PipeWire  0.3.40
spa/examples/local-v4l2.c

Example using libspa-v4l2, with only SPA

/* Spa
*
* 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]
Example using libspa-v4l2, with only \ref api_spa
[title]
*/
#include "config.h"
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <dlfcn.h>
#include <poll.h>
#include <pthread.h>
#include <errno.h>
#include <sys/mman.h>
#include <SDL2/SDL.h>
#include <spa/node/node.h>
#include <spa/node/io.h>
#include <spa/node/utils.h>
#include <spa/debug/pod.h>
static SPA_LOG_IMPL(default_log);
#define MAX_BUFFERS 8
struct buffer {
struct spa_buffer buffer;
struct spa_meta metas[1];
struct spa_meta_header header;
struct spa_data datas[1];
struct spa_chunk chunks[1];
SDL_Texture *texture;
};
struct data {
const char *plugin_dir;
struct spa_log *log;
struct spa_system *system;
struct spa_loop *loop;
struct spa_loop_control *control;
struct spa_support support[5];
uint32_t n_support;
struct spa_node *source;
struct spa_hook listener;
struct spa_io_buffers source_output[1];
SDL_Renderer *renderer;
SDL_Window *window;
SDL_Texture *texture;
bool use_buffer;
bool running;
pthread_t thread;
struct spa_buffer *bp[MAX_BUFFERS];
struct buffer buffers[MAX_BUFFERS];
unsigned int n_buffers;
};
static int load_handle(struct data *data, struct spa_handle **handle, const char *lib, const char *name)
{
int res;
void *hnd;
uint32_t i;
char *path = NULL;
if ((path = spa_aprintf("%s/%s", data->plugin_dir, lib)) == NULL) {
return -ENOMEM;
}
if ((hnd = dlopen(path, RTLD_NOW)) == NULL) {
printf("can't load %s: %s\n", path, dlerror());
free(path);
return -ENOENT;
}
free(path);
if ((enum_func = dlsym(hnd, SPA_HANDLE_FACTORY_ENUM_FUNC_NAME)) == NULL) {
printf("can't find enum function\n");
return -ENOENT;
}
for (i = 0;;) {
const struct spa_handle_factory *factory;
if ((res = enum_func(&factory, &i)) <= 0) {
if (res != 0)
printf("can't enumerate factories: %s\n", spa_strerror(res));
break;
}
if (factory->version < 1)
continue;
if (!spa_streq(factory->name, name))
continue;
*handle = calloc(1, spa_handle_factory_get_size(factory, NULL));
if ((res = spa_handle_factory_init(factory, *handle,
NULL, data->support,
data->n_support)) < 0) {
printf("can't make factory instance: %d\n", res);
return res;
}
return 0;
}
return -EBADF;
}
static int make_node(struct data *data, struct spa_node **node, const char *lib, const char *name)
{
struct spa_handle *handle = NULL;
void *iface;
int res;
if ((res = load_handle(data, &handle, lib, name)) < 0)
return res;
if ((res = spa_handle_get_interface(handle, SPA_TYPE_INTERFACE_Node, &iface)) < 0) {
printf("can't get interface %d\n", res);
return res;
}
*node = iface;
return 0;
}
static int on_source_ready(void *_data, int status)
{
struct data *data = _data;
int res;
struct buffer *b;
void *sdata, *ddata;
int sstride, dstride;
int i;
uint8_t *src, *dst;
struct spa_data *datas;
struct spa_io_buffers *io = &data->source_output[0];
io->buffer_id >= MAX_BUFFERS)
return -EINVAL;
b = &data->buffers[io->buffer_id];
datas = b->buffer.datas;
if (b->texture) {
SDL_Texture *texture = b->texture;
SDL_UnlockTexture(texture);
SDL_RenderClear(data->renderer);
SDL_RenderCopy(data->renderer, texture, NULL, NULL);
SDL_RenderPresent(data->renderer);
if (SDL_LockTexture(texture, NULL, &sdata, &sstride) < 0) {
fprintf(stderr, "Couldn't lock texture: %s\n", SDL_GetError());
return -EIO;
}
} else {
