PipeWire 0.3.77
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tutorial5.c

Tutorial - Part 5: Capturing Video Frames

/*
[title]
\ref page_tutorial5
[title]
*/
/* [code] */
#include <spa/param/video/format-utils.h>
#include <spa/param/video/type-info.h>
struct data {
struct pw_main_loop *loop;
struct pw_stream *stream;
struct spa_video_info format;
};
/* [on_process] */
static void on_process(void *userdata)
{
struct data *data = userdata;
struct pw_buffer *b;
struct spa_buffer *buf;
if ((b = pw_stream_dequeue_buffer(data->stream)) == NULL) {
pw_log_warn("out of buffers: %m");
return;
}
buf = b->buffer;
if (buf->datas[0].data == NULL)
return;
printf("got a frame of size %d\n", buf->datas[0].chunk->size);
pw_stream_queue_buffer(data->stream, b);
}
/* [on_process] */
static void on_param_changed(void *userdata, uint32_t id, const struct spa_pod *param)
{
struct data *data = userdata;
if (param == NULL || id != SPA_PARAM_Format)
return;
if (spa_format_parse(param,
&data->format.media_type,
&data->format.media_subtype) < 0)
return;
if (data->format.media_type != SPA_MEDIA_TYPE_video ||
data->format.media_subtype != SPA_MEDIA_SUBTYPE_raw)
return;
if (spa_format_video_raw_parse(param, &data->format.info.raw) < 0)
return;
printf("got video format:\n");
printf(" format: %d (%s)\n", data->format.info.raw.format,
data->format.info.raw.format));
printf(" size: %dx%d\n", data->format.info.raw.size.width,
data->format.info.raw.size.height);
printf(" framerate: %d/%d\n", data->format.info.raw.framerate.num,
data->format.info.raw.framerate.denom);
}
static const struct pw_stream_events stream_events = {
.param_changed = on_param_changed,
.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));
struct pw_properties *props;
pw_init(&argc, &argv);
data.loop = pw_main_loop_new(NULL);
PW_KEY_MEDIA_ROLE, "Camera",
NULL);
if (argc > 1)
data.stream = pw_stream_new_simple(
"video-capture",
props,
&stream_events,
&data);
&SPA_RECTANGLE(320, 240),
&SPA_RECTANGLE(1, 1),
&SPA_RECTANGLE(4096, 4096)),
&SPA_FRACTION(25, 1),
&SPA_FRACTION(0, 1),
&SPA_FRACTION(1000, 1)));
pw_stream_connect(data.stream,
params, 1);
pw_main_loop_run(data.loop);
pw_stream_destroy(data.stream);
return 0;
}
/* [code] */
#define PW_ID_ANY
Definition: core.h:66
#define PW_KEY_MEDIA_TYPE
Media.
Definition: src/pipewire/keys.h:431
#define PW_KEY_TARGET_OBJECT
a target object to link to.
Definition: src/pipewire/keys.h:496
#define PW_KEY_MEDIA_ROLE
Role: Movie, Music, Camera, Screen, Communication, Game, Notification, DSP, Production,...
Definition: src/pipewire/keys.h:437
#define PW_KEY_MEDIA_CATEGORY
Media Category: Playback, Capture, Duplex, Monitor, Manager.
Definition: src/pipewire/keys.h:434
#define pw_log_warn(...)
Definition: src/pipewire/log.h:143
void pw_main_loop_destroy(struct pw_main_loop *loop)
Destroy a loop.
Definition: main-loop.c:70
int pw_main_loop_run(struct pw_main_loop *loop)
Run a main loop.
Definition: main-loop.c:119
struct pw_main_loop * pw_main_loop_new(const struct spa_dict *props)
Create a new main loop.
Definition: main-loop.c:60
struct pw_loop * pw_main_loop_get_loop(struct pw_main_loop *loop)
Get the loop implementation.
Definition: main-loop.c:93
void pw_init(int *argc, char **argv[])
Initialize PipeWire.
Definition: pipewire.c:555
#define PW_DIRECTION_INPUT
Definition: port.h:48
struct pw_properties * pw_properties_new(const char *key,...) 1
Make a new properties object.
