Museum Technology's approach of controlling multiple Pioneer 7400 DVD players requires certain steps to be taken in preparing the discs. The basic technique is to send the same commands to all of the players. Hence, all the discs must start at the same point. For example, in a three screen installation, the left screen's disc starts at Chapter 1, center screen at chapter 1, and the right screen also at chapter 1. In this way, when the Museum Technology control unit sends its command, all three players will start in sync at the start of chapter 1. They will then play to end of chapter 1, as defined by the first frame of chapter 2.
The Pioneer 7400 DVD player may be addressed either by chapter number or by frame number. Operationally, they are equal in performance, however, in multi-screen applications it is recommended that chapter addressing be used. In general, it is better for the chapter mark to be precisely placed on the start frame of each disc during the editing process.
When using chapters, it is vital that one more chapter be placed at the end of the material. This is because the Pioneer protocol instructs the player to seek and start playing at the start of a chapter, and play until the start of the next chapter. In other words, play from chapter 1 to chapter 2. Hence, in order to play chapter 1, there must be a chapter 2. The end chapter, as a minimum, need be only 15 frames of black.
When using frames, make sure that the disc is authored such that search-by-time is enabled. For example, DVD Studio Pro has this function disabled by default.
In this application, the DVD players are under external control. The Museum Technology controller takes care of all "housekeeping" functions, such as start up and attract loop if used. There should not be any commands authored on the disc; these will cause contention with the external commands.
Other considerations:
It is well to keep in mind that the Pioneer 7400 incorporates a frame buffer, which grabs and holds the last frame it was on when a new command is issued. It holds this frame for the duration of its seek to the start of the new material. This feature can be used to advantage if a "seamless" loop is desired. If the "out" ending frame matches the content of the "in" starting frame, the frame buffer will serve to "plug the gap" while the player searches.
However, it can be a disadvantage when multiple programs are on the same disc which do not begin and end with black. This is because the player will, when it reaches its stop point (which is the start frame of the next chapter) freeze that frame while searching. It might well be that that frame in inappropriate. If the selections all begin and end in black, this is not a concern. If the material starts with a cut, it is recommended that a short"dummy" chapter be placed between the active chapters. For example, if the disc contains 4 active selections, it would be laid out as follows:
Chap 1 Active Video #1
Chap 2 1 second black
Chap 3 Active Video #2
Chap 4 1 second black
Chap 5 Active Video #3
Chap 6 1 second black
Chap 7 Active Video #4
Chap 8 1 second black
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