1. Overview

The branch playback library is a library for reading a stream without interruption based on a predetermined scenario. This allows the stream to be read while branching smoothly.
However, the branch playback library only manages the streams required for branching. To play video etc. from the stream, use a library dedicated to the decoder (MPEG, Cinepak, etc.).

1.1 Library configuration

Figure 1.1 shows the CD-related library structure.

Figure 1.1 CD-related library configuration

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

In order to use the branch playback library, each library of stream system, file system, and CD communication interface is required.

1.2 Functional overview of the branch playback library

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

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

(2) Stream look-ahead function required for branching

Manage the open / close of the stream so that the stream can be branched smoothly. By pre-reading the opened stream (candidate branch destination) 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 the branch destination candidates.

(4) Notification function of branch destination stream

Notifies the application of the next stream to play according to the selected branch destination.

Figure 1.2 Overview of stream system

1.3 Precautions

1. Version of library to use

Be sure to use Ver.1.21 or later for each library of stream system and file system. Both libraries are closely related. We do not guarantee any operation if the other is an older version or in combination with an unspecified version.

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

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