audio.h

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/*
 * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
 
#ifndef _PICO_AUDIO_H
#define _PICO_AUDIO_H
 
#include "pico.h"
#include "pico/util/buffer.h"
#include "hardware/sync.h"
 
#ifdef __cplusplus
extern "C" {
#endif
 
// PICO_CONFIG: SPINLOCK_ID_AUDIO_FREE_LIST_LOCK, Spinlock number for the audio free list, min=0, max=31, default=6, group=audio
#ifndef SPINLOCK_ID_AUDIO_FREE_LIST_LOCK
#define SPINLOCK_ID_AUDIO_FREE_LIST_LOCK 6
#endif
 
// PICO_CONFIG: SPINLOCK_ID_AUDIO_PREPARED_LISTS_LOCK, Spinlock number for the audio prepared list, min=0, max=31, default=7, group=audio
#ifndef SPINLOCK_ID_AUDIO_PREPARED_LISTS_LOCK
#define SPINLOCK_ID_AUDIO_PREPARED_LISTS_LOCK 7
#endif
 
// PICO_CONFIG: PICO_AUDIO_NOOP, Enable/disable audio by forcing NOOPS, type=bool, default=0, group=audio
#ifndef PICO_AUDIO_NOOP
#define PICO_AUDIO_NOOP 0
#endif
 
 
#define AUDIO_BUFFER_FORMAT_PCM_S16 1          
#define AUDIO_BUFFER_FORMAT_PCM_S8 2           
#define AUDIO_BUFFER_FORMAT_PCM_U16 3          
#define AUDIO_BUFFER_FORMAT_PCM_U8 4           
 
 
typedef struct audio_format {
    uint32_t sample_freq;      
    uint16_t format;           
    uint16_t channel_count;    
} audio_format_t;
 
typedef struct audio_buffer_format {
    const audio_format_t *format;      
    uint16_t sample_stride;                 
} audio_buffer_format_t;
 
typedef struct audio_buffer {
    mem_buffer_t *buffer;
    const audio_buffer_format_t *format;
    uint32_t sample_count;
    uint32_t max_sample_count;
    uint32_t user_data; // only valid while the user has the buffer
    // private - todo make an internal version
    struct audio_buffer *next;
} audio_buffer_t;
 
typedef struct audio_connection audio_connection_t;
 
typedef struct audio_buffer_pool {
    enum {
        ac_producer, ac_consumer
    } type;
    const audio_format_t *format;
    // private
    audio_connection_t *connection;
    spin_lock_t *free_list_spin_lock;
    // ----- begin protected by free_list_spin_lock -----
    audio_buffer_t *free_list;
    spin_lock_t *prepared_list_spin_lock;
    audio_buffer_t *prepared_list;
    audio_buffer_t *prepared_list_tail;
} audio_buffer_pool_t;
 
typedef struct audio_connection audio_connection_t;
 
struct audio_connection {
    audio_buffer_t *(*producer_pool_take)(audio_connection_t *connection, bool block);
 
    void (*producer_pool_give)(audio_connection_t *connection, audio_buffer_t *buffer);
 
    audio_buffer_t *(*consumer_pool_take)(audio_connection_t *connection, bool block);
 
    void (*consumer_pool_give)(audio_connection_t *connection, audio_buffer_t *buffer);
 
    audio_buffer_pool_t *producer_pool;
    audio_buffer_pool_t *consumer_pool;
};
 
audio_buffer_pool_t *audio_new_producer_pool(audio_buffer_format_t *format, int buffer_count,
                                                         int buffer_sample_count);
 
audio_buffer_pool_t *audio_new_consumer_pool(audio_buffer_format_t *format, int buffer_count,
                                                         int buffer_sample_count);
 
audio_buffer_t *audio_new_wrapping_buffer(audio_buffer_format_t *format, mem_buffer_t *buffer);
 
audio_buffer_t *audio_new_buffer(audio_buffer_format_t *format, int buffer_sample_count);
 
void audio_init_buffer(audio_buffer_t *audio_buffer, audio_buffer_format_t *format, int buffer_sample_count);
 
void give_audio_buffer(audio_buffer_pool_t *ac, audio_buffer_t *buffer);
 
audio_buffer_t *take_audio_buffer(audio_buffer_pool_t *ac, bool block);
 
static inline void release_audio_buffer(audio_buffer_pool_t *ac, audio_buffer_t *buffer) {
    buffer->sample_count = 0;
    give_audio_buffer(ac, buffer);
}
 
void audio_upsample(int16_t *input, int16_t *output, uint output_count, uint32_t step);
 
void audio_upsample_words(int16_t *input, int16_t *output_aligned, uint output_word_count, uint32_t step);
 
void audio_upsample_double(int16_t *input, int16_t *output, uint output_count, uint32_t step);
 
void audio_complete_connection(audio_connection_t *connection, audio_buffer_pool_t *producer,
                                      audio_buffer_pool_t *consumer);
 
audio_buffer_t *get_free_audio_buffer(audio_buffer_pool_t *context, bool block);
 
void queue_free_audio_buffer(audio_buffer_pool_t *context, audio_buffer_t *ab);
 
audio_buffer_t *get_full_audio_buffer(audio_buffer_pool_t *context, bool block);
 
void queue_full_audio_buffer(audio_buffer_pool_t *context, audio_buffer_t *ab);
 
void consumer_pool_give_buffer_default(audio_connection_t *connection, audio_buffer_t *buffer);
 
audio_buffer_t *consumer_pool_take_buffer_default(audio_connection_t *connection, bool block);
 
void producer_pool_give_buffer_default(audio_connection_t *connection, audio_buffer_t *buffer);
 
audio_buffer_t *producer_pool_take_buffer_default(audio_connection_t *connection, bool block);
 
enum audio_correction_mode {
    none,
    fixed_dither,
    dither,
    noise_shaped_dither,
};
 
struct buffer_copying_on_consumer_take_connection {
    struct audio_connection core;
    audio_buffer_t *current_producer_buffer;
    uint32_t current_producer_buffer_pos;
};
 
struct producer_pool_blocking_give_connection {
    audio_connection_t core;
    audio_buffer_t *current_consumer_buffer;
    uint32_t current_consumer_buffer_pos;
};
 
audio_buffer_t *mono_to_mono_consumer_take(audio_connection_t *connection, bool block);
 
audio_buffer_t *mono_s8_to_mono_consumer_take(audio_connection_t *connection, bool block);
 
audio_buffer_t *stereo_to_stereo_consumer_take(audio_connection_t *connection, bool block);
 
audio_buffer_t *mono_to_stereo_consumer_take(audio_connection_t *connection, bool block);
 
audio_buffer_t *mono_s8_to_stereo_consumer_take(audio_connection_t *connection, bool block);
 
void stereo_to_stereo_producer_give(audio_connection_t *connection, audio_buffer_t *buffer);
 
// not worth a separate header for now
typedef struct __packed pio_audio_channel_config {
    uint8_t base_pin;
    uint8_t dma_channel;
    uint8_t pio_sm;
} pio_audio_channel_config_t;
 
#ifdef __cplusplus
}
#endif
 
#endif //_AUDIO_H