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      1 /*	$NetBSD: psgpam_enc.c,v 1.3 2023/01/15 05:08:33 tsutsui Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2018 Yosuke Sugahara. All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     20  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     21  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     22  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     23  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     25  * SUCH DAMAGE.
     26  */
     27 
     28 /*
     29  * PSGPAM, PSGPCM encoders
     30  * Function names are PSGPAM, but also used by PSGPCM.
     31  *
     32  * PSGPAM and PSGPCM internally use the unsigned type auint_t for
     33  * intermediate calculations to manage non-linear conversions.
     34  */
     35 
     36 #include <sys/types.h>
     37 
     38 #if defined(_KERNEL)
     39 #include <sys/device.h>
     40 #include <sys/audioio.h>
     41 #include <dev/audio/audio_if.h>
     42 #include <luna68k/dev/psgpam_enc.h>
     43 #include <luna68k/dev/psgpam_table.h>
     44 #else
     45 #include <stdint.h>
     46 #include <stdlib.h>
     47 #include "audio/userland.h"
     48 #include "psgpam_enc.h"
     49 #include "psgpam_table.c"
     50 #include "psgpam_table.h"
     51 #endif
     52 
     53 void
     54 psgpam_init_context(struct psgpam_codecvar *ctx, u_int sample_rate)
     55 {
     56 
     57 	ctx->offset = 65535;
     58 	ctx->sample_rate = sample_rate;
     59 	ctx->expire_initial = sample_rate / 10;
     60 	ctx->expire = ctx->expire_initial;
     61 }
     62 
     63 static inline auint_t
     64 dynamic_offset(struct psgpam_codecvar *ctx, auint_t v)
     65 {
     66 
     67 	/*
     68 	 * if (the passed value cannot be handled by current offset) {
     69 	 *   update offset to handle the passed value
     70 	 * } else {
     71 	 *   increment offset
     72 	 * }
     73 	 */
     74 	if (v <= ctx->offset) {
     75 		ctx->offset = v;
     76 	} else {
     77 		if (--ctx->expire < 0) {
     78 			ctx->offset += 1;
     79 			ctx->expire = ctx->expire_initial;
     80 		}
     81 	}
     82 	return v - ctx->offset;
     83 }
     84 
     85 #define BULK(table) *d++ = table[v]
     86 
     87 #define W8(table) *d++ = table[v]
     88 
     89 #define W16(table) do {							\
     90 	uint16_t t = (uint16_t)table[v];				\
     91 	*d++ = ((t & 0xf0) << 4) | (t & 0x0f);				\
     92 } while (0)
     93 
     94 #define W32(table) do {							\
     95 	uint32_t t = (uint32_t)table[v];				\
     96 	*d++ = ((t & 0xf000) << 12)					\
     97 	     | ((t & 0x0f00) <<  8)					\
     98 	     | ((t & 0x00f0) <<  4)					\
     99 	     | ((t & 0x000f));						\
    100 } while (0)
    101 
    102 #define SPLIT3(table) do {						\
    103 	uint16_t t = (uint16_t)table[v];				\
    104 	*d++ = ((t & 0xf000) >> 12);					\
    105 	*d++ = ((t & 0x0f00) >>  8);					\
    106 	*d++ = ((t & 0x000f));						\
    107 } while (0)
    108 
    109 #define ENCODER_DEFINE(enc, TT, table, writer)				\
    110 void									\
    111 psgpam_aint_to_##enc(audio_filter_arg_t *arg)				\
    112 {									\
    113 	const aint_t *s = arg->src;					\
    114 	TT *d = arg->dst;						\
    115 									\
    116 	for (int i = 0; i < arg->count; i++) {				\
    117 		auint_t v = (*s++) ^ AINT_T_MIN;			\
    118 		v >>= (AUDIO_INTERNAL_BITS - table##_BITS);		\
    119 		writer(table);						\
    120 	}								\
    121 }
    122 
    123 #define ENCODER_D_DEFINE(enc, TT, table, writer)			\
    124 void									\
    125 psgpam_aint_to_##enc##_d(audio_filter_arg_t *arg)			\
    126 {									\
    127 	const aint_t *s = arg->src;					\
    128 	TT *d = arg->dst;						\
    129 									\
    130 	for (int i = 0; i < arg->count; i++) {				\
    131 		auint_t v = (*s++) ^ AINT_T_MIN;			\
    132 		v >>= (AUDIO_INTERNAL_BITS - table##_BITS);		\
    133 		v = dynamic_offset(arg->context, v);			\
    134 		writer(table);						\
    135 	}								\
    136 }
    137 
    138 ENCODER_DEFINE(pam2a, uint16_t, PAM2A_TABLE, W16)
    139 ENCODER_DEFINE(pam2b, uint16_t, PAM2B_TABLE, W16)
    140 ENCODER_DEFINE(pam3a, uint32_t, PAM3A_TABLE, W32)
    141 ENCODER_DEFINE(pam3b, uint32_t, PAM3B_TABLE, W32)
    142 ENCODER_DEFINE(pcm1, uint8_t,  PCM1_TABLE, W8)
    143 ENCODER_DEFINE(pcm2, uint16_t, PCM2_TABLE, W16)
    144 ENCODER_DEFINE(pcm3, uint8_t,  PCM3_TABLE, SPLIT3)
    145 
    146 ENCODER_D_DEFINE(pam2a, uint16_t, PAM2A_TABLE, W16)
    147 ENCODER_D_DEFINE(pam2b, uint16_t, PAM2B_TABLE, W16)
    148 ENCODER_D_DEFINE(pam3a, uint32_t, PAM3A_TABLE, W32)
    149 ENCODER_D_DEFINE(pam3b, uint32_t, PAM3B_TABLE, W32)
    150 ENCODER_D_DEFINE(pcm1, uint8_t,  PCM1_TABLE, W8)
    151 ENCODER_D_DEFINE(pcm2, uint16_t, PCM2_TABLE, W16)
    152 ENCODER_D_DEFINE(pcm3, uint8_t,  PCM3_TABLE, SPLIT3)
    153