A GTK3 camera application that knows how to deal with the media request api
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megapixels/main.c

499 lines
11 KiB

#include <errno.h>
#include <fcntl.h>
#include <linux/videodev2.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <asm/errno.h>
#include <gtk/gtk.h>
#include "ini.h"
enum io_method {
IO_METHOD_READ,
IO_METHOD_MMAP,
IO_METHOD_USERPTR,
};
struct buffer {
void *start;
size_t length;
};
struct buffer *buffers;
static unsigned int n_buffers;
static char *rear_dev_name;
static char *front_dev_name;
static char *dev_name;
static enum io_method io = IO_METHOD_MMAP;
static int preview_width = -1;
static int preview_height = -1;
static int preview_fmt = V4L2_PIX_FMT_RGB24;
GObject *preview_image;
static int
xioctl(int fd, int request, void *arg)
{
int r;
do {
r = ioctl(fd, request, arg);
} while (r == -1 && errno == EINTR);
return r;
}
static void
errno_exit(const char *s)
{
fprintf(stderr, "%s error %d, %s\n", s, errno, strerror(errno));
exit(EXIT_FAILURE);
}
static void
start_capturing(int fd)
{
enum v4l2_buf_type type;
switch (io) {
case IO_METHOD_READ:
/* Nothing to do. */
break;
case IO_METHOD_MMAP:
for (int i = 0; i < n_buffers; ++i) {
struct v4l2_buffer buf = {
.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
.memory = V4L2_MEMORY_MMAP,
.index = i,
};
if (xioctl(fd, VIDIOC_QBUF, &buf) == -1) {
errno_exit("VIDIOC_QBUF");
}
}
type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (xioctl(fd, VIDIOC_STREAMON, &type) == -1) {
errno_exit("VIDIOC_STREAMON");
}
break;
case IO_METHOD_USERPTR:
for (int i = 0; i < n_buffers; ++i) {
struct v4l2_buffer buf = {
.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
.memory = V4L2_MEMORY_USERPTR,
.index = i,
};
buf.m.userptr = (unsigned long)buffers[i].start;
buf.length = buffers[i].length;
if (xioctl(fd, VIDIOC_QBUF, &buf) == -1) {
errno_exit("VIDIOC_QBUF");
}
}
type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (xioctl(fd, VIDIOC_STREAMON, &type) == -1) {
errno_exit("VIDIOC_STREAMON");
}
break;
}
}
static void
init_mmap(int fd)
{
struct v4l2_requestbuffers req = { 0 };
req.count = 4;
req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
req.memory = V4L2_MEMORY_MMAP;
if (xioctl(fd, VIDIOC_REQBUFS, &req) == -1) {
if (errno == EINVAL) {
fprintf(stderr, "%s does not support memory mapping",
dev_name);
exit(EXIT_FAILURE);
} else {
errno_exit("VIDIOC_REQBUFS");
}
}
if (req.count < 2) {
fprintf(stderr, "Insufficient buffer memory on %s\n",
dev_name);
exit(EXIT_FAILURE);
}
buffers = calloc(req.count, sizeof(buffers[0]));
if (!buffers) {
fprintf(stderr, "Out of memory\\n");
exit(EXIT_FAILURE);
}
for (n_buffers = 0; n_buffers < req.count; ++n_buffers) {
struct v4l2_buffer buf = {
.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
.memory = V4L2_MEMORY_MMAP,
.index = n_buffers,
};
if (xioctl(fd, VIDIOC_QUERYBUF, &buf) == -1) {
errno_exit("VIDIOC_QUERYBUF");
}
buffers[n_buffers].length = buf.length;
buffers[n_buffers].start = mmap(NULL /* start anywhere */,
buf.length,
PROT_READ | PROT_WRITE /* required */,
MAP_SHARED /* recommended */,
fd, buf.m.offset);
if (MAP_FAILED == buffers[n_buffers].start) {
errno_exit("mmap");
}
}
}
static void
init_device(int fd)
{
struct v4l2_capability cap;
if (xioctl(fd, VIDIOC_QUERYCAP, &cap) == -1) {
if (errno == EINVAL) {
fprintf(stderr, "%s is no V4L2 device\n",
dev_name);
exit(EXIT_FAILURE);
} else {
errno_exit("VIDIOC_QUERYCAP");
}
}
if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
fprintf(stderr, "%s is no video capture device\n",