uint8_t *map;
if (SDL_LockTexture(data->texture, NULL, &ddata, &dstride) < 0) {
fprintf(stderr, "Couldn't lock texture: %s\n", SDL_GetError());
return -EIO;
}
sdata = datas[0].data;
if (datas[0].type == SPA_DATA_MemFd ||
datas[0].type == SPA_DATA_DmaBuf) {
map = mmap(NULL, datas[0].maxsize + datas[0].mapoffset, PROT_READ,
MAP_PRIVATE, datas[0].fd, 0);
if (map == MAP_FAILED)
return -errno;
sdata = SPA_PTROFF(map, datas[0].mapoffset, uint8_t);
} else if (datas[0].type == SPA_DATA_MemPtr) {
map = NULL;
sdata = datas[0].data;
} else
return -EIO;
sstride = datas[0].chunk->stride;
for (i = 0; i < 240; i++) {
src = ((uint8_t *) sdata + i * sstride);
dst = ((uint8_t *) ddata + i * dstride);
memcpy(dst, src, SPA_MIN(sstride, dstride));
}
SDL_UnlockTexture(data->texture);
SDL_RenderClear(data->renderer);
SDL_RenderCopy(data->renderer, data->texture, NULL, NULL);
SDL_RenderPresent(data->renderer);
if (map)
munmap(map, datas[0].maxsize + datas[0].mapoffset);
}
if ((res = spa_node_process(data->source)) < 0)
printf("got process error %d\n", res);
return 0;
}
static const struct spa_node_callbacks source_callbacks = {
.ready = on_source_ready,
};
static int make_nodes(struct data *data, const char *device)
{
int res;
struct spa_pod *props;
struct spa_pod_builder b = { 0 };
uint8_t buffer[256];
uint32_t index;
if ((res =
make_node(data, &data->source,
"v4l2/libspa-v4l2.so",
printf("can't create v4l2-source: %d\n", res);
return res;
}
spa_node_set_callbacks(data->source, &source_callbacks, data);
index = 0;
spa_pod_builder_init(&b, buffer, sizeof(buffer));
&index, NULL, &props, &b)) == 1) {
spa_debug_pod(0, NULL, props);
}
spa_pod_builder_init(&b, buffer, sizeof(buffer));
SPA_PROP_device, SPA_POD_String(device ? device : "/dev/video0"));
if ((res = spa_node_set_param(data->source, SPA_PARAM_Props, 0, props)) < 0)
printf("got set_props error %d\n", res);
return res;
}
static int setup_buffers(struct data *data)
{
int i;
for (i = 0; i < MAX_BUFFERS; i++) {
struct buffer *b = &data->buffers[i];
data->bp[i] = &b->buffer;
b->texture = NULL;
b->buffer.metas = b->metas;
b->buffer.n_metas = 1;
b->buffer.datas = b->datas;
b->buffer.n_datas = 1;
b->header.flags = 0;
b->header.seq = 0;
b->header.pts = 0;
b->header.dts_offset = 0;
b->metas[0].type = SPA_META_Header;
b->metas[0].data = &b->header;
b->metas[0].size = sizeof(b->header);
b->datas[0].type = 0;
b->datas[0].flags = 0;
b->datas[0].fd = -1;
b->datas[0].mapoffset = 0;
b->datas[0].maxsize = 0;
b->datas[0].data = NULL;
b->datas[0].chunk = &b->chunks[0];
b->datas[0].chunk->offset = 0;
b->datas[0].chunk->size = 0;
b->datas[0].chunk->stride = 0;
}
data->n_buffers = MAX_BUFFERS;
return 0;
}
static int sdl_alloc_buffers(struct data *data)
{
int i;
for (i = 0; i < MAX_BUFFERS; i++) {
struct buffer *b = &data->buffers[i];
SDL_Texture *texture;
void *ptr;
int stride;
texture = SDL_CreateTexture(data->renderer,
SDL_PIXELFORMAT_YUY2,
SDL_TEXTUREACCESS_STREAMING, 320, 240);
if (!texture) {
printf("can't create texture: %s\n", SDL_GetError());
return -ENOMEM;
}
if (SDL_LockTexture(texture, NULL, &ptr, &stride) < 0) {
fprintf(stderr, "Couldn't lock texture: %s\n", SDL_GetError());
return -EIO;
}
b->texture = texture;
b->datas[0].type = SPA_DATA_MemPtr;
b->datas[0].maxsize = stride * 240;
b->datas[0].data = ptr;
b->datas[0].chunk->offset = 0;
b->datas[0].chunk->size = stride * 240;
