Did you know that the jit.movie (or jit.qt.movie) object will report when it has completed a ‘read’ operation? You can show that report to the user as visual feedback, and/or you can use that report to trigger other events in your program, such as querying for information about the movie that is being read.

When jit.movie receives a ‘read’ message it opens the specified movie file and reads in the first frame of video (followed by successive frames if the ‘autostart’ attribute is on). It also sends out a ‘read’ message of its own out its right outlet, reporting the name of the file and a “flag” (a 1 or a 0) telling whether the read operation was successful. A typical output message might look like ‘read dishes.mov 1’. By looking for that success flag in the outgoing ‘read’ message (using a select 1 object), you can confirm that the operation was successful, and can trigger other things to happen.

report when movie is read

The route object in this patch looks for the selector ‘read’ and sends the rest of the message (the filename and the success flag) out its left outlet, the unpack object separates the symbol (the filename) from the integer (the flag), and the sel 1 object sends a ‘bang’ if the file opened successfully.

The example patches “Movie attributes” and “Attributes of jit.qt.movie” show how to use that ‘bang’ to query the jit.movie object for other useful information contained in the movie’s attributes, such as its duration, its frame rate, etc.