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linear.c revision 1.3.10.1
      1  1.3.10.1  thorpej /*	$NetBSD: linear.c,v 1.3.10.1 2021/08/01 22:42:21 thorpej Exp $	*/
      2       1.2    isaki 
      3       1.2    isaki /*
      4       1.2    isaki  * Copyright (C) 2017 Tetsuya Isaki. All rights reserved.
      5       1.2    isaki  * Copyright (C) 2017 Y.Sugahara (moveccr). All rights reserved.
      6       1.2    isaki  *
      7       1.2    isaki  * Redistribution and use in source and binary forms, with or without
      8       1.2    isaki  * modification, are permitted provided that the following conditions
      9       1.2    isaki  * are met:
     10       1.2    isaki  * 1. Redistributions of source code must retain the above copyright
     11       1.2    isaki  *    notice, this list of conditions and the following disclaimer.
     12       1.2    isaki  * 2. Redistributions in binary form must reproduce the above copyright
     13       1.2    isaki  *    notice, this list of conditions and the following disclaimer in the
     14       1.2    isaki  *    documentation and/or other materials provided with the distribution.
     15       1.2    isaki  *
     16       1.2    isaki  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17       1.2    isaki  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18       1.2    isaki  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19       1.2    isaki  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20       1.2    isaki  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21       1.2    isaki  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     22       1.2    isaki  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23       1.2    isaki  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24       1.2    isaki  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25       1.2    isaki  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26       1.2    isaki  * SUCH DAMAGE.
     27       1.2    isaki  */
     28       1.2    isaki 
     29       1.2    isaki #include <sys/cdefs.h>
     30  1.3.10.1  thorpej __KERNEL_RCSID(0, "$NetBSD: linear.c,v 1.3.10.1 2021/08/01 22:42:21 thorpej Exp $");
     31       1.2    isaki 
     32  1.3.10.1  thorpej #include <sys/param.h>
     33       1.2    isaki #include <sys/types.h>
     34       1.2    isaki #include <sys/systm.h>
     35       1.2    isaki #include <sys/device.h>
     36       1.2    isaki #include <dev/audio/audiovar.h>
     37       1.2    isaki #include <dev/audio/linear.h>
     38       1.2    isaki 
     39       1.2    isaki /*
     40       1.2    isaki  * audio_linear8_to_internal:
     41       1.2    isaki  *	This filter performs conversion from [US]LINEAR8 to internal format.
     42       1.2    isaki  */
     43       1.2    isaki void
     44       1.2    isaki audio_linear8_to_internal(audio_filter_arg_t *arg)
     45       1.2    isaki {
     46       1.2    isaki 	const uint8_t *s;
     47       1.2    isaki 	aint_t *d;
     48       1.2    isaki 	uint8_t xor;
     49       1.2    isaki 	u_int sample_count;
     50       1.2    isaki 	u_int i;
     51       1.2    isaki 
     52       1.2    isaki 	DIAGNOSTIC_filter_arg(arg);
     53       1.2    isaki 	KASSERT(audio_format2_is_linear(arg->srcfmt));
     54       1.2    isaki 	KASSERT(arg->srcfmt->precision == 8);
     55       1.2    isaki 	KASSERT(arg->srcfmt->stride == 8);
     56       1.2    isaki 	KASSERT(audio_format2_is_internal(arg->dstfmt));
     57       1.2    isaki 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
     58       1.2    isaki 
     59       1.2    isaki 	s = arg->src;
     60       1.2    isaki 	d = arg->dst;
     61       1.2    isaki 	sample_count = arg->count * arg->srcfmt->channels;
     62       1.2    isaki 	xor = audio_format2_is_signed(arg->srcfmt) ? 0 : 0x80;
     63       1.2    isaki 
     64       1.2    isaki 	for (i = 0; i < sample_count; i++) {
     65       1.2    isaki 		uint8_t val;
     66       1.2    isaki 		val = *s++;
     67       1.2    isaki 		val ^= xor;
     68       1.2    isaki 		*d++ = (auint_t)val << (AUDIO_INTERNAL_BITS - 8);
     69       1.2    isaki 	}
     70       1.2    isaki }
     71       1.2    isaki 
     72       1.2    isaki /*
     73       1.2    isaki  * audio_internal_to_linear8:
     74       1.2    isaki  *	This filter performs conversion from internal format to [US]LINEAR8.