Definition: properties.c:84
int pw_properties_set(struct pw_properties *properties, const char *key, const char *value)
Set a property value.
Definition: properties.c:421
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:1879
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:2381
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:2409
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:1578
#define PW_VERSION_STREAM_EVENTS
Definition: stream.h:321
void pw_stream_destroy(struct pw_stream *stream)
Destroy a stream.
Definition: stream.c:1672
@ PW_STREAM_FLAG_MAP_BUFFERS
mmap the buffers except DmaBuf
Definition: stream.h:369
@ PW_STREAM_FLAG_AUTOCONNECT
try to automatically connect this stream
Definition: stream.h:364
static const char * spa_debug_type_find_name(const struct spa_type_info *info, uint32_t type)
Definition: types.h:53
static int spa_format_parse(const struct spa_pod *format, uint32_t *media_type, uint32_t *media_subtype)
Definition: format-utils.h:27
static const struct spa_type_info spa_type_video_format[]
Definition: video/raw-types.h:29
static int spa_format_video_raw_parse(const struct spa_pod *format, struct spa_video_info_raw *info)
Definition: video/raw-utils.h:27
@ SPA_MEDIA_TYPE_video
Definition: param/format.h:28
@ SPA_PARAM_Format
configured format as SPA_TYPE_OBJECT_Format
Definition: param.h:34
@ SPA_PARAM_EnumFormat
available formats as SPA_TYPE_OBJECT_Format
Definition: param.h:33
@ SPA_FORMAT_VIDEO_framerate
frame rate (Fraction)
Definition: param/format.h:124
@ SPA_FORMAT_mediaType
media type (Id enum spa_media_type)
Definition: param/format.h:93
@ SPA_FORMAT_VIDEO_size
size (Rectangle)
Definition: param/format.h:123
@ SPA_FORMAT_VIDEO_format
video format (Id enum spa_video_format)
Definition: param/format.h:120
@ SPA_FORMAT_mediaSubtype
media subtype (Id enum spa_media_subtype)
Definition: param/format.h:94
@ SPA_MEDIA_SUBTYPE_raw
Definition: param/format.h:38
@ SPA_VIDEO_FORMAT_YUY2
Definition: video/raw.h:49
@ SPA_VIDEO_FORMAT_RGBA
Definition: video/raw.h:56
@ SPA_VIDEO_FORMAT_RGBx
Definition: video/raw.h:52
@ SPA_VIDEO_FORMAT_BGRx
Definition: video/raw.h:53
@ SPA_VIDEO_FORMAT_I420
Definition: video/raw.h:47
@ SPA_VIDEO_FORMAT_RGB
Definition: video/raw.h:60
#define SPA_POD_CHOICE_ENUM_Id(n_vals,...)
Definition: vararg.h:51
#define SPA_POD_CHOICE_RANGE_Fraction(def, min, max)
Definition: vararg.h:115
#define SPA_POD_Id(val)
Definition: vararg.h:49
#define SPA_POD_BUILDER_INIT(buffer, size)
Definition: builder.h:62
#define SPA_POD_CHOICE_RANGE_Rectangle(def, min, max)
Definition: vararg.h:106
#define spa_pod_builder_add_object(b, type, id,...)
Definition: builder.h:659
@ SPA_TYPE_OBJECT_Format
Definition: spa/include/spa/utils/type.h:76
#define SPA_FRACTION(num, denom)
Definition: defs.h:122
#define SPA_RECTANGLE(width, height)
Definition: defs.h:101
pipewire/pipewire.h
a buffer structure obtained from pw_stream_dequeue_buffer().
Definition: stream.h:194
struct spa_buffer * buffer
the spa buffer
Definition: stream.h:195
A main loop object.
Definition: properties.h:33
Events for a stream.
Definition: stream.h:319
A Buffer.
Definition: buffer/buffer.h:90
struct spa_data * datas
array of data members
Definition: buffer/buffer.h:94
uint32_t size
size of valid data.
Definition: buffer/buffer.h:47
struct spa_chunk * chunk
valid chunk of memory
Definition: buffer/buffer.h:86
void * data
optional data pointer
Definition: buffer/buffer.h:85
Definition: builder.h:53
Definition: pod/pod.h:43
Definition: param/video/format.h:27
spa/debug/types.h