PipeWire  0.3.58
audio-capture.c

Audio capture using pw_stream.

/* PipeWire
*
* Copyright © 2022 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 capture using \ref pw_stream "pw_stream".
[title]
*/
#include <stdio.h>
#include <errno.h>
#include <math.h>
#include <signal.h>
struct data {
struct pw_main_loop *loop;
struct pw_stream *stream;
struct spa_audio_info format;
};
/* our data processing function is in general:
*
* struct pw_buffer *b;
* b = pw_stream_dequeue_buffer(stream);
*
* .. consume 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;
float *samples, max;
uint32_t c, n, n_channels, n_samples, peak;
if ((b = pw_stream_dequeue_buffer(data->stream)) == NULL) {
pw_log_warn("out of buffers: %m");
return;
}
buf = b->buffer;
if ((samples = buf->datas[0].data) == NULL)
return;
n_channels = data->format.info.raw.channels;
n_samples = buf->datas[0].chunk->size / sizeof(float);
fprintf(stdout, "captured %d samples\n", n_samples / n_channels);
for (c = 0; c < data->format.info.raw.channels; c++) {
max = 0.0f;
for (n = c; n < n_samples; n += n_channels)
max = fmaxf(max, fabsf(samples[n]));
peak = SPA_CLAMP(max * 30, 0, 39);
fprintf(stdout, "channel %d: |%*s%*s| peak:%f\n",
c, peak+1, "*", 40 - peak, "", max);
}
/* move cursor up */
fprintf(stdout, "%c[%dA", 0x1b, n_channels + 1);
fflush(stdout);
pw_stream_queue_buffer(data->stream, b);
}
/* Be notified when the stream param changes. We're only looking at the
* format changes.
*/
static void
on_stream_param_changed(void *_data, uint32_t id, const struct spa_pod *param)
{
struct data *data = _data;
/* NULL means to clear the format */
if (param == NULL || id != SPA_PARAM_Format)
return;
if (spa_format_parse(param, &data->format.media_type, &data->format.media_subtype) < 0)
return;
/* only accept raw audio */
if (data->format.media_type != SPA_MEDIA_TYPE_audio ||
data->format.media_subtype != SPA_MEDIA_SUBTYPE_raw)
return;
/* call a helper function to parse the format for us. */
spa_format_audio_raw_parse(param, &data->format.info.raw);
fprintf(stdout, "capturing rate:%d channels:%d\n",
data->format.info.raw.rate, data->format.info.raw.channels);
}
static const struct pw_stream_events stream_events = {
.param_changed = on_stream_param_changed,
.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), 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.
*/
NULL);
if (argc > 1)
/* Set stream target if given on command line */
/* uncomment if you want to capture from the sink monitor ports */
/* pw_properties_set(props, PW_KEY_STREAM_CAPTURE_SINK, "true"); */
"audio-capture",
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).
* We leave the channels and rate empty to accept the native graph
* rate and channels. */
.format = SPA_AUDIO_FORMAT_F32));
/* Now connect this stream. We ask that our process function is
* called in a realtime thread. */
params, 1);
/* and wait while we let things run */
return 0;
}
#define PW_ID_ANY
Definition: core.h:83
#define PW_KEY_MEDIA_TYPE
Media.
Definition: keys.h:438
#define PW_KEY_TARGET_OBJECT
a target object to link to
Definition: keys.h:508
#define PW_KEY_MEDIA_ROLE
Role: Movie, Music, Camera, Screen, Communication, Game, Notification, DSP, Production,...
Definition: keys.h:444
#define PW_KEY_MEDIA_CATEGORY
Media Category: Playback, Capture, Duplex, Monitor, Manager.
Definition: keys.h:441
#define pw_log_warn(...)
Definition: log.h:163
#define pw_loop_add_signal(l,...)
Definition: loop.h:83
struct pw_main_loop * pw_main_loop_new(const struct spa_dict *props)
Create a new main loop.
Definition: main-loop.c:80
int pw_main_loop_quit(struct pw_main_loop *loop)
Quit a main loop.
Definition: main-loop.c:125
void pw_main_loop_destroy(struct pw_main_loop *loop)
Destroy a loop.
