Webm to Mp4 encoding color problem

[Gigi1303]

Hello, long time lurker here, but I'd like to say thanks for all the help you gave me in the past, this is a wonderful community.
Now onto my problem. I didn't know the exact section where to post, because my problem is also web related somehow, so I'll post it here, feel free to move the topic to the current section.
I have two videos uploaded on a website:

- http://stage.fightbean.it/alephd/wp-content/themes/alephd/img/video/solutions/AlephD_s...lutions01.webm is the webm version, which doesn't give problems and the blue is correct
- http://stage.fightbean.it/alephd/wp-content/themes/alephd/img/video/solutions/AlephD_solutions01.mp4 - this is the converted mp4 version of the webm above. the quality is ok, but the blue is different and that's a big problem for me because I have it playing on a website which has a background with the very same blue color, and it's not a pleasant view.

Now, after all this blurb, my question is: is there a tool, or a program (it doesn't matter if it's free or not), or some codec settings that can export an mp4 without correcting or dulling the colors? I used many different programs to export the mp4, from video.online-convert.com to iMovie and after effects (for Mac) but it doesn't make any difference, the mp4 version has duller and different colors.
Thanks for your time and sorry for the long first post.

[jagabo]

Here I've overlaid the webm video onto the top left corner of the MP4 video. Is this the difference you are seeing?



If so, the issue is that the MP4 video is flagged as rec.709 colors and the webm video is unflagged. Generally, rec.601 is used for standard definition video and rec.709 is used for high definition video. The player is assuming the webm video is rec.601 since it's unflagged and smaller than 1280x720.

https://forum.videohelp.com/threads/329866-incorrect-collor-display-in-video-playback?p...=1#post2045830
https://en.wikipedia.org/wiki/Rec._601
https://en.wikipedia.org/wiki/Rec._709

If you flag the MP4 video as rec.601 the player might display it correctly. The other way of fixing it is to convert the colors from rec.601 to rec.709 so that they play properly when decoded with a rec.709 matrix. But players don't always follow the flagged colors. Some always use rec.601, some always use rec.709, some use rec.601 for SD, rec.709 for HD -- and it varies what frame size is consider SD vs. HD.

[Gigi1303]

Yes, that's exactly the difference!
Thanks. I will try your solution and let you know.

[Gigi1303]

Would you suggest any tool or program that could handle this conversion on a Mac? I can't seem to find anything at the moment....