Redrock Micro and image flip, loss in quality in post? at DVinfo.net

Lonnie Bell · August 26th, 2006, 01:15 AM

it has been explained to me, and please correct me if i'm wrong, that any effect, transition, most anything other than a simple straight cut edit, involves a renderering (although today's g5's do it faster than real time), there's still mathmatical computations and truncating of data or rounding off of data - thus a minor loss in quality...

now my question is: with the Redrock Micro, obviously every frame has to go through the image flip in post, and therefore the above mentioned hoops, bells, and whistles, so is the quality loss just negligible of this type of "effect" (an image flip)...

any Redrock Micro people care to chime in...
(i originally posted with P&S, and it was suggested i come here...thanks)

your thoughts would be appreciated,
Lonnie

Sam Jankis · August 26th, 2006, 11:15 AM

I've never noticed a loss in quality with 180 degree rotations.

Ben Winter · August 26th, 2006, 01:06 PM

In a way, you're right; unless your work files are uncompressed, which would be huge, you're going to have to stay inside the bounds of whatever compression you're working in (usually the 25mbit/sec mpeg-2 compression you imported in), so everytime you render an effect, your video gets run through the same compressor. That's why Cineform is great for HDV, because it converts your files to heftier, more flexible video that can be manipulated without "generation loss". But since rotating 180 degrees doesn't add or subtract data, the compressor has little effect if any on the resulting image anyway.

Frank Hool · August 27th, 2006, 12:46 AM

i'll start opposite words to Ben :). In a way You're wrong... re-placing pixels(or group of pixels) shouldn't generate any loss from itself. Theres no compression algoritm what says heads should be upper screen and be aware if You see a man with earring in his left ear.
...but it if You haven't habit to work with only uncompressed(or lossless compression) videodata then flipping evoke just another lossy compression step in between Your camera footage and Your final piece.
So, i don't have so huge storage to have habit to work with only losless codecs, thatswhy i worked out following workflow.

Kurt August · August 27th, 2006, 04:15 AM

Just make sure you're onlining progressive footage. With FCP 4.5 I have noticed a difference. In general, it depends on a couple of factors, I think: recording mode, NLE and a Good Eye.

If you have the time and internal urge, I would try using Shake, which is a bargain these days. And it's good fun.

August 26th, 2006, 01:15 AM	#1
Lonnie Bell Major Player Join Date: Mar 2006 Location: Las Vegas, NV United States Posts: 361	Redrock Micro and image flip, loss in quality in post? it has been explained to me, and please correct me if i'm wrong, that any effect, transition, most anything other than a simple straight cut edit, involves a renderering (although today's g5's do it faster than real time), there's still mathmatical computations and truncating of data or rounding off of data - thus a minor loss in quality... now my question is: with the Redrock Micro, obviously every frame has to go through the image flip in post, and therefore the above mentioned hoops, bells, and whistles, so is the quality loss just negligible of this type of "effect" (an image flip)... any Redrock Micro people care to chime in... (i originally posted with P&S, and it was suggested i come here...thanks) your thoughts would be appreciated, Lonnie __________________ Lonnie Bell mamas boy productions Las Vegas, NV

August 26th, 2006, 01:06 PM	#3
Ben Winter Trustee Join Date: Jun 2005 Location: Hollywood, CA Posts: 1,675 Images: 1	In a way, you're right; unless your work files are uncompressed, which would be huge, you're going to have to stay inside the bounds of whatever compression you're working in (usually the 25mbit/sec mpeg-2 compression you imported in), so everytime you render an effect, your video gets run through the same compressor. That's why Cineform is great for HDV, because it converts your files to heftier, more flexible video that can be manipulated without "generation loss". But since rotating 180 degrees doesn't add or subtract data, the compressor has little effect if any on the resulting image anyway. __________________ BenWinter.com

August 27th, 2006, 12:46 AM	#4
Frank Hool Major Player Join Date: Apr 2006 Location: Barca Spain Posts: 384	i'll start opposite words to Ben :). In a way You're wrong... re-placing pixels(or group of pixels) shouldn't generate any loss from itself. Theres no compression algoritm what says heads should be upper screen and be aware if You see a man with earring in his left ear. ...but it if You haven't habit to work with only uncompressed(or lossless compression) videodata then flipping evoke just another lossy compression step in between Your camera footage and Your final piece. So, i don't have so huge storage to have habit to work with only losless codecs, thatswhy i worked out following workflow. Last edited by Frank Hool; August 27th, 2006 at 12:10 PM.

August 26th, 2006, 11:15 AM	#2
Sam Jankis Major Player Join Date: Jun 2006 Location: St. Pete, FL Posts: 223	I've never noticed a loss in quality with 180 degree rotations.

August 27th, 2006, 04:15 AM	#5
Kurt August Regular Crew Join Date: Aug 2005 Location: Belgium Posts: 94	Just make sure you're onlining progressive footage. With FCP 4.5 I have noticed a difference. In general, it depends on a couple of factors, I think: recording mode, NLE and a Good Eye. If you have the time and internal urge, I would try using Shake, which is a bargain these days. And it's good fun.