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linear.c revision 1.3
      1  1.3  isaki /*	$NetBSD: linear.c,v 1.3 2020/01/11 04:06:13 isaki 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  isaki __KERNEL_RCSID(0, "$NetBSD: linear.c,v 1.3 2020/01/11 04:06:13 isaki Exp $");
     31  1.2  isaki 
     32  1.2  isaki #include <sys/types.h>
     33  1.2  isaki #include <sys/systm.h>
     34  1.2  isaki #include <sys/device.h>
     35  1.2  isaki #include <dev/audio/audiovar.h>
     36  1.2  isaki #include <dev/audio/linear.h>
     37  1.2  isaki 
     38  1.2  isaki /*
     39  1.2  isaki  * audio_linear8_to_internal:
     40  1.2  isaki  *	This filter performs conversion from [US]LINEAR8 to internal format.
     41  1.2  isaki  */
     42  1.2  isaki void
     43  1.2  isaki audio_linear8_to_internal(audio_filter_arg_t *arg)
     44  1.2  isaki {
     45  1.2  isaki 	const uint8_t *s;
     46  1.2  isaki 	aint_t *d;
     47  1.2  isaki 	uint8_t xor;
     48  1.2  isaki 	u_int sample_count;
     49  1.2  isaki 	u_int i;
     50  1.2  isaki 
     51  1.2  isaki 	DIAGNOSTIC_filter_arg(arg);
     52  1.2  isaki 	KASSERT(audio_format2_is_linear(arg->srcfmt));
     53  1.2  isaki 	KASSERT(arg->srcfmt->precision == 8);
     54  1.2  isaki 	KASSERT(arg->srcfmt->stride == 8);
     55  1.2  isaki 	KASSERT(audio_format2_is_internal(arg->dstfmt));
     56  1.2  isaki 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
     57  1.2  isaki 
     58  1.2  isaki 	s = arg->src;
     59  1.2  isaki 	d = arg->dst;
     60  1.2  isaki 	sample_count = arg->count * arg->srcfmt->channels;
     61  1.2  isaki 	xor = audio_format2_is_signed(arg->srcfmt) ? 0 : 0x80;
     62  1.2  isaki 
     63  1.2  isaki 	for (i = 0; i < sample_count; i++) {
     64  1.2  isaki 		uint8_t val;
     65  1.2  isaki 		val = *s++;
     66  1.2  isaki 		val ^= xor;
     67  1.2  isaki 		*d++ = (auint_t)val << (AUDIO_INTERNAL_BITS - 8);
     68  1.2  isaki 	}
     69  1.2  isaki }
     70  1.2  isaki 
     71  1.2  isaki /*
     72  1.2  isaki  * audio_internal_to_linear8:
     73  1.2  isaki  *	This filter performs conversion from internal format to [US]LINEAR8.
     74  1.2  isaki  */
     75  1.2  isaki void
     76  1.2  isaki audio_internal_to_linear8(audio_filter_arg_t *arg)
     77  1.2  isaki {
     78  1.2  isaki 	const aint_t *s;
     79  1.2  isaki 	uint8_t *d;
     80  1.2  isaki 	uint8_t xor;
     81  1.2  isaki 	u_int sample_count;
     82  1.2  isaki 	u_int i;
     83  1.2  isaki 
     84  1.2  isaki 	DIAGNOSTIC_filter_arg(arg);
     85  1.2  isaki 	KASSERT(audio_format2_is_linear(arg->dstfmt));
     86  1.2  isaki 	KASSERT(arg->dstfmt->precision == 8);
     87  1.2  isaki 	KASSERT(arg->dstfmt->stride == 8);
     88  1.2  isaki 	KASSERT(audio_format2_is_internal(arg->srcfmt));
     89  1.2  isaki 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
     90  1.2  isaki 
     91  1.2  isaki 	s = arg->src;
     92  1.2  isaki 	d = arg->dst;
     93  1.2  isaki 	sample_count = arg->count * arg->srcfmt->channels;
     94  1.2  isaki 	xor = audio_format2_is_signed(arg->dstfmt) ? 0 : 0x80;
     95  1.2  isaki 
     96  1.2  isaki 	for (i = 0; i < sample_count; i++) {
     97  1.2  isaki 		uint8_t val;
     98  1.2  isaki 		val = (*s++) >> (AUDIO_INTERNAL_BITS - 8);
     99  1.2  isaki 		val ^= xor;
    100  1.2  isaki 		*d++ = val;
    101  1.2  isaki 	}
    102  1.2  isaki }
    103  1.2  isaki 
    104  1.2  isaki /*
    105  1.2  isaki  * audio_linear16_to_internal:
    106  1.2  isaki  *	This filter performs conversion from [US]LINEAR16{LE,BE} to internal
    107  1.2  isaki  *	format.
