path: root/audio.c

/*  coveraudiod -- plays sounds while using surface touch covers
	Copyright (C) 2014 Javier S. Pedro <dev.git@javispedro.com>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <stdio.h>

#include <pulse/glib-mainloop.h>
#include <pulse/pulseaudio.h>
#include <sndfile.h>

#include "audio.h"

static pa_context *context;

#define PA_SAMPLE_NAME_PREFIX "coveraudiod-"
#define SAMPLE_FILES_PATH "/usr/share/coveraudiod/"

struct sample_info {
	const char *name;
} samples[NUM_SAMPLES] = {
	{"key1"},
	{"key2"},
    {"key3"},
    {"key4"},
    {"key5"},
    {"key6"},
	{"mod1"},
	{"mod2"}
};

struct sample_loading_status {
	const struct sample_info *sample;
	SNDFILE *sndfile;
	pa_stream *stream;
	size_t nbytes;
};

static const char *build_file_name(const struct sample_info *sample)
{
	static char buffer[sizeof(SAMPLE_FILES_PATH) * 2];

	snprintf(buffer, sizeof(buffer), "%s%s.%s", SAMPLE_FILES_PATH, sample->name, "wav");

	return buffer;
}

static const char *build_sample_name(const struct sample_info *sample)
{
	static char buffer[sizeof(PA_SAMPLE_NAME_PREFIX) * 2];

	snprintf(buffer, sizeof(buffer), "%s%s", PA_SAMPLE_NAME_PREFIX, sample->name);

	return buffer;
}

static void handle_stream_request(pa_stream *s, size_t nbytes, void *userdata)
{
	struct sample_loading_status *ldstatus = (struct sample_loading_status*) userdata;

	void *buffer;

	int err = pa_stream_begin_write(s, &buffer, &nbytes);
	g_return_if_fail(err == 0);

	sf_count_t read = sf_read_raw(ldstatus->sndfile, buffer, nbytes);

	err = pa_stream_write(s, buffer, read, NULL, 0, PA_SEEK_RELATIVE);
	if (err) {
		g_warning("Failed to upload data to PulseAudio");
		pa_stream_disconnect(s);
	}

	ldstatus->nbytes -= read;

	if (read < nbytes || ldstatus->nbytes <= 0) {
		// EOF
		pa_stream_finish_upload(s);
	}
}

static void handle_stream_notify(pa_stream *p, void *userdata)
{
	struct sample_loading_status *ldstatus = (struct sample_loading_status*) userdata;

	pa_stream_state_t status = pa_stream_get_state(p);
	switch (status) {
	case PA_STREAM_READY:
		// Nothing to do, write request will be shortly called by PA.
		break;
	case PA_STREAM_FAILED:
		g_warning("PulseAudio stream upload failed, closing");
		// Fallthrough
	case PA_STREAM_TERMINATED:
		pa_stream_unref(ldstatus->stream);
		sf_close(ldstatus->sndfile);
		free(ldstatus);
		break;
	default:
		break;
	}
}

static bool load_sample(const struct sample_info *sample)
{
	struct sample_loading_status *ldstatus = calloc(1, sizeof(struct sample_loading_status));
	ldstatus->sample = sample;

	const char *file_name = build_file_name(sample);
	SF_INFO info;

	ldstatus->sndfile = sf_open(file_name, SFM_READ, &info);
	if (!ldstatus->sndfile) {
		g_warning("Could not open sample: %s", file_name);
		return false;
	}

	pa_sample_spec spec;
	spec.rate = info.samplerate;
	spec.channels = info.channels;

	switch (info.format & SF_FORMAT_SUBMASK) {
	case SF_FORMAT_PCM_16:
		spec.format = PA_SAMPLE_S16NE;
		break;
	case SF_FORMAT_PCM_24:
		spec.format = PA_SAMPLE_S24NE;
		break;
	case SF_FORMAT_PCM_32:
		spec.format = PA_SAMPLE_S32NE;
		break;
	case SF_FORMAT_ULAW:
		spec.format = PA_SAMPLE_ULAW;
		break;
	case SF_FORMAT_FLOAT:
	case SF_FORMAT_DOUBLE:
		spec.format = PA_SAMPLE_FLOAT32NE;
		break;
	default:
		g_warning("Unknown sample format: %s", file_name);
		sf_close(ldstatus->sndfile);
		free(ldstatus);
		return false;
	}

	g_return_val_if_fail(pa_sample_spec_valid(&spec), false);

	ldstatus->nbytes = pa_frame_size(&spec) * info.frames;

	pa_proplist *prop = pa_proplist_new();
	pa_proplist_sets(prop, PA_PROP_MEDIA_ROLE, "event");
	pa_proplist_sets(prop, PA_PROP_MEDIA_FILENAME, file_name);

	ldstatus->stream = pa_stream_new_with_proplist(context, build_sample_name(sample),
	                                               &spec, NULL, prop);

	pa_stream_set_state_callback(ldstatus->stream, handle_stream_notify, ldstatus);
	pa_stream_set_write_callback(ldstatus->stream, handle_stream_request, ldstatus);

	int err = pa_stream_connect_upload(ldstatus->stream, ldstatus->nbytes);
	if (err) {
		g_warning("pa_stream_connect_upload failed");
		pa_stream_unref(ldstatus->stream);
		sf_close(ldstatus->sndfile);
		free(ldstatus);
		return false;
	}

	return true;
}

static void load_samples()
{
	for (int i = 0; i < NUM_SAMPLES; i++) {
		if (!load_sample(&samples[i])) {
			return;
		}
	}
}

static void handle_context_notify(pa_context *c, void *userdata)
{
	pa_context_state_t state = pa_context_get_state(c);
	switch (state) {
	case PA_CONTEXT_READY:
		load_samples();
		break;
	case PA_CONTEXT_FAILED:
		g_warning("Cannot connect to PulseAudio");
		break;
	default:
		break;
	}
}

bool audio_init()
{
	pa_glib_mainloop *paloop = pa_glib_mainloop_new(NULL);
	context = pa_context_new(pa_glib_mainloop_get_api(paloop), "coveraudiod");

	if (!context) {
		g_warning("Cannot create PulseAudio context");
		return false;
	}

	pa_context_set_state_callback(context, handle_context_notify, NULL);

	int err = pa_context_connect(context, NULL, 0, NULL);
	if (err) {
		g_warning("Cannot connect to PulseAudio");
		return false;
	}

	return true;
}

void audio_close()
{
	pa_context_unref(context);
}

void audio_play_sample(int num_sample)
{
	const char *sample_name = build_sample_name(&samples[num_sample]);

	pa_operation *op = pa_context_play_sample(context, sample_name, NULL,
	                                          PA_VOLUME_NORM, NULL, NULL);

	pa_operation_unref(op);
}