mirror of
https://gitlab.freedesktop.org/pipewire/pipewire.git
synced 2025-11-03 09:01:54 -05:00
112 lines
2.4 KiB
C
112 lines
2.4 KiB
C
/*
|
|
[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] */
|