     75       1.2    isaki  */
     76       1.2    isaki void
     77       1.2    isaki audio_internal_to_linear8(audio_filter_arg_t *arg)
     78       1.2    isaki {
     79       1.2    isaki 	const aint_t *s;
     80       1.2    isaki 	uint8_t *d;
     81       1.2    isaki 	uint8_t xor;
     82       1.2    isaki 	u_int sample_count;
     83       1.2    isaki 	u_int i;
     84       1.2    isaki 
     85       1.2    isaki 	DIAGNOSTIC_filter_arg(arg);
     86       1.2    isaki 	KASSERT(audio_format2_is_linear(arg->dstfmt));
     87       1.2    isaki 	KASSERT(arg->dstfmt->precision == 8);
     88       1.2    isaki 	KASSERT(arg->dstfmt->stride == 8);
     89       1.2    isaki 	KASSERT(audio_format2_is_internal(arg->srcfmt));
     90       1.2    isaki 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
     91       1.2    isaki 
     92       1.2    isaki 	s = arg->src;
     93       1.2    isaki 	d = arg->dst;
     94       1.2    isaki 	sample_count = arg->count * arg->srcfmt->channels;
     95       1.2    isaki 	xor = audio_format2_is_signed(arg->dstfmt) ? 0 : 0x80;
     96       1.2    isaki 
     97       1.2    isaki 	for (i = 0; i < sample_count; i++) {
     98       1.2    isaki 		uint8_t val;
     99       1.2    isaki 		val = (*s++) >> (AUDIO_INTERNAL_BITS - 8);
    100       1.2    isaki 		val ^= xor;
    101       1.2    isaki 		*d++ = val;
    102       1.2    isaki 	}
    103       1.2    isaki }
    104       1.2    isaki 
    105       1.2    isaki /*
    106       1.2    isaki  * audio_linear16_to_internal:
    107       1.2    isaki  *	This filter performs conversion from [US]LINEAR16{LE,BE} to internal
    108       1.2    isaki  *	format.
    109       1.2    isaki  */
    110       1.2    isaki void
    111       1.2    isaki audio_linear16_to_internal(audio_filter_arg_t *arg)
    112       1.2    isaki {
    113       1.2    isaki 	const uint16_t *s;
    114       1.2    isaki 	aint_t *d;
    115       1.2    isaki 	uint16_t xor;
    116       1.2    isaki 	u_int sample_count;
    117       1.2    isaki 	u_int shift;
    118       1.2    isaki 	u_int i;
    119       1.2    isaki 	bool is_src_NE;
    120       1.2    isaki 
    121       1.2    isaki 	DIAGNOSTIC_filter_arg(arg);
    122       1.2    isaki 	KASSERT(audio_format2_is_linear(arg->srcfmt));
    123       1.2    isaki 	KASSERT(arg->srcfmt->precision == 16);
    124       1.2    isaki 	KASSERT(arg->srcfmt->stride == 16);
    125       1.2    isaki 	KASSERT(audio_format2_is_internal(arg->dstfmt));
    126       1.2    isaki 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
    127       1.2    isaki 
    128       1.2    isaki 	s = arg->src;
    129       1.2    isaki 	d = arg->dst;
    130       1.2    isaki 	sample_count = arg->count * arg->srcfmt->channels;
    131       1.2    isaki 
    132       1.2    isaki 	shift = AUDIO_INTERNAL_BITS - 16;
    133       1.2    isaki 	xor = audio_format2_is_signed(arg->srcfmt) ? 0 : 0x8000;
    134       1.2    isaki 	is_src_NE = (audio_format2_endian(arg->srcfmt) == BYTE_ORDER);
    135       1.2    isaki 
    136       1.2    isaki 	/*
    137       1.2    isaki 	 * Since slinear16_OppositeEndian to slinear_NativeEndian is used
    138       1.2    isaki 	 * so much especially on big endian machines, so it's expanded.
