nkeynes@66 | 1 | /**
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nkeynes@465 | 2 | * $Id: audio.c,v 1.11 2007-10-27 05:47:21 nkeynes Exp $
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nkeynes@66 | 3 | *
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nkeynes@66 | 4 | * Audio mixer core. Combines all the active streams into a single sound
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nkeynes@66 | 5 | * buffer for output.
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nkeynes@66 | 6 | *
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nkeynes@66 | 7 | * Copyright (c) 2005 Nathan Keynes.
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nkeynes@66 | 8 | *
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nkeynes@66 | 9 | * This program is free software; you can redistribute it and/or modify
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nkeynes@66 | 10 | * it under the terms of the GNU General Public License as published by
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nkeynes@66 | 11 | * the Free Software Foundation; either version 2 of the License, or
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nkeynes@66 | 12 | * (at your option) any later version.
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nkeynes@66 | 13 | *
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nkeynes@66 | 14 | * This program is distributed in the hope that it will be useful,
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nkeynes@66 | 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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nkeynes@66 | 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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nkeynes@66 | 17 | * GNU General Public License for more details.
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nkeynes@66 | 18 | */
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nkeynes@66 | 19 |
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nkeynes@66 | 20 | #include "aica/aica.h"
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nkeynes@66 | 21 | #include "aica/audio.h"
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nkeynes@66 | 22 | #include "glib/gmem.h"
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nkeynes@66 | 23 | #include "dream.h"
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nkeynes@66 | 24 | #include <assert.h>
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nkeynes@66 | 25 | #include <string.h>
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nkeynes@66 | 26 |
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nkeynes@66 | 27 | #define NUM_BUFFERS 3
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nkeynes@434 | 28 | #define MS_PER_BUFFER 100
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nkeynes@66 | 29 |
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nkeynes@66 | 30 | #define BUFFER_EMPTY 0
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nkeynes@66 | 31 | #define BUFFER_WRITING 1
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nkeynes@66 | 32 | #define BUFFER_FULL 2
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nkeynes@66 | 33 |
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nkeynes@66 | 34 | struct audio_state {
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nkeynes@66 | 35 | audio_buffer_t output_buffers[NUM_BUFFERS];
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nkeynes@66 | 36 | int write_buffer;
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nkeynes@66 | 37 | int read_buffer;
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nkeynes@66 | 38 | uint32_t output_format;
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nkeynes@66 | 39 | uint32_t output_rate;
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nkeynes@66 | 40 | uint32_t output_sample_size;
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nkeynes@465 | 41 | struct audio_channel channels[AUDIO_CHANNEL_COUNT];
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nkeynes@66 | 42 | } audio;
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nkeynes@66 | 43 |
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nkeynes@66 | 44 | audio_driver_t audio_driver = NULL;
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nkeynes@66 | 45 |
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nkeynes@66 | 46 | #define NEXT_BUFFER() ((audio.write_buffer == NUM_BUFFERS-1) ? 0 : audio.write_buffer+1)
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nkeynes@66 | 47 |
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nkeynes@66 | 48 | extern char *arm_mem;
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nkeynes@66 | 49 |
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nkeynes@66 | 50 | /**
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nkeynes@465 | 51 | * Preserve audio channel state only - don't bother saving the buffers
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nkeynes@465 | 52 | */
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nkeynes@465 | 53 | void audio_save_state( FILE *f )
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nkeynes@465 | 54 | {
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nkeynes@465 | 55 | fwrite( &audio.channels[0], sizeof(struct audio_channel), AUDIO_CHANNEL_COUNT, f );
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nkeynes@465 | 56 | }
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nkeynes@465 | 57 |
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nkeynes@465 | 58 | int audio_load_state( FILE *f )
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nkeynes@465 | 59 | {
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nkeynes@465 | 60 | int read = fread( &audio.channels[0], sizeof(struct audio_channel), AUDIO_CHANNEL_COUNT, f );
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nkeynes@465 | 61 | return (read == AUDIO_CHANNEL_COUNT ? 0 : -1 );
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nkeynes@465 | 62 | }
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nkeynes@465 | 63 |
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nkeynes@465 | 64 | /**
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nkeynes@66 | 65 | * Set the output driver, sample rate and format. Also initializes the
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nkeynes@66 | 66 | * output buffers, flushing any current data and reallocating as
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nkeynes@66 | 67 | * necessary.
