Module openpol::sounddat

sound.dat data access operations.

sound.dat file format

The file consists of concatenated N sounds followed by N little endian 32-bit unsigned integer sizes (in bytes). The nth size corresponds to the nth sound, the file layout looks like this:

[ 0th sound ] [ 1st sound ] ... [ N-2th sound ] [N-1th sound] [ 0th size ] [ 1st size ] ... [ N-2th size ] [ N-1th size]

The original game hardcodes the number of sounds when opening the sound.dat file, but it's possible to autodect it. This module performs autodetection like this: read 4-byte integers starting with the very end of the file and add them together until the sum is equal to B - 4 * N (where B is total file size in bytes and N is the number of sizes read so far).

The algorithm has been verified with sound.dat coming from the CD version of Polanie (SHA1 hash 8033978a51c176122ba507e417e8d758fdaa70a9, 3 681 170 bytes) - the file contains 183 sounds.

Sound format

The individual sounds are unsigned bytes containing single channel of 22 050Hz-sampled raw audio data.

Example

An openpol-extract-audio sample binary which uses this code is provided. You can listen to a chosen sound using sox and mpv like this:

sox -r22050 -t ub -c 1 <(cargo run --bin openpol-extract-audio -- SOUND.DAT 20) -t wav - | mpv -

Structs

Sounddat

A way to access sound.dat contents.