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video-setup/dev/cli/v4l2_view_cli.c
mikael-lovqvists-claude-agent 61c81398bb feat: node-to-node MJPEG streaming CLIs and shared V4L2 format header 
Add stream_send_cli (V4L2 capture → TCP → VIDEO_FRAME) and
stream_recv_cli (TCP → threaded frame slot → GLFW display) to
exercise end-to-end streaming between two nodes on the same machine
or across the network.

Add include/stream_stats.h (header-only rolling-window fps/Mbps tracker)
and include/v4l2_fmt.h (header-only V4L2 format enumeration shared between
v4l2_view_cli and stream_send_cli). Refactor v4l2_view_cli to use the
shared header.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-03-28 22:31:54 +00:00

395 lines
14 KiB
C
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <sys/mman.h>
#include <sys/select.h>
#include "v4l2_fmt.h"
#include "xorg.h"
#define N_BUFS 4
/* ------------------------------------------------------------------ */
/* YUYV → planar YUV420 conversion */
/* ------------------------------------------------------------------ */
static void yuyv_to_yuv420(const uint8_t *yuyv, int stride,
int w, int h,
uint8_t *y_out, uint8_t *cb_out, uint8_t *cr_out)
{
for (int row = 0; row < h; row++) {
const uint8_t *src = yuyv + row * stride;
uint8_t *dst = y_out + row * w;
for (int col = 0; col < w; col++) {
dst[col] = src[col * 2];
}
}
for (int row = 0; row < h; row += 2) {
const uint8_t *src = yuyv + row * stride;
int c_row = row / 2;
for (int col = 0; col < w; col += 2) {
cb_out[c_row * (w / 2) + col / 2] = src[col * 2 + 1];
cr_out[c_row * (w / 2) + col / 2] = src[col * 2 + 3];
}
}
}
/* ------------------------------------------------------------------ */
/* Mmap buffers */
/* ------------------------------------------------------------------ */
typedef struct { void *start; size_t length; } Mmap_Buf;
/* ------------------------------------------------------------------ */
/* Usage */
/* ------------------------------------------------------------------ */
static void usage(void)
{
fprintf(stderr,
"usage: v4l2_view_cli [--device PATH]\n"
" [--width N --height N]\n"
" [--format mjpeg|yuyv]\n"
" [--scale stretch|fit|fill|1:1]\n"
" [--anchor center|topleft]\n"
" [--x N] [--y N]\n"
"\n"
"Opens a V4L2 capture device and displays the live feed.\n"
"Without --width/--height, selects the highest-FPS mode\n"
"and within that the largest resolution.\n"
"Q or Escape closes the window.\n"
"\n"
"defaults: /dev/video0 auto fit center at 0,0\n");
}
/* ------------------------------------------------------------------ */
/* Main */
/* ------------------------------------------------------------------ */
int main(int argc, char **argv)
{
const char *device = "/dev/video0";
int req_width = 0;
int req_height = 0;
int win_x = 0;
int win_y = 0;
Xorg_Scale scale = XORG_SCALE_FIT;
Xorg_Anchor anchor = XORG_ANCHOR_CENTER;
uint32_t fmt_filter = 0; /* 0 = auto */
for (int i = 1; i < argc; i++) {
if (strcmp(argv[i], "--device") == 0 && i + 1 < argc) {
device = argv[++i];
} else if (strcmp(argv[i], "--width") == 0 && i + 1 < argc) {
req_width = atoi(argv[++i]);
} else if (strcmp(argv[i], "--height") == 0 && i + 1 < argc) {
req_height = atoi(argv[++i]);
} else if (strcmp(argv[i], "--x") == 0 && i + 1 < argc) {
