checking capabilities

git-svn-id: svn://anubis/misc/WebcamTracker@120 bd8a9e45-a331-0410-811e-c64571078777

WebcamTracker.cc

@@ -6,19 +6,54 @@
 #include <sys/ioctl.h>              /* ioctl() */
 #include <libv4lconvert.h>
 #include <iostream>
+#include "WebcamTracker.h"
 using namespace std;
 
 int main(int argc, char * argv[])
 {
-    int fd = open("/dev/video0", O_RDWR);
-    if (fd < 0)
-    {
-        cerr << "bad fd" << endl;
-        exit(1);
-    }
-
-    struct v4l2_capability cap;
-    ioctl(fd, VIDIOC_QUERYCAP, &cap);
-
-    close(fd);
+    WebcamTracker("/dev/video0");
+}
+
+WebcamTracker::WebcamTracker(const char * device)
+{
+    m_open = false;
+    m_fd = open(device, O_RDWR);
+    if (m_fd >= 0)
+    {
+        m_open = true;
+
+        struct v4l2_capability cap;
+        ioctl(m_fd, VIDIOC_QUERYCAP, &cap);
+#define check_cap(x) do { \
+    if (cap.capabilities & (x)) \
+        cout << " cap: " << #x << endl; \
+    } while (0)
+        check_cap(V4L2_CAP_VIDEO_CAPTURE);
+        check_cap(V4L2_CAP_VIDEO_OUTPUT);
+        check_cap(V4L2_CAP_VIDEO_OVERLAY);
+        check_cap(V4L2_CAP_VBI_CAPTURE);
+        check_cap(V4L2_CAP_VBI_OUTPUT);
+        check_cap(V4L2_CAP_SLICED_VBI_CAPTURE);
+        check_cap(V4L2_CAP_SLICED_VBI_OUTPUT);
+        check_cap(V4L2_CAP_RDS_CAPTURE);
+        check_cap(V4L2_CAP_VIDEO_OUTPUT_OVERLAY);
+        check_cap(V4L2_CAP_TUNER);
+        check_cap(V4L2_CAