1. Overview

1.1 Purpose

PCM/ADPCM playback library is a library for easily playing PCM on SEGASATURN.

1.2 Features

Easy PCM playback

Users periodically call PCM task functions.
The library reads from the CD, manages the ring buffer, manages time, supplies data to the PCM buffer, and issues commands to the sound driver.

ADPCM compatible

You can play ADPCM compressed data while decompressing it.
ADPCM is a method specified as the data format for CD-ROM XA Audio, and can achieve excellent sound quality with a compression ratio of approximately 1/4.

Supports four types of file formats

1. AIFF format (PCM uncompressed)
2. CD-ROM XA Audio format (ADPCM compression)
3. Specified ADPCM format (CRC Research Institute AudioStack output format)
4. SaturnPCM format (PCM uncompressed)

Pause function

Although the hardware does not have a pause function for PCM playback, you can easily pause it using this library.

multi play

You can play 4 PCMs at the same time.
Applications such as playing BGM and having three people's lines asynchronously overlap and pronounce them are possible.
(Cannot contain two or more ADPCM compressed data)

1.3 System image

The system image of this library is shown in the figure below.

Figure 1.1 System image (playback of PCM uncompressed data)

Figure 1.2 System image (playback of ADPCM compressed data)