ym2149-ym-replayer

YM file format parser and music replayer for YM2149 PSG chips.

This crate provides comprehensive support for parsing and playing back YM chiptune files, including YM2/3/5/6 formats, tracker modes, and various hardware effects.

Features

• YM Format Support: YM2, YM3, YM5, YM6 file formats with LHA decompression
• Tracker Modes: YMT1 and YMT2 tracker format support
• Format Profiles: FormatProfile trait encapsulates format quirks (YM2 drum mixing, YM5 effect encoding, YM6 sentinel handling) so new formats plug in without bloating YmPlayerGeneric
• Frame Sequencer: Dedicated FrameSequencer stores frames + timing and exposes seek/loop APIs
• Effects Pipeline: EffectsPipeline wraps the low-level EffectsManager, tracking SID/digidrum state for visualization/metadata
• Hardware Effects:
  • Mad Max digi-drums
  • YM6 SID voice effects
  • Sync buzzer effects
• Backend Agnostic: Works with any Ym2149Backend implementation
• Timing control: Defaults to 44.1 kHz / 2 MHz but supports custom host sample rates; YM5/6 master clocks are applied automatically
• Optional Features: Streaming audio output

Install

Add the crate to your Cargo.toml:

[dependencies]
ym2149-ym-replayer = "0.9"

Usage

Basic Playback

use ym2149_ym_replayer::{load_song, ChiptunePlayer, PlaybackMetadata};

let data = std::fs::read("song.ym")?;
let (mut player, summary) = load_song(&data)?;

// Use the unified ChiptunePlayer interface
player.play();
let samples = player.generate_samples(summary.samples_per_frame as usize);

// Access metadata
println!("{} by {}", player.metadata().title(), player.metadata().author());

Loading from Files

use ym2149_ym_replayer::loader;

// From file path
let frames = loader::load_file("song.ym")?;

// From bytes
let data = std::fs::read("song.ym")?;
let frames = loader::load_bytes(&data)?;

Format Profiles & Effects Pipeline

Internally the player is split into three layers:

1. FrameSequencer – Owns the register frames, loop point, and PAL/NTSC timing and offers seek/loop APIs.
2. FormatProfile – Trait implemented per format (YM2/YM5/YM6/basic) so register preprocessing and effect decoding live behind FormatMode strategies instead of is_ym*_mode flags.
3. EffectsPipeline – Wraps the low-level EffectsManager, tracks which SID/digidrum voices are active, and feeds the backend every sample.

load_song automatically selects the right profile, and custom loaders can create a profile via ym2149_ym_replayer::player::create_profile. Metadata and Bevy visualizers now query effect state through the pipeline.

Architecture

This crate was extracted from ym2149-core to provide better separation of concerns:

• ym2149-core: Pure YM2149 chip emulation
• ym2149-ym-replayer: YM file parsing and playback (this crate)

Migration from ym2149-core < 0.6

If you were using the deprecated modules from ym2149-core:

// Old (deprecated)
use ym2149::replayer::Ym6Player;
use ym2149::ym_loader;

// New (recommended)
use ym2149_ym_replayer::YmPlayer;
use ym2149_ym_replayer::loader;

Feature Flags

• default: Includes effects, tracker, and digi-drums support
• effects: Enable YM6 effect processing
• tracker: Enable tracker mode support
• digidrums: Enable Mad Max digi-drums
• export-wav: Enable WAV file export (requires hound)

MP3 export was removed because the LAME/Autotools toolchain is fragile across environments. Export WAV and transcode externally (e.g., ffmpeg).

License

See the main ym2149-rs repository for license information.