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nkeynes@66 | 68 | */
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nkeynes@111 | 69 | gboolean audio_set_driver( audio_driver_t driver,
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nkeynes@111 | 70 | uint32_t samplerate, int format )
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nkeynes@66 | 71 | {
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nkeynes@66 | 72 | uint32_t bytes_per_sample = 1;
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nkeynes@66 | 73 | uint32_t samples_per_buffer;
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nkeynes@66 | 74 | int i;
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nkeynes@66 | 75 |
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nkeynes@111 | 76 | if( audio_driver == NULL || driver != NULL ) {
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nkeynes@111 | 77 | if( driver == NULL )
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nkeynes@111 | 78 | driver = &audio_null_driver;
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nkeynes@111 | 79 | if( driver != audio_driver ) {
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nkeynes@111 | 80 | if( !driver->set_output_format( samplerate, format ) )
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nkeynes@111 | 81 | return FALSE;
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nkeynes@111 | 82 | audio_driver = driver;
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nkeynes@111 | 83 | }
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nkeynes@111 | 84 | }
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nkeynes@111 | 85 |
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nkeynes@66 | 86 | if( format & AUDIO_FMT_16BIT )
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nkeynes@66 | 87 | bytes_per_sample = 2;
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nkeynes@66 | 88 | if( format & AUDIO_FMT_STEREO )
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nkeynes@66 | 89 | bytes_per_sample <<= 1;
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nkeynes@66 | 90 | if( samplerate == audio.output_rate &&
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nkeynes@66 | 91 | bytes_per_sample == audio.output_sample_size )
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nkeynes@431 | 92 | return TRUE;
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nkeynes@66 | 93 | samples_per_buffer = (samplerate * MS_PER_BUFFER / 1000);
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nkeynes@66 | 94 | for( i=0; i<NUM_BUFFERS; i++ ) {
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nkeynes@66 | 95 | if( audio.output_buffers[i] != NULL )
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nkeynes@66 | 96 | free(audio.output_buffers[i]);
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nkeynes@66 | 97 | audio.output_buffers[i] = g_malloc0( sizeof(struct audio_buffer) + samples_per_buffer * bytes_per_sample );
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nkeynes@73 | 98 | audio.output_buffers[i]->length = samples_per_buffer * bytes_per_sample;
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nkeynes@66 | 99 | audio.output_buffers[i]->posn = 0;
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nkeynes@66 | 100 | audio.output_buffers[i]->status = BUFFER_EMPTY;
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nkeynes@66 | 101 | }
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nkeynes@66 | 102 | audio.output_format = format;
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nkeynes@66 | 103 | audio.output_rate = samplerate;
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nkeynes@66 | 104 | audio.output_sample_size = bytes_per_sample;
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nkeynes@66 | 105 | audio.write_buffer = 0;
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nkeynes@66 | 106 | audio.read_buffer = 0;
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nkeynes@66 | 107 |
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nkeynes@111 | 108 | return TRUE;
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nkeynes@66 | 109 | }
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nkeynes@66 | 110 |
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nkeynes@66 | 111 | /**
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nkeynes@66 | 112 | * Mark the current write buffer as full and prepare the next buffer for
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nkeynes@66 | 113 | * writing. Returns the next buffer to write to.
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nkeynes@66 | 114 | * If all buffers are full, returns NULL.