    108  1.2  isaki  */
    109  1.2  isaki void
    110  1.2  isaki audio_linear16_to_internal(audio_filter_arg_t *arg)
    111  1.2  isaki {
    112  1.2  isaki 	const uint16_t *s;
    113  1.2  isaki 	aint_t *d;
    114  1.2  isaki 	uint16_t xor;
    115  1.2  isaki 	u_int sample_count;
    116  1.2  isaki 	u_int shift;
    117  1.2  isaki 	u_int i;
    118  1.2  isaki 	bool is_src_NE;
    119  1.2  isaki 
    120  1.2  isaki 	DIAGNOSTIC_filter_arg(arg);
    121  1.2  isaki 	KASSERT(audio_format2_is_linear(arg->srcfmt));
    122  1.2  isaki 	KASSERT(arg->srcfmt->precision == 16);
    123  1.2  isaki 	KASSERT(arg->srcfmt->stride == 16);
    124  1.2  isaki 	KASSERT(audio_format2_is_internal(arg->dstfmt));
    125  1.2  isaki 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
    126  1.2  isaki 
    127  1.2  isaki 	s = arg->src;
    128  1.2  isaki 	d = arg->dst;
    129  1.2  isaki 	sample_count = arg->count * arg->srcfmt->channels;
    130  1.2  isaki 
    131  1.2  isaki 	shift = AUDIO_INTERNAL_BITS - 16;
    132  1.2  isaki 	xor = audio_format2_is_signed(arg->srcfmt) ? 0 : 0x8000;
    133  1.2  isaki 	is_src_NE = (audio_format2_endian(arg->srcfmt) == BYTE_ORDER);
    134  1.2  isaki 
    135  1.2  isaki 	/*
    136  1.2  isaki 	 * Since slinear16_OppositeEndian to slinear_NativeEndian is used
    137  1.2  isaki 	 * so much especially on big endian machines, so it's expanded.
    138  1.2  isaki 	 * Other conversions are rarely used, so they are compressed.
    139  1.2  isaki 	 */
    140  1.2  isaki 	if (__predict_true(xor == 0) && is_src_NE == false) {
    141  1.2  isaki 		/* slinear16_OE to slinear<AI>_NE */
    142  1.2  isaki 		for (i = 0; i < sample_count; i++) {
    143  1.2  isaki 			uint16_t val;
    144  1.2  isaki 			val = *s++;
    145  1.2  isaki 			val = bswap16(val);
    146  1.2  isaki 			*d++ = (auint_t)val << shift;
    147  1.2  isaki 		}
    148  1.2  isaki 	} else {
    149  1.2  isaki 		/* slinear16_NE      to slinear<AI>_NE */
    150  1.2  isaki 		/* ulinear16_{NE,OE} to slinear<AI>_NE */
    151  1.2  isaki 		for (i = 0; i < sample_count; i++) {
    152  1.2  isaki 			uint16_t val;
    153  1.2  isaki 			val = *s++;
    154  1.2  isaki 			if (!is_src_NE)
    155  1.2  isaki 				val = bswap16(val);
    156  1.2  isaki 			val ^= xor;
    157  1.2  isaki 			*d++ = (auint_t)val << shift;
    158  1.2  isaki 		}
    159  1.2  isaki 	}
    160  1.2  isaki }
    161  1.2  isaki 
    162  1.2  isaki /*
    163  1.2  isaki  * audio_internal_to_linear16:
    164  1.2  isaki  *	This filter performs conversion from internal format to
    165  1.2  isaki  *	[US]LINEAR16{LE,BE}.
