Magic Lantern Forum

Using Magic Lantern => Raw Video => Raw Video Postprocessing => Topic started by: Aarkon on March 02, 2016, 07:49:20 PM

Title: Green colors when converting .mlv with ffmpeg
Post by: Aarkon on March 02, 2016, 07:49:20 PM
Hello everyone!

I googled this one extensively, but as always, I might have failed to use the right words to make clear what I want. So just point me in the right direction if this is the case. Otherwise:
Recently, I was playing around with the raw video function of magic lantern once more, as I learned that the new version of magic lantern stores the raw video in a format that the latest version of ffmpeg finally understands. I was excited to try it out. And indeed, I was able to transcode the .mlv-files to anything ffmpeg provides as an output format.
Strangely, all my exports are green! Different codecs make me always see the same shift in colour:
http://imgur.com/GIJIDyo (http://imgur.com/GIJIDyo)

Strangely, using mlrawviewer, the colours look just fine.
http://imgur.com/tmamOUI (http://imgur.com/tmamOUI)

I would prefer to be able to use ffmpeg though, because then I could automate my work flow just a bit more. Also, even the latest version of mlrawviewer (1.4.3) appears to be buggy: When adding files to the export queue, I suffer a good chance mlrawvier hangs completely, and the only result I ever see is that video files of either 0 or 185 bytes of size appear. CPU usage never goes above ~ 15 percent on a quadcore. Still, my main issue is ffmpeg. (Apparently, it's a lot faster, too)

Has anyone fumbled around with this already? I just don't get the hang on it. I already tried to read the console printouts of mlrawviewer and figure out which ffmpeg parameters it uses to make the green mist disappear. But because it might use a certain combination of parameters to do so, the list of things have to try is literally endless. And maybe someone has already solved this, which I secretly hope. :) Thanks in advance, in any case.

Edit: If I command mlrawviewer to export all videos in the folder, I can see the queue, but it never goes on.
http://imgur.com/HHWkxDg (http://imgur.com/HHWkxDg)
Title: Re: Green colors when converting .mlv with ffmpeg
Post by: dfort on March 03, 2016, 12:46:23 AM
MLV support for ffmpeg was one of those Google Summer of Code projects that seemed to get just so far then ceased development before it was working properly. There was lots of excitement when it was first announced.

http://www.magiclantern.fm/forum/index.php?topic=11566.0

Too bad because it seems that it is almost working. It would be great if the ffmpeg developers take another look at it. Maybe it is time to file a bug report on the ffmpeg development site?

https://ffmpeg.org/bugreports.html