REWRAPPING CINEPLAY TV

Dropping video frames resulted in visible judder, which was unacceptable for the prestigious project. Pitch shifting the audio was not an option. Specification limitations require a 23.976 source due to the increased data rate required for simultaneous playback of two streams of 1920 × 1080 video.

REWRAPPING CINEPLAY TV

Originally shot for European TV at 1920 × 50i, our job was to meet 3-D Blu-ray needs. The most complicated frame rate conversion I've worked with was a recent 3-D shoot of a classical pianist. By the 1930s, the UK had already standardized on 25/50, so moving between the frame rates was required. This provided a decent picture in a living room environment with minimal motion artifacts. TV frame rate was standardized in 1941, the best that could be economically achieved was 30fps interlaced at 2:1.

In most theatres, film is projected at 72fps via a shutter showing the same frame three times before the next is moved into place. The process inserts additional frames so that the duration is unchanged. Speeding up from film would be visible therefore, 2:3 pulldown was invented. The television frame rate in the Americas is 30fps.

But, the same version in Europe is 228.5 minutes, leading many people to think 10 minutes were cut! “Gone with the Wind” is 238 minutes long. The duration is reduced by 1/24 every second, but we cannot see this. One simply plays back at 25fps and shifts the audio pitch. The most common example is when moving from film at 24fps to PAL at 25fps.

Time-lapse footage shot at one frame per minute and played back at 30fps or 25fps for TV is an example. The simplest frame-rate conversion presents the original frames at a different rate than at which they were shot. But, how do we know what the “native” frame rate of a piece of video is supposed to be? Also, time-lapse or high-speed filming is done with a planned presentation frame rate different from the capture frame rate. When a ramp-up or ramp-down is done during creation, the native frame rate must be specified as it is no longer constant throughout the piece. The convention is that motion imaging has a native frame rate - the number of images created over a particular period of time.

Rewrapping cineplay