    166  1.2  isaki  */
    167  1.2  isaki void
    168  1.2  isaki audio_internal_to_linear16(audio_filter_arg_t *arg)
    169  1.2  isaki {
    170  1.2  isaki 	const aint_t *s;
    171  1.2  isaki 	uint16_t *d;
    172  1.2  isaki 	uint16_t xor;
    173  1.2  isaki 	u_int sample_count;
    174  1.2  isaki 	u_int shift;
    175  1.2  isaki 	u_int i;
    176  1.2  isaki 	bool is_dst_NE;
    177  1.2  isaki 
    178  1.2  isaki 	DIAGNOSTIC_filter_arg(arg);
    179  1.2  isaki 	KASSERT(audio_format2_is_linear(arg->dstfmt));
    180  1.2  isaki 	KASSERT(arg->dstfmt->precision == 16);
    181  1.2  isaki 	KASSERT(arg->dstfmt->stride == 16);
    182  1.2  isaki 	KASSERT(audio_format2_is_internal(arg->srcfmt));
    183  1.2  isaki 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
    184  1.2  isaki 
    185  1.2  isaki 	s = arg->src;
    186  1.2  isaki 	d = arg->dst;
    187  1.2  isaki 	sample_count = arg->count * arg->srcfmt->channels;
    188  1.2  isaki 
    189  1.2  isaki 	shift = AUDIO_INTERNAL_BITS - 16;
    190  1.2  isaki 	xor = audio_format2_is_signed(arg->dstfmt) ? 0 : 0x8000;
    191  1.2  isaki 	is_dst_NE = (audio_format2_endian(arg->dstfmt) == BYTE_ORDER);
    192  1.2  isaki 
    193  1.2  isaki 	/*
    194  1.2  isaki 	 * Since slinear_NativeEndian to slinear16_OppositeEndian is used
    195  1.2  isaki 	 * so much especially on big endian machines, so it's expanded.
    196  1.2  isaki 	 * Other conversions are rarely used, so they are compressed.
    197  1.2  isaki 	 */
    198  1.2  isaki 	if (__predict_true(xor == 0) && is_dst_NE == false) {
    199  1.2  isaki 		/* slinear<AI>_NE -> slinear16_OE */
    200  1.2  isaki 		for (i = 0; i < sample_count; i++) {
    201  1.2  isaki 			uint16_t val;
    202  1.2  isaki 			val = (*s++) >> shift;
    203  1.2  isaki 			val = bswap16(val);
    204  1.2  isaki 			*d++ = val;
    205  1.2  isaki 		}
    206  1.2  isaki 	} else {
    207  1.2  isaki 		/* slinear<AI>_NE -> slinear16_NE */
    208  1.2  isaki 		/* slinear<AI>_NE -> ulinear16_{NE,OE} */
    209  1.2  isaki 		for (i = 0; i < sample_count; i++) {
    210  1.2  isaki 			uint16_t val;
    211  1.2  isaki 			val = (*s++) >> shift;
    212  1.2  isaki 			val ^= xor;
    213  1.2  isaki 			if (!is_dst_NE)
    214  1.2  isaki 				val = bswap16(val);
    215  1.2  isaki 			*d++ = val;
    216  1.2  isaki 		}
    217  1.2  isaki 	}
    218  1.2  isaki }
    219  1.2  isaki 
    220  1.2  isaki #if defined(AUDIO_SUPPORT_LINEAR24)
    221  1.2  isaki /*
    222  1.2  isaki  * audio_linear24_to_internal:
    223  1.2  isaki  *	This filter performs conversion from [US]LINEAR24/24{LE,BE} to
    224  1.2  isaki  *	internal format.  Since it's rerely used, it's size optimized.
    225  1.2  isaki  */
    226  1.2  isaki void
    227  1.2  isaki audio_linear24_to_internal(audio_filter_arg_t *arg)
    228  1.2  isaki {
    229  1.2  isaki 	const uint8_t *s;
    230  1.2  isaki 	aint_t *d;
    231  1.2  isaki 	auint_t xor;
    232  1.2  isaki 	u_int sample_count;
    233  1.2  isaki 	u_int i;
    234  1.2  isaki 	bool is_src_LE;
    235  1.2  isaki 
    236  1.2  isaki 	DIAGNOSTIC_filter_arg(arg);
    237  1.2  isaki 	KASSERT(audio_format2_is_linear(arg->srcfmt));
    238  1.2  isaki 	KASSERT(arg->srcfmt->precision == 24);
    239  1.2  isaki 	KASSERT(arg->srcfmt->stride == 24);
    240  1.2  isaki 	KASSERT(audio_format2_is_internal(arg->dstfmt));
    241  1.2  isaki 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
    242  1.2  isaki 
    243  1.2  isaki 	s = arg->src;
    244  1.2  isaki 	d = arg->dst;
    245  1.2  isaki 	sample_count = arg->count * arg->srcfmt->channels;
    246  1.2  isaki 	xor = audio_format2_is_signed(arg->srcfmt)
    247  1.2  isaki 	    ? 0 : (1 << (AUDIO_INTERNAL_BITS - 1));
    248  1.2  isaki 	is_src_LE = (audio_format2_endian(arg->srcfmt) == LITTLE_ENDIAN);
    249  1.2  isaki 
    250  1.2  isaki 	for (i = 0; i < sample_count; i++) {
    251  1.2  isaki 		uint32_t val;
    252  1.2  isaki 		if (is_src_LE) {
    253  1.2  isaki 			val = s[0] | (s[1] << 8) | (s[2] << 16);
    254  1.2  isaki 		} else {
    255  1.2  isaki 			val = (s[0] << 16) | (s[1] << 8) | s[2];
    256  1.2  isaki 		}
    257  1.2  isaki 		s += 3;
    258  1.2  isaki 
    259  1.2  isaki #if AUDIO_INTERNAL_BITS < 24
    260  1.2  isaki 		val >>= 24 - AUDIO_INTERNAL_BITS;
    261  1.2  isaki #else
    262  1.2  isaki 		val <<= AUDIO_INTERNAL_BITS - 24;
    263  1.2  isaki #endif
    264  1.2  isaki 		val ^= xor;
    265  1.2  isaki 		*d++ = val;
    266  1.2  isaki 	}
    267  1.2  isaki }
    268  1.2  isaki 
    269  1.2  isaki /*
    270  1.2  isaki  * audio_internal_to_linear24:
    271  1.2  isaki  *	This filter performs conversion from internal format to
    272  1.2  isaki  *	[US]LINEAR24/24{LE,BE}.  Since it's rarely used, it's size optimized.