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nkeynes@66 | 115 | */
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nkeynes@66 | 116 | audio_buffer_t audio_next_write_buffer( )
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nkeynes@66 | 117 | {
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nkeynes@66 | 118 | audio_buffer_t result = NULL;
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nkeynes@66 | 119 | audio_buffer_t current = audio.output_buffers[audio.write_buffer];
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nkeynes@66 | 120 | current->status = BUFFER_FULL;
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nkeynes@66 | 121 | if( audio.read_buffer == audio.write_buffer &&
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nkeynes@66 | 122 | audio_driver->process_buffer( current ) ) {
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nkeynes@66 | 123 | audio_next_read_buffer();
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nkeynes@66 | 124 | }
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nkeynes@66 | 125 | audio.write_buffer = NEXT_BUFFER();
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nkeynes@66 | 126 | result = audio.output_buffers[audio.write_buffer];
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nkeynes@66 | 127 | if( result->status == BUFFER_FULL )
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nkeynes@66 | 128 | return NULL;
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nkeynes@66 | 129 | else {
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nkeynes@66 | 130 | result->status = BUFFER_WRITING;
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nkeynes@66 | 131 | return result;
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nkeynes@66 | 132 | }
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nkeynes@66 | 133 | }
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nkeynes@66 | 134 |
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nkeynes@66 | 135 | /**
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nkeynes@66 | 136 | * Mark the current read buffer as empty and return the next buffer for
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nkeynes@66 | 137 | * reading. If there is no next buffer yet, returns NULL.
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nkeynes@66 | 138 | */
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nkeynes@66 | 139 | audio_buffer_t audio_next_read_buffer( )
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nkeynes@66 | 140 | {
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nkeynes@66 | 141 | audio_buffer_t current = audio.output_buffers[audio.read_buffer];
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nkeynes@66 | 142 | assert( current->status == BUFFER_FULL );
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nkeynes@66 | 143 | current->status = BUFFER_EMPTY;
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nkeynes@66 | 144 | current->posn = 0;
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nkeynes@66 | 145 | audio.read_buffer++;
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nkeynes@66 | 146 | if( audio.read_buffer == NUM_BUFFERS )
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nkeynes@66 | 147 | audio.read_buffer = 0;
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nkeynes@66 | 148 |
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nkeynes@66 | 149 | current = audio.output_buffers[audio.read_buffer];
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nkeynes@66 | 150 | if( current->status == BUFFER_FULL )
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nkeynes@66 | 151 | return current;
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nkeynes@66 | 152 | else return NULL;
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nkeynes@66 | 153 | }
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nkeynes@66 | 154 |
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nkeynes@66 | 155 | /*************************** ADPCM ***********************************/
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nkeynes@66 | 156 |
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nkeynes@66 | 157 | /**
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nkeynes@66 | 158 | * The following section borrows heavily from ffmpeg, which is
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nkeynes@66 | 159 | * copyright (c) 2001-2003 by the fine folks at the ffmpeg project,
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nkeynes@66 | 160 | * distributed under the GPL version 2 or later.
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nkeynes@66 | 161 | */
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nkeynes@66 | 162 |
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nkeynes@66 | 163 | #define CLAMP_TO_SHORT(value) \
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nkeynes@66 | 164 | if (value > 32767) \
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nkeynes@66 | 165 | value = 32767; \
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nkeynes@66 | 166 | else if (value < -32768) \
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nkeynes@66 | 167 | value = -32768; \
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nkeynes@66 | 168 |
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nkeynes@66 | 169 | static const int yamaha_indexscale[] = {
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nkeynes@66 | 170 | 230, 230, 230, 230, 307, 409, 512, 614,
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nkeynes@66 | 171 | 230, 230, 230, 230, 307, 409, 512, 614
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nkeynes@66 | 172 | };
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nkeynes@66 | 173 |
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nkeynes@66 | 174 | static const int yamaha_difflookup[] = {
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nkeynes@66 | 175 | 1, 3, 5, 7, 9, 11, 13, 15,
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nkeynes@66 | 176 | -1, -3, -5, -7, -9, -11, -13, -15
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nkeynes@66 | 177 | };
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nkeynes@66 | 178 |
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nkeynes@66 | 179 | static inline short adpcm_yamaha_decode_nibble( audio_channel_t c,
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nkeynes@66 | 180 | unsigned char nibble )
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nkeynes@66 | 181 | {
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nkeynes@66 | 182 | if( c->adpcm_step == 0 ) {
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nkeynes@66 | 183 | c->adpcm_predict = 0;
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nkeynes@66 | 184 | c->adpcm_step = 127;
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nkeynes@66 | 185 | }
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nkeynes@66 | 186 |
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nkeynes@66 | 187 | c->adpcm_predict += (c->adpcm_step * yamaha_difflookup[nibble]) >> 3;
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nkeynes@66 | 188 | CLAMP_TO_SHORT(c->adpcm_predict);
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nkeynes@66 | 189 | c->adpcm_step = (c->adpcm_step * yamaha_indexscale[nibble]) >> 8;
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nkeynes@66 | 190 | c->adpcm_step = CLAMP(c->adpcm_step, 127, 24567);
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nkeynes@66 | 191 | return c->adpcm_predict;
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nkeynes@66 | 192 | }
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nkeynes@66 | 193 |
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nkeynes@66 | 194 | /*************************** Sample mixer *****************************/
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nkeynes@66 | 195 |
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nkeynes@66 | 196 | /**
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nkeynes@66 | 197 | * Mix a single output sample.
