[HELP] My problems with Hybrid

[Selur]

Perhaps I shouldn't use FFV1 (For example, ProRes opens quickly.), or maybe I should use the old library instead, as it's faster.

... or report the issue to the LSMASHSource folks, or use BestSource ...
I can confirm, that with your FFV1 file, I can reproduce the problem with LWLibavSource.

Issue seems to be that mkvtoolnix uses V_MS/VFW/FOURCC here, I first thought it might be a vfw wrapper problem

Codec ID                                 : V_MS/VFW/FOURCC / FFV1

using ffmpeg instead of mkvmerge for the muxing, one gets:

Format                                   : FFV1

but the indexing is still slow.

Cu Selur