Crate ym2149_sndh_replayer 

ym2149-sndh-replayer

SNDH file parser and Atari ST machine emulation for YM2149 chiptune playback.

This crate provides playback support for SNDH files, a popular format for Atari ST chiptune music. It includes:

• SNDH Parser: Parses SNDH file headers and metadata
• ICE Depacker: Decompresses ICE! 2.4 packed SNDH files
• 68000 CPU Emulation: Via the m68000 crate for executing SNDH drivers
• MFP68901 Timer Emulation: For accurate timer-based effects (SID voice, etc.)
• Atari ST Machine: Memory-mapped I/O emulation for YM2149 and timers

Example

use ym2149_sndh_replayer::{SndhPlayer, load_sndh};
use ym2149_common::ChiptunePlayer;

let data = std::fs::read("music.sndh")?;
let mut player = load_sndh(&data, 44100)?;

// Select subsong (1-based index)
player.init_subsong(1)?;
player.play();

// Generate audio samples
let mut buffer = vec![0.0f32; 882]; // ~50Hz at 44100 sample rate
player.generate_samples_into(&mut buffer);

SNDH Format

SNDH is a standard format for Atari ST music that embeds the original 68000 replay code along with the music data. The format uses a simple header followed by executable code:

• Entry point + 0: Initialize subsong (D0 = subsong number)
• Entry point + 4: Exit/cleanup
• Entry point + 8: Play one frame (called at player rate, typically 50Hz)

Many SNDH files are ICE! packed for smaller file sizes.

Structs

BasicMetadata

Basic metadata container implementing PlaybackMetadata.

SndhFile

SNDH file representation

SndhFlags

SNDH feature flags (from FLAG tag, SNDH v2.2)

SndhMetadata

SNDH file metadata

SndhPlayer

SNDH file player.

SubsongInfo

Information about a specific subsong

Enums

DmaSampleRate

DMA sample rates for STE and Falcon

PlaybackState

Playback state for chiptune players.

SndhError

Errors that can occur during SNDH parsing and playback.

Traits

ChiptunePlayer

Unified player interface for chiptune formats.

PlaybackMetadata

Unified metadata trait for chiptune playback.

Functions

ice_depack

Depack ICE! 2.4 compressed data.

is_ice_packed

Check if data is ICE! 2.4 packed.

is_sndh_data

Check if data appears to be SNDH format.

load_sndh

Load an SNDH file and create a player.

Type Aliases

Result

Result type for SNDH operations.