sphinx_eurosound_smd_file.bt

//------------------------------------------------
//--- 010 Editor v12.0.1 Binary Template
//
//      File: Eurocom SMD (Sound Marker Data?)
//   Authors: Swyter
//   Version: 2022.03.26
//   Purpose: Look-up-table created by Eurosound to precalculate the ADPCM states required for loop/jump points.
//            You can load the listenable data in Audacity by importing as raw data and picking the following settings:
//              * Signed 16-bit PCM, little-endia, Stereo, start offset 4, amount to import 100%, sample rate 11025Hz.
//                This works because the first 16-bits of each state is the previously-decoded ADPCM sample, and the next
//                16-bits are the rest and we can discard them to the other channel. 11025Hz is 44100 Hz / 4, this is
//                because the raw WAV is 44100 Hz, when resampled the ADPCM data is 22050 Hz, and we only need states for
//                even samples, not odd ones (the other half of each ADPCM byte, which stores two nibbles; two encoded samples).
//                So we end up accidentally storing 1/4 of the decoded data in there and it's actually listenable.
//  Category: Game, Audio
// File Mask: *.smd
//  ID Bytes: 00 00 00 00
//------------------------------------------------
struct state
{
    short  valpred; /* swy: previous decoded ADPCM sample to use as base */

    ushort inputbuffer : 8 <format=hex>; /* the last encoded ADPCM byte, two samples, two nibbles */

    ushort bufferstep  : 7 <format=hex>;
    ushort index       : 1 <format=hex>;

} states [FileSize() / sizeof(state)] <read=Str("%3i", valpred)>;