPS". I understand that the first FPS indicator represents the Playback FPS so that one should not change, but it seems like the second FPS indicator (the one that represents the actual measured fps) should be changing when the Source FPS changes. For example, after changing the Source FPS to 10, one would expect the second indicator to hover around 10. Instead, it continues to hover around the Playback FPS value (i.e. 24) even though the video is clearly playing at 10 FPS. Could this be a bug?

Some more comments per a team member of mine:

Based on this in the rv docs:
“There are two FPS indicators on the timeline. The first indicates the target FPS, the second the actual measured playback FPS.”

It really sounds like both numbers should be looking at whatever is current, not just the Global FPS setting, and that at least the 2nd number should be accurate, if it’s the “actual measured playback FPS”. It’s not intuitive to set a source FPS at 10 FPS, have playback be 10 fps, but have that computed FPS indicator number always right around 24. Is there a good reason that you couldn’t instead display the actual computed FPS in that kind of case?

It’s especially hard when doing a Sync with other users, to know if they’re getting the same FPS change that you set on your session, when there’s no UI element to display that.

Thanks

[Kevin]

Hello!

Your described behavior is what I would expect of the application. For example in the image attached - Playback is set to 30fps and the measured rate is 30.3. Which version of RV are you using? Also, is this happening only during a sync session only or in just normal operation of RV?

Cheer,
Kevin

[Kevin]

Hi @cjlee!

I’ve included a short video to explain this, maybe it’s just setting the wrong FPS. In the attached video you can see me change the playback FPS and the source FPS.

RV FPS vs SourceFPS

The playback FPS sets the output FPS that RV is trying to playback at. RV can handle multiple types of media of mixed rate & size at the same time. For example you could have 23.976fps & 24fps content playback together synced to a 24fps playback rate.

The fps indicator next to it, is meant to be more like a “confidence monitor” of the fps you’re actually achieving. It should always be reporting against the FPS rate set for playback.

Now the source FPS is what RV interprets the FPS to be set in the file. Usually this is read from the meta-data in the media file. Sometimes this can be improperly set by whatever encoded the media or you could be dealing with image sequences that might not contain that metadata. If so, you can change and override that source FPS. This allows RV to properly interpret playback for that selected media. When I change it on a movie file from 24 to 10fps, I’m in essence increasing the length of “time” that clip lasts because I’m saying this clip was encoded at 10fps. This shouldn’t affect the confidence monitor as the playback rate is still set to 30 or 24. If I change the playback rate to 10, I would expect the monitor to report back against that rate.

Please let us know if you’re not seeing the above outcomes and we’ll see if there’s a bug somewhere…

Cheers,
Kevin