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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:28:17 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:28:17 +0000 |
commit | 7a46c07230b8d8108c0e8e80df4522d0ac116538 (patch) | |
tree | d483300dab478b994fe199a5d19d18d74153718a /doc/tutorial4.c | |
parent | Initial commit. (diff) | |
download | pipewire-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.c | 112 |
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] */ |