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wav.c revision 1.5 
      1 /*	$NetBSD: wav.c,v 1.5 2003/04/06 18:20:14 wiz Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2002 Matthew R. Green
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. The name of the author may not be used to endorse or promote products
     16  *    derived from this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     23  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     25  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     26  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     28  * SUCH DAMAGE.
     29  */
     30 
     31 /*
     32  * WAV support for the audio tools; thanks go to the sox utility for
     33  * clearing up issues with WAV files.
     34  */
     35 
     36 #include <sys/types.h>
     37 #include <sys/audioio.h>
     38 #include <sys/ioctl.h>
     39 #include <sys/time.h>
     40 
     41 #include <ctype.h>
     42 #include <err.h>
     43 #include <stdio.h>
     44 #include <stdlib.h>
     45 #include <string.h>
     46 
     47 #include "libaudio.h"
     48 
     49 struct {
     50 	int	wenc;
     51 	const char *wname;
     52 } wavencs[] = {
     53 	{ WAVE_FORMAT_UNKNOWN, 	"Microsoft Official Unknown" },
     54 	{ WAVE_FORMAT_PCM,	"Microsoft PCM" },
     55 	{ WAVE_FORMAT_ADPCM,	"Microsoft ADPCM" },
     56 	{ WAVE_FORMAT_ALAW,	"Microsoft A-law" },
     57 	{ WAVE_FORMAT_MULAW,	"Microsoft mu-law" },
     58 	{ WAVE_FORMAT_OKI_ADPCM,"OKI ADPCM" },
     59 	{ WAVE_FORMAT_DIGISTD,	"Digistd format" },
     60 	{ WAVE_FORMAT_DIGIFIX,	"Digifix format" },
     61 	{ -1, 			"?Unknown?" },
     62 };
     63 
     64 const char *
     65 wav_enc_from_val(int encoding)
     66 {
     67 	int	i;
     68 
     69 	for (i = 0; wavencs[i].wenc != -1; i++)
     70 		if (wavencs[i].wenc == encoding)
     71 			break;
     72 	return (wavencs[i].wname);
     73 }
     74 
     75 /*
     76  * sample header is:
     77  *
     78  *   RIFF\^@^C^@WAVEfmt ^P^@^@^@^A^@^B^@D<AC>^@^@^P<B1>^B^@^D^@^P^@data^@^@^C^@^@^@^@^@^@^@^@^@^@
     79  *
     80  */
     81 /*
     82  * WAV format helpers
     83  */
     84 /*
     85  * find a .wav header, etc. returns header length on success
     86  */
     87 ssize_t
     88 audio_wav_parse_hdr(hdr, sz, enc, prec, sample, channels, datasize)
     89 	void	*hdr;
     90 	size_t	sz;
     91 	int	*enc;
     92 	int	*prec;
     93 	int	*sample;
     94 	int	*channels;
     95 	size_t *datasize;
     96 {
     97 	char	*where = hdr, *owhere;
     98 	wav_audioheaderpart part;
     99 	wav_audioheaderfmt fmt;
    100 	char	*end = (((char *)hdr) + sz);
    101 	int	newenc, newprec;
    102 	static const char
    103 	    strfmt[4] = "fmt ",
    104 	    strRIFF[4] = "RIFF",
    105 	    strWAVE[4] = "WAVE",
    106 	    strdata[4] = "data";
    107 
    108 	if (sz < 32)
    109 		return (AUDIO_ENOENT);
    110 
    111 	if (strncmp(where, strRIFF, sizeof strRIFF))
    112 		return (AUDIO_ENOENT);
    113 	where += 8;
    114 	if (strncmp(where, strWAVE, sizeof strWAVE))
    115 		return (AUDIO_ENOENT);
    116 	where += 4;
    117 
    118 	do {
    119 		memcpy(&part, where, sizeof part);
    120 		owhere = where;
    121 		where += getle32(part.len) + 8;
    122 	} while (where < end && strncmp(part.name, strfmt, sizeof strfmt));
    123 
    124 	/* too short ? */
    125 	if (where + sizeof fmt > end)
    126 		return (AUDIO_ESHORTHDR);
    127 
    128 	memcpy(&fmt, (owhere + 8), sizeof fmt);
    129 
    130 	switch (getle16(fmt.tag)) {
    131 	case WAVE_FORMAT_UNKNOWN:
    132 	case WAVE_FORMAT_ADPCM:
    133 	case WAVE_FORMAT_OKI_ADPCM:
    134 	case WAVE_FORMAT_DIGISTD:
    135 	case WAVE_FORMAT_DIGIFIX:
    136 	case IBM_FORMAT_MULAW:
    137 	case IBM_FORMAT_ALAW:
    138 	case IBM_FORMAT_ADPCM:
    139 	default:
    140 		return (AUDIO_EWAVUNSUPP);
    141 
    142 	case WAVE_FORMAT_PCM:
    143 		switch (getle16(fmt.bits_per_sample)) {
    144 		case 8:
    145 			newprec = 8;
    146 			break;
    147 		case 16:
    148 			newprec = 16;
    149 			break;
    150 		case 24:
    151 			newprec = 24;
    152 			break;
    153 		case 32:
    154 			newprec = 32;
    155 			break;
    156 		default:
    157 			return (AUDIO_EWAVBADPCM);
    158 		}
    159 		if (newprec == 8)
    160 			newenc = AUDIO_ENCODING_ULINEAR_LE;
    161 		else
    162 			newenc = AUDIO_ENCODING_SLINEAR_LE;
    163 		break;
    164 	case WAVE_FORMAT_ALAW:
    165 		newenc = AUDIO_ENCODING_ALAW;
    166 		newprec = 8;
    167 		break;
    168 	case WAVE_FORMAT_MULAW:
    169 		newenc = AUDIO_ENCODING_ULAW;
    170 		newprec = 8;
    171 		break;
    172 	}
    173 
    174 	do {
    175 		memcpy(&part, where, sizeof part);
    176 		owhere = where;
    177 		where += (getle32(part.len) + 8);
    178 	} while (where < end && strncmp(part.name, strdata, sizeof strdata));
    179 
    180 	if ((where - getle32(part.len)) <= end) {
    181 		if (channels)
    182 			*channels = getle16(fmt.channels);
    183 		if (sample)
    184 			*sample = getle32(fmt.sample_rate);
    185 		if (enc)
    186 			*enc = newenc;
    187 		if (prec)
    188 			*prec = newprec;
    189 		if (datasize)
    190 			*datasize = (size_t)getle32(part.len);
    191 		return (owhere - (char *)hdr + 8);
    192 	}
    193 	return (AUDIO_EWAVNODATA);
    194 }
    195