export-spa-device.c

Exporting and loading a SPA device, using Core API.

/* PipeWire */
/* SPDX-FileCopyrightText: Copyright © 2019 Wim Taymans */
/* SPDX-License-Identifier: MIT */
 
/*
 [title]
 Exporting and loading a SPA device, using \ref api_pw_core.
 [title]
 */
 
#include <stdio.h>
#include <sys/mman.h>
#include <signal.h>
 
#include <spa/utils/result.h>
#include <spa/param/video/format-utils.h>
#include <spa/param/props.h>
 
#include <pipewire/impl.h>
 
struct data {
        struct pw_main_loop *loop;
 
        struct pw_context *context;
 
        struct pw_core *core;
        struct spa_hook core_listener;
 
        struct pw_impl_device *device;
        const char *library;
        const char *factory;
        const char *path;
};
 
static int make_device(struct data *data)
{
        struct pw_impl_factory *factory;
        struct pw_properties *props;
 
        factory = pw_context_find_factory(data->context, "spa-device-factory");
        if (factory == NULL)
                return -1;
 
        props = pw_properties_new(SPA_KEY_LIBRARY_NAME, data->library,
                                  SPA_KEY_FACTORY_NAME, data->factory, NULL);
 
        data->device = pw_impl_factory_create_object(factory,
                                              NULL,
                                              PW_TYPE_INTERFACE_Device,
                                              PW_VERSION_DEVICE,
                                              props, SPA_ID_INVALID);
 
        pw_core_export(data->core, SPA_TYPE_INTERFACE_Device, NULL,
                        pw_impl_device_get_implementation(data->device), 0);
 
        return 0;
}
 
static void on_core_error(void *data, uint32_t id, int seq, int res, const char *message)
{
        struct data *d = data;
 
        pw_log_error("error id:%u seq:%d res:%d (%s): %s",
                        id, seq, res, spa_strerror(res), message);
 
        if (id == PW_ID_CORE)
                pw_main_loop_quit(d->loop);
}
 
static const struct pw_core_events core_events = {
        PW_VERSION_CORE_EVENTS,
        .error = on_core_error,
};
 
static void do_quit(void *data, int signal_number)
{
        struct data *d = data;
        pw_main_loop_quit(d->loop);
}
 
int main(int argc, char *argv[])
{
        struct data data = { 0, };
        struct pw_loop *l;
 
        pw_init(&argc, &argv);
 
        if (argc < 3) {
                fprintf(stderr, "usage: %s <library> <factory>\n\n"
                                "\texample: %s v4l2/libspa-v4l2 api.v4l2.device\n\n",
                                argv[0], argv[0]);
                return -1;
        }
 
        data.loop = pw_main_loop_new(NULL);
        l = pw_main_loop_get_loop(data.loop);
        pw_loop_add_signal(l, SIGINT, do_quit, &data);
        pw_loop_add_signal(l, SIGTERM, do_quit, &data);
        data.context = pw_context_new(l, NULL, 0);
        data.library = argv[1];
        data.factory = argv[2];
 
        pw_context_load_module(data.context, "libpipewire-module-spa-device-factory", NULL, NULL);
 
        data.core = pw_context_connect(data.context, NULL, 0);
        if (data.core == NULL) {
                pw_log_error("can't connect %m");
                return -1;
        }
 
        pw_core_add_listener(data.core, &data.core_listener, &core_events, &data);
 
        if (make_device(&data) < 0) {
                pw_log_error("can't make device");
                return -1;
        }
 
        pw_main_loop_run(data.loop);
 
        pw_context_destroy(data.context);
        pw_main_loop_destroy(data.loop);
 
        return 0;
}