darrrkmanxxx wrote: ↑Sat Feb 08, 2025 11:31 am
Hey guys,
at which step davinci rersolve does a bad job with hevc?
Scene detection or the analyzing itself?
IME, it isn't the scene detection or CM analysis, per se, it's that the frames are decoded inaccurately from the start, so bad data is fed to both algorithms, making both inaccurate as a result. Garbage in, garbage out.
In my testing, the HEVC decoding in Resolve was inserting additional frames, so as a result the scene starts and durations were all inaccurate, not because the scene detection algo is bad, but because (as you can see when scrubbing through the video) the scenes actually do start and end at inaccurate frames. And the DV CM algo is based on scenes and frames, so if it doesn't get accurate data, it's going to start and stop scenes at inaccurate times.
For example ---
3 actual scenes:
(1) Start frame: 0, Duration: 100; (2) Start frame: 100, Duration: 100; (3) Start frame: 200, Duration: 100
Resolve-decoded HEVC:
(1) Start frame: 0, Duration: 101; (2) Start frame: 101, Duration: 103; (3) Start frame: 204, Duration: 100
So all the scenes in the DV metadata start sliding later by a couple/few frames each time another frame decoding error is introduced (in scenes 1 & 2).