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wav.c revision 1.6
      1 /*	$NetBSD: wav.c,v 1.6 2003/06/23 12:15:01 agc 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 #include <sys/cdefs.h>
     36 
     37 #ifndef lint
     38 __RCSID("$NetBSD: wav.c,v 1.6 2003/06/23 12:15:01 agc Exp $");
     39 #endif
     40 
     41 
     42 #include <sys/types.h>
     43 #include <sys/audioio.h>
     44 #include <sys/ioctl.h>
     45 #include <sys/time.h>
     46 
     47 #include <ctype.h>
     48 #include <err.h>
     49 #include <stdio.h>
     50 #include <stdlib.h>
     51 #include <string.h>
     52 
     53 #include "libaudio.h"
     54 
     55 struct {
     56 	int	wenc;
     57 	const char *wname;
     58 } wavencs[] = {
     59 	{ WAVE_FORMAT_UNKNOWN, 	"Microsoft Official Unknown" },
     60 	{ WAVE_FORMAT_PCM,	"Microsoft PCM" },
     61 	{ WAVE_FORMAT_ADPCM,	"Microsoft ADPCM" },
     62 	{ WAVE_FORMAT_ALAW,	"Microsoft A-law" },
     63 	{ WAVE_FORMAT_MULAW,	"Microsoft mu-law" },
     64 	{ WAVE_FORMAT_OKI_ADPCM,"OKI ADPCM" },
     65 	{ WAVE_FORMAT_DIGISTD,	"Digistd format" },
     66 	{ WAVE_FORMAT_DIGIFIX,	"Digifix format" },
     67 	{ -1, 			"?Unknown?" },
     68 };
     69 
     70 const char *
     71 wav_enc_from_val(int encoding)
     72 {
     73 	int	i;
     74 
     75 	for (i = 0; wavencs[i].wenc != -1; i++)
     76 		if (wavencs[i].wenc == encoding)
     77 			break;
     78 	return (wavencs[i].wname);
     79 }
     80 
     81 /*
     82  * sample header is:
     83  *
     84  *   RIFF\^@^C^@WAVEfmt ^P^@^@^@^A^@^B^@D<AC>^@^@^P<B1>^B^@^D^@^P^@data^@^@^C^@^@^@^@^@^@^@^@^@^@
     85  *
     86  */
     87 /*
     88  * WAV format helpers
     89  */
     90 /*
     91  * find a .wav header, etc. returns header length on success
     92  */
     93 ssize_t
     94 audio_wav_parse_hdr(hdr, sz, enc, prec, sample, channels, datasize)
     95 	void	*hdr;
     96 	size_t	sz;
     97 	int	*enc;
     98 	int	*prec;
     99 	int	*sample;
    100 	int	*channels;
    101 	size_t *datasize;
    102 {
    103 	char	*where = hdr, *owhere;
    104 	wav_audioheaderpart part;
    105 	wav_audioheaderfmt fmt;
    106 	char	*end = (((char *)hdr) + sz);
    107 	int	newenc, newprec;
    108 	static const char
    109 	    strfmt[4] = "fmt ",
    110 	    strRIFF[4] = "RIFF",
    111 	    strWAVE[4] = "WAVE",
    112 	    strdata[4] = "data";
    113 
    114 	if (sz < 32)
    115 		return (AUDIO_ENOENT);
    116 
    117 	if (strncmp(where, strRIFF, sizeof strRIFF))
    118 		return (AUDIO_ENOENT);
    119 	where += 8;
    120 	if (strncmp(where, strWAVE, sizeof strWAVE))
    121 		return (AUDIO_ENOENT);
    122 	where += 4;
    123 
    124 	do {
    125 		memcpy(&part, where, sizeof part);
    126 		owhere = where;
    127 		where += getle32(part.len) + 8;
    128 	} while (where < end && strncmp(part.name, strfmt, sizeof strfmt));
    129 
    130 	/* too short ? */
    131 	if (where + sizeof fmt > end)
    132 		return (AUDIO_ESHORTHDR);
    133 
    134 	memcpy(&fmt, (owhere + 8), sizeof fmt);
    135 
    136 	switch (getle16(fmt.tag)) {
    137 	case WAVE_FORMAT_UNKNOWN:
    138 	case WAVE_FORMAT_ADPCM:
    139 	case WAVE_FORMAT_OKI_ADPCM:
    140 	case WAVE_FORMAT_DIGISTD:
    141 	case WAVE_FORMAT_DIGIFIX:
    142 	case IBM_FORMAT_MULAW:
    143 	case IBM_FORMAT_ALAW:
    144 	case IBM_FORMAT_ADPCM:
    145 	default:
    146 		return (AUDIO_EWAVUNSUPP);
    147 
    148 	case WAVE_FORMAT_PCM:
    149 		switch (getle16(fmt.bits_per_sample)) {
    150 		case 8:
    151 			newprec = 8;
    152 			break;
    153 		case 16:
    154 			newprec = 16;
    155 			break;
    156 		case 24:
    157 			newprec = 24;
    158 			break;
    159 		case 32:
    160 			newprec = 32;
    161 			break;
    162 		default:
    163 			return (AUDIO_EWAVBADPCM);
    164 		}
    165 		if (newprec == 8)
    166 			newenc = AUDIO_ENCODING_ULINEAR_LE;
    167 		else
    168 			newenc = AUDIO_ENCODING_SLINEAR_LE;
    169 		break;
    170 	case WAVE_FORMAT_ALAW:
    171 		newenc = AUDIO_ENCODING_ALAW;
    172 		newprec = 8;
    173 		break;
    174 	case WAVE_FORMAT_MULAW:
    175 		newenc = AUDIO_ENCODING_ULAW;
    176 		newprec = 8;
    177 		break;
    178 	}
    179 
    180 	do {
    181 		memcpy(&part, where, sizeof part);
    182 		owhere = where;
    183 		where += (getle32(part.len) + 8);
    184 	} while (where < end && strncmp(part.name, strdata, sizeof strdata));
    185 
    186 	if ((where - getle32(part.len)) <= end) {
    187 		if (channels)
    188 			*channels = getle16(fmt.channels);
    189 		if (sample)
    190 			*sample = getle32(fmt.sample_rate);
    191 		if (enc)
    192 			*enc = newenc;
    193 		if (prec)
    194 			*prec = newprec;
    195 		if (datasize)
    196 			*datasize = (size_t)getle32(part.len);
    197 		return (owhere - (char *)hdr + 8);
    198 	}
    199 	return (AUDIO_EWAVNODATA);
    200 }
    201