Quicktime Video Too Dark

mindbend · #1 December 28th, 2006, 03:55 PM

No, this isn't another thread about Mac vs. PC gamma. This is about Quicktime Player playing movies much darker than VLC.

See here:
http://www.mindbendtoo.biz/qtvsvlc/qt_vs_vlc_a.jpg

Per this thread, I have been trying to find the perfect way to rip DVDs in preparation for iTV:

http://macosx.com/forums/mac-os-x-sy...tunes-itv.html

Nobody responded, but I think I've got a workflow I'm reasonably happy with (Macthe Ripper to extract the VBO and ffmpeg to reencode).

However, there's one big problem. Quicktime Player is playing the exact same movie files darker than VLC Player. So basically any movie I play on this same exact machine, but using the two different players, QTP is too dark. VLC looks excellent. I have noticed this on two different machines, so it's not a fluke.

I can't find any preferences in QTP to use a different color profile or anything like that.

At first I thought it was a side effect of the encoding process, but then I realized that even if I use the master video file before re-encoding it, it's still too dark in QTP.

I also tried playing the movies via iTunes. Same issue. In fact, it may have even been darker still, though I didn't bother to prove that to myself. I haven't tried other players yet.

What's going on!

Mikuro · #2 December 28th, 2006, 04:32 PM

I've observed this same behavior. I'm not sure exactly what the cause is, but I don't think it's a bug in either VLC or QuickTime Player. I think slight differences from different decoders are to be expected, partly because many will try to be "smart" and "improve" the video (with varying degrees of success).

It might also have to do with the fact that MPEG2/4 video uses YUV color, not RGB, and any computer decoder must convert the colors to RGB for display. It's possible that different decoders use different conversion formulas or different rounding rules (or something of that sort).

Theories aside, you could try using more VLC-like codecs for QuickTime if you prefer that look. Perian is based on the same open-source tools as VLC, and will override QuickTime's standard MPEG4 decoder. I have noticed it to be brighter than QuickTime's built-in decoder. I'm not sure if it will deal with MPEG2 video, though. I've never tested it.