b->datas[0].chunk->stride = stride;
}
return 0;
}
static int negotiate_formats(struct data *data)
{
int res;
struct spa_pod *format;
uint8_t buffer[256];
struct spa_pod_builder b = SPA_POD_BUILDER_INIT(buffer, sizeof(buffer));
data->source_output[0] = SPA_IO_BUFFERS_INIT;
if ((res =
&data->source_output[0], sizeof(data->source_output[0]))) < 0)
return res;
.size = SPA_RECTANGLE(320, 240),
.framerate = SPA_FRACTION(25,1)));
if ((res = spa_node_port_set_param(data->source,
format)) < 0)
return res;
setup_buffers(data);
if (data->use_buffer) {
if ((res = sdl_alloc_buffers(data)) < 0)
return res;
if ((res = spa_node_port_use_buffers(data->source,
data->bp, data->n_buffers)) < 0) {
printf("can't allocate buffers: %s\n", spa_strerror(res));
return -1;
}
} else {
unsigned int n_buffers;
data->texture = SDL_CreateTexture(data->renderer,
SDL_PIXELFORMAT_YUY2,
SDL_TEXTUREACCESS_STREAMING, 320, 240);
if (!data->texture) {
printf("can't create texture: %s\n", SDL_GetError());
return -1;
}
n_buffers = MAX_BUFFERS;
if ((res = spa_node_port_use_buffers(data->source,
data->bp, n_buffers)) < 0) {
printf("can't allocate buffers: %s\n", spa_strerror(res));
return -1;
}
data->n_buffers = n_buffers;
}
return 0;
}
static void *loop(void *user_data)
{
struct data *data = user_data;
printf("enter thread\n");
spa_loop_control_enter(data->control);
while (data->running) {
spa_loop_control_iterate(data->control, -1);
}
printf("leave thread\n");
spa_loop_control_leave(data->control);
return NULL;
}
static void run_async_source(struct data *data)
{
int res, err;
struct spa_command cmd;
SDL_Event event;
bool running = true;
if ((res = spa_node_send_command(data->source, &cmd)) < 0)
printf("got error %d\n", res);
spa_loop_control_leave(data->control);
data->running = true;
if ((err = pthread_create(&data->thread, NULL, loop, data)) != 0) {
printf("can't create thread: %d %s", err, strerror(err));
data->running = false;
}
while (running && SDL_WaitEvent(&event)) {
switch (event.type) {
case SDL_QUIT:
running = false;
break;
}
}
if (data->running) {
data->running = false;
pthread_join(data->thread, NULL);
}
spa_loop_control_enter(data->control);
if ((res = spa_node_send_command(data->source, &cmd)) < 0)
printf("got error %d\n", res);
}
int main(int argc, char *argv[])
{
struct data data = { 0 };
int res;
const char *str;
struct spa_handle *handle = NULL;
void *iface;
if ((str = getenv("SPA_PLUGIN_DIR")) == NULL)
str = PLUGINDIR;
data.plugin_dir = str;
if ((res = load_handle(&data, &handle,
"support/libspa-support.so",
return res;
if ((res = spa_handle_get_interface(handle, SPA_TYPE_INTERFACE_System, &iface)) < 0) {
printf("can't get System interface %d\n", res);
return res;
}
data.system = iface;
data.support[data.n_support++] = SPA_SUPPORT_INIT(SPA_TYPE_INTERFACE_System, data.system);
if ((res = load_handle(&data, &handle,
"support/libspa-support.so",
return res;
if ((res = spa_handle_get_interface(handle, SPA_TYPE_INTERFACE_Loop, &iface)) < 0) {
printf("can't get interface %d\n", res);
return res;
}
data.loop = iface;
if ((res = spa_handle_get_interface(handle, SPA_TYPE_INTERFACE_LoopControl, &iface)) < 0) {
printf("can't get interface %d\n", res);
return res;
}
data.control = iface;
data.use_buffer = true;
data.log = &default_log.log;
if ((str = getenv("SPA_DEBUG")))
data.log->level = atoi(str);
data.support[data.n_support++] = SPA_SUPPORT_INIT(SPA_TYPE_INTERFACE_Log, data.log);
