GH5 GH5 4k 8bit 60P much better than 8bit 30P
- Thread starter Vesku
- Start date
visceralpsyche
Well-known member
More fps = less change between frames = better motion estimation = less macroblocking errors 
Thomas Smet
Veteran
Yup same concept that benefited 720p 60p broadcasts and why they could get away with a lower bitrate and still look very good and why 60p 1080p can also look spectacular at a less than 2x bitrate compared to 30p. IPB encoding is all about changes between frames and the more frames you have the less change there is with each frame. Same reason why optical flow type slow motion in post works much better with a 60p source than it does with a 24p source. Much easier to predict and create motion vectors due to a much smaller change between frames.
This is precisely why I always preferred 720p 60p broadcasts to 1080i. 1080i is not only attempting to encode 30 frames with large changes between those frames but the video was interlaced and yielded vertical detail not much higher then 720p. Even horizontal detail back in the day was limited since most 1080 HD cameras recorded 1440x1080 including the Sony HDCAM F900 which I used a lot. The GH5 today is lightyears ahead of what the F900 could do which is really amazing considering the F900 was a $100,000 camera back then.
Don't even get me started on the chroma sub sampling of interlaced broadcast video which is absolute garbage compared to progressive in terms of look and the encoder attempting to predict motion/changes. 720p always sounded inferior on paper but it had so many other advantages. It was the 60p that made it great. 1080p 60p is the true holy grail for broadcast TV and I will be very happy when we say goodbye to interlaced forever. From an engineering perspective interlaced was ingenious on analog TVs but it has no place in a digital world anymore.
Sorry a bit of a tangent there. I guess my point was just how much encoders struggle with not only 24/30 fps but how interlaced really butchered the efficiency as well. Ironically 24p struggles a lot more with IPB encoders than 60p does which is the opposite one would expect. Kind of why I always preferred 50p in Europe and in general always felt PAL was a superior format to NTSC. To me it better matched 24p with a slight pitch shift or audio retiming and had higher resolution so it reproached cinema material better.
Again another tangent. Maybe I should stop now.
This is precisely why I always preferred 720p 60p broadcasts to 1080i. 1080i is not only attempting to encode 30 frames with large changes between those frames but the video was interlaced and yielded vertical detail not much higher then 720p. Even horizontal detail back in the day was limited since most 1080 HD cameras recorded 1440x1080 including the Sony HDCAM F900 which I used a lot. The GH5 today is lightyears ahead of what the F900 could do which is really amazing considering the F900 was a $100,000 camera back then.
Don't even get me started on the chroma sub sampling of interlaced broadcast video which is absolute garbage compared to progressive in terms of look and the encoder attempting to predict motion/changes. 720p always sounded inferior on paper but it had so many other advantages. It was the 60p that made it great. 1080p 60p is the true holy grail for broadcast TV and I will be very happy when we say goodbye to interlaced forever. From an engineering perspective interlaced was ingenious on analog TVs but it has no place in a digital world anymore.
Sorry a bit of a tangent there. I guess my point was just how much encoders struggle with not only 24/30 fps but how interlaced really butchered the efficiency as well. Ironically 24p struggles a lot more with IPB encoders than 60p does which is the opposite one would expect. Kind of why I always preferred 50p in Europe and in general always felt PAL was a superior format to NTSC. To me it better matched 24p with a slight pitch shift or audio retiming and had higher resolution so it reproached cinema material better.
Again another tangent. Maybe I should stop now.
My view of 1080i is that it is 60 fields with the same temporal motion as 60P just half the vertical resolution an odd or even field. The camera is taking just as many images as 60P it is just only recording or transmitting half the vertical resolution as an odd or even field. It is not 30 progressive frames split up into 60 fields. 29.97fps is the sync pulse for interlace sync ( tells down stream equipment when to start the interlace sequence ) and is used as the timecode. Yes it worked wonderfully for CRT's in a analogue world.
Yeah but that is 6.25 MB more per second of footage. I can't afford that. Its 625 MB for 100 seconds. ~188 TB a year!
Mushy crap it is for me then. Oh, no, wait!
But both look like mushy crap?
Indeed but 4k 30fps is slighty sharper than 4k 60fps ( only if you pixel peep =) ).
You see?
Even when you fish without the bait you'll catch one if there are enough fishes at one place at the time.
I was just pointing out unrelated but trendy argument to the case.
GH5 4k 8bit 30P and 60P are made from the same sensor data. IQ should be identical before compression which is better in 60P.