Render Cache (Smart & User) - Auto Blanking Footage Issue

Good Day everyone,

I have the weirdest issue with 18.6.4. As soon as I add a CST in Color page (no setting/default), after a few seconds of playing, Resolve adds output blanking to the footage. I have checked the timeline blanking and reset it just in case, checked the sizing tab and reset it also. Nothing helps.

Does anyone know what this issue is?

I haven't seen any other reports like this.

You should consider updating to the current 18.6.6 to make sure any bugs in the area are actually still there.

Hello Jim,

Same issue with 18.6.6. And what I noticed as I put footage on the Video track 1 and the problem video on track 2. It is actually making an alpha channel, so the black bars are actually a "crop".

It only shows up when the user of smart cache has been generated. I have never seen something like this before.

Does this give you any ideas?

Thank you in advance

OK.

Let's take a step back from Color to Edit.

What's your timeline resolution? The resolution(s) of the clips on V1 and V2? What camera(s) was used to record those clips?

I placed a compound clip above the problem track, and just the parts where the compound track is. The video does not generate the bars. The compound clip is made up of two titles. So as the playhead meets the compound clip (1/3 in) the transparent/blanking area goes away, the moment it is off of the compound clip, the "cropping" returns.

OK.

Let's take a step back from Color to Edit.

What's your timeline resolution? The resolution(s) of the clips on V1 and V2? What camera(s) was used to record those clips?

Ok, on the edit page. The resolution is 1920x1080 (Panasonic DVCPro .mxf). The cropping is seen on the color and edit page.

There are sometimes issues with Compound Clips, one of those issues involves alpha channels.

For now, eliminate the Compound. Set things up without that. Report back.

Another interesting thing I just tested. So I put a fusion composition above both of those clips (compound & trouble clip) and now the cropping shows up even in the parts where the compound was showing normal.

In the fusion clip, I added a transparent background (100% transparent) and connected it to the media out.

There are sometimes issues with Compound Clips, one of those issues involves alpha channels.

For now, eliminate the Compound. Set things up without that. Report back.

Just for clarity, the only time the video looked normal was when the playhead was over the compound clip, but if I put a fusion clip above them. The blanking issues return.
I removed the both of them, and the blanking issue is now over the entire clip where the cache has been generated. And for clarity, the parts where the clip's cache has not been generated, it looks normal (no cropping). If I turn of caching, it also looks normal, so no cropping of the clip.

Hello Jim,

You will not believe what/how this has been fixed. But it is still a serious bug in my opinion. As you cannot export as you think it should work. I have used the settings "scale to fit" for many years with this footage from this camera. But by putting the project settings to "Scale full frame with crop", it displays like it should.

Here are the exact specs of the footage and timeline, and I would also like to send you a short piece of footage from this camera so you can recreate this issue also.

Notice the timeline has a different scaling than the project, when it is set as the project setting "scale to full and crop", it fixes the issue. The fourth image is placed in the next message, as only three attachments per message.

Screenshot 2024-03-25 at 18.02.47.png (961.28 KiB) Viewed 279 times

Screenshot 2024-03-25 at 18.01.52.png (951.96 KiB) Viewed 279 times

Screenshot 2024-03-25 at 18.02.30.png (966.65 KiB) Viewed 279 times

Are you from Blackmagic Design?


Greetings,
Robert

Late screen shot

Screenshot 2024-03-25 at 18.00.24.png (1016.22 KiB) Viewed 279 times

Also, here is the technical spec according to Media Info.
The Pixel aspect ratio acording to Fusion is 1.33333

Screenshot 2024-03-25 at 18.15.25.png (985.84 KiB) Viewed 264 times

The Pixel aspect ratio acording to Fusion is 1.33333

That may play a role here.

Are you from Blackmagic Design?

No, I'm just a user like you.