1. Overview

The branch playback library is a library for seamlessly loading streams based on predetermined scenarios. This allows the stream to be read while branching smoothly.
However, the branch playback library only manages the streams necessary for branching. To play videos etc. from a stream, use a library dedicated to the decoder (MPEG, Cinepak, etc.).

1.1 Library configuration

Figure 1.1 shows the CD-related library configuration.

Figure 1.1 CD-related library configuration

       ┌────────────────────────────────────────┐      
       │                                        │      
       │           Application                  │      
       │                                        │      
       └────────────────────────────────────────┘      
       ┌───────┐┌───────┐┏━━━━━━━━┓┌──────┐┌─────┐      
       │       ││Cinepak│┃Branch  ┃│      ││     │      
       │       ││library│┃playback┃│      ││     │      
       │MPEG   ││       │┃library ┃│  ┌───┘│     │      
       │library│└───────┘┗━━━━━━━━┛│  │┌───┘     │      
       │       │┌──────────────────┘  ││File     │      
       │       ││CD communication     ││system   │      
       │       ││interface library    ││library  │      
       └───────┘└─────────────────────┘└─────┐   │      
       ┌────────────────────────────────────┐│   │      
       │       Stream System library        ││   │      
       └───────────┬────────────────────────┘└─┬─┘      
Software           │                           │        
━━━━━━━━━━━━━━━━━━━┿━━━━━━━━━━━━━━━━━━━━━━━━━━━┿━━━━━━━━
Hardware           │                           │        
            ┌──────┴─────┐            ┌────────┴──────┐ 
            │  CD block  │            │SIMM, SCSI file│ 
            └────────────┘            └───────────────┘ 

In order to use the branch playback library, the stream system, file system, and CD communication interface libraries are required.

1.2 Functional overview of branch playback library

(1) Overview of branch destination information (scenario) settings

Set branch destination candidates for each stream as branch destination information (scenario).

(2) Stream look-ahead function required for branching

Manage stream opening/closing in order to branch streams smoothly. By prefetching the opened stream (branch destination candidate) into the CD buffer, it can be retrieved without interruption when the branch destination is determined.

(3) Branch destination selection function

Select the actual branch destination from among the branch destination candidates.

(4)Notification function of branch destination stream

Tells the application which stream to play next according to the selected branch destination.

Figure 1.2 Stream system overview diagram

1.3 Notes

1. Library version used

Be sure to use version 1.21 or later of the stream system and file system libraries. Both libraries are closely related. Operation is not guaranteed if the other version is an older version or is used in combination with an unspecified version.

2. Prohibition of use of SCU-DMA (Prohibition of A-Bus access during SCU-DMA transfer)

The branch playback library does not support SCU-DMA transfer. When using the branch replay library, DMA transfer by SCU is prohibited. Please use a stream system transfer mode or transfer function other than SCU-DMA.