    139       1.2    isaki 	 * Other conversions are rarely used, so they are compressed.
    140       1.2    isaki 	 */
    141       1.2    isaki 	if (__predict_true(xor == 0) && is_src_NE == false) {
    142       1.2    isaki 		/* slinear16_OE to slinear<AI>_NE */
    143       1.2    isaki 		for (i = 0; i < sample_count; i++) {
    144       1.2    isaki 			uint16_t val;
    145       1.2    isaki 			val = *s++;
    146       1.2    isaki 			val = bswap16(val);
    147       1.2    isaki 			*d++ = (auint_t)val << shift;
    148       1.2    isaki 		}
    149       1.2    isaki 	} else {
    150       1.2    isaki 		/* slinear16_NE      to slinear<AI>_NE */
    151       1.2    isaki 		/* ulinear16_{NE,OE} to slinear<AI>_NE */
    152       1.2    isaki 		for (i = 0; i < sample_count; i++) {
    153       1.2    isaki 			uint16_t val;
    154       1.2    isaki 			val = *s++;
    155       1.2    isaki 			if (!is_src_NE)
    156       1.2    isaki 				val = bswap16(val);
    157       1.2    isaki 			val ^= xor;
    158       1.2    isaki 			*d++ = (auint_t)val << shift;
    159       1.2    isaki 		}
    160       1.2    isaki 	}
    161       1.2    isaki }
    162       1.2    isaki 
    163       1.2    isaki /*
    164       1.2    isaki  * audio_internal_to_linear16:
    165       1.2    isaki  *	This filter performs conversion from internal format to
    166       1.2    isaki  *	[US]LINEAR16{LE,BE}.
    167       1.2    isaki  */
    168       1.2    isaki void
    169       1.2    isaki audio_internal_to_linear16(audio_filter_arg_t *arg)
    170       1.2    isaki {
    171       1.2    isaki 	const aint_t *s;
    172       1.2    isaki 	uint16_t *d;
    173       1.2    isaki 	uint16_t xor;
    174       1.2    isaki 	u_int sample_count;
    175       1.2    isaki 	u_int shift;
    176       1.2    isaki 	u_int i;
    177       1.2    isaki 	bool is_dst_NE;
    178       1.2    isaki 
    179       1.2    isaki 	DIAGNOSTIC_filter_arg(arg);
    180       1.2    isaki 	KASSERT(audio_format2_is_linear(arg->dstfmt));
    181       1.2    isaki 	KASSERT(arg->dstfmt->precision == 16);
    182       1.2    isaki 	KASSERT(arg->dstfmt->stride == 16);
    183       1.2    isaki 	KASSERT(audio_format2_is_internal(arg->srcfmt));
    184       1.2    isaki 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
    185       1.2    isaki 
    186       1.2    isaki 	s = arg->src;
    187       1.2    isaki 	d = arg->dst;
    188       1.2    isaki 	sample_count = arg->count * arg->srcfmt->channels;
    189       1.2    isaki 
    190       1.2    isaki 	shift = AUDIO_INTERNAL_BITS - 16;
    191       1.2    isaki 	xor = audio_format2_is_signed(arg->dstfmt) ? 0 : 0x8000;
    192       1.2    isaki 	is_dst_NE = (audio_format2_endian(arg->dstfmt) == BYTE_ORDER);
    193       1.2    isaki 
    194       1.2    isaki 	/*
    195       1.2    isaki 	 * Since slinear_NativeEndian to slinear16_OppositeEndian is used
    196       1.2    isaki 	 * so much especially on big endian machines, so it's expanded.
    197       1.2    isaki 	 * Other conversions are rarely used, so they are compressed.
