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Diffstat (limited to '')
| -rw-r--r-- | src/examples/audio-src.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/src/examples/audio-src.c b/src/examples/audio-src.c new file mode 100644 index 0000000..1217732 --- /dev/null +++ b/src/examples/audio-src.c @@ -0,0 +1,186 @@ +/* PipeWire + * + * Copyright © 2018 Wim Taymans + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + */ + +/* + [title] + Audio source using \ref pw_stream "pw_stream". + [title] + */ + +#include <stdio.h> +#include <errno.h> +#include <math.h> +#include <signal.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; +}; + +static void fill_f32(struct data *d, void *dest, int n_frames) +{ + float *dst = dest, val; + int i, c; + + for (i = 0; i < n_frames; i++) { + d->accumulator += M_PI_M2 * 440 / DEFAULT_RATE; + if (d->accumulator >= M_PI_M2) + d->accumulator -= M_PI_M2; + + val = sin(d->accumulator) * DEFAULT_VOLUME; + for (c = 0; c < DEFAULT_CHANNELS; c++) + *dst++ = val; + } +} + +/* our data processing function is in general: + * + * struct pw_buffer *b; + * b = pw_stream_dequeue_buffer(stream); + * + * .. generate stuff in the buffer ... + * + * pw_stream_queue_buffer(stream, b); + */ +static void on_process(void *userdata) +{ + struct data *data = userdata; + struct pw_buffer *b; + struct spa_buffer *buf; + int n_frames, stride; + uint8_t *p; + + if ((b = pw_stream_dequeue_buffer(data->stream)) == NULL) { + pw_log_warn("out of buffers: %m"); + return; + } + + buf = b->buffer; + if ((p = buf->datas[0].data) == NULL) + return; + + stride = sizeof(float) * DEFAULT_CHANNELS; + n_frames = SPA_MIN(b->requested, buf->datas[0].maxsize / stride); + + fill_f32(data, p, n_frames); + + 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); +} + +static const struct pw_stream_events stream_events = { + PW_VERSION_STREAM_EVENTS, + .process = on_process, +}; + +static void do_quit(void *userdata, int signal_number) +{ + struct data *data = userdata; + pw_main_loop_quit(data->loop); +} + +int main(int argc, char *argv[]) +{ + struct data data = { 0, }; + const struct spa_pod *params[1]; + uint8_t buffer[1024]; + struct pw_properties *props; + struct spa_pod_builder b = SPA_POD_BUILDER_INIT(buffer, sizeof(buffer)); + + pw_init(&argc, &argv); + + /* make a main loop. If you already have another main loop, you can add + * the fd of this pipewire mainloop to it. */ + data.loop = pw_main_loop_new(NULL); + + pw_loop_add_signal(pw_main_loop_get_loop(data.loop), SIGINT, do_quit, &data); + pw_loop_add_signal(pw_main_loop_get_loop(data.loop), SIGTERM, do_quit, &data); + + /* Create a simple stream, the simple stream manages the core and remote + * objects for you if you don't need to deal with them. + * + * If you plan to autoconnect your stream, you need to provide at least + * media, category and role properties. + * + * Pass your events and a user_data pointer as the last arguments. This + * will inform you about the stream state. The most important event + * you need to listen to is the process event where you need to produce + * the data. + */ + props = pw_properties_new(PW_KEY_MEDIA_TYPE, "Audio", + PW_KEY_MEDIA_CATEGORY, "Playback", + PW_KEY_MEDIA_ROLE, "Music", + NULL); + if (argc > 1) + /* Set stream target if given on command line */ + pw_properties_set(props, PW_KEY_TARGET_OBJECT, argv[1]); + data.stream = pw_stream_new_simple( + pw_main_loop_get_loop(data.loop), + "audio-src", + props, + &stream_events, + &data); + + /* Make one parameter with the supported formats. The SPA_PARAM_EnumFormat + * id means that this is a format enumeration (of 1 value). */ + params[0] = spa_format_audio_raw_build(&b, SPA_PARAM_EnumFormat, + &SPA_AUDIO_INFO_RAW_INIT( + .format = SPA_AUDIO_FORMAT_F32, + .channels = DEFAULT_CHANNELS, + .rate = DEFAULT_RATE )); + + /* Now connect this stream. We ask that our process function is + * called in a realtime thread. */ + 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); + + /* and wait while we let things run */ + pw_main_loop_run(data.loop); + + pw_stream_destroy(data.stream); + pw_main_loop_destroy(data.loop); + pw_deinit(); + + return 0; +} |