RustyKaraoke

RustyKaraoke is an attempt to create a universal karaoke player in the Rust programming language by Cappy Ishihara after encountering various frutstrations with various proprietary Thai karaoke software (Nick Karaoke, eXtreme Karaoke), while development on its open-source alternative HandyKaraoke was stagnant.

RustyKaraoke was primarily created to support the various Thai karaoke formats (NCN, EMK), but with planned support for other formats including Video with ASS subtitles, MP3/CD+G and more.

Various reverse-engineering efforts were made to dissect the proprietary Karaoke formats.

The NCN Format (MIDI, .cur, .lyr)

NCN is a basic timing format made for Nick Karaoke, with a plain-text .lyr file usually encoded in TIS-620 and a set of 16-bit unsigned integers in the .cur file.

Lyrics (.lyr)

The first 4 lines of the lyrics file is metadata, including the title, artist, and key. The fourth line is used as a delimiter.

Title
Artist
Key

Lyrics....

Each character after the fourth line will be scrolled according to the MIDI ticks in the cursor file

Cursor file (.cur)

The cursor file contains a list of 16-bit unsigned integers indicating when each character will be scrolled to the song. The entire MIDI song is split into 65535 ticks. The formula for figuring out the current NCN tick is as follows:

$C={\frac {\left({\frac {\mathrm {tick} }{\mathrm {resolution} }}\right)}{\mathrm {BPM} }}\cdot 24\cdot 60$

MIDI

A standard MIDI file, that accompanies the lyrics and the cursor file.

eXtreme Karaoke MIDI Archive (.emk)

EMK files are simply an archive of the NCN format, compressed into one single file.

An EMK file contains the following data:

• EMK Header (extra metadata)
• NCN Lyrics
• NCN Cursor
• MIDI

All EMK files are XOR encrypted with the magic key AFF24C9CE9EA994, which when decrypted becomes a DEFLATE stream of an archive with 4 chunks containing these files.

Once extracted, it can be played like a normal NCN file, with extra metadata in the headers.