    198       1.2    isaki 	 */
    199       1.2    isaki 	if (__predict_true(xor == 0) && is_dst_NE == false) {
    200       1.2    isaki 		/* slinear<AI>_NE -> slinear16_OE */
    201       1.2    isaki 		for (i = 0; i < sample_count; i++) {
    202       1.2    isaki 			uint16_t val;
    203       1.2    isaki 			val = (*s++) >> shift;
    204       1.2    isaki 			val = bswap16(val);
    205       1.2    isaki 			*d++ = val;
    206       1.2    isaki 		}
    207       1.2    isaki 	} else {
    208       1.2    isaki 		/* slinear<AI>_NE -> slinear16_NE */
    209       1.2    isaki 		/* slinear<AI>_NE -> ulinear16_{NE,OE} */
    210       1.2    isaki 		for (i = 0; i < sample_count; i++) {
    211       1.2    isaki 			uint16_t val;
    212       1.2    isaki 			val = (*s++) >> shift;
    213       1.2    isaki 			val ^= xor;
    214       1.2    isaki 			if (!is_dst_NE)
    215       1.2    isaki 				val = bswap16(val);
    216       1.2    isaki 			*d++ = val;
    217       1.2    isaki 		}
    218       1.2    isaki 	}
    219       1.2    isaki }
    220       1.2    isaki 
    221       1.2    isaki #if defined(AUDIO_SUPPORT_LINEAR24)
    222       1.2    isaki /*
    223       1.2    isaki  * audio_linear24_to_internal:
    224       1.2    isaki  *	This filter performs conversion from [US]LINEAR24/24{LE,BE} to
    225       1.2    isaki  *	internal format.  Since it's rerely used, it's size optimized.
    226       1.2    isaki  */
    227       1.2    isaki void
    228       1.2    isaki audio_linear24_to_internal(audio_filter_arg_t *arg)
    229       1.2    isaki {
    230       1.2    isaki 	const uint8_t *s;
    231       1.2    isaki 	aint_t *d;
    232       1.2    isaki 	auint_t xor;
    233       1.2    isaki 	u_int sample_count;
    234       1.2    isaki 	u_int i;
    235       1.2    isaki 	bool is_src_LE;
    236       1.2    isaki 
    237       1.2    isaki 	DIAGNOSTIC_filter_arg(arg);
    238       1.2    isaki 	KASSERT(audio_format2_is_linear(arg->srcfmt));
    239       1.2    isaki 	KASSERT(arg->srcfmt->precision == 24);
    240       1.2    isaki 	KASSERT(arg->srcfmt->stride == 24);
    241       1.2    isaki 	KASSERT(audio_format2_is_internal(arg->dstfmt));
    242       1.2    isaki 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
    243       1.2    isaki 
    244       1.2    isaki 	s = arg->src;
    245       1.2    isaki 	d = arg->dst;
    246       1.2    isaki 	sample_count = arg->count * arg->srcfmt->channels;
    247       1.2    isaki 	xor = audio_format2_is_signed(arg->srcfmt)
    248       1.2    isaki 	    ? 0 : (1 << (AUDIO_INTERNAL_BITS - 1));
    249       1.2    isaki 	is_src_LE = (audio_format2_endian(arg->srcfmt) == LITTLE_ENDIAN);
    250       1.2    isaki 
    251       1.2    isaki 	for (i = 0; i < sample_count; i++) {
    252       1.2    isaki 		uint32_t val;
    253       1.2    isaki 		if (is_src_LE) {
    254       1.2    isaki 			val = s[0] | (s[1] << 8) | (s[2] << 16);
    255       1.2    isaki 		} else {
    256       1.2    isaki 			val = (s[0] << 16) | (s[1] << 8) | s[2];
    257       1.2    isaki 		}
    258       1.2    isaki 		s += 3;
    259       1.2    isaki 
    260       1.2    isaki #if AUDIO_INTERNAL_BITS < 24
    261       1.2    isaki 		val >>= 24 - AUDIO_INTERNAL_BITS;
    262       1.2    isaki #else
    263       1.2    isaki 		val <<= AUDIO_INTERNAL_BITS - 24;
    264       1.2    isaki #endif
    265       1.2    isaki 		val ^= xor;
    266       1.2    isaki 		*d++ = val;
    267       1.2    isaki 	}
    268       1.2    isaki }
    269       1.2    isaki 
    270       1.2    isaki /*
    271       1.2    isaki  * audio_internal_to_linear24:
    272       1.2    isaki  *	This filter performs conversion from internal format to
    273       1.2    isaki  *	[US]LINEAR24/24{LE,BE}.  Since it's rarely used, it's size optimized.
