7th Sense Delta Kullanıcı Kılavuzu - Sayfa 5

Sunucu 7th Sense Delta için çevrimiçi göz atın veya pdf Kullanıcı Kılavuzu indirin. 7th Sense Delta 20 sayfaları. Synchronising delta media systems

Marking Time

However accurate quartz system clocks are, they do remain individual and separate. This means that the

precise duration of a second varies between them. The difference will be very small, but over a day,

fractions of a second either way accumulate, and at 60 fps, drift between system elements can become

apparent. This guide provides a basic overview to how the elements in a Delta Media Server show

system can be synchronised, and when and why this matters.

DeltaServer synchronises frame display with the refresh clock of the server's output GPU(s). The first

pixel is presented at the very start of the first line, every time. But when we have a number of servers,

or multiple GPUs in each, many display devices, audio, and other parts of the system, show controllers

and so on, how do we keep everything perfectly in sync?

Time, and Displaying Frames (Refresh)

Multiple graphical displays shared across several servers on the same display system will not be

synchronous unless the graphical processing units (GPUs) in all servers themselves are fully

synchronised. Display hardware must synchronise the screen refresh across all display devices, by using

a common, repeating timing pulse to trigger the VSync signal in every display and synchronise the

HSync. Absolute or elapsed time does not matter: but each new frame will be displayed simultaneously

across all devices. A genlock input per server, and a simple house-sync pulse generator is all that is

required for display synchronisation.

Matching Frame Delivery and Display

When frames are passed from DeltaServer to a graphics processor (GPU), the frame will be held until the

VSync signal is ready. When in 'Auto' or 'Hardware Timed' mode, DeltaServer is locked to the GPU

refresh clock, whether this is internal to the GPU, or drawn from an external sync reference. Frames

must therefore be completely loaded before the VSync, otherwise a frame may be dropped. Delta pre-

caches a configurable number of frames from disk to ensure this does not happen. Presenting frames

from disk through to display requires adequate disk performance, graphics performance and processing

capacity, so the higher the media resolution, and the more blending, warping or effects being applied,

the more will be demanded from the server.

Movie Time

Sequential movies are always in frames, so the framerate is defined in its format. Delta allows the

application of framerate compensation, so that media of different framerates can be played on the

same timeline. This can be smoothed by choosing interpolation.

Synchroni s i ng Del ta Medi a Sys tems