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nkeynes@66 | 198 | */
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nkeynes@73 | 199 | void audio_mix_samples( int num_samples )
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nkeynes@66 | 200 | {
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nkeynes@66 | 201 | int i, j;
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nkeynes@73 | 202 | int32_t result_buf[num_samples][2];
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nkeynes@73 | 203 |
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nkeynes@73 | 204 | memset( &result_buf, 0, sizeof(result_buf) );
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nkeynes@66 | 205 |
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nkeynes@465 | 206 | for( i=0; i < AUDIO_CHANNEL_COUNT; i++ ) {
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nkeynes@66 | 207 | audio_channel_t channel = &audio.channels[i];
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nkeynes@66 | 208 | if( channel->active ) {
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nkeynes@66 | 209 | int32_t sample;
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nkeynes@82 | 210 | int vol_left = (channel->vol * (32 - channel->pan)) >> 5;
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nkeynes@82 | 211 | int vol_right = (channel->vol * (channel->pan + 1)) >> 5;
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nkeynes@66 | 212 | switch( channel->sample_format ) {
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nkeynes@66 | 213 | case AUDIO_FMT_16BIT:
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nkeynes@73 | 214 | for( j=0; j<num_samples; j++ ) {
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nkeynes@434 | 215 | sample = ((int16_t *)(arm_mem + channel->start))[channel->posn];
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nkeynes@82 | 216 | result_buf[j][0] += sample * vol_left;
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nkeynes@82 | 217 | result_buf[j][1] += sample * vol_right;
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nkeynes@73 | 218 |
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nkeynes@73 | 219 | channel->posn_left += channel->sample_rate;
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nkeynes@73 | 220 | while( channel->posn_left > audio.output_rate ) {
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nkeynes@73 | 221 | channel->posn_left -= audio.output_rate;
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nkeynes@73 | 222 | channel->posn++;
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nkeynes@73 | 223 |
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nkeynes@73 | 224 | if( channel->posn == channel->end ) {
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nkeynes@463 | 225 | if( channel->loop ) {
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nkeynes@73 | 226 | channel->posn = channel->loop_start;
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nkeynes@463 | 227 | channel->loop = LOOP_LOOPED;
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nkeynes@463 | 228 | } else {
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nkeynes@73 | 229 | audio_stop_channel(i);
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nkeynes@73 | 230 | j = num_samples;
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nkeynes@73 | 231 | break;
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nkeynes@73 | 232 | }
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nkeynes@73 | 233 | }
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nkeynes@73 | 234 | }
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nkeynes@73 | 235 | }
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nkeynes@66 | 236 | break;
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nkeynes@66 | 237 | case AUDIO_FMT_8BIT:
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nkeynes@73 | 238 | for( j=0; j<num_samples; j++ ) {
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nkeynes@434 | 239 | sample = ((int8_t *)(arm_mem + channel->start))[channel->posn] << 8;
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nkeynes@82 | 240 | result_buf[j][0] += sample * vol_left;
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nkeynes@82 | 241 | result_buf[j][1] += sample * vol_right;
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nkeynes@73 | 242 |
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nkeynes@73 | 243 | channel->posn_left += channel->sample_rate;
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nkeynes@73 | 244 | while( channel->posn_left > audio.output_rate ) {
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nkeynes@73 | 245 | channel->posn_left -= audio.output_rate;
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nkeynes@73 | 246 | channel->posn++;
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nkeynes@73 | 247 |
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nkeynes@73 | 248 | if( channel->posn == channel->end ) {
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nkeynes@463 | 249 | if( channel->loop ) {
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nkeynes@73 | 250 | channel->posn = channel->loop_start;
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nkeynes@463 | 251 | channel->loop = LOOP_LOOPED;
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nkeynes@463 | 252 | } else {
