Final Cut uncompressed brightness playback issue at DVinfo.net

Nathan Troutman · April 26th, 2007, 11:37 PM

I have Final Cut 5.0.whatever and I have an 8bit 4:2:2 uncompressed timeline that I'm doing my final "online" edit in. I have this glitch, I guess. When I render and play the video the brightness (or gamma curve) is darker, but when I stop playback the frame that the playhead stops then gets brighter. Anybody what this is and why it's happening? I'm trying to figure out which is the real image. I only seem to have this problem with uncompressed but since I rough in effects work using single frames it makes it tough to get a real result if the rendered footage is going to look darker than the frame did when I set everything up. It doesn't seem to be the rendering since as soon as I stop playback on the rendered footage the frame displayed in the viewer becomes brighter. HELP

Shane Ross · April 27th, 2007, 08:46 AM

THis is a sign of a slow drive raid. It isn't fast enough to play back in RT, so FCP plays back a lighter (or darker) proxie image.

What drives are you using for this? And are you looking at this on an external monitor, or only the computer monitor?

Nathan Troutman · April 27th, 2007, 10:21 AM

I'm using only a three drive RAID 0 that gives me about 100MB/sec. This is within the data rate playback range of the uncompressed SHEER video codec I'm using, but your observation about reaching the RT ceiling and FCP making some kind of sacrifice to maintain playback was also my theory. I am viewing my video on my computer monitor not an external monitor running off of a card like Kona or Decklink. I tested a portion of the video by exporting it to see which of the two brightness would be in the final export and it seemed to be the brightess that the viewer displays when the current frame is being displayed rather than what it shows during normal video playback. So it does seem that for playback FCP is lowering the quality of something to allow for playback. The most important part for me is that the final output is what I'm seeing when I'm looking at single frames. Thanks for your help.

April 26th, 2007, 11:37 PM	#1
Nathan Troutman Regular Crew Join Date: May 2006 Location: Hoboken, NJ (New York metro area) Posts: 105	Final Cut uncompressed brightness playback issue I have Final Cut 5.0.whatever and I have an 8bit 4:2:2 uncompressed timeline that I'm doing my final "online" edit in. I have this glitch, I guess. When I render and play the video the brightness (or gamma curve) is darker, but when I stop playback the frame that the playhead stops then gets brighter. Anybody what this is and why it's happening? I'm trying to figure out which is the real image. I only seem to have this problem with uncompressed but since I rough in effects work using single frames it makes it tough to get a real result if the rendered footage is going to look darker than the frame did when I set everything up. It doesn't seem to be the rendering since as soon as I stop playback on the rendered footage the frame displayed in the viewer becomes brighter. HELP

April 27th, 2007, 08:46 AM	#2
Shane Ross Major Player Join Date: Apr 2004 Location: Los Angeles, USA Posts: 539	THis is a sign of a slow drive raid. It isn't fast enough to play back in RT, so FCP plays back a lighter (or darker) proxie image. What drives are you using for this? And are you looking at this on an external monitor, or only the computer monitor?

April 27th, 2007, 10:21 AM	#3
Nathan Troutman Regular Crew Join Date: May 2006 Location: Hoboken, NJ (New York metro area) Posts: 105	I'm using only a three drive RAID 0 that gives me about 100MB/sec. This is within the data rate playback range of the uncompressed SHEER video codec I'm using, but your observation about reaching the RT ceiling and FCP making some kind of sacrifice to maintain playback was also my theory. I am viewing my video on my computer monitor not an external monitor running off of a card like Kona or Decklink. I tested a portion of the video by exporting it to see which of the two brightness would be in the final export and it seemed to be the brightess that the viewer displays when the current frame is being displayed rather than what it shows during normal video playback. So it does seem that for playback FCP is lowering the quality of something to allow for playback. The most important part for me is that the final output is what I'm seeing when I'm looking at single frames. Thanks for your help.