Open GOP
When encoding MPEG video, a GOP which uses referenced pictures from the previous GOP at the current GOP boundary. For example the GOP is open when B Frames at the start of a GOP rely on I or P frames from the immediately previous GOP. Also see Closed GOP.



Overburn
According to the official standards, a cd (and a cd-r disc as well) should have a capacity of 650MB or 700MB of data, or an equivalent of 74 minutes or 80 minutes of audio.

As the laser beam in a cd recorder writes on cd-r media, it travels from the center of the disc towards its edge. Before the physical edge of the cd, there is an already set limit to prevent the laser beam writing beyond that, so that the physical edge of the cd's writable surface will never be met.

This means that there exists a security zone at the edge of the cd-r media. If we could write into that security zone, we could gain in capacity, since we would be able to write more data on the cd. This is called overburning.



Overscan
The area at the edges of a television tube that is covered to hide possible video distortion. Overscan typically covers about 4 or 5 percent of the picture.

back to the top