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nkeynes@73 | 253 | audio_stop_channel(i);
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nkeynes@73 | 254 | j = num_samples;
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nkeynes@73 | 255 | break;
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nkeynes@73 | 256 | }
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nkeynes@73 | 257 | }
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nkeynes@73 | 258 | }
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nkeynes@73 | 259 | }
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nkeynes@66 | 260 | break;
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nkeynes@66 | 261 | case AUDIO_FMT_ADPCM:
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nkeynes@73 | 262 | for( j=0; j<num_samples; j++ ) {
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nkeynes@73 | 263 | sample = (int16_t)channel->adpcm_predict;
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nkeynes@82 | 264 | result_buf[j][0] += sample * vol_left;
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nkeynes@82 | 265 | result_buf[j][1] += sample * vol_right;
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nkeynes@73 | 266 | channel->posn_left += channel->sample_rate;
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nkeynes@73 | 267 | while( channel->posn_left > audio.output_rate ) {
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nkeynes@73 | 268 | channel->posn_left -= audio.output_rate;
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nkeynes@434 | 269 | channel->posn++;
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nkeynes@434 | 270 | if( channel->posn == channel->end ) {
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nkeynes@434 | 271 | if( channel->loop ) {
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nkeynes@434 | 272 | channel->posn = channel->loop_start;
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nkeynes@463 | 273 | channel->loop = LOOP_LOOPED;
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nkeynes@434 | 274 | channel->adpcm_predict = 0;
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nkeynes@434 | 275 | channel->adpcm_step = 0;
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nkeynes@434 | 276 | } else {
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nkeynes@434 | 277 | audio_stop_channel(i);
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nkeynes@434 | 278 | j = num_samples;
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nkeynes@73 | 279 | break;
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nkeynes@73 | 280 | }
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nkeynes@434 | 281 | }
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nkeynes@434 | 282 | uint8_t data = ((uint8_t *)(arm_mem + channel->start))[channel->posn>>1];
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nkeynes@434 | 283 | if( channel->posn&1 ) {
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nkeynes@434 | 284 | adpcm_yamaha_decode_nibble( channel, (data >> 4) & 0x0F );
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nkeynes@434 | 285 | } else {
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nkeynes@73 | 286 | adpcm_yamaha_decode_nibble( channel, data & 0x0F );
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nkeynes@73 | 287 | }
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nkeynes@73 | 288 | }
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nkeynes@73 | 289 | }
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nkeynes@73 | 290 | break;
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nkeynes@66 | 291 | default:
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nkeynes@73 | 292 | break;
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nkeynes@66 | 293 | }
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nkeynes@66 | 294 | }
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nkeynes@66 | 295 | }
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nkeynes@73 | 296 |
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nkeynes@66 | 297 | /* Down-render to the final output format */
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nkeynes@73 | 298 |
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nkeynes@66 | 299 | if( audio.output_format & AUDIO_FMT_16BIT ) {
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nkeynes@73 | 300 | audio_buffer_t buf = audio.output_buffers[audio.write_buffer];
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nkeynes@73 | 301 | uint16_t *data = (uint16_t *)&buf->data[buf->posn];
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nkeynes@73 | 302 | for( j=0; j < num_samples; j++ ) {
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nkeynes@82 | 303 | *data++ = (int16_t)(result_buf[j][0] >> 6);
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nkeynes@82 | 304 | *data++ = (int16_t)(result_buf[j][1] >> 6);
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nkeynes@73 | 305 | buf->posn += 4;
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nkeynes@73 | 306 | if( buf->posn == buf->length ) {
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nkeynes@73 | 307 | audio_next_write_buffer();
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nkeynes@73 | 308 | buf = audio.output_buffers[audio.write_buffer];