Definition: main-loop.c:90
int pw_main_loop_run(struct pw_main_loop *loop)
Run a main loop.
Definition: main-loop.c:139
struct pw_loop * pw_main_loop_get_loop(struct pw_main_loop *loop)
Get the loop implementation.
Definition: main-loop.c:113
void pw_init(int *argc, char **argv[])
Initialize PipeWire.
Definition: pipewire.c:580
void pw_deinit(void)
Deinitialize PipeWire.
Definition: pipewire.c:683
#define PW_DIRECTION_INPUT
Definition: port.h:65
struct pw_properties * pw_properties_new(const char *key,...) 1
Make a new properties object.
Definition: properties.c:102
int pw_properties_set(struct pw_properties *properties, const char *key, const char *value)
Set a property value.
Definition: properties.c:439
int pw_stream_connect(struct pw_stream *stream, enum pw_direction direction, uint32_t target_id, enum pw_stream_flags flags, const struct spa_pod **params, uint32_t n_params)
Connect a stream for input or output on port_path.
Definition: stream.c:1792
struct pw_stream * pw_stream_new_simple(struct pw_loop *loop, const char *name, struct pw_properties *props, const struct pw_stream_events *events, void *data)
Definition: stream.c:1539
struct pw_buffer * pw_stream_dequeue_buffer(struct pw_stream *stream)
Get a buffer that can be filled for playback streams or consumed for capture streams.
Definition: stream.c:2247
int pw_stream_queue_buffer(struct pw_stream *stream, struct pw_buffer *buffer)
Submit a buffer for playback or recycle a buffer for capture.
Definition: stream.c:2274
#define PW_VERSION_STREAM_EVENTS
Definition: stream.h:337
void pw_stream_destroy(struct pw_stream *stream)
Destroy a stream.
Definition: stream.c:1601
@ PW_STREAM_FLAG_MAP_BUFFERS
mmap the buffers except DmaBuf
Definition: stream.h:385
@ PW_STREAM_FLAG_AUTOCONNECT
try to automatically connect this stream
Definition: stream.h:380
@ PW_STREAM_FLAG_RT_PROCESS
call process from the realtime thread.
Definition: stream.h:387
static struct spa_pod * spa_format_audio_raw_build(struct spa_pod_builder *builder, uint32_t id, struct spa_audio_info_raw *info)
Definition: format-utils.h:108
static int spa_format_parse(const struct spa_pod *format, uint32_t *media_type, uint32_t *media_subtype)
Definition: format-utils.h:47
static int spa_format_audio_raw_parse(const struct spa_pod *format, struct spa_audio_info_raw *info)
Definition: format-utils.h:48
#define SPA_AUDIO_INFO_RAW_INIT(...)
Definition: raw.h:307
@ SPA_MEDIA_TYPE_audio
Definition: format.h:47
@ SPA_PARAM_Format
configured format as SPA_TYPE_OBJECT_Format
Definition: param.h:54
@ SPA_PARAM_EnumFormat
available formats as SPA_TYPE_OBJECT_Format
Definition: param.h:53
@ SPA_MEDIA_SUBTYPE_raw
Definition: format.h:58
@ SPA_AUDIO_FORMAT_F32
Definition: raw.h:126
#define SPA_POD_BUILDER_INIT(buffer, size)
Definition: builder.h:82
#define SPA_CLAMP(v, low, high)
Definition: defs.h:175
pipewire/pipewire.h
a buffer structure obtained from pw_stream_dequeue_buffer().
Definition: stream.h:210
struct spa_buffer * buffer
the spa buffer
Definition: stream.h:211
A main loop object.
Definition: properties.h:53
Events for a stream.
Definition: stream.h:335
Definition: format.h:47
A Buffer.
Definition: buffer.h:109
struct spa_data * datas
array of data members
Definition: buffer.h:113
uint32_t size
size of valid data.
Definition: buffer.h:66
struct spa_chunk * chunk
valid chunk of memory
Definition: buffer.h:105
void * data
optional data pointer
Definition: buffer.h:104
Definition: builder.h:73
void * data
Definition: builder.h:74
Definition: pod.h:63