examples: add example audio source

src/examples/audio-src.c

@@ -0,0 +1,200 @@
+/* PipeWire
+ * Copyright (C) 2018 Wim Taymans <wim.taymans@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <time.h>
+#include <math.h>
+#include <sys/mman.h>
+
+#include <spa/support/type-map.h>
+#include <spa/param/format-utils.h>
+#include <spa/param/audio/format-utils.h>
+#include <spa/param/props.h>
+#include <spa/lib/debug.h>
+
+#include <pipewire/pipewire.h>
+
+#define M_PI_M2 ( M_PI + M_PI )
+
+#define DEFAULT_RATE		44100
+#define DEFAULT_CHANNELS	1
+
+struct type {
+	struct spa_type_media_type media_type;
+	struct spa_type_media_subtype media_subtype;
+	struct spa_type_format_audio format_audio;
+	struct spa_type_audio_format audio_format;
+};
+
+static inline void init_type(struct type *type, struct spa_type_map *map)
+{
+	spa_type_media_type_map(map, &type->media_type);
+	spa_type_media_subtype_map(map, &type->media_subtype);
+	spa_type_format_audio_map(map, &type->format_audio);
+	spa_type_audio_format_map(map, &type->audio_format);
+}
+
+struct data {
+	struct type type;
+
+	struct pw_main_loop *loop;
+
+	struct pw_core *core;
+	struct pw_type *t;
+	struct pw_remote *remote;
+	struct spa_hook remote_listener;
+
+	struct pw_stream *stream;
+	struct spa_hook stream_listener;
+
+	struct spa_audio_info_raw format;
+
+	double accumulator;
+};
+
+static void fill_f32(struct data *d, void *dest, int avail)
+{
+	float *dst = dest;
+	int n_samples = avail / (sizeof(float) * d->format.channels);
+	int i, c;
+
+        for (i = 0; i < n_samples; i++) {
+		float val;
+
+                d->accumulator += M_PI_M2 * 440 / d->format.rate;
+                if (d->accumulator >= M_PI_M2)
+                        d->accumulator -= M_PI_M2;
+
+                val = sin(d->accumulator);
+
+                for (c = 0; c < d->format.channels; c++)
+                        *dst++ = val;
+        }
+}
+
+static void on_need_buffer(void *userdata)
+{
+	struct data *data = userdata;
+	uint32_t id;
+	struct spa_buffer *buf;
+	uint8_t *p;
+
+	id = pw_stream_get_empty_buffer(data->stream);
+	if (id == SPA_ID_INVALID)
+		return;
+
+	buf = pw_stream_peek_buffer(data->stream, id);
+
+	if ((p = buf->datas[0].data) == NULL)
+		return;
+
+	fill_f32(data, p, buf->datas[0].maxsize);
+
+	buf->datas[0].chunk->size = buf->datas[0].maxsize;
+
+	pw_stream_send_buffer(data->stream, id);
+}
+
+static const struct pw_stream_events stream_events = {
+	PW_VERSION_STREAM_EVENTS,
+	.need_buffer = on_need_buffer,
+};
+
+static void on_state_changed(void *_data, enum pw_remote_state old, enum pw_remote_state state, const char *error)
+{
+	struct data *data = _data;
+	struct pw_remote *remote = data->remote;
+
+	switch (state) {
+	case PW_REMOTE_STATE_ERROR:
+		printf("remote error: %s\n", error);
+		pw_main_loop_quit(data->loop);
+		break;
+
+	case PW_REMOTE_STATE_CONNECTED:
+	{
+		const struct spa_pod *params[1];
+		uint8_t buffer[1024];
+		struct spa_pod_builder b = SPA_POD_BUILDER_INIT(buffer, sizeof(buffer));
+
+		printf("remote state: \"%s\"\n",
+		       pw_remote_state_as_string(state));
+
+		data->stream = pw_stream_new(remote, "audio-src", NULL);
+
+		params[0] = spa_pod_builder_object(&b,
+			data->t->param.idEnumFormat, data->t->spa_format,
+			"I", data->type.media_type.audio,
+			"I", data->type.media_subtype.raw,
+			":", data->type.format_audio.format,    "I", data->type.audio_format.F32,
+			":", data->type.format_audio.channels,  "i", DEFAULT_CHANNELS,
+			":", data->type.format_audio.rate,	"i", DEFAULT_RATE);
+
+		data->format.channels = DEFAULT_CHANNELS;
+		data->format.rate = DEFAULT_RATE;
+
+		pw_stream_add_listener(data->stream,
+				       &data->stream_listener,
+				       &stream_events,
+				       data);
+
+		pw_stream_connect(data->stream,
+				  PW_DIRECTION_OUTPUT,
+				  NULL,
+				  PW_STREAM_FLAG_AUTOCONNECT |
+				  PW_STREAM_FLAG_MAP_BUFFERS,
+				  params, 1);
+		break;
+	}
+	default:
+		printf("remote state: \"%s\"\n", pw_remote_state_as_string(state));
+		break;
+	}
+}
+
+static const struct pw_remote_events remote_events = {
+	PW_VERSION_REMOTE_EVENTS,
+	.state_changed = on_state_changed,
+};
+
+int main(int argc, char *argv[])
+{
+	struct data data = { 0, };
+
+	pw_init(&argc, &argv);
+
+	data.loop = pw_main_loop_new(NULL);
+	data.core = pw_core_new(pw_main_loop_get_loop(data.loop), NULL);
+	data.t = pw_core_get_type(data.core);
+	data.remote = pw_remote_new(data.core, NULL, 0);
+
+	init_type(&data.type, data.t->map);
+
+	pw_remote_add_listener(data.remote, &data.remote_listener, &remote_events, &data);
+
+	pw_remote_connect(data.remote);
+
+	pw_main_loop_run(data.loop);
+
+	pw_core_destroy(data.core);
+	pw_main_loop_destroy(data.loop);
+
+	return 0;
+}

src/examples/meson.build

@@ -3,6 +3,11 @@ executable('video-src',
   install: false,
   dependencies : [pipewire_dep],
 )
+executable('audio-src',
+  'audio-src.c',
+  install: false,
+  dependencies : [pipewire_dep, mathlib],
+)
 executable('export-source',
   'export-source.c',
   install: false,