pipewire/spa/plugins/alsa/alsa-pcm.h

/* Spa ALSA Sink */
/* SPDX-FileCopyrightText: Copyright © 2018 Wim Taymans */
/* SPDX-License-Identifier: MIT */

#ifndef SPA_ALSA_UTILS_H
#define SPA_ALSA_UTILS_H

#ifdef __cplusplus
extern "C" {
#endif

#include <stddef.h>
#include <math.h>

#include <alsa/asoundlib.h>
#include <alsa/use-case.h>

#include <spa/support/plugin.h>
#include <spa/support/loop.h>
#include <spa/utils/list.h>
#include <spa/utils/json.h>
#include <spa/utils/dll.h>

#include <spa/node/node.h>
#include <spa/node/utils.h>
#include <spa/node/io.h>
#include <spa/debug/types.h>
#include <spa/param/param.h>
#include <spa/param/latency-utils.h>
#include <spa/param/audio/format-utils.h>

#include "alsa.h"


#define MAX_RATES	16

#define DEFAULT_PERIOD		1024u
#define DEFAULT_RATE		48000u
#define DEFAULT_CHANNELS	2u
#define DEFAULT_USE_CHMAP	false

struct props {
	char device[64];
	char device_name[128];
	char card_name[128];
	bool use_chmap;
};

#define MAX_BUFFERS 32
#define MAX_POLL 16

struct buffer {
	uint32_t id;
#define BUFFER_FLAG_OUT	(1<<0)
	uint32_t flags;
	struct spa_buffer *buf;
	struct spa_meta_header *h;
	struct spa_list link;
};

#define BW_MAX		0.128
#define BW_MED		0.064
#define BW_MIN		0.016
#define BW_PERIOD	(3 * SPA_NSEC_PER_SEC)

struct channel_map {
	uint32_t channels;
	uint32_t pos[SPA_AUDIO_MAX_CHANNELS];
};

struct card {
	struct spa_list link;
	int ref;
	uint32_t index;
	snd_use_case_mgr_t *ucm;
	char *ucm_prefix;
	int format_ref;
	uint32_t rate;
};

struct ratelimit {
	uint64_t interval;
	uint64_t begin;
	unsigned burst;
	unsigned n_printed, n_missed;
};

struct state {
	struct spa_handle handle;
	struct spa_node node;

	struct spa_log *log;
	struct spa_system *data_system;
	struct spa_loop *data_loop;

	FILE *log_file;
	struct ratelimit rate_limit;

	uint32_t card_index;
	struct card *card;
	snd_pcm_stream_t stream;
	snd_output_t *output;

	struct spa_hook_list hooks;
	struct spa_callbacks callbacks;

	uint64_t info_all;
	struct spa_node_info info;
#define NODE_PropInfo		0
#define NODE_Props		1
#define NODE_IO			2
#define NODE_ProcessLatency	3
#define N_NODE_PARAMS		4
	struct spa_param_info params[N_NODE_PARAMS];
	struct props props;

	bool opened;
	snd_pcm_t *hndl;

	bool have_format;
	struct spa_audio_info current_format;

	uint32_t default_period_size;
	uint32_t default_period_num;
	uint32_t default_headroom;
	uint32_t default_start_delay;
	uint32_t default_format;
	unsigned int default_channels;
	unsigned int default_rate;
	uint32_t allowed_rates[MAX_RATES];
	uint32_t n_allowed_rates;
	struct channel_map default_pos;
	unsigned int disable_mmap;
	unsigned int disable_batch;
	unsigned int disable_tsched;
	char clock_name[64];
	uint32_t quantum_limit;

	snd_pcm_uframes_t buffer_frames;
	snd_pcm_uframes_t period_frames;
	snd_pcm_format_t format;
	int rate;
	int channels;
	size_t frame_size;
	size_t frame_scale;
	int blocks;
	uint32_t rate_denom;
	uint32_t delay;
	uint32_t read_size;

	uint64_t port_info_all;
	struct spa_port_info port_info;
#define PORT_EnumFormat		0
#define PORT_Meta		1
#define PORT_IO			2
#define PORT_Format		3
#define PORT_Buffers		4
#define PORT_Latency		5
#define N_PORT_PARAMS		6
	struct spa_param_info port_params[N_PORT_PARAMS];
	enum spa_direction port_direction;
	struct spa_io_buffers *io;
	struct spa_io_clock *clock;
	struct spa_io_position *position;
	struct spa_io_rate_match *rate_match;

	struct buffer buffers[MAX_BUFFERS];
	unsigned int n_buffers;

	struct spa_list free;
	struct spa_list ready;

	size_t ready_offset;

	bool started;
	/* Either a single source for tsched, or a set of pollfds from ALSA */
	struct spa_source source[MAX_POLL];
	int timerfd;
	struct pollfd pfds[MAX_POLL];
	int n_fds;
	uint32_t threshold;
	uint32_t last_threshold;
	uint32_t headroom;
	uint32_t start_delay;
	uint32_t min_delay;
	uint32_t max_delay;

	uint32_t duration;
	unsigned int alsa_started:1;
	unsigned int alsa_sync:1;
	unsigned int alsa_sync_warning:1;
	unsigned int alsa_recovering:1;
	unsigned int following:1;
	unsigned int matching:1;
	unsigned int resample:1;
	unsigned int use_mmap:1;
	unsigned int planar:1;
	unsigned int freewheel:1;
	unsigned int open_ucm:1;
	unsigned int is_iec958:1;
	unsigned int is_hdmi:1;
	unsigned int multi_rate:1;

