Why is horizontal movement jerky/blurry?
This is a side-effect of converting interlaced TV content for display on a progressive PC monitor. For a quick explanation of this, a TV frame is made up of 2 fields, running at 50Hz (50 frames per second) with field 1 covering odd lines (1,3,5,…,571,573,575) and field 2 covering even lines (2,4,6,…,572,574,576). A whole “screen” (of 576 lines) updates every 1/25th of a second (25FPS). This means that neither field 1 nor field 2 contain a whole image, and hence it will have gaps in it. This isn’t a problem on a TV screen since they’re designed to update this way, but a PC monitor updates it’s whole screen every “pass”, so the resulting image will contain elements of two different points in time. If the video is shown without any deinterlacing you get horizontal lines next to any moving objects as shown below: Here you can see the horizontal lines next to moving objects. 1 field will contain the current frame, but the other field contains the previous field, hence a difference – in
