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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:28:17 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:28:17 +0000
commit7a46c07230b8d8108c0e8e80df4522d0ac116538 (patch)
treed483300dab478b994fe199a5d19d18d74153718a /doc/tutorial4.c
parentInitial commit. (diff)
downloadpipewire-7a46c07230b8d8108c0e8e80df4522d0ac116538.tar.xz
pipewire-7a46c07230b8d8108c0e8e80df4522d0ac116538.zip
Adding upstream version 0.3.65.upstream/0.3.65upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--doc/tutorial4.c112
1 files changed, 112 insertions, 0 deletions
diff --git a/doc/tutorial4.c b/doc/tutorial4.c
new file mode 100644
index 0000000..ff0cb27
--- /dev/null
+++ b/doc/tutorial4.c
@@ -0,0 +1,112 @@
+/*
+ [title]
+ \ref page_tutorial4
+ [title]
+ */
+/* [code] */
+#include <math.h>
+
+#include <spa/param/audio/format-utils.h>
+
+#include <pipewire/pipewire.h>
+
+#define M_PI_M2 ( M_PI + M_PI )
+
+#define DEFAULT_RATE 44100
+#define DEFAULT_CHANNELS 2
+#define DEFAULT_VOLUME 0.7
+
+struct data {
+ struct pw_main_loop *loop;
+ struct pw_stream *stream;
+ double accumulator;
+};
+
+/* [on_process] */
+static void on_process(void *userdata)
+{
+ struct data *data = userdata;
+ struct pw_buffer *b;
+ struct spa_buffer *buf;
+ int i, c, n_frames, stride;
+ int16_t *dst, val;
+
+ if ((b = pw_stream_dequeue_buffer(data->stream)) == NULL) {
+ pw_log_warn("out of buffers: %m");
+ return;
+ }
+
+ buf = b->buffer;
+ if ((dst = buf->datas[0].data) == NULL)
+ return;
+
+ stride = sizeof(int16_t) * DEFAULT_CHANNELS;
+ n_frames = buf->datas[0].maxsize / stride;
+
+ for (i = 0; i < n_frames; i++) {
+ data->accumulator += M_PI_M2 * 440 / DEFAULT_RATE;
+ if (data->accumulator >= M_PI_M2)
+ data->accumulator -= M_PI_M2;
+
+ val = sin(data->accumulator) * DEFAULT_VOLUME * 16767.f;
+ for (c = 0; c < DEFAULT_CHANNELS; c++)
+ *dst++ = val;
+ }
+
+ buf->datas[0].chunk->offset = 0;
+ buf->datas[0].chunk->stride = stride;
+ buf->datas[0].chunk->size = n_frames * stride;
+
+ pw_stream_queue_buffer(data->stream, b);
+}
+/* [on_process] */
+
+static const struct pw_stream_events stream_events = {
+ PW_VERSION_STREAM_EVENTS,
+ .process = on_process,
+};
+
+int main(int argc, char *argv[])
+{
+ struct data data = { 0, };
+ const struct spa_pod *params[1];
+ uint8_t buffer[1024];
+ struct spa_pod_builder b = SPA_POD_BUILDER_INIT(buffer, sizeof(buffer));
+
+ pw_init(&argc, &argv);
+
+ data.loop = pw_main_loop_new(NULL);
+
+ data.stream = pw_stream_new_simple(
+ pw_main_loop_get_loop(data.loop),
+ "audio-src",
+ pw_properties_new(
+ PW_KEY_MEDIA_TYPE, "Audio",
+ PW_KEY_MEDIA_CATEGORY, "Playback",
+ PW_KEY_MEDIA_ROLE, "Music",
+ NULL),
+ &stream_events,
+ &data);
+
+ params[0] = spa_format_audio_raw_build(&b, SPA_PARAM_EnumFormat,
+ &SPA_AUDIO_INFO_RAW_INIT(
+ .format = SPA_AUDIO_FORMAT_S16,
+ .channels = DEFAULT_CHANNELS,
+ .rate = DEFAULT_RATE ));
+
+ pw_stream_connect(data.stream,
+ PW_DIRECTION_OUTPUT,
+ PW_ID_ANY,
+ PW_STREAM_FLAG_AUTOCONNECT |
+ PW_STREAM_FLAG_MAP_BUFFERS |
+ PW_STREAM_FLAG_RT_PROCESS,
+ params, 1);
+
+ pw_main_loop_run(data.loop);
+
+ pw_stream_destroy(data.stream);
+ pw_main_loop_destroy(data.loop);
+
+ return 0;
+}
+/* [code] */