    274       1.2    isaki  */
    275       1.2    isaki void
    276       1.2    isaki audio_internal_to_linear24(audio_filter_arg_t *arg)
    277       1.2    isaki {
    278       1.2    isaki 	const aint_t *s;
    279       1.2    isaki 	uint8_t *d;
    280       1.2    isaki 	auint_t xor;
    281       1.2    isaki 	u_int sample_count;
    282       1.2    isaki 	u_int i;
    283       1.2    isaki 	bool is_dst_LE;
    284       1.2    isaki 
    285       1.2    isaki 	DIAGNOSTIC_filter_arg(arg);
    286       1.2    isaki 	KASSERT(audio_format2_is_linear(arg->dstfmt));
    287       1.2    isaki 	KASSERT(arg->dstfmt->precision == 24);
    288       1.2    isaki 	KASSERT(arg->dstfmt->stride == 24);
    289       1.2    isaki 	KASSERT(audio_format2_is_internal(arg->srcfmt));
    290       1.2    isaki 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
    291       1.2    isaki 
    292       1.2    isaki 	s = arg->src;
    293       1.2    isaki 	d = arg->dst;
    294       1.2    isaki 	sample_count = arg->count * arg->srcfmt->channels;
    295       1.2    isaki 	xor = audio_format2_is_signed(arg->dstfmt)
    296       1.2    isaki 	    ? 0 : (1 << (AUDIO_INTERNAL_BITS - 1));
    297       1.2    isaki 	is_dst_LE = (audio_format2_endian(arg->dstfmt) == LITTLE_ENDIAN);
    298       1.2    isaki 
    299       1.2    isaki 	for (i = 0; i < sample_count; i++) {
    300       1.2    isaki 		uint32_t val;
    301       1.2    isaki 		val = *s++;
    302       1.2    isaki 		val ^= xor;
    303       1.2    isaki #if AUDIO_INTERNAL_BITS < 24
    304       1.2    isaki 		val <<= 24 - AUDIO_INTERNAL_BITS;
    305       1.2    isaki #else
    306       1.2    isaki 		val >>= AUDIO_INTERNAL_BITS - 24;
    307       1.2    isaki #endif
    308       1.2    isaki 		if (is_dst_LE) {
    309       1.2    isaki 			d[0] = val & 0xff;
    310       1.2    isaki 			d[1] = (val >> 8) & 0xff;
    311       1.2    isaki 			d[2] = (val >> 16) & 0xff;
    312       1.2    isaki 		} else {
    313       1.2    isaki 			d[0] = (val >> 16) & 0xff;
    314       1.2    isaki 			d[1] = (val >> 8) & 0xff;
    315       1.2    isaki 			d[2] = val & 0xff;
    316       1.2    isaki 		}
    317       1.2    isaki 		d += 3;
    318       1.2    isaki 	}
    319       1.2    isaki }
    320       1.2    isaki #endif /* AUDIO_SUPPORT_LINEAR24 */
    321       1.2    isaki 
    322       1.2    isaki /*
    323       1.2    isaki  * audio_linear32_to_internal:
    324       1.2    isaki  *	This filter performs conversion from [US]LINEAR32{LE,BE} to internal
    325       1.2    isaki  *	format.  Since it's rarely used, it's size optimized.
