Initial commit: akai-fetch - AKAI sampler ISO downloader & extractor

- fetch: Go CLI tool for searching, downloading, and extracting
  AKAI sampler ISOs from archive.org
- scripts/extract_wavs.sh: Shell script driving akaiutil to
  convert samples to WAV
- Dockerfile: Multi-stage build packaging akaiutil + fetch
- third_party/akaiutil: Vendored akaiutil v4.6.7 source (GPLv2)
- docs/akaiutil.md: Full akaiutil reference

third_party/akaiutil/akaiutil_wav.h

@@ -0,0 +1,99 @@
+#ifndef __AKAIUTIL_WAV_H
+#define __AKAIUTIL_WAV_H
+/*
+* Copyright (C) 2010,2019 Klaus Michael Indlekofer. All rights reserved.
+*
+* m.indlekofer@gmx.de
+*
+* This program is free software; you can redistribute it and/or
+* modify it under the terms of the GNU General Public License
+* as published by the Free Software Foundation; either version 2
+* of the License, or (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program; if not, write to the Free Software
+* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+*/
+
+
+
+#include "commoninclude.h"
+
+
+
+/* RIFF WAVE format header */
+/* Note: WAV-file is little-endian!!! */
+
+struct wav_riffhead_s{
+/* begin RIFFWAVEChunk */
+#define WAV_RIFFHEAD_RIFFSTR "RIFF"
+	char riffstr[4];   /* must be "RIFF" */
+	u_char fsize[4];   /* following file-size in Bytes */
+#define WAV_RIFFHEAD_WAVESTR "WAVE"
+	char wavestr[4];   /* must be "WAVE" */
+/* end RIFFWAVEChunk */
+};
+
+struct wav_chunkhead_s{
+	char typestr[4];   /* chunk type */
+	u_char csize[4];   /* following chunk-size in Bytes */
+};
+#define WAV_CHUNKHEAD_FMTSTR	"fmt "
+#define WAV_CHUNKHEAD_DATASTR	"data"
+
+struct wav_fmthead_s{
+/* continued FormatChunk */
+#define WAV_HEAD_FTAG_PCM 0x0001 /* 1: PCM/umcompressed */
+	u_char ftag[2];    /* format tag */
+	u_char chnr[2];    /* number of channels */
+	u_char srate[4];   /* sample rate in samples/sec */
+	u_char drate[4];   /* total data rate in Bytes/sec */
+	u_char balign[2];  /* number of Bytes per sample * chnr */
+	u_char bitnr[2];   /* number of Bits per sample */
+/* end FormatChunk */
+};
+
+
+
+#define WAV_HEAD_SIZE	(sizeof(struct wav_riffhead_s)+sizeof(struct wav_chunkhead_s)+sizeof(struct wav_fmthead_s)+sizeof(struct wav_chunkhead_s))
+
+
+
+#ifndef WAV_AKAIHEAD_DISABLE
+/* AKAI header chunks */
+#define WAV_CHUNKHEAD_AKAIS900SAMPLEHEADSTR		"S9H "
+#define WAV_CHUNKHEAD_AKAIS1000SAMPLEHEADSTR	"S1H "
+#define WAV_CHUNKHEAD_AKAIS3000SAMPLEHEADSTR	"S3H "
+#define WAV_CHUNKHEAD_AKAIDDTAKEHEADSTR			"TKH "
+#endif
+
+
+
+/* Declarations */
+
+extern int wav_write_head(int outdes,
+						  u_int datasize,u_int chnr,u_int samprate,u_int bitnr,
+						  u_int extrasize);
+
+extern int wav_read_head(int indes,u_int *bcountp,
+						 u_int *datasizep,u_int *chnrp,u_int *sampratep,u_int *bitnrp,
+						 u_int *extrasizep,
+						 char **errstrp);
+
+#ifndef WAV_AKAIHEAD_DISABLE
+#define WAV_AKAIHEADTYPE_NONE			0x00
+#define WAV_AKAIHEADTYPE_SAMPLE900		0x09
+#define WAV_AKAIHEADTYPE_SAMPLE1000		0x01
+#define WAV_AKAIHEADTYPE_SAMPLE3000		0x03
+#define WAV_AKAIHEADTYPE_DDTAKE			0xdd
+int wav_find_akaihead(int indes,u_int *bcountp,u_int *csizep,u_int remain,u_int searchtype);
+#endif
+
+
+
+#endif /* !__AKAIUTIL_WAV_H */