|Video||1 stream only||MPEG-1 or MPEG-2 Video|
|Audio||maximum of 8 streams||Linear PCM and/or:|
Dolby AC-3 (NTSC)
MPEG audio (PAL)
|Sub-picture||max 32 streams||Run-length encoded with bitmap of 2 bits/pixel|
max total of combined audio and video: 9.8 Mbit/sec max sum of Elementary streams + systems overhead: 10.08 Mbit/sec.
The program chain (PGC) can be presented either serially (linear) or in random/shuffle (non-linear) fashion.
For example, a quiz title should break each question into separate programs. The next program chain branched to would be determined by the answered provided by the user.
Still pictures are coded as MPEG intra frames. They may be displayed for indefinite duration. They can be accompanied by background music, or audio can be muted.
still function is created by the action of the navigation system The same video frame and sub-picture is frozen (displayed over and over again on the TV) while audio is or playing in background.
There are three types of the Still Function:
|Type||Timing||Still time in seconds|
|PGC Still||Stills at end of the PGC||0-254, limitless|
|Cell Still||Stills at end of the Cell||0-254, limitless|
|VOBU Still||Stills in every VOBU in the Cell||limitless|
Within a program chain (PGC), commands can be located at the front of the chain, in between cells of the chain, and at the end of the chain.
Program chain [Pre-Commands] [Cell] [Cell] [Cell-Command] [Cell] [Post-Commands] Each cell can have one command. There is a restriction that no more than 128 commands can be contained within a program chain: Pre-commands + Cell Commands + Post Commands <= 128 Further, there are a maximum of 36 buttons, each of which can have one associated command.
3 quiz problems are presented to the user. Each quiz problem/question is coded as a separate program chain. One of the questions prompts the user for a "Yes" or "No" answer.
The Link command is used to branch from the original top-level menu to one of the three program chains. The Set Command is used to tally a score. Finally, the CompareLink command (which consist of two commands, Compare & Link) branches to a particular Program depending on the user's answer.