GBPresenter

GBPresenter is a tool I wrote to generate visualizations of GameBoy chiptunes, based on SameBoy, FFmpeg, and Slint. The visualization design is essentially a port of the piano roll from RusticNES. It supports playing music from GBS files and from save files for most versions of Little Sound Dj.

Functionality

GBPresenter runs your GBS or LSDj ROM in SameBoy and captures the state of the APU channels every frame. It then generates a visualization and feeds it to FFmpeg to be encoded as a video.

Features

• Supports GBS files and LSDj ROM+SAV.
  • Support for additional formats (LSDSNG, VGM, GBTPlayer) is planned.
• Built on SameBoy for extremely accurate sound emulation.
  • It usually sounds just as good as a recording of a DMG with a ProSound mod.
• Outputs a video file:
  • Customizable resolution (default 1080p) at 59.97 FPS (the GameBoy's true framerate).
  • MPEG-4 container with fast-start (moov atom at beginning of file).
  • Matroska (MKV) containers are also supported.
  • yuv420p H.264 video stream encoded with libx264, crf: 16.
  • Stereo AAC LC audio stream encoded with FFmpeg's aac encoder, bitrate: 384k.
• Video files are suitable for direct upload to most websites:
  • Outputs the recommended format for YouTube, Twitter, and Discord (w/ Nitro).
  • Typical exports (1080p, up to 5 minutes) are usually below 100MB.
• Loop detection for LSDj songs.
  • Supported on LSDj 5.x and up.
  • Support for HFF detection is planned.
  • Support for loop detection for tracker-exported GBS files is planned.

Installation

Windows: head to the Releases page and grab the latest binary release. Simply unzip and run the executable, and you're all set.

Linux: no binaries yet, but you can compile from source. You'll need:

• FFmpeg + development libraries
• Qt6 development packages
• a proper SameBoy build environment

Clone the repo with submodules (git clone --recursive), cd in, and run cargo build --release to build.

Usage

GUI

1. Click Browse... to select a GBS or an LSDj ROM file.
2. If you selected an LSDj ROM file, select Browse... next to the LSDj SAV field to select your LSDj save file.
3. Select a track to be rendered from the dropdown.
4. Select the duration of the output video. Available duration types are:
   • Seconds: explicit duration in seconds.
   • Frames: explicit duration in frames (1/59.97 of a second).
   • Loops: if loop detection is supported, number of loops to be played.
5. Select the duration of the fadeout in frames. This is not included in the video duration above, rather it's added on to the end.
6. Select the output video resolution. You can enter a custom resolution or use the 1080p/4K presets.
7. Click Render! to select the output video filename and begin rendering the visualization.
8. Once the render is complete, you can select another track or even change modules to render another tune.

CLI

If GBPresenter is started with command line arguments, it runs in CLI mode. This allows for the automation of rendering visualizations which in turn allows for batch rendering and even automated uploads.

The most basic invocation is this:

gb-presenter-rs --lsdj lsdj.gb songs.sav path/to/output.mp4

or

gb-presenter-rs --gbs songs.gbs path/to/output.mkv

Additional options:

• -R [rate]: set the sample rate of the audio (default: 44100)
• -T [track]: select the GBS/LSDj track index (default: 0)
• -s [condition]: select the output duration (default: time:300):
  • time:[seconds]
  • frames:[frames]
  • loops:[loops] (if supported)
• -S [fadeout]: select the fadeout duration in frames (default: 180).
• --ow [width]: select the output resolution width (default: 1920)
• --oh [height]: select the output resolution height (default: 1080)
• -h: Additional help + options
  • Note: options not listed here are unstable and may cause crashes or other errors.