Color grading causes bad frames in rendered output

john-rappl wrote on 2/19/2020, 11:25 AM

VP 17 (387).

Long time VP user but first time trying to use Color Grading. This has happened on every project I have tried using Color Grading. Rendering using Magix AVC/AAC MP4 using Mainconcept and QSV and it happens for both - I have not tried other templates.

Rendered output from any event I add VP17 Color Grading to has a few random bad frames (in a 14 second video). The bad frames can be either a totally white frame (single frame!) or a frame with white and colored pixelation across parts of the frame that is not present in the source video. If the exact same event is rendered without Color Grading the output is good without bad frames.

I've tried several different sources (non-log profiles and Sony NX80 log3, Panasonic Cine4, Canon EOS R C-log) and it happens in all cases.

Bug or am I missing something?

Comments

fr0sty wrote on 2/19/2020, 1:10 PM

Could have to do with the QSV rendering... try updating your intel graphics drivers, or if you have a Nvidia or AMD GPU, try to render NVENC or VCE instead, or do a CPU only render.

The way to tell for sure would be to do a CPU only render (any template that doesn't have Quicksync, VCE, or NVENC next to it) and see if the problem persists.

john-rappl wrote on 2/19/2020, 2:53 PM

As I mentioned in my original post I have the same result using Mainconcept (CPU only) and QSV (Intel HD 630) rendering.

I have the latest Intel HD 630 driver (7755) installed but I might try an older one to see if there is a change. Intel has broken stuff before with these DCH drivers.

I have a couple AMD RX cards (560 and 580) but pulled them out because of problems with stability with VP17 with both GPUs installed. In addition, if I only use the Intel HD 630 I see timeline editing speed improvements (especially in pan & zoom) that disappear if both GPUs are installed and active. I like the idea of GPU accelerated FX and encodes but not at the expense of timeline editing performance!

And, just for reference, using VP15 I was able to use both the Intel built-in HD 630 (and get the timeline speed improvements) and the AMD GPU for FX and rendering UNTIL Intel changed to the new architecture DCH video drivers! At the time Intel claimed that they were aware of the issue but the only fix would be to have the application rebuilt with the newest Intel Media SDK. Magix would not do that with VP15 so I upgraded to VP17. Both GPUs now show up but VP17 does not use them correctly. If both are installed I get lags in pan and zoom just moving the scrubber!

fr0sty wrote on 2/19/2020, 4:57 PM

I guess the next step would be to try to render it out using another format... try Sony Avc and see if you get the same result.

fifonik wrote on 2/19/2020, 5:01 PM

I bet the issue would be fixed if you disable iGPU in VP preferences. Unfortunately, everything would be slow.

BTW, I do have RX 580 (recently replaced my RX 470) and do not have stability issues when it is used in VP15 & VP17. Possible, I do not know where I should find the pan/zoom performance drop you mentioned.

fr0sty wrote on 2/19/2020, 6:11 PM

Yeah, even if the GPU isn't being used to render, it's still being used on the timeline. Disabling GPU acceleration in the video tab of preferences might be the ticket.

john-rappl wrote on 2/19/2020, 6:13 PM

I did go back and test other formats (Sony AVC/MVC, Magix Intermediate and WMV) and they all failed with the bad frames. I turned off GPU in preferences and they all rendered correctly. Not the first time there have been issues with GPUs and VP but GPU acceleration is one of the reasons I use VP! I suspect I can find an earlier version of the Intel HD 630 driver that does not have the issue - not a fix, just a work around. It's a bug in either VP or the Intel driver!

To reproduce the GPU timeline acceleration issue... Drop a 4k video on the timeline, something longer than about 45 seconds. Open the pan and crop tool (sync cursor enabled) and just drag the scrubber back and forth. If I only have the Intel GPU enabled the scrubber is very responsive and using the task manager performance tab you can see the Intel GPU being used while you move the scrubber. If I have the intel GPU disabled and use the RX 580 or even if I have both GPUs installed and enabled there is a noticeable lag on my machine (i7-8700K, 16GB, 2 fast NVMe M.2 SSDs, Samsung PM981, WD Black) and again checking the performance tab neither GPU is getting used for that operation. Note that the last time I tried this was with the original release build of VP17. I may try again when I get time drop the RX 580 back in...

fifonik wrote on 2/20/2020, 1:34 AM

It is possible that you are talking about GPU decoding and when moving fast through you footage it helps a lot with 4K.

Unfortunately decoding with AMD GPU was not supported by VP17 until the very recent build 421 that is just released.