From f0c704a818e29915018d2d307648d087721e53e6 Mon Sep 17 00:00:00 2001
From: tth <sigfood@dinorama.fr>
Date: Mon, 2 Sep 2019 11:47:51 +0200
Subject: [PATCH] cumul image can be converted to gray

---
 v4l2/grabvidseq.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/v4l2/grabvidseq.c b/v4l2/grabvidseq.c
index 97ea611..a15fc5e 100644
--- a/v4l2/grabvidseq.c
+++ b/v4l2/grabvidseq.c
@@ -71,6 +71,7 @@ if (verbosity) {
 	}
 puts("options :");
 puts("\t-d /dev/?\tselect video device");
+puts("\t-g\t\tconvert to gray");
 puts("\t-n NNN\t\thow many frames ?");
 puts("\t-O ./\t\tset Output dir");
 puts("\t-o bla\t\tset output filename");
@@ -103,6 +104,7 @@ int		opt;
 int		width = 640;
 int		height = 480;
 double		t_final;
+int		to_gray = 0;
 char		*dest_dir = ".";	/* no trailing slash */
 char		*outfile = "out.pnm";
 
@@ -110,9 +112,10 @@ char		*outfile = "out.pnm";
 FloatImg	grab, cumul;
 #endif
 
-while ((opt = getopt(argc, argv, "d:hn:o:O:p:s:v")) != -1) {
+while ((opt = getopt(argc, argv, "d:ghn:o:O:p:s:v")) != -1) {
 	switch(opt) {
 		case 'd':	dev_name = optarg;		break;
+		case 'g':	to_gray = 1;			break;
 		case 'h':	help(0);			break;
 		case 'n':	nbre_capt = atoi(optarg);	break;
 		case 'O':	dest_dir = optarg;		break;
@@ -143,6 +146,7 @@ fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_RGB24;
 fmt.fmt.pix.field       = V4L2_FIELD_INTERLACED;
 xioctl(fd, VIDIOC_S_FMT, &fmt);
 if (fmt.fmt.pix.pixelformat != V4L2_PIX_FMT_RGB24) {
+	/* are others formats usable ? */
 	printf("Libv4l didn't accept RGB24 format. Can't proceed.\n");
 	exit(EXIT_FAILURE);
 	}
@@ -197,11 +201,10 @@ foo = fimg_create(&cumul,
 		FIMG_TYPE_RGB);
 fimg_clear(&cumul);
 cumul.fval = 255.0;
+cumul.count = 0;
 #endif
 
 
-
-
 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 xioctl(fd, VIDIOC_STREAMON, &type);
 
@@ -282,6 +285,10 @@ fprintf(stderr, "pid %d : elapsed time %g s\n", getpid(), t_final);
 fprintf(stderr, "\t%.2f fps\n", (double)nbre_capt / t_final);
 
 #if SAVE_AS_CUMUL
+if (to_gray) {
+	if (verbosity)	fputs("converting to gray\n", stderr);
+	foo = fimg_to_gray(&cumul);
+	}
 	// save cumul to file
 foo = fimg_save_as_pnm(&cumul, outfile, 0);
 	// free buffers