    326       1.2    isaki  */
    327       1.2    isaki void
    328       1.2    isaki audio_linear32_to_internal(audio_filter_arg_t *arg)
    329       1.2    isaki {
    330       1.2    isaki 	const uint32_t *s;
    331       1.2    isaki 	aint_t *d;
    332       1.2    isaki 	auint_t xor;
    333       1.2    isaki 	u_int sample_count;
    334       1.2    isaki 	u_int i;
    335       1.2    isaki 	bool is_src_NE;
    336       1.2    isaki 
    337       1.2    isaki 	DIAGNOSTIC_filter_arg(arg);
    338       1.2    isaki 	KASSERT(audio_format2_is_linear(arg->srcfmt));
    339       1.2    isaki 	KASSERT(arg->srcfmt->precision == 32);
    340       1.2    isaki 	KASSERT(arg->srcfmt->stride == 32);
    341       1.2    isaki 	KASSERT(audio_format2_is_internal(arg->dstfmt));
    342       1.2    isaki 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
    343       1.2    isaki 
    344       1.2    isaki 	s = arg->src;
    345       1.2    isaki 	d = arg->dst;
    346       1.2    isaki 	sample_count = arg->count * arg->srcfmt->channels;
    347       1.2    isaki 	xor = audio_format2_is_signed(arg->srcfmt)
    348       1.2    isaki 	    ? 0 : (1 << (AUDIO_INTERNAL_BITS - 1));
    349       1.2    isaki 	is_src_NE = (audio_format2_endian(arg->srcfmt) == BYTE_ORDER);
    350       1.2    isaki 
    351       1.2    isaki 	for (i = 0; i < sample_count; i++) {
    352       1.2    isaki 		uint32_t val;
    353       1.2    isaki 		val = *s++;
    354       1.2    isaki 		if (!is_src_NE)
    355       1.2    isaki 			val = bswap32(val);
    356       1.2    isaki 		val >>= 32 - AUDIO_INTERNAL_BITS;
    357       1.2    isaki 		val ^= xor;
    358       1.2    isaki 		*d++ = val;
    359       1.2    isaki 	}
    360       1.2    isaki }
    361       1.2    isaki 
    362       1.2    isaki /*
    363       1.2    isaki  * audio_internal_to_linear32:
    364       1.2    isaki  *	This filter performs conversion from internal format to
    365       1.2    isaki  *	[US]LINEAR32{LE,BE}.  Since it's rarely used, it's size optimized.
    366       1.2    isaki  */
    367       1.2    isaki void
    368       1.2    isaki audio_internal_to_linear32(audio_filter_arg_t *arg)
    369       1.2    isaki {
    370       1.2    isaki 	const aint_t *s;
    371       1.2    isaki 	uint32_t *d;
    372       1.2    isaki 	auint_t xor;
    373       1.2    isaki 	u_int sample_count;
    374       1.2    isaki 	u_int i;
    375       1.2    isaki 	bool is_dst_NE;
    376       1.2    isaki 
    377       1.2    isaki 	DIAGNOSTIC_filter_arg(arg);
    378       1.2    isaki 	KASSERT(audio_format2_is_linear(arg->dstfmt));
    379       1.2    isaki 	KASSERT(arg->dstfmt->precision == 32);
    380       1.2    isaki 	KASSERT(arg->dstfmt->stride == 32);
    381       1.2    isaki 	KASSERT(audio_format2_is_internal(arg->srcfmt));
    382       1.2    isaki 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
    383       1.2    isaki 
    384       1.2    isaki 	s = arg->src;
    385       1.2    isaki 	d = arg->dst;
    386       1.2    isaki 	sample_count = arg->count * arg->srcfmt->channels;
    387       1.2    isaki 	xor = audio_format2_is_signed(arg->dstfmt)
    388       1.2    isaki 	    ? 0 : (1 << (AUDIO_INTERNAL_BITS - 1));
    389       1.2    isaki 	is_dst_NE = (audio_format2_endian(arg->dstfmt) == BYTE_ORDER);
    390       1.2    isaki 
    391       1.2    isaki 	for (i = 0; i < sample_count; i++) {
    392       1.2    isaki 		uint32_t val;
    393       1.2    isaki 		val = *s++;
    394       1.2    isaki 		val ^= xor;
    395       1.2    isaki 		val <<= 32 - AUDIO_INTERNAL_BITS;
    396       1.2    isaki 		if (!is_dst_NE)
    397       1.2    isaki 			val = bswap32(val);
    398       1.2    isaki 		*d++ = val;
    399       1.2    isaki 	}
    400       1.2    isaki }
    401