Summary: | Some transparent clips appears with black background on timeline or in Project bin | ||
---|---|---|---|
Product: | [Applications] kdenlive | Reporter: | Andrew Shark <ashark> |
Component: | Video Display & Export | Assignee: | Jean-Baptiste Mardelle <jb> |
Status: | RESOLVED FIXED | ||
Severity: | normal | CC: | ashark |
Priority: | NOR | ||
Version: | 17.12.3 | ||
Target Milestone: | --- | ||
Platform: | Arch Linux | ||
OS: | Linux | ||
Latest Commit: | Version Fixed In: | ||
Attachments: | Videos encoded in different codecs with transparent background |
Description
Andrew Shark
2018-03-17 12:59:05 UTC
I have tested mlt for supporting transparency in these codecs. I used the following command: melt normal_video.mp4 -track <file> -transition affine where <file> is a png or video file with transparency. Result is the same as for ffmpeg. Here is a table of results: +-----------------+--------+-----+----------+ | container-codec | ffmpeg | mlt | kdenlive | +-----------------+--------+-----+----------+ | png-none | yes | yes | yes | +-----------------+--------+-----+----------+ | qt-animation | yes | yes | yes | +-----------------+--------+-----+----------+ | avi-tscc | no | no | no | +-----------------+--------+-----+----------+ | qt-prores | yes | yes | no | +-----------------+--------+-----+----------+ | qt-cineform | yes | yes | no | +-----------------+--------+-----+----------+ So I can say that the fact that kdenlive is not supporting qt-prores and qt-cineform is definitely a bug. And tscc is probably ffmpeg's unimplemented feature. Thanks for your detailed report. It is indeed a bug in MLT's qtblend transition that I wrote. It does not correctly detect the alpha channel. I am investigating, but in the meantime, as a workaround you can add a transition to your clips, like cairo blend to force the alpha compositing. Thanks for reply and for suggestion. I did not know that you are also a developer of mlt. Great respect to you =)! Now fixed in MLT's git master |