Resolume Forum

Hi

I have a set of video files that came from a film editor. They were ProRes422HQ, 1080/24p. I need to show them on a monitor thats behind the actor on a film set. We will shoot the scene with a digital camera running 24.

The screen is driven by arena in 1080/60Hz. I have checked for flicker, etc, but modern TVs look okay with almost any input, except for a small percentage that has a backlight that flickers madly.

Okay, so we shot a test and we can see a high number of frames blended together. Like almost every second frame. We tried multiple configs to try to narrow down the problem. We tried Mac Pro, Macbook, several PCs. We tried Arena 4 and 5. The PC reported 170fps when playing the single HD image without any effect with DXV files. It did 120fps with the native Prores files.

Such a high fps means it CANNOT be a frame drop or lack of horsepower. The multiple hardware and codec means its not a DXV conversion problem or a hardware problem.

What is most maddeding that I tried ProVideoPlayer - which I hate, and it created a very bad looking, jagged image, but without any frame blending.

Any ideas?

do you see the blended frames in the shot only? have you tried to drive the monitor with 24 fps? if you drive at 60 with a 24fps footage it can well be that you see the blended frames in the shot because the footage/ monitor changes frames while the camera shoots it.
edit: thinking of it, switching the output to 24hz doesn't necessarily mean that the footage will be played in sync with that without frame blending, but at least it would happen in Resolume, Joris could confirm that.
So the next step I think would be to sync your camera to resolume via SMPTE/blackburst/genlock.
You can sync resolume playback to SMPTE LTC, that way your frames in the camera and the frames in resolume should be in sync, (regardless of the outputs frame rate, but stay @24hz to be sure.)

But there is surely someone who has done a setup like this on the forum.

okay I have spent the night thinking and here is what I think:

the monitor is 60Hz. If its real 60 or 59,97, its anyone's guess, but I'll go for 60.

Meaning it doesnt matter if I play 24 or 25 or 29 to it, it will show 60 frames anyway. the only change that the conversion will still happen, but it will happen in the monitor' electronics, and not in Resolume. And its not neccessary will be any better, even if I sync them. That would only help if the monitor would be a real broadcast 24p monitor.

I think the next question is: how does resolume convert 24fps to 60 on the fly, and is there any frame blending happening? There should not be, as 24*2,5=60, meaning it should play each frames twice and half of them a thirs time - there are no broken frames, there is no point of doing blending.

Thanks

you don't see the blended frames because of the conversion.
you see it because the camera sees two footage frames for its 1/24 sec frame time if the footage is not synced to the camera.
If you can't sync, you could try to lower shutter time, and increase ISO so you have a better chance of capturing only one frame of the footage, but then you might catch the screen refresh of the monitor.

so basically the camera is doing the blending.

beg pardon, but you're wrong.

if the cause of the blending would be the camera, I'd see it evenly on any material. It wont change regardless of any hardware or software change. But it does.

And a 'camera blending' is only an issue if you have some inter-time change the camera can catch - ie something that is changing between takes. If its a CRT, the camera can catch the black bar. In a plasma, the camera can catch the tearing of the slowly fading color segments. An LCD will change in 7-10ms, which is a quarter of a time of a camera frame time (42ms in 24fps), so you wont see the change even if it happen 'on camera'.

Bottom line: if I play a file from Qucktime player, all the frames are clear. If I play it from PVP, all the frames are clear. If I play it from resolume, there is doubled edges of any movement. and thats regardless of OS, hardware, in Arena 4 or 5. Why??

that's why I asked if you se the blending only in the camera footage.

Could you post a video and/or frames of the camera recording then, so we can see what you're seeing?

hi

yes I only see the issue in the camera footage.
I have attached a cropped image showing an edge moving (its actually travelling towards the bottom of the screen). Here you can see the resolume playback (top row) has a fainter trailing edge, which is about 100px wide...very noticeable, and its on almost every moving edge. It makes text hard to read.
On the bottom row you can see quicktime player playing a clean image - altough you can see a faint line on #2. On the quicktime footage, there is such a bended edge on a couple of frames in a 1min video, while on the resolume its on almost every second frame.

Can you switch the camera to a higher fps like 60p just for a test? that would show every frame the monitor displays.
this still looks like a double frame exposition for me, with the quicktime playback being slightly more in sync.
I'm 99% sure that resolume doesn't do frame blending on the output.

When playing back a 24p footage at a 60 fps monitor, then recorded with 60p you should see one source frame clear for 2 frames, and one for 3 in the recording, (and one blended every 2 and 3 if out of sync)