Hello all, I'm new here but I've had my HDPVR for a few weeks and have it working well except for one gigantic PITA. I bought it primarily to record gameplay from an XBox 360, but I have done some recording of some HD movies and TV shows as well, the problem is universal whether input from XBox or STB.
Quicktime is Colorsync aware and VLC and other programs are not. When I view the m2ts file in VLC it appears fine, a little flat but all the information is there. The same file post processed into mp4 through HDPVRC looks identical to the m2ts when viewed in VLC and when streamed to my XBox 360 it looks visually almost identical to the broadcast in color and contrast. The mp4 viewed in the Quicktime player, Final Cut or iMovie though gains a ton of density and appears visually way to dark.
I've done some poking around and it seems to be a problem with the h.264 codec and Quicktime and is exacerbated by using custom monitor profiles. I found this at thedvshow.com:"Quicktime has a feature, mostly hidden from users, which is designed to adjust the display gamma of quicktime movies on different machines to compensate for display difference.
Deep within the file, there is sometimes a little tag called 'gama' lurking which tells the Quicktime player what gamma correction the file was encoded with. While this is well-intentioned, motivated by the difference in display gamma between PCs and Macs, the Quicktime player offers no way to view this tag and change it. To work around this issue, we have created a small tool that strips the 'gama' tag out of offending quicktimes. It's a very simple tool which operates on all the file names and folders given to it."
I downloaded this app but its a terminal app with no instructions that I understand. If somebody could let me know how to use it I'd be willing to test it out.
So here is where I'm at:
Final Cut can't import the m2ts file and the mp4 files get the bad gamma added so I need to transcode the m2ts into the AIC codec using Voltaic which seems to be gamma free.
Viewing movies and TV shows in VLC and not QT would be ok but only on the computer and I want to add them to my iTunes library in order to stream to my XBox for viewing on the TV, the XBox can only play the mp4's.
Therefore I really need and want to use the mp4's but I can't overcome the gamma issue without transcoding which causes a loss in quality, disk space and time.
Steve I sort of addressed this with you a few weeks ago and as the trascoding for editing seemed to be ok but now that I'm playing with some TV/Movie programming its bugging me again.
If this gamma stripping app works would there be a way to include it into your post processing feature? As it appears to only affect the people with custom profiles and the results seem to vary and be bad then I would think that not having gamma info tied to the file would be beneficial for all.
A few links to help explain the issue. Sorry, apparently I don't have enough posting history to provide hotlinks yet.
Some info on this issue in a After Effects group:
The gamma atom program.
Its kinda weird to navigate to. But it is there under software.
Screen caps comparing the same file viewed in VLC on the Top QT on the bottom.