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nkeynes@73 | 309 | data = (uint16_t *)&buf->data[0];
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nkeynes@73 | 310 | }
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nkeynes@73 | 311 | }
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nkeynes@66 | 312 | } else {
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nkeynes@73 | 313 | audio_buffer_t buf = audio.output_buffers[audio.write_buffer];
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nkeynes@73 | 314 | uint8_t *data = (uint8_t *)&buf->data[buf->posn];
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nkeynes@73 | 315 | for( j=0; j < num_samples; j++ ) {
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nkeynes@73 | 316 | *data++ = (uint8_t)(result_buf[j][0] >> 16);
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nkeynes@73 | 317 | *data++ = (uint8_t)(result_buf[j][1] >> 16);
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nkeynes@73 | 318 | buf->posn += 2;
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nkeynes@73 | 319 | if( buf->posn == buf->length ) {
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nkeynes@73 | 320 | audio_next_write_buffer();
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nkeynes@73 | 321 | buf = audio.output_buffers[audio.write_buffer];
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nkeynes@73 | 322 | data = (uint8_t *)&buf->data[0];
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nkeynes@73 | 323 | }
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nkeynes@73 | 324 | }
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nkeynes@66 | 325 | }
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nkeynes@66 | 326 | }
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nkeynes@66 | 327 |
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nkeynes@66 | 328 | /********************** Internal AICA calls ***************************/
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nkeynes@66 | 329 |
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nkeynes@66 | 330 | audio_channel_t audio_get_channel( int channel )
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nkeynes@66 | 331 | {
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nkeynes@66 | 332 | return &audio.channels[channel];
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nkeynes@66 | 333 | }
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nkeynes@66 | 334 |
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nkeynes@434 | 335 | void audio_start_stop_channel( int channel, gboolean start )
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nkeynes@434 | 336 | {
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nkeynes@434 | 337 | if( audio.channels[channel].active ) {
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nkeynes@434 | 338 | if( !start ) {
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nkeynes@434 | 339 | audio_stop_channel(channel);
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nkeynes@434 | 340 | }
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nkeynes@434 | 341 | } else if( start ) {
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nkeynes@434 | 342 | audio_start_channel(channel);
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nkeynes@434 | 343 | }
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nkeynes@434 | 344 | }
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nkeynes@434 | 345 |
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nkeynes@66 | 346 | void audio_stop_channel( int channel )
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nkeynes@66 | 347 | {
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nkeynes@66 | 348 | audio.channels[channel].active = FALSE;
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nkeynes@66 | 349 | }
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nkeynes@66 | 350 |
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nkeynes@66 | 351 |
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nkeynes@66 | 352 | void audio_start_channel( int channel )
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nkeynes@66 | 353 | {
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nkeynes@66 | 354 | audio.channels[channel].posn = 0;
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nkeynes@66 | 355 | audio.channels[channel].posn_left = 0;
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nkeynes@66 | 356 | audio.channels[channel].active = TRUE;
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nkeynes@434 | 357 | if( audio.channels[channel].sample_format == AUDIO_FMT_ADPCM ) {
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nkeynes@434 | 358 | audio.channels[channel].adpcm_step = 0;
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nkeynes@434 | 359 | audio.channels[channel].adpcm_predict = 0;
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nkeynes@434 | 360 | uint8_t data = ((uint8_t *)(arm_mem + audio.channels[channel].start))[0];
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nkeynes@434 | 361 | adpcm_yamaha_decode_nibble( &audio.channels[channel], data & 0x0F );
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nkeynes@434 | 362 | }
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nkeynes@66 | 363 | }
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