    273  1.2  isaki  */
    274  1.2  isaki void
    275  1.2  isaki audio_internal_to_linear24(audio_filter_arg_t *arg)
    276  1.2  isaki {
    277  1.2  isaki 	const aint_t *s;
    278  1.2  isaki 	uint8_t *d;
    279  1.2  isaki 	auint_t xor;
    280  1.2  isaki 	u_int sample_count;
    281  1.2  isaki 	u_int i;
    282  1.2  isaki 	bool is_dst_LE;
    283  1.2  isaki 
    284  1.2  isaki 	DIAGNOSTIC_filter_arg(arg);
    285  1.2  isaki 	KASSERT(audio_format2_is_linear(arg->dstfmt));
    286  1.2  isaki 	KASSERT(arg->dstfmt->precision == 24);
    287  1.2  isaki 	KASSERT(arg->dstfmt->stride == 24);
    288  1.2  isaki 	KASSERT(audio_format2_is_internal(arg->srcfmt));
    289  1.2  isaki 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
    290  1.2  isaki 
    291  1.2  isaki 	s = arg->src;
    292  1.2  isaki 	d = arg->dst;
    293  1.2  isaki 	sample_count = arg->count * arg->srcfmt->channels;
    294  1.2  isaki 	xor = audio_format2_is_signed(arg->dstfmt)
    295  1.2  isaki 	    ? 0 : (1 << (AUDIO_INTERNAL_BITS - 1));
    296  1.2  isaki 	is_dst_LE = (audio_format2_endian(arg->dstfmt) == LITTLE_ENDIAN);
    297  1.2  isaki 
    298  1.2  isaki 	for (i = 0; i < sample_count; i++) {
    299  1.2  isaki 		uint32_t val;
    300  1.2  isaki 		val = *s++;
    301  1.2  isaki 		val ^= xor;
    302  1.2  isaki #if AUDIO_INTERNAL_BITS < 24
    303  1.2  isaki 		val <<= 24 - AUDIO_INTERNAL_BITS;
    304  1.2  isaki #else
    305  1.2  isaki 		val >>= AUDIO_INTERNAL_BITS - 24;
    306  1.2  isaki #endif
    307  1.2  isaki 		if (is_dst_LE) {
    308  1.2  isaki 			d[0] = val & 0xff;
    309  1.2  isaki 			d[1] = (val >> 8) & 0xff;
    310  1.2  isaki 			d[2] = (val >> 16) & 0xff;
    311  1.2  isaki 		} else {
    312  1.2  isaki 			d[0] = (val >> 16) & 0xff;
    313  1.2  isaki 			d[1] = (val >> 8) & 0xff;
    314  1.2  isaki 			d[2] = val & 0xff;
    315  1.2  isaki 		}
    316  1.2  isaki 		d += 3;
    317  1.2  isaki 	}
    318  1.2  isaki }
    319  1.2  isaki #endif /* AUDIO_SUPPORT_LINEAR24 */
    320  1.2  isaki 
    321  1.2  isaki /*
    322  1.2  isaki  * audio_linear32_to_internal:
    323  1.2  isaki  *	This filter performs conversion from [US]LINEAR32{LE,BE} to internal
    324  1.2  isaki  *	format.  Since it's rarely used, it's size optimized.