dev_name);
exit(EXIT_FAILURE);
}
switch (io) {
case IO_METHOD_READ:
if (!(cap.capabilities & V4L2_CAP_READWRITE)) {
fprintf(stderr, "%s does not support read i/o\n",
dev_name);
exit(EXIT_FAILURE);
}
break;
case IO_METHOD_MMAP:
case IO_METHOD_USERPTR:
if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
fprintf(stderr, "%s does not support streaming i/o\n",
dev_name);
exit(EXIT_FAILURE);
}
break;
}
/* Select video input, video standard and tune here. */
struct v4l2_cropcap cropcap = {
.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
};
struct v4l2_crop crop = { 0 };
if (xioctl(fd, VIDIOC_CROPCAP, &cropcap) == 0) {
crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
crop.c = cropcap.defrect; /* reset to default */
if (xioctl(fd, VIDIOC_S_CROP, &crop) == -1) {
switch (errno) {
case EINVAL:
/* Cropping not supported. */
break;
default:
/* Errors ignored. */
break;
}
}
} else {
/* Errors ignored. */
}
struct v4l2_format fmt = {
.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
};
if (preview_width > 0) {
fmt.fmt.pix.width = preview_width;
fmt.fmt.pix.height = preview_height;
fmt.fmt.pix.pixelformat = preview_fmt;
fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
if (xioctl(fd, VIDIOC_S_FMT, &fmt) == -1) {
errno_exit("VIDIOC_S_FMT");
}
/* Note VIDIOC_S_FMT may change width and height. */
} else {
/* Preserve original settings as set by v4l2-ctl for example */
if (xioctl(fd, VIDIOC_G_FMT, &fmt) == -1) {
errno_exit("VIDIOC_G_FMT");
}
}
/* Buggy driver paranoia. */
unsigned int min = fmt.fmt.pix.width * 2;
if (fmt.fmt.pix.bytesperline < min) {
fmt.fmt.pix.bytesperline = min;
}
min = fmt.fmt.pix.bytesperline * fmt.fmt.pix.height;
if (fmt.fmt.pix.sizeimage < min) {
fmt.fmt.pix.sizeimage = min;
}
switch (io) {
case IO_METHOD_READ:
//init_read(fmt.fmt.pix.sizeimage);
break;
case IO_METHOD_MMAP:
init_mmap(fd);
break;
case IO_METHOD_USERPTR:
//init_userp(fmt.fmt.pix.sizeimage);
break;
}
}
static void
process_image(const void *p, int size)
{
GdkPixbuf *pixbuf = gdk_pixbuf_new_from_data(p, GDK_COLORSPACE_RGB,
FALSE, 8, 640, 480, 2 * 640, NULL, NULL);
gtk_image_set_from_pixbuf(preview_image, pixbuf);
}
static int
read_frame(int fd)
{
struct v4l2_buffer buf = { 0 };
switch (io) {
case IO_METHOD_READ:
if (read(fd, buffers[0].start, buffers[0].length) == -1) {
switch (errno) {
case EAGAIN:
return 0;
case EIO:
/* Could ignore EIO, see spec. */
/* fallthrough */
default:
errno_exit("read");
break;
}
}
process_image(buffers[0].start, buffers[0].length);
break;
case IO_METHOD_MMAP:
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
if (xioctl(fd, VIDIOC_DQBUF, &buf) == -1) {
switch (errno) {
case EAGAIN:
return 0;
case EIO:
/* Could ignore EIO, see spec. */
/* fallthrough */
default:
errno_exit("VIDIOC_DQBUF");
break;
}
}
//assert(buf.index < n_buffers);
process_image(buffers[buf.index].start, buf.bytesused);
if (xioctl(fd, VIDIOC_QBUF, &buf) == -1) {
errno_exit("VIDIOC_QBUF");
}
break;
case IO_METHOD_USERPTR:
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_USERPTR;
if (xioctl(fd, VIDIOC_DQBUF, &buf) == -1) {
switch (errno) {
case EAGAIN:
return 0;
case EIO:
/* Could ignore EIO, see spec. */
/* fallthrough */
default:
errno_exit("VIDIOC_DQBUF");
break;
}
}
unsigned int i;
for (i = 0; i < n_buffers; ++i) {
if (buf.m.userptr == (unsigned long)buffers[i].start
&& buf.length == buffers[i].length) {
break;
}
}
//assert(i < n_buffers);
process_image((void *)buf.m.userptr, buf.bytesused);
if (xioctl(fd, VIDIOC_QBUF, &buf) == -1) {
errno_exit("VIDIOC_QBUF");
}
break;
}
return 1;
}
static void
