pwstreamissue.c

#include <stdio.h>
#include <unistd.h>

#include <pipewire/pipewire.h>
#include <spa/param/audio/format-utils.h>

#define SINKLATENCY "1024/48000"

//Change this according to the sink's quantum to stop the stream
//Assuming a sample rate of 48000
//For a quantum of 1024 that's ~21300us
//2048 is ~42600us
//and so on...
#define WAIT 21300

static void on_stream_process(void *data)
{
	struct pw_stream *s = data;
	struct pw_buffer *b = pw_stream_dequeue_buffer(s);

	usleep(WAIT);
	printf("Processed\n");

	pw_stream_queue_buffer(s, b);
}

static void on_sink_bound(void *data, uint32_t global_id)
{
	enum spa_audio_channel pos[2] = {SPA_AUDIO_CHANNEL_FL, SPA_AUDIO_CHANNEL_FR};

	uint8_t buffer[2048];
	struct spa_pod_builder b = SPA_POD_BUILDER_INIT(buffer, sizeof(buffer));
	const struct spa_pod *params[1];

	params[0] = spa_pod_builder_add_object(&b, SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat, SPA_FORMAT_mediaType,
										   SPA_POD_Id(SPA_MEDIA_TYPE_audio), SPA_FORMAT_mediaSubtype,
										   SPA_POD_Id(SPA_MEDIA_SUBTYPE_raw), SPA_FORMAT_AUDIO_channels, SPA_POD_Int(2),
										   SPA_FORMAT_AUDIO_position,
										   SPA_POD_Array(sizeof(enum spa_audio_channel), SPA_TYPE_Id, 2, pos),
										   SPA_FORMAT_AUDIO_format,
										   SPA_POD_CHOICE_ENUM_Id(4, SPA_AUDIO_FORMAT_U8, SPA_AUDIO_FORMAT_S16_LE,
																  SPA_AUDIO_FORMAT_S32_LE, SPA_AUDIO_FORMAT_F32_LE));

	pw_stream_connect(data, PW_DIRECTION_INPUT, global_id,
					  PW_STREAM_FLAG_AUTOCONNECT | PW_STREAM_FLAG_DONT_RECONNECT | PW_STREAM_FLAG_MAP_BUFFERS, params,
					  1);
}

int main(void)
{
	struct pw_thread_loop *loop;
	struct pw_context *context;
	struct pw_core *core;

	pw_init(NULL, NULL);

	loop = pw_thread_loop_new("Loop", NULL);
	context = pw_context_new(pw_thread_loop_get_loop(loop), NULL, 0);

	pw_thread_loop_lock(loop);
	pw_thread_loop_start(loop);

	core = pw_context_connect(context, NULL, 0);

	struct pw_properties *stream_props = pw_properties_new(PW_KEY_MEDIA_TYPE, "Audio", PW_KEY_MEDIA_CATEGORY, "Capture",
														   PW_KEY_MEDIA_ROLE, "Production", PW_KEY_STREAM_CAPTURE_SINK,
														   "true", PW_KEY_NODE_LATENCY, SINKLATENCY, NULL);

	struct spa_hook stream_listener;
	spa_zero(stream_listener);

	struct pw_stream *stream = pw_stream_new(core, "Stream", stream_props);
	pw_stream_add_listener(stream, &stream_listener,
						   &(const struct pw_stream_events){PW_VERSION_STREAM_EVENTS, .process = on_stream_process},
						   stream);

	struct pw_properties *sink_props = pw_properties_new(PW_KEY_NODE_NAME, "Sink", PW_KEY_FACTORY_NAME,
														 "support.null-audio-sink", PW_KEY_MEDIA_CLASS, "Audio/Sink",
														 PW_KEY_NODE_VIRTUAL, "true", "audio.position", "FL,FR",
														 PW_KEY_AUDIO_CHANNELS, "2", NULL);

	struct spa_hook sink_listener;
	spa_zero(sink_listener);

	struct pw_proxy *sink =
		pw_core_create_object(core, "adapter", PW_TYPE_INTERFACE_Node, PW_VERSION_NODE, &sink_props->dict, 0);

	pw_proxy_add_listener(sink, &sink_listener,
						  &(const struct pw_proxy_events){PW_VERSION_PROXY_EVENTS, .bound = on_sink_bound}, stream);

	pw_thread_loop_unlock(loop);

	for (;;)
		;
}