mpeg - interface to the mpeg device driver .EX include "draw.m"; include "mpeg.m"; mpeg:= load Mpeg Mpeg->PATH; play: fn(d: ref Display, w: ref Image, dopaint: int, r: Rect, file: string, notify: chan of string): string; ctl: fn(msg: string): int; keycolor: fn(d: ref Display): ref Image; Mpeg provides a primitive interface to the mpeg (3) device.

Play plays the specified MPEG file in rectangle r within window w on display d . The dopaint flag specifies whether, before playing the movie, to paint the rectangle with the chroma key colour of the device.

Notify is a channel upon which to receive errors and status. If notify is nil , play runs synchronously, returning the empty string ("") when the movie completes, or a description of any error. If notify is not nil , play spawns an asynchronous process to play the movie and returns the empty string immediately; the process returns the status on the notify channel when the movie completes.

Ctl writes msg , the string given as an argument, to the MPEG control interface /dev/mpegctl .

Keycolor uses the Display d to create a single-pixel, replicated off screen Image of colour Chroma ( 16r05 ).

/dev/mpeg

/dev/mpegctl

/appl/lib/mpeg.b