(OT) Rotating Video 90 degrees Without Quality LossI

[Darius1968]

I apologize in advance that this is probably off topic, but decided to post this here because folks using IMatch deal a lot with video files. 
Okay, so a Facebook friend sent me some videos he shot with his whatever that are in mp4 format.  I wanted a way to download these for local use on my PC.  I found a Firefox plugin that allowed me to do just this.  The problem:  The video is downloaded just fine, but rotated wrongly by 90 degrees CCW.  Is there a simple way for me to just rotate this video 90 degrees CW to correct the issue, without actually having to re-encode that video and consequently lose quality? 

[Mario]

I have no idea. I don't know if videos have something like a rotation flag. Did you try another player?

[Ferdinand]

Is there a simple way for me to just rotate this video 90 degrees CW to correct the issue, without actually having to re-encode that video and consequently lose quality?

I don't deal with video very often, and so I don't know a lot.  But on the few occasions that I've needed to do this I had to re-encode.

[cytochrome]

Try this:

- open your mp4 in VLC
- hit Pause
- CTRL-E
- click Video effects (my VLC is french, should be something like that)/Geometry
- click Rotation and use the mouse to rotate

Francis

The video I tested it with is pretty bad so not so sure about any loss of quality..