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tutorial5.c

Tutorial - Part 5: Capturing Video Frames

Tutorial - Part 5: Capturing Video Frames

/*
[title]
\ref page_tutorial5
[title]
*/
/* [code] */
#include <spa/param/video/format-utils.h>
#include <spa/debug/types.h>
#include <spa/param/video/type-info.h>
#include <pipewire/pipewire.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,
spa_debug_type_find_name(spa_type_video_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 = {
PW_VERSION_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);
props = pw_properties_new(PW_KEY_MEDIA_TYPE, "Video",
PW_KEY_MEDIA_CATEGORY, "Capture",
PW_KEY_MEDIA_ROLE, "Camera",
NULL);
if (argc > 1)
pw_properties_set(props, PW_KEY_TARGET_OBJECT, argv[1]);
data.stream = pw_stream_new_simple(
pw_main_loop_get_loop(data.loop),
"video-capture",
props,
&stream_events,
&data);
params[0] = spa_pod_builder_add_object(&b,
SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat,
SPA_FORMAT_mediaType, SPA_POD_Id(SPA_MEDIA_TYPE_video),
SPA_FORMAT_mediaSubtype, SPA_POD_Id(SPA_MEDIA_SUBTYPE_raw),
SPA_FORMAT_VIDEO_format, SPA_POD_CHOICE_ENUM_Id(7,
SPA_VIDEO_FORMAT_RGB,
SPA_VIDEO_FORMAT_RGB,
SPA_VIDEO_FORMAT_RGBA,
SPA_VIDEO_FORMAT_RGBx,
SPA_VIDEO_FORMAT_BGRx,
SPA_VIDEO_FORMAT_YUY2,
SPA_VIDEO_FORMAT_I420),
SPA_FORMAT_VIDEO_size, SPA_POD_CHOICE_RANGE_Rectangle(
&SPA_RECTANGLE(320, 240),
&SPA_RECTANGLE(1, 1),
&SPA_RECTANGLE(4096, 4096)),
SPA_FORMAT_VIDEO_framerate, SPA_POD_CHOICE_RANGE_Fraction(
&SPA_FRACTION(25, 1),
&SPA_FRACTION(0, 1),
&SPA_FRACTION(1000, 1)));
pw_stream_connect(data.stream,
PW_DIRECTION_INPUT,
PW_ID_ANY,
PW_STREAM_FLAG_AUTOCONNECT |
PW_STREAM_FLAG_MAP_BUFFERS,
params, 1);
pw_main_loop_run(data.loop);
pw_stream_destroy(data.stream);
pw_main_loop_destroy(data.loop);
return 0;
}
/* [code] */
PW_ID_ANY
#define PW_ID_ANY
Definition core.h:77
PW_KEY_MEDIA_TYPE
#define PW_KEY_MEDIA_TYPE
Media.
Definition keys.h:512
PW_KEY_TARGET_OBJECT
#define PW_KEY_TARGET_OBJECT
a target object to link to.
Definition keys.h:579
PW_KEY_MEDIA_ROLE
#define PW_KEY_MEDIA_ROLE
Role: Movie, Music, Camera, Screen, Communication, Game, Notification, DSP, Production,...
Definition keys.h:518
PW_KEY_MEDIA_CATEGORY
#define PW_KEY_MEDIA_CATEGORY
Media Category: Playback, Capture, Duplex, Monitor, Manager.
Definition keys.h:515
pw_log_warn
#define pw_log_warn(...)
Definition log.h:179
pw_main_loop_destroy
void pw_main_loop_destroy(struct pw_main_loop *loop)
Destroy a loop.
Definition main-loop.c:73
pw_main_loop_run
int pw_main_loop_run(struct pw_main_loop *loop)
Run a main loop.
Definition main-loop.c:122
pw_main_loop_new
struct pw_main_loop * pw_main_loop_new(const struct spa_dict *props)
Create a new main loop.
Definition main-loop.c:63
pw_main_loop_get_loop
struct pw_loop * pw_main_loop_get_loop(struct pw_main_loop *loop)
Get the loop implementation.
Definition main-loop.c:96
pw_init
void pw_init(int *argc, char **argv[])
Initialize PipeWire.
Definition pipewire.c:488
PW_DIRECTION_INPUT
#define PW_DIRECTION_INPUT
Definition port.h:53
pw_properties_new
struct pw_properties * pw_properties_new(const char *key,...)
Make a new properties object.
Definition properties.c:97
pw_properties_set
int pw_properties_set(struct pw_properties *properties, const char *key, const char *value)
Set a property value.
Definition properties.c:586
pw_stream_connect
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:1968
pw_stream_dequeue_buffer
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:2539
pw_stream_queue_buffer
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:2580
pw_stream_new_simple
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:1657
PW_VERSION_STREAM_EVENTS
#define PW_VERSION_STREAM_EVENTS
Definition stream.h:424
pw_stream_destroy
void pw_stream_destroy(struct pw_stream *stream)
