[FFmpeg-trac] #7883(ffmpeg:new): Videos with alpha channel are corrupted by scaling
FFmpeg
trac at avcodec.org
Mon May 6 02:44:39 EEST 2019
#7883: Videos with alpha channel are corrupted by scaling
-------------------------------------+-------------------------------------
Reporter: Acru | Type: defect
Status: new | Priority: normal
Component: ffmpeg | Version: git-
Keywords: scale alpha | master
regression | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
Summary of the bug:
When using the scale filter on a video with an alpha channel, or if the
format is changed to rgba etc, the video is corrupted. I have not checked
if other filters are also effected.
This issue appeared between build 20190312-d227ed5-win64-static and build
ffmpeg-20190315-def18ac-win64-static, narrowing down what commit caused,
though I am uncertain exactly which. The issue persists in the latest
build available to me, 20190505-e384f6f-win64-static
How to reproduce:
{{{
A command such as the following, on a video with alpha;
ffmpeg -i "Door (png).mov" -vf "scale=iw*0.5:-1" -y out.mp4
Or any video when the format is changed to rgba;
ffmpeg -i in.mp4 -vf "format=rgba,scale=iw*0.5:-1" -y out.mp4
The output log does not indicate any differences, before and after the bug
was introduced.
}}}
Some alpha-channeled videos are available here, for testing;
https://drive.google.com/open?id=0Bxp60P6x4uM2clU3VF91bzlYMnc
--
Ticket URL: <https://trac.ffmpeg.org/ticket/7883>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker
More information about the FFmpeg-trac
mailing list