    325  1.2  isaki  */
    326  1.2  isaki void
    327  1.2  isaki audio_linear32_to_internal(audio_filter_arg_t *arg)
    328  1.2  isaki {
    329  1.2  isaki 	const uint32_t *s;
    330  1.2  isaki 	aint_t *d;
    331  1.2  isaki 	auint_t xor;
    332  1.2  isaki 	u_int sample_count;
    333  1.2  isaki 	u_int i;
    334  1.2  isaki 	bool is_src_NE;
    335  1.2  isaki 
    336  1.2  isaki 	DIAGNOSTIC_filter_arg(arg);
    337  1.2  isaki 	KASSERT(audio_format2_is_linear(arg->srcfmt));
    338  1.2  isaki 	KASSERT(arg->srcfmt->precision == 32);
    339  1.2  isaki 	KASSERT(arg->srcfmt->stride == 32);
    340  1.2  isaki 	KASSERT(audio_format2_is_internal(arg->dstfmt));
    341  1.2  isaki 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
    342  1.2  isaki 
    343  1.2  isaki 	s = arg->src;
    344  1.2  isaki 	d = arg->dst;
    345  1.2  isaki 	sample_count = arg->count * arg->srcfmt->channels;
    346  1.2  isaki 	xor = audio_format2_is_signed(arg->srcfmt)
    347  1.2  isaki 	    ? 0 : (1 << (AUDIO_INTERNAL_BITS - 1));
    348  1.2  isaki 	is_src_NE = (audio_format2_endian(arg->srcfmt) == BYTE_ORDER);
    349  1.2  isaki 
    350  1.2  isaki 	for (i = 0; i < sample_count; i++) {
    351  1.2  isaki 		uint32_t val;
    352  1.2  isaki 		val = *s++;
    353  1.2  isaki 		if (!is_src_NE)
    354  1.2  isaki 			val = bswap32(val);
    355  1.2  isaki 		val >>= 32 - AUDIO_INTERNAL_BITS;
    356  1.2  isaki 		val ^= xor;
    357  1.2  isaki 		*d++ = val;
    358  1.2  isaki 	}
    359  1.2  isaki }
    360  1.2  isaki 
    361  1.2  isaki /*
    362  1.2  isaki  * audio_internal_to_linear32:
    363  1.2  isaki  *	This filter performs conversion from internal format to
    364  1.2  isaki  *	[US]LINEAR32{LE,BE}.  Since it's rarely used, it's size optimized.
    365  1.2  isaki  */
    366  1.2  isaki void
    367  1.2  isaki audio_internal_to_linear32(audio_filter_arg_t *arg)
    368  1.2  isaki {
    369  1.2  isaki 	const aint_t *s;
    370  1.2  isaki 	uint32_t *d;
    371  1.2  isaki 	auint_t xor;
    372  1.2  isaki 	u_int sample_count;
    373  1.2  isaki 	u_int i;
    374  1.2  isaki 	bool is_dst_NE;
    375  1.2  isaki 
    376  1.2  isaki 	DIAGNOSTIC_filter_arg(arg);
    377  1.2  isaki 	KASSERT(audio_format2_is_linear(arg->dstfmt));
    378  1.2  isaki 	KASSERT(arg->dstfmt->precision == 32);
    379  1.2  isaki 	KASSERT(arg->dstfmt->stride == 32);
    380  1.2  isaki 	KASSERT(audio_format2_is_internal(arg->srcfmt));
    381  1.2  isaki 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
    382  1.2  isaki 
    383  1.2  isaki 	s = arg->src;
    384  1.2  isaki 	d = arg->dst;
    385  1.2  isaki 	sample_count = arg->count * arg->srcfmt->channels;
    386  1.2  isaki 	xor = audio_format2_is_signed(arg->dstfmt)
    387  1.2  isaki 	    ? 0 : (1 << (AUDIO_INTERNAL_BITS - 1));
    388  1.2  isaki 	is_dst_NE = (audio_format2_endian(arg->dstfmt) == BYTE_ORDER);
    389  1.2  isaki 
    390  1.2  isaki 	for (i = 0; i < sample_count; i++) {
    391  1.2  isaki 		uint32_t val;
    392  1.2  isaki 		val = *s++;
    393  1.2  isaki 		val ^= xor;
    394  1.2  isaki 		val <<= 32 - AUDIO_INTERNAL_BITS;
    395  1.2  isaki 		if (!is_dst_NE)
    396  1.2  isaki 			val = bswap32(val);
    397  1.2  isaki 		*d++ = val;
    398  1.2  isaki 	}
    399  1.2  isaki }
    400