What features are supported by CEA-608 closed captions for standard definition?
CEA-608 supports only a single sized, mono-spaced font with characters appearing over an opaque black background. The captions can be displayed one block at a time (pop-on), one character at a time (paint-on), or one line at a time with previous lines rolling up as new lines are drawn in (roll-up). A caption block can have up to 4 lines and up to 32 characters per line, although for accessibility reasons, it is recommended not to exceed 2 lines and 26 characters per line. The captions can be placed at various points on the screen, but there are some restrictions on placement depending on the mode. Characters can be drawn in a few different colors, although typically only white is used for the actual caption text. Other fonts, styles or sizes cannot be specified. The characters can be italicized or flash on/off. Since the text and formatting codes are decoded into an image by the TV, the TV has some control over the appearance of the captions. Some newer TVs allow the user to override t