Destroy a stream.
Definition stream.c:1776
PW_STREAM_FLAG_MAP_BUFFERS
@ PW_STREAM_FLAG_MAP_BUFFERS
mmap the buffers except DmaBuf that is not explicitly marked as mappable.
Definition stream.h:476
PW_STREAM_FLAG_AUTOCONNECT
@ PW_STREAM_FLAG_AUTOCONNECT
try to automatically connect this stream
Definition stream.h:471
spa_debug_type_find_name
SPA_API_DEBUG_TYPES const char * spa_debug_type_find_name(const struct spa_type_info *info, uint32_t type)
Definition types.h:61
spa_format_video_raw_parse
SPA_API_VIDEO_RAW_UTILS int spa_format_video_raw_parse(const struct spa_pod *format, struct spa_video_info_raw *info)
Definition raw-utils.h:38
spa_type_video_format
static const struct spa_type_info spa_type_video_format[]
Definition raw-types.h:40
spa_format_parse
SPA_API_FORMAT_UTILS int spa_format_parse(const struct spa_pod *format, uint32_t *media_type, uint32_t *media_subtype)
Definition format-utils.h:37
SPA_MEDIA_TYPE_video
@ SPA_MEDIA_TYPE_video
Definition format.h:28
SPA_PARAM_Format
@ SPA_PARAM_Format
configured format as SPA_TYPE_OBJECT_Format
Definition param.h:34
SPA_PARAM_EnumFormat
@ SPA_PARAM_EnumFormat
available formats as SPA_TYPE_OBJECT_Format
Definition param.h:33
SPA_FORMAT_VIDEO_framerate
@ SPA_FORMAT_VIDEO_framerate
frame rate (Fraction)
Definition format.h:134
SPA_FORMAT_mediaType
@ SPA_FORMAT_mediaType
media type (Id enum spa_media_type)
Definition format.h:99
SPA_FORMAT_VIDEO_size
@ SPA_FORMAT_VIDEO_size
size (Rectangle)
Definition format.h:133
SPA_FORMAT_VIDEO_format
@ SPA_FORMAT_VIDEO_format
video format (Id enum spa_video_format)
Definition format.h:130
SPA_FORMAT_mediaSubtype
@ SPA_FORMAT_mediaSubtype
media subtype (Id enum spa_media_subtype)
Definition format.h:100
SPA_MEDIA_SUBTYPE_raw
@ SPA_MEDIA_SUBTYPE_raw
Definition format.h:38
SPA_VIDEO_FORMAT_YUY2
@ SPA_VIDEO_FORMAT_YUY2
Definition raw.h:49
SPA_VIDEO_FORMAT_RGBA
@ SPA_VIDEO_FORMAT_RGBA
Definition raw.h:56
SPA_VIDEO_FORMAT_RGBx
@ SPA_VIDEO_FORMAT_RGBx
Definition raw.h:52
SPA_VIDEO_FORMAT_BGRx
@ SPA_VIDEO_FORMAT_BGRx
Definition raw.h:53
SPA_VIDEO_FORMAT_I420
@ SPA_VIDEO_FORMAT_I420
Definition raw.h:47
SPA_VIDEO_FORMAT_RGB
@ SPA_VIDEO_FORMAT_RGB
Definition raw.h:60
SPA_POD_CHOICE_ENUM_Id
#define SPA_POD_CHOICE_ENUM_Id(n_vals,...)
Definition vararg.h:55
SPA_POD_CHOICE_RANGE_Fraction
#define SPA_POD_CHOICE_RANGE_Fraction(def, min, max)
Definition vararg.h:123
SPA_POD_Id
#define SPA_POD_Id(val)
Definition vararg.h:53
SPA_POD_BUILDER_INIT
#define SPA_POD_BUILDER_INIT(buffer, size)
Definition builder.h:72
SPA_POD_CHOICE_RANGE_Rectangle
#define SPA_POD_CHOICE_RANGE_Rectangle(def, min, max)
Definition vararg.h:114
spa_pod_builder_add_object
#define spa_pod_builder_add_object(b, type, id,...)
Definition builder.h:725
SPA_TYPE_OBJECT_Format
@ SPA_TYPE_OBJECT_Format
Definition type.h:87
SPA_FRACTION
#define SPA_FRACTION(num, denom)
Definition defs.h:136
SPA_RECTANGLE
#define SPA_RECTANGLE(width, height)
Definition defs.h:115
pipewire.h
pipewire/pipewire.h
pw_buffer
a buffer structure obtained from pw_stream_dequeue_buffer().
Definition stream.h:261
pw_buffer::buffer
struct spa_buffer * buffer
the spa buffer
Definition stream.h:262
pw_main_loop
A main loop object.
pw_properties
Definition properties.h:39
pw_stream_events
Events for a stream.
Definition stream.h:422
pw_stream
spa_buffer
A Buffer.
Definition buffer.h:110
spa_buffer::datas
struct spa_data * datas
array of data members
Definition buffer.h:114
spa_chunk::size
uint32_t size
size of valid data.
Definition buffer.h:63
spa_data::chunk
struct spa_chunk * chunk
valid chunk of memory
Definition buffer.h:106
spa_data::data
void * data
optional data pointer
Definition buffer.h:105
spa_pod_builder
Definition builder.h:63
spa_pod
Definition pod.h:57
spa_video_info
Definition format.h:27
types.h
spa/debug/types.h