data.support[data.n_support++] = SPA_SUPPORT_INIT(SPA_TYPE_INTERFACE_Loop, data.loop);
data.support[data.n_support++] = SPA_SUPPORT_INIT(SPA_TYPE_INTERFACE_DataLoop, data.loop);
if (SDL_Init(SDL_INIT_VIDEO) < 0) {
printf("can't initialize SDL: %s\n", SDL_GetError());
return -1;
}
if (SDL_CreateWindowAndRenderer
(320, 240, SDL_WINDOW_RESIZABLE, &data.window, &data.renderer)) {
printf("can't create window: %s\n", SDL_GetError());
return -1;
}
if ((res = make_nodes(&data, argv[1])) < 0) {
printf("can't make nodes: %d\n", res);
return -1;
}
if ((res = negotiate_formats(&data)) < 0) {
printf("can't negotiate nodes: %d\n", res);
return -1;
}
spa_loop_control_enter(data.control);
run_async_source(&data);
spa_loop_control_leave(data.control);
SDL_DestroyRenderer(data.renderer);
return 0;
}
spa/debug/pod.h
@ SPA_META_Header
struct spa_meta_header
Definition: meta.h:47
@ SPA_DATA_MemFd
generic fd, mmap to get to memory
Definition: buffer.h:54
@ SPA_DATA_MemPtr
pointer to memory, the data field in struct spa_data is set.
Definition: buffer.h:52
@ SPA_DATA_DmaBuf
fd to dmabuf memory
Definition: buffer.h:55
static int spa_debug_pod(int indent, const struct spa_type_info *info, const struct spa_pod *pod)
Definition: pod.h:205
int(* spa_handle_factory_enum_func_t)(const struct spa_handle_factory **factory, uint32_t *index)
The function signature of the entry point in a plugin.
Definition: plugin.h:202
#define SPA_HANDLE_FACTORY_ENUM_FUNC_NAME
Definition: plugin.h:206
#define SPA_SUPPORT_INIT(type, data)
Definition: plugin.h:115
#define spa_handle_factory_init(h,...)
Definition: plugin.h:190
#define spa_handle_get_interface(h,...)
Definition: plugin.h:80
#define spa_handle_factory_get_size(h,...)
Definition: plugin.h:189
#define SPA_LOG_IMPL(name)
Definition: log-impl.h:138
#define SPA_TYPE_INTERFACE_Log
The Log interface.
Definition: log.h:78
#define spa_loop_control_enter(l)
Enter a loop.
Definition: loop.h:253
#define spa_loop_control_leave(l)
Leave a loop.
Definition: loop.h:256
#define spa_loop_control_iterate(l,...)
Perform one iteration of the loop.
Definition: loop.h:259
#define SPA_TYPE_INTERFACE_DataLoop
Definition: loop.h:53
#define SPA_TYPE_INTERFACE_Loop
Definition: loop.h:51
#define SPA_TYPE_INTERFACE_LoopControl
Definition: loop.h:59
#define SPA_NAME_SUPPORT_LOOP
A Loop/LoopControl/LoopUtils interface.
Definition: names.h:54
#define SPA_NAME_SUPPORT_SYSTEM
A System interface.
Definition: names.h:57
#define SPA_NAME_API_V4L2_SOURCE
a v4l2 Node interface for capturing
Definition: names.h:166
static int spa_node_enum_params_sync(struct spa_node *node, uint32_t id, uint32_t *index, const struct spa_pod *filter, struct spa_pod **param, struct spa_pod_builder *builder)
Definition: utils.h:65
#define SPA_STATUS_HAVE_DATA
Definition: io.h:104
#define SPA_TYPE_INTERFACE_Node
Definition: node.h:57
#define SPA_VERSION_NODE_CALLBACKS
Definition: node.h:254
#define SPA_STATUS_NEED_DATA
Definition: io.h:102
#define spa_node_port_set_io(n,...)
Configure the given memory area with id on port_id.
Definition: node.h:751
#define spa_node_process(n)
Process the node.
Definition: node.h:758
#define spa_node_set_param(n,...)
Set the configurable parameter in node.
Definition: node.h:727
#define spa_node_port_set_param(n,...)
Set a parameter on port_id of node.
Definition: node.h:745
#define spa_node_send_command(n,...)
