1080i vs 720p / Sky+ Firmware Update
For those with a Sky+ PVR, the firmware was updated to a new HD look last night. This prompted me to check the HD output settings, and I realised that I could make a better choice for the HD output format.
The i in 1080i means that each frame is split in two, the odd lines and even lines are sent in two consecutive frames, which means each individual frame is 540 lines. Your eyes blue the two frames to make a complete picture, of one frame.
The p in 720p means all the lines in the frame are displayed one after another from top to bottom, progressively, all in one frame.
IT people adopted the ‘p’ format when they designed LCD screens as a simpler way to update a video display. Old fashioned CRTs use the i format.
The end result is that I switched the output of the Sky box from 1080i to 720p, which means in each pair of frames I see 1480 lines, compared with only 1080 lines in the interlaced format.
If you don’t get it, just try it, and see if you can see the extra detail your flat screen displays using the 720 lines per frame rather than 540.
I will now stop blogging for a while. Bill.