win_x = atoi(argv[++i]);
} else if (strcmp(argv[i], "--y") == 0 && i + 1 < argc) {
win_y = atoi(argv[++i]);
} else if (strcmp(argv[i], "--format") == 0 && i + 1 < argc) {
i++;
if (strcmp(argv[i], "mjpeg") == 0) { fmt_filter = V4L2_PIX_FMT_MJPEG; }
else if (strcmp(argv[i], "yuyv") == 0) { fmt_filter = V4L2_PIX_FMT_YUYV; }
else { fprintf(stderr, "unknown format: %s\n", argv[i]); usage(); return 1; }
} else if (strcmp(argv[i], "--scale") == 0 && i + 1 < argc) {
i++;
if (strcmp(argv[i], "stretch") == 0) { scale = XORG_SCALE_STRETCH; }
else if (strcmp(argv[i], "fit") == 0) { scale = XORG_SCALE_FIT; }
else if (strcmp(argv[i], "fill") == 0) { scale = XORG_SCALE_FILL; }
else if (strcmp(argv[i], "1:1") == 0) { scale = XORG_SCALE_1_1; }
else { fprintf(stderr, "unknown scale: %s\n", argv[i]); usage(); return 1; }
} else if (strcmp(argv[i], "--anchor") == 0 && i + 1 < argc) {
i++;
if (strcmp(argv[i], "center") == 0) { anchor = XORG_ANCHOR_CENTER; }
else if (strcmp(argv[i], "topleft") == 0) { anchor = XORG_ANCHOR_TOP_LEFT; }
else { fprintf(stderr, "unknown anchor: %s\n", argv[i]); usage(); return 1; }
} else {
usage(); return 1;
}
}
if (!xorg_available()) {
fprintf(stderr, "v4l2_view_cli: built without HAVE_GLFW — viewer not available\n");
return 1;
}
/* ---------------------------------------------------------------- */
/* Open V4L2 device */
/* ---------------------------------------------------------------- */
int fd = open(device, O_RDWR | O_NONBLOCK);
if (fd < 0) { perror(device); return 1; }
struct v4l2_capability cap = {0};
if (v4l2_xioctl(fd, VIDIOC_QUERYCAP, &cap) < 0) {
perror("VIDIOC_QUERYCAP"); close(fd); return 1;
}
if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
fprintf(stderr, "%s: not a capture device\n", device); close(fd); return 1;
}
if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
fprintf(stderr, "%s: does not support streaming\n", device); close(fd); return 1;
}
/* ---------------------------------------------------------------- */
/* Format selection */
/* ---------------------------------------------------------------- */
int width, height, stride;
int use_mjpeg;
int sel_fps_n, sel_fps_d;
if (req_width > 0 && req_height > 0) {
/*
* Explicit size requested — skip enumeration, negotiate directly.
* Try MJPEG first (or whatever fmt_filter says), fall back to YUYV.
*/
struct v4l2_format fmt = {0};
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
fmt.fmt.pix.width = (uint32_t)req_width;
fmt.fmt.pix.height = (uint32_t)req_height;
fmt.fmt.pix.field = V4L2_FIELD_ANY;
use_mjpeg = 0;
if (fmt_filter != V4L2_PIX_FMT_YUYV) {
fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_MJPEG;
if (v4l2_xioctl(fd, VIDIOC_S_FMT, &fmt) == 0 &&
fmt.fmt.pix.pixelformat == V4L2_PIX_FMT_MJPEG) {
use_mjpeg = 1;
}
}
if (!use_mjpeg) {
fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_YUYV;
if (v4l2_xioctl(fd, VIDIOC_S_FMT, &fmt) < 0 ||
fmt.fmt.pix.pixelformat != V4L2_PIX_FMT_YUYV) {
fprintf(stderr, "%s: could not set %dx%d in MJPEG or YUYV\n",
device, req_width, req_height);
close(fd); return 1;
}
}
width = (int)fmt.fmt.pix.width;
height = (int)fmt.fmt.pix.height;
stride = (int)fmt.fmt.pix.bytesperline;
sel_fps_n = 0; sel_fps_d = 1; /* unknown until G_PARM below */
} else {
/* Enumerate all supported modes and pick the best. */