Send a command to a node.
Definition: node.h:733
#define SPA_IO_BUFFERS_INIT
Definition: io.h:114
#define SPA_NODE_BUFFERS_FLAG_ALLOC
flags to pass to the use_buffers functions
Definition: node.h:306
#define SPA_NODE_COMMAND_INIT(id)
Definition: command.h:69
#define spa_node_port_use_buffers(n,...)
Tell the port to use the given buffers.
Definition: node.h:748
#define spa_node_set_callbacks(n,...)
Set callbacks to on node.
Definition: node.h:718
@ SPA_IO_Buffers
area to exchange buffers, struct spa_io_buffers
Definition: io.h:58
@ SPA_NODE_COMMAND_Pause
pause a node.
Definition: command.h:48
@ SPA_NODE_COMMAND_Start
start a node, this makes it start emitting scheduling events
Definition: command.h:50
static struct spa_pod * spa_format_video_raw_build(struct spa_pod_builder *builder, uint32_t id, struct spa_video_info_raw *info)
Definition: format-utils.h:80
#define SPA_VIDEO_INFO_RAW_INIT(...)
Definition: raw.h:208
@ SPA_PROP_device
Definition: props.h:67
@ SPA_PARAM_Format
configured format as SPA_TYPE_OBJECT_Format
Definition: param.h:54
@ SPA_PARAM_Props
properties as SPA_TYPE_OBJECT_Props
Definition: param.h:52
@ SPA_VIDEO_FORMAT_YUY2
Definition: raw.h:69
#define SPA_POD_String(val)
Definition: vararg.h:114
#define SPA_POD_BUILDER_INIT(buffer, size)
Definition: builder.h:82
#define spa_pod_builder_add_object(b, type, id,...)
Definition: builder.h:677
static void spa_pod_builder_init(struct spa_pod_builder *builder, void *data, uint32_t size)
Definition: builder.h:107
#define spa_strerror(err)
Definition: result.h:69
static bool spa_streq(const char *s1, const char *s2)
Definition: string.h:59
#define SPA_TYPE_INTERFACE_System
a collection of core system functions
Definition: system.h:59
@ SPA_TYPE_OBJECT_Props
Definition: type.h:95
#define spa_aprintf(_fmt,...)
Definition: defs.h:400
#define SPA_MIN(a, b)
Definition: defs.h:146
#define SPA_FRACTION(num, denom)
Definition: defs.h:120
#define SPA_PTROFF(ptr_, offset_, type_)
Return the address (buffer + offset) as pointer of type.
Definition: defs.h:183
#define SPA_RECTANGLE(width, height)
Definition: defs.h:99
@ SPA_DIRECTION_OUTPUT
Definition: defs.h:92
spa/node/io.h
spa/support/log-impl.h
spa/utils/names.h
spa/param/param.h
spa/support/plugin.h
spa/utils/result.h
spa/node/node.h
spa/support/loop.h
spa/utils/string.h
A Buffer.
Definition: buffer.h:105
Chunk of memory, can change for each buffer.
Definition: buffer.h:62
int32_t stride
stride of valid data
Definition: buffer.h:68
Definition: command.h:49
Data for a buffer this stays constant for a buffer.
Definition: buffer.h:77
struct spa_chunk * chunk
valid chunk of memory
Definition: buffer.h:101
void * data
optional data pointer
Definition: buffer.h:100
Definition: plugin.h:117
uint32_t version
Definition: plugin.h:121
Definition: plugin.h:50
A hook, contains the structure with functions and the data passed to the functions.
Definition: hook.h:342
IO area to exchange buffers.
Definition: io.h:98
int32_t status
the status code
Definition: io.h:109
uint32_t buffer_id
a buffer id
Definition: io.h:110
Definition: log.h:81
Definition: loop.h:62
Definition: loop.h:56
Describes essential buffer header metadata such as flags and timestamps.
Definition: meta.h:80
A metadata element.
Definition: meta.h:66
Node callbacks.
Definition: node.h:252
Definition: node.h:61
Definition: builder.h:73
void * data
Definition: builder.h:74
uint32_t size
Definition: builder.h:75
Definition: pod.h:63
Extra supporting infrastructure passed to the init() function of a factory.
Definition: plugin.h:96
Definition: system.h:65