interlaced video: unpredictable quality

[Zoltán]

Indeed, that is what I meant with 'nice comb edges': it's not a desired effect, it's just a symptom I use to try understanding what's happening; comb artefacts (especially when freezing) just show that fields are merged without any deinterlacing processing during encoding or diplay.

Inventing Interlacing was a flawed workaround for the problem of giving better experience of movements to the user using the same bandwidth.

I understand that, but have no clue; when playing video, even with multiple layers, none of the system counters (Win Task Manager) report any resource being bottlenecked (GPU, CPU, RAM, disk,...are all below 25% utilization)

Do you also see this on the Resolume output monitor?
Maybe you could upload a video so we can see what's going on exactly on your display, and Resolume UI?

[benoitvm]

I should do that..but I'm in a super hurry to finalize a setup for a show coming WE.
I will resume t'shooting and provide samples sometime after that - thx for your fast response time !!!

It is also quite possible that the root cause of my problems is that when using Resolume for this show (i.e. with this 50i constraint), the GPU may not like the fact that the primary display (where Avenue runs) is the laptop panel @60p and the Arena output is sent to the external videomixer (BMD ATEM Television Studio v1) via the laptop's HDMI configured as 1080i50....this framerate mismatch may give us a clue...

[benoitvm]

Inventing Interlacing was a flawed workaround for the problem of giving better experience of movements to the user using the same bandwidth.

True, at that time CRT phosphor latency allowed easy deinterlacing so at that time it was a smart design decision (I'm from that generation )

[benoitvm]

I should do that..but I'm in a super hurry to finalize a setup for a show coming WE.
I will resume t'shooting and provide samples sometime after that - thx for your fast response time !!!

It is also quite possible that the root cause of my problems is that when using Resolume for this show (i.e. with this 50i constraint), the GPU may not like the fact that the primary display (where Avenue runs) is the laptop panel @60p and the Arena output is sent to the external videomixer (BMD ATEM Television Studio v1) via the laptop's HDMI configured as 1080i50....this framerate mismatch may give us a clue...

OK, my show is now over, and I had indeed some moments where the connected projector had not-so-smooth playback of DXV3 video (mostly progressive!); I need to go to the bottom of this and understand why the output fps constanly varies in the range 47 to 50 fps (comp is set to 50) with no bottleneck (setting the fps to auto shows there is ample resource available for higher fps), even when idle (all layers ejected or simple PNG displayed without any sfx). I think I need to dig into undertanding how frames are supposed to sync (or not) between a computer with HDMI and an external display like TV or projector, and how to address the problem.
Avenue is a great solution for my type of performance, but fixing [unpredictably] unsmooth video is absolutely necessary.

I'm even ready to jump into your lab with my 'offending' laptop (6 Core i7-8850H, 32 GB RAM, Quadro P2000/4GB, NVMe SSD) to discuss & test this....if not too far away from Belgium....

[Zoltán]

There are some threads on the forum on unsmooth playback.

Sometimes the answer is simple as having differen refresh rates between devices, and frame alignment is not matching up perfectly. Thus you see frame jitter, 1 input frame displaying for 2 output frames, then output skipping a frame.
Resolume renders at a variable frame rate, the FPS display you see is an average of 1 seconds. If you see this FPS dip, something occupied the system so Resolume couldn't render all the frames you asked it to.

Keeping an eye on the resource monitor tools, windows already offers is a great way to find a bottleneck.

[benoitvm]

There are some threads on the forum on unsmooth playback.

Sometimes the answer is simple as having differen refresh rates between devices, and frame alignment is not matching up perfectly. Thus you see frame jitter, 1 input frame displaying for 2 output frames, then output skipping a frame.

I guess this occurs even when devices have identical fps, b/c their clocks aren't sync'ed ?
In our case, the PC HDMI output (=Avenue full-screen output) was set to 50i (common denominator for our show as explained earlier in this thread), BUT the internal laptop panel (Avenue control display) was set to 60p (50p not available). All videos were set to DXV3 25p and the comp. was set to 50p.

Resolume renders at a variable frame rate, the FPS display you see is an average of 1 seconds. If you see this FPS dip, something occupied the system so Resolume couldn't render all the frames you asked it to.

OK, but why would the fps continue to vary between 47 & 50 during the diplay of a single PNG w/o any effect ?

Keeping an eye on the resource monitor tools, windows already offers is a great way to find a bottleneck.

Not a single resource has exceeded 25% utilization at any time. When I set the comp to auto and send content accordingly, the actual fps keeps up easily (but varying between 57 & 60 fps, so there is ample room to process things at 50 steady)
And again I insist on this point: when a video plays too unsmoothly, sometimes restarting it (or restarting Avenue) fixes the problem, sometimes not (this is another proof that the system is not bottlenecked). That is my main questioning.
I will do a search on unsmooth pb in the forum as you suggest, but I continue thinking the root cause is lack of sync between Resolume's fps and the downstream device fps, even when there is NO bottleneck.
Of course, if that's the root cause, I see not solution