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doc: add tutorials as Doxygen examples

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This commit is contained in:
Pauli Virtanen 2021-10-10 00:09:32 +03:00
parent 98a0e54d5f
commit 336caa9db3
14 changed files with 528 additions and 594 deletions
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154
doc/tutorial5.dox
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@ -11,136 +11,7 @@ example is very similar to \ref page_tutorial4.
Let's take a look at the code before we break it down:
\code{.c}
#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;
};
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;
/** copy frame data to screen */
printf("got a frame of size %d\n", buf->datas[0].chunk->size);
pw_stream_queue_buffer(data->stream, b);
}
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);
/** prepare to render video of this size */
}
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));
pw_init(&argc, &argv);
data.loop = pw_main_loop_new(NULL);
data.stream = pw_stream_new_simple(
pw_main_loop_get_loop(data.loop),
"video-capture",
pw_properties_new(
PW_KEY_MEDIA_TYPE, "Video",
PW_KEY_MEDIA_CATEGORY, "Capture",
PW_KEY_MEDIA_ROLE, "Camera",
NULL),
&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,
argc > 1 ? (uint32_t)atoi(argv[1]) : 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;
}
\endcode
\snippet tutorial5.c code
Save as tutorial5.c and compile with:
@ -337,28 +208,7 @@ deal with the format.
After negotiation, the process function is called for each new frame. Check out
\ref page_tutorial4 for another example.
\code{.c}
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;
/** copy frame data to screen */
printf("got a frame of size %d\n", buf->datas[0].chunk->size);
pw_stream_queue_buffer(data->stream, b);
}
\endcode
\snippet tutorial5.c on_process
In a real playback application, one would do something with the data, like
copy it to the screen or encode it into a file.