v2.18.0 initial black frame

[IoannisSyrogiannis]

I am making a post, instead of filling a bug because it might be something I miss in the way the packaging works.
I was creating somewhat different DCPs out of the same excerpt of a 4K ProRes file. I was setting the timing from a specific frame to a specific frame, both not beginning or end frames. I then demuxed the j2c images with asdcp-test.
The thing is that on all DCPs, the first frame was black, contrary to the original frame (when first encountered that, I thought it could have been a scene change).
It's an easy-to-miss thing, since most first frames of a video are black, or most last frames before a feature are black.
The version update logs don't mention anything for 2.18.2 (or previous). Can anyone else confirm that same behavior? (Or is the first .mxf frame I get from exporting with asdcp-lib not shown?)

[StephW999]

Hello,
Indeed I just did a little test with DoM 2.18.0 with a ProRes 422 with a duration of 1min15sec,08frames
I cut the beginning at 4sec,3frames and the end at 1min4sec,18frames. That is a playback duration of 6sec,11f
I made a DCP Flat 4K with version 2.18.0 and 2.16.66
By unwrapping the one made with version 2.18.0 the first image is Black
By unwrapping the one made with version 2.16.66 the first image is normal.

Capture218_j2c0.PNG (73.15 KiB) Viewed 2637 times

Capture218.PNG (23.89 KiB) Viewed 2637 times

Capture216.PNG (24.82 KiB) Viewed 2637 times

[carl]

Sounds like a bug indeed - I will take a look. Feel free to file it (then you'll get updates on progress) - or I can.

[carl]

It could have the same cause as or be related to https://dcpomatic.com/bugs/view.php?id=2932

[StephW999]

It could have the same cause as or be related to https://dcpomatic.com/bugs/view.php?id=2932

probably

[carl]

I would be interested to here if you have the same problems in 2.18.3.

[StephW999]

With 2.18.3 it works perfectly. Theres 's no black image at the beginning when I cut the video.
Thanks !

[carl]

Thanks for checking it out!

[IoannisSyrogiannis]

Excuse me for being absent on this. Yet, I was wondering if the 2.18.4 lost a bug for another to spring up.
I was cropping a video, today, by using the timing tab. I was going to the scene change and choosing to "trim up to current position".
The weird thing is that the first frame of the composition would either not be cut off, or would not change to the one supposed to be.
It would seem to me that if frame 1 is from the previous take and frame 2 was the first frame of the subsequent, if I was navigating to frame 3 and trimmed, the first frame would stay the same and the second would have now been what was previously the 3rd.
The un-tamed frame would be encoded to the final DCPs as well. (You never know.)

That would have made me think that the matter has to do something with key frames of the video. Though, the original video is a 4K ProRes 422 HQ .mov file.

[carl]

Can you share your ProRes file?