Video corruption outside Mocha defined areas

I am using Mocha Continuum (ver 6.0.2) inside BCC 2019 plugins for Avid Media Composer (6.5.2). I have discovered sever image mottling outside the specific area I have defined by using Mocha. It is particularly evident if I use more than one effect in successive tracks above the clip. In other words, if, for example, I use mocha Tone and Color to change luminance or whatever in a specific area — using Mocha — then, say, I add another BCC effect, like Brightness and Contrast, above that track (again using Mocha to delimit the effect), there seems to arise, in a cumulative way, a degradation, or mottling, of the entire image. Has anyone run into this? Is there a setting in Mocha, or in the BCC effects individually, that I have missed or somehow messed up? Any help would be appreciated. I am at the end of an exhausting two-hour doc, and trying to figure this out is draining me.

I can’t think of a reason that stacked filters would affect the Mocha PixelChooser behavior, but can you break it down into individual steps to analyze it. For the bottommost effect (with the others disabled) try turning on the View Mask / Matte option in the PixelChooser controls and confirming the mask/matte looks like what you’d expect. Then do the same in the stacked effects and see if the mask/matte looks correct in those too. Does that offer any clues as to where things are going astray? If not, can you provide some screenshots to help illustrate what you’re seeing?


Jason, thank you for your reply.Yes I have looked at the masks and they are all as defined by me. What’s more, the anticipated effect is functional as required in each track. It’s just that image degrades globally, especially as other effects are added above. I have closed the machine for the night. I will generate a screenshot tomorrow. Thanks again…

Jason, my source footage are MOV. files, high definition, 24P. They were imported into Avid as DNxHD 175. I am using an old mini max matrox box to send the image to an exterior monitor. But the monitor will not show the image if Avid Project Type is selected as 1080p/23.976. So I have been editing in Project Type 720p/23.976. But, oddly, I have just lately noticed that if I render the effects in question while in 720p, the problem at hand is greatly diminished, almost nonexistent. The images I sent to you were rendered under Project Type 1080. Why do you think this is happening? Any ideas? And most importantly, are there any downsides to re rendering everything in 720p even though the footage is DNxHD 175 imported while in 1080p? I am also seeing that there is actually an ever so slight degree of greater sharpness in the image rendered at 720p, as opposed to 1080p.


Hi, Peter,

I somehow missed the images you sent. Could you try resending them and let me know how they were sent. If they can be shared publicly you could just attach them to this forum. You can also send a Private Message through forum by clicking on my name/icon and choosing the Message button that pops up. Or you could email me directly: jclement at borisfx dot com

As for the configuration, my first thought is to ask what happens if you enable the Bypass option at the top of each Continuum filter to temporarily turn them off. If you still see the mottling then it suggests this is something outside the Continuum filters themselves and instead something else inside pipeline - perhaps related to the host’s own resizing/reformatting in the workflow you describe.