	uint64_t iec958_codecs;

	int64_t sample_count;

	int64_t sample_time;
	uint64_t next_time;
	uint64_t base_time;

	uint64_t underrun;

	struct spa_dll dll;
	double max_error;

	struct spa_latency_info latency[2];
	struct spa_process_latency_info process_latency;
};

struct spa_pod *spa_alsa_enum_propinfo(struct state *state,
		uint32_t idx, struct spa_pod_builder *b);
int spa_alsa_add_prop_params(struct state *state, struct spa_pod_builder *b);
int spa_alsa_parse_prop_params(struct state *state, struct spa_pod *params);

int spa_alsa_enum_format(struct state *state, int seq,
		     uint32_t start, uint32_t num,
		     const struct spa_pod *filter);

int spa_alsa_set_format(struct state *state, struct spa_audio_info *info, uint32_t flags);

int spa_alsa_init(struct state *state, const struct spa_dict *info);
int spa_alsa_clear(struct state *state);

int spa_alsa_open(struct state *state, const char *params);
int spa_alsa_start(struct state *state);
int spa_alsa_reassign_follower(struct state *state);
int spa_alsa_pause(struct state *state);
int spa_alsa_close(struct state *state);

int spa_alsa_write(struct state *state);
int spa_alsa_read(struct state *state);
int spa_alsa_skip(struct state *state);

void spa_alsa_recycle_buffer(struct state *state, uint32_t buffer_id);

static inline uint32_t spa_alsa_format_from_name(const char *name, size_t len)
{
	int i;
	for (i = 0; spa_type_audio_format[i].name; i++) {
		if (strncmp(name, spa_debug_type_short_name(spa_type_audio_format[i].name), len) == 0)
			return spa_type_audio_format[i].type;
	}
	return SPA_AUDIO_FORMAT_UNKNOWN;
}

static inline uint32_t spa_alsa_channel_from_name(const char *name)
{
	int i;
	for (i = 0; spa_type_audio_channel[i].name; i++) {
		if (strcmp(name, spa_debug_type_short_name(spa_type_audio_channel[i].name)) == 0)
			return spa_type_audio_channel[i].type;
	}
	return SPA_AUDIO_CHANNEL_UNKNOWN;
}

static inline void spa_alsa_parse_position(struct channel_map *map, const char *val, size_t len)
{
	struct spa_json it[2];
	char v[256];

	spa_json_init(&it[0], val, len);
        if (spa_json_enter_array(&it[0], &it[1]) <= 0)
                spa_json_init(&it[1], val, len);

	map->channels = 0;
	while (spa_json_get_string(&it[1], v, sizeof(v)) > 0 &&
	    map->channels < SPA_AUDIO_MAX_CHANNELS) {
		map->pos[map->channels++] = spa_alsa_channel_from_name(v);
	}
}

static inline uint32_t spa_alsa_parse_rates(uint32_t *rates, uint32_t max, const char *val, size_t len)
{
	struct spa_json it[2];
	char v[256];
	uint32_t count;

	spa_json_init(&it[0], val, len);
        if (spa_json_enter_array(&it[0], &it[1]) <= 0)
                spa_json_init(&it[1], val, len);

	count = 0;
	while (spa_json_get_string(&it[1], v, sizeof(v)) > 0 && count < max)
		rates[count++] = atoi(v);
	return count;
}

static inline uint32_t spa_alsa_iec958_codec_from_name(const char *name)
{
	int i;
	for (i = 0; spa_type_audio_iec958_codec[i].name; i++) {
		if (strcmp(name, spa_debug_type_short_name(spa_type_audio_iec958_codec[i].name)) == 0)
			return spa_type_audio_iec958_codec[i].type;
	}
	return SPA_AUDIO_IEC958_CODEC_UNKNOWN;
}

static inline void spa_alsa_parse_iec958_codecs(uint64_t *codecs, const char *val, size_t len)
{
	struct spa_json it[2];
	char v[256];

	spa_json_init(&it[0], val, len);
        if (spa_json_enter_array(&it[0], &it[1]) <= 0)
                spa_json_init(&it[1], val, len);

	*codecs = 0;
	while (spa_json_get_string(&it[1], v, sizeof(v)) > 0)
		*codecs |= 1ULL << spa_alsa_iec958_codec_from_name(v);
}

static inline uint32_t spa_alsa_get_iec958_codecs(struct state *state, uint32_t *codecs,
		uint32_t max_codecs)
{
	uint64_t mask = state->iec958_codecs;
	uint32_t i = 0, j = 0;
	if (!(state->is_iec958 || state->is_hdmi))
		return 0;
	while (mask && i < max_codecs) {
		if (mask & 1)
			codecs[i++] = j;
		mask >>= 1;
		j++;
	}
	return i;
}

static inline int ratelimit_test(struct ratelimit *r, uint64_t now)
{
	unsigned missed = 0;
	if (r->begin + r->interval < now) {
		missed = r->n_missed;
		r->begin = now;
		r->n_printed = 0;
		r->n_missed = 0;
	} else if (r->n_printed >= r->burst) {
		r->n_missed++;
		return -1;
	}
	r->n_printed++;
	return missed;
}


#ifdef __cplusplus
} /* extern "C" */
#endif

#endif /* SPA_ALSA_UTILS_H */