get_frame(int fd)
{
while (1) {
fd_set fds;
struct timeval tv;
int r;
FD_ZERO(&fds);
FD_SET(fd, &fds);
/* Timeout. */
tv.tv_sec = 2;
tv.tv_usec = 0;
r = select(fd + 1, &fds, NULL, NULL, &tv);
if (r == -1) {
if (EINTR == errno) {
continue;
}
errno_exit("select");
} else if (r == 0) {
fprintf(stderr, "select timeout\\n");
exit(EXIT_FAILURE);
}
if (read_frame(fd)) {
break;
}
/* EAGAIN - continue select loop. */
}
}
static int
config_ini_handler(void *user, const char *section, const char *name,
const char *value) {
if (strcmp(section, "preview") == 0) {
if (strcmp(name, "width") == 0) {
preview_width = strtol(value, NULL, 10);
} else if (strcmp(name, "height") == 0) {
preview_height = strtol(value, NULL, 10);
} else if (strcmp(name, "fmt") == 0) {
if (strcmp(value, "RGB") == 0){
preview_fmt = V4L2_PIX_FMT_RGB24;
} else if (strcmp(value, "UYVY8") == 0) {
preview_fmt = V4L2_PIX_FMT_UYVY;
} else if (strcmp(value, "JPEG") == 0) {
preview_fmt = V4L2_PIX_FMT_JPEG;
} else if (strcmp(value, "NV12") == 0) {
preview_fmt = V4L2_PIX_FMT_NV12;
} else if (strcmp(value, "YUV420") == 0
|| strcmp(value, "I420") == 0
|| strcmp(value, "YU12") == 0) {
preview_fmt = V4L2_PIX_FMT_YUV420;
} else if (strcmp(value, "YVU420") == 0
|| strcmp(value, "YV12") == 0) {
preview_fmt = V4L2_PIX_FMT_YVU420;
} else {
g_printerr("Unsupported pixelformat %s\n", value);
exit(1);
}
preview_fmt = strtol(value, NULL, 10);
} else {
g_printerr("Unknown key '%s' in [preview]\n", name);
exit(1);
}
} else if (strcmp(section, "device") == 0) {
if (strcmp(name, "rear") == 0) {
rear_dev_name = strdup(value);
} else if (strcmp(name, "front") == 0) {
front_dev_name = strdup(value);
} else {
g_printerr("Unknown key '%s' in [device]\n", name);
exit(1);
}
} else {
g_printerr("Unknown section '%s' in config file\n", section);
exit(1);
}
return 1;
}
int
main(int argc, char *argv[])
{
if (argc != 2) {
g_printerr("Usage: camera configfile\n");
return 1;
}
GError *error = NULL;
gtk_init(&argc, &argv);
GtkBuilder *builder = gtk_builder_new();
char* glade_file = "/usr/share/camera/ui/camera.glade";
if (access( "camera.glade", F_OK) != -1) {
glade_file = "camera.glade";
}
if (gtk_builder_add_from_file(builder, glade_file, &error) == 0) {
g_printerr("Error loading file: %s\n", error->message);
g_clear_error(&error);
return 1;
}
GObject *window = gtk_builder_get_object(builder, "window");
GObject *preview_box = gtk_builder_get_object(builder, "preview_box");
preview_image = gtk_builder_get_object(builder, "preview");
g_signal_connect(window, "destroy", G_CALLBACK(gtk_main_quit), NULL);
GtkCssProvider *provider = gtk_css_provider_new();
if (access( "camera.css", F_OK) != -1) {
gtk_css_provider_load_from_path(provider, "camera.css", NULL);
} else {
gtk_css_provider_load_from_path(provider, "/usr/share/camera/ui/camera.css", NULL);
}
GtkStyleContext *context = gtk_widget_get_style_context(preview_box);
gtk_style_context_add_provider(context,
GTK_STYLE_PROVIDER(provider),
GTK_STYLE_PROVIDER_PRIORITY_USER);
int result = ini_parse(argv[1], config_ini_handler, NULL);
if (result == -1) {
g_printerr("Config file not found\n");
return 1;
} else if (result == -2) {
g_printerr("Could not allocate memory to parse config file\n");
return 1;
} else if (result != 0) {
g_printerr("Could not parse config file\n");
return 1;
}
dev_name = rear_dev_name;
int fd = open(dev_name, O_RDWR);
if (fd == -1) {
g_printerr("Error opening video device: %s\n", dev_name);
return 1;
}
init_device(fd);
start_capturing(fd);
get_frame(fd);
gtk_widget_show(window);
gtk_main();
return 0;
}