113 lines
2.5 KiB
C
113 lines
2.5 KiB
C
/*
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[title]
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\ref page_tutorial4
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[title]
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*/
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/* [code] */
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#include <math.h>
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#include <spa/param/audio/format-utils.h>
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#include <pipewire/pipewire.h>
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#define M_PI_M2 ( M_PI + M_PI )
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#define DEFAULT_RATE 44100
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#define DEFAULT_CHANNELS 2
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#define DEFAULT_VOLUME 0.7
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struct data {
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struct pw_main_loop *loop;
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struct pw_stream *stream;
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double accumulator;
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};
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/* [on_process] */
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static void on_process(void *userdata)
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{
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struct data *data = userdata;
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struct pw_buffer *b;
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struct spa_buffer *buf;
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int i, c, n_frames, stride;
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int16_t *dst, val;
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if ((b = pw_stream_dequeue_buffer(data->stream)) == NULL) {
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pw_log_warn("out of buffers: %m");
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return;
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}
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buf = b->buffer;
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if ((dst = buf->datas[0].data) == NULL)
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return;
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stride = sizeof(int16_t) * DEFAULT_CHANNELS;
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n_frames = buf->datas[0].maxsize / stride;
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for (i = 0; i < n_frames; i++) {
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data->accumulator += M_PI_M2 * 440 / DEFAULT_RATE;
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if (data->accumulator >= M_PI_M2)
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data->accumulator -= M_PI_M2;
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val = sin(data->accumulator) * DEFAULT_VOLUME * 16767.f;
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for (c = 0; c < DEFAULT_CHANNELS; c++)
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*dst++ = val;
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}
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buf->datas[0].chunk->offset = 0;
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buf->datas[0].chunk->stride = stride;
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buf->datas[0].chunk->size = n_frames * stride;
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pw_stream_queue_buffer(data->stream, b);
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}
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/* [on_process] */
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static const struct pw_stream_events stream_events = {
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PW_VERSION_STREAM_EVENTS,
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.process = on_process,
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};
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int main(int argc, char *argv[])
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{
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struct data data = { 0, };
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const struct spa_pod *params[1];
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uint8_t buffer[1024];
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struct spa_pod_builder b = SPA_POD_BUILDER_INIT(buffer, sizeof(buffer));
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pw_init(&argc, &argv);
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data.loop = pw_main_loop_new(NULL);
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data.stream = pw_stream_new_simple(
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pw_main_loop_get_loop(data.loop),
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"audio-src",
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pw_properties_new(
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PW_KEY_MEDIA_TYPE, "Audio",
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PW_KEY_MEDIA_CATEGORY, "Playback",
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PW_KEY_MEDIA_ROLE, "Music",
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NULL),
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&stream_events,
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&data);
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params[0] = spa_format_audio_raw_build(&b, SPA_PARAM_EnumFormat,
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&SPA_AUDIO_INFO_RAW_INIT(
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.format = SPA_AUDIO_FORMAT_S16,
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.channels = DEFAULT_CHANNELS,
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.rate = DEFAULT_RATE ));
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pw_stream_connect(data.stream,
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PW_DIRECTION_OUTPUT,
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PW_ID_ANY,
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PW_STREAM_FLAG_AUTOCONNECT |
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PW_STREAM_FLAG_MAP_BUFFERS |
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PW_STREAM_FLAG_RT_PROCESS,
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params, 1);
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pw_main_loop_run(data.loop);
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pw_stream_destroy(data.stream);
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pw_main_loop_destroy(data.loop);
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return 0;
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}
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/* [code] */
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