V4l2_Fmt_Option *opts = malloc(V4L2_FMT_MAX_OPTS * sizeof(*opts));
if (!opts) { fprintf(stderr, "out of memory\n"); close(fd); return 1; }
int n = v4l2_enumerate_formats(fd, opts, V4L2_FMT_MAX_OPTS, fmt_filter);
if (n == 0) {
fprintf(stderr, "%s: no usable formats found (MJPEG/YUYV)\n", device);
free(opts); close(fd); return 1;
}
const V4l2_Fmt_Option *best = v4l2_select_best(opts, n);
/* Apply the selected format. */
struct v4l2_format fmt = {0};
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
fmt.fmt.pix.pixelformat = best->pixfmt;
fmt.fmt.pix.width = (uint32_t)best->w;
fmt.fmt.pix.height = (uint32_t)best->h;
fmt.fmt.pix.field = V4L2_FIELD_ANY;
if (v4l2_xioctl(fd, VIDIOC_S_FMT, &fmt) < 0) {
perror("VIDIOC_S_FMT"); free(opts); close(fd); return 1;
}
use_mjpeg = (fmt.fmt.pix.pixelformat == V4L2_PIX_FMT_MJPEG);
width = (int)fmt.fmt.pix.width;
height = (int)fmt.fmt.pix.height;
stride = (int)fmt.fmt.pix.bytesperline;
sel_fps_n = best->fps_n;
sel_fps_d = best->fps_d;
free(opts);
}
/* Request the selected frame rate (driver may ignore, but try). */
{
struct v4l2_streamparm parm = {0};
parm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
parm.parm.capture.timeperframe.numerator = (uint32_t)sel_fps_d;
parm.parm.capture.timeperframe.denominator = (uint32_t)sel_fps_n;
v4l2_xioctl(fd, VIDIOC_S_PARM, &parm);
/* Read back what the driver actually set. */
if (v4l2_xioctl(fd, VIDIOC_G_PARM, &parm) == 0 &&
parm.parm.capture.timeperframe.denominator > 0) {
sel_fps_n = (int)parm.parm.capture.timeperframe.denominator;
sel_fps_d = (int)parm.parm.capture.timeperframe.numerator;
}
}
printf("device: %s (%s)\n", device, (char *)cap.card);
printf("format: %s %dx%d stride=%d target=%.1f fps\n",
use_mjpeg ? "MJPEG" : "YUYV", width, height, stride,
sel_fps_d > 0 ? (double)sel_fps_n / sel_fps_d : 0.0);
/* ---------------------------------------------------------------- */
/* Mmap buffers + stream on */
/* ---------------------------------------------------------------- */
struct v4l2_requestbuffers req = {0};
req.count = N_BUFS;
req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
req.memory = V4L2_MEMORY_MMAP;
if (v4l2_xioctl(fd, VIDIOC_REQBUFS, &req) < 0) {
perror("VIDIOC_REQBUFS"); close(fd); return 1;
}
Mmap_Buf bufs[N_BUFS] = {0};
for (unsigned i = 0; i < req.count; i++) {
struct v4l2_buffer buf = {0};
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
buf.index = i;
if (v4l2_xioctl(fd, VIDIOC_QUERYBUF, &buf) < 0) {
perror("VIDIOC_QUERYBUF"); close(fd); return 1;
}
bufs[i].length = buf.length;
bufs[i].start = mmap(NULL, buf.length, PROT_READ | PROT_WRITE,
MAP_SHARED, fd, buf.m.offset);
if (bufs[i].start == MAP_FAILED) {
perror("mmap"); close(fd); return 1;
}
}
for (unsigned i = 0; i < req.count; i++) {
struct v4l2_buffer buf = {0};
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
buf.index = i;
if (v4l2_xioctl(fd, VIDIOC_QBUF, &buf) < 0) {
perror("VIDIOC_QBUF"); close(fd); return 1;
}
}
enum v4l2_buf_type stream_type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (v4l2_xioctl(fd, VIDIOC_STREAMON, &stream_type) < 0) {
perror("VIDIOC_STREAMON"); close(fd); return 1;
}
/* ---------------------------------------------------------------- */
/* Open viewer */
/* ---------------------------------------------------------------- */
Xorg_Viewer *v = xorg_viewer_open(win_x, win_y, width, height, "v4l2_view_cli");
if (!v) {
fprintf(stderr, "v4l2_view_cli: failed to open viewer window\n");
v4l2_xioctl(fd, VIDIOC_STREAMOFF, &stream_type);
close(fd); return 1;
}
xorg_viewer_set_scale(v, scale);
xorg_viewer_set_anchor(v, anchor);
/* ---------------------------------------------------------------- */
/* YUYV conversion buffer */
/* ---------------------------------------------------------------- */
uint8_t *yuv420_buf = NULL;
if (!use_mjpeg) {
yuv420_buf = malloc((size_t)(width * height * 3 / 2));
if (!yuv420_buf) {
fprintf(stderr, "v4l2_view_cli: out of memory\n");
xorg_viewer_close(v);
v4l2_xioctl(fd, VIDIOC_STREAMOFF, &stream_type);
close(fd); return 1;
}
}
/* ---------------------------------------------------------------- */
/* Capture loop */
/* ---------------------------------------------------------------- */
struct timespec t_fps;
clock_gettime(CLOCK_MONOTONIC, &t_fps);
int fps_frame_count = 0;
float displayed_fps = 0.0f;
/* Set initial info overlay; fps will be filled in once measured. */
const char *fmt_name = use_mjpeg ? "MJPEG" : "YUYV";
{
char info[64];
snprintf(info, sizeof(info), "%s %dx%d @ --.- fps", fmt_name, width, height);
xorg_viewer_set_overlay_text(v, 0, 10, 10, info, 1.0f, 1.0f, 0.8f);
}
while (1) {
fd_set fds;
FD_ZERO(&fds);
FD_SET(fd, &fds);
struct timeval tv = {1, 0};
int r = select(fd + 1, &fds, NULL, NULL, &tv);
if (r < 0) {
if (errno == EINTR) { continue; }
perror("select"); break;
}
if (r == 0) {
fprintf(stderr, "v4l2_view_cli: select timeout — no frames\n");
continue;
}
struct v4l2_buffer buf = {0};
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
if (v4l2_xioctl(fd, VIDIOC_DQBUF, &buf) < 0) {
if (errno == EAGAIN) { continue; }
perror("VIDIOC_DQBUF"); break;
}
const uint8_t *data = bufs[buf.index].start;
if (use_mjpeg) {
xorg_viewer_push_mjpeg(v, data, buf.bytesused);
} else {
uint8_t *y_p = yuv420_buf;
uint8_t *cb_p = y_p + width * height;
uint8_t *cr_p = cb_p + width * height / 4;
yuyv_to_yuv420(data, stride, width, height, y_p, cb_p, cr_p);
xorg_viewer_push_yuv420(v, y_p, cb_p, cr_p, width, height);
}
if (v4l2_xioctl(fd, VIDIOC_QBUF, &buf) < 0) {
perror("VIDIOC_QBUF"); break;
}
/* Update FPS overlay every 0.5s. */
fps_frame_count++;
struct timespec now;
clock_gettime(CLOCK_MONOTONIC, &now);
double elapsed = (now.tv_sec - t_fps.tv_sec) +
(now.tv_nsec - t_fps.tv_nsec) * 1e-9;
if (elapsed >= 0.5) {
displayed_fps = (float)(fps_frame_count / elapsed);
fps_frame_count = 0;
t_fps = now;
char info[64];
snprintf(info, sizeof(info), "%s %dx%d @ %.1f fps",
fmt_name, width, height, displayed_fps);
xorg_viewer_set_overlay_text(v, 0, 10, 10, info, 1.0f, 1.0f, 0.8f);
}
if (!xorg_viewer_handle_events(v)) { break; }
}
/* ---------------------------------------------------------------- */
/* Cleanup */
/* ---------------------------------------------------------------- */
xorg_viewer_close(v);
v4l2_xioctl(fd, VIDIOC_STREAMOFF, &stream_type);
for (unsigned i = 0; i < req.count; i++) {
if (bufs[i].start && bufs[i].start != MAP_FAILED) {
munmap(bufs[i].start, bufs[i].length);
}
}
free(yuv420_buf);
close(fd);
return 0;
}
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