[Patch] Moving v4l1 ioctls from kernel to libv4l1

[Huzaifa Sidhpurwala <huzaifas@redhat.com>]

Hi All,
I have been working with Hans for moving the v4l1 ioctls from the kernel
to libv4l1.
It would be best to work on one ioctl at a time.
The enclosed patch attempts to implement VIDIOCGCAP in the libv4l1.

Note: Hans is working with Bill, asking for permission to re-use the
v4l1-compat.c code under the LGPL



diff --git a/lib/libv4l1/libv4l1.c b/lib/libv4l1/libv4l1.c
index eae3b43..8571651 100644
--- a/lib/libv4l1/libv4l1.c
+++ b/lib/libv4l1/libv4l1.c
@@ -61,6 +61,10 @@
 #define V4L1_PIX_FMT_TOUCHED    0x04
 #define V4L1_PIX_SIZE_TOUCHED   0x08

+#ifndef min
+	#define min( a, b ) ( ((a) < (b)) ? (a) : (b) )
+#endif
+
 static pthread_mutex_t v4l1_open_mutex = PTHREAD_MUTEX_INITIALIZER;
 static struct v4l1_dev_info devices[V4L1_MAX_DEVICES] = {
 	{ .fd = -1 },
@@ -130,6 +134,45 @@ static unsigned int pixelformat_to_palette(unsigned
int pixelformat)
 	return 0;
 }

+static int count_inputs(int fd)
+{
+	struct v4l2_input input2;
+	int i;
+	for (i = 0;; i++) {
+		memset(&input2, 0, sizeof(input2));
+		input2.index = i;
+		if (0 != SYS_IOCTL(fd, VIDIOC_ENUMINPUT, &input2))
+			break;
+		}
+	return i;
+}
+
+static int check_size(int fd,int *maxw,int *maxh)
+{
+	struct v4l2_fmtdesc desc2;
+	struct v4l2_format fmt2;
+
+	memset(&desc2, 0, sizeof(desc2));
+	memset(&fmt2, 0, sizeof(fmt2));
+
+	desc2.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	if (0 != SYS_IOCTL(fd, VIDIOC_ENUM_FMT, &desc2))
+		goto done;
+
+	fmt2.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	fmt2.fmt.pix.width = 10000;
+	fmt2.fmt.pix.height = 10000;
+	fmt2.fmt.pix.pixelformat = desc2.pixelformat;
+	if (0 != SYS_IOCTL(fd, VIDIOC_TRY_FMT, &fmt2))
+		goto done;
+
+	*maxw = fmt2.fmt.pix.width;
+	*maxh = fmt2.fmt.pix.height;
+
+	done:
+	return 0;
+}
+
 static int v4l1_set_format(int index, unsigned int width,
 		unsigned int height, int v4l1_pal, int width_height_may_differ)
 {
@@ -492,7 +535,54 @@ int v4l1_ioctl(int fd, unsigned long int request, ...)
 	case VIDIOCGCAP: {
 		struct video_capability *cap = arg;

-		result = SYS_IOCTL(fd, request, arg);
+		long err;
+		struct v4l2_framebuffer fbuf;
+		struct v4l2_capability *cap2;
+
+		cap2 = malloc (sizeof(*cap2));
+		if (!cap2) {
+			return -ENOMEM;
+		}
+
+		memset(cap,0,sizeof(*cap));
+		memset(&fbuf, 0, sizeof(fbuf));
+
+		err = SYS_IOCTL(fd, VIDIOC_QUERYCAP,cap2);
+		if (err < 0)
+			goto done;
+
+		if (cap2->capabilities & V4L2_CAP_VIDEO_OVERLAY) {
+			err = SYS_IOCTL(fd, VIDIOC_G_FBUF, &fbuf);
+			if (err < 0) {
+				memset(&fbuf, 0, sizeof(fbuf));
+			}
+			err = 0;
+		}
+		
+		memcpy(cap->name,  cap2->card,
min(sizeof(cap->name),sizeof(cap2->card)) );
+		
+		cap->name[sizeof(cap->name) -1 ] = 0;
+	
+		if (cap2->capabilities & V4L2_CAP_VIDEO_CAPTURE)
+			cap->type |= VID_TYPE_CAPTURE;
+		if (cap2->capabilities & V4L2_CAP_TUNER)
+			cap->type |= VID_TYPE_TUNER;
+		if (cap2->capabilities & V4L2_CAP_VBI_CAPTURE)
+			cap->type |= VID_TYPE_TELETEXT;
+		if (cap2->capabilities & V4L2_CAP_VIDEO_OVERLAY)
+			cap->type |= VID_TYPE_OVERLAY;
+		if (fbuf.capability & V4L2_FBUF_CAP_LIST_CLIPPING)
+			cap->type |= VID_TYPE_CLIPPING;
+
+		cap->channels = count_inputs(fd);
+
+		check_size(fd,
+			&cap->maxwidth, &cap->maxheight);
+					
+		
+	/*	result = SYS_IOCTL(fd, request, arg);*/
+
+

 		/* override kernel v4l1 compat min / max size with our own more
 		   accurate values */
@@ -500,7 +590,10 @@ int v4l1_ioctl(int fd, unsigned long int request, ...)
 		cap->minheight = devices[index].min_height;
 		cap->maxwidth  = devices[index].max_width;
 		cap->maxheight = devices[index].max_height;
-		break;
+
+		done:
+			free(cap2);
+			break;
 	}

 	case VIDIOCSPICT: {

-- 
Regards,
Huzaifa Sidhpurwala, RHCE, CCNA (IRC: huzaifas)
IT Desktop R&D Lead.
Global Help Desk, Pune (India)
Phone: +91 20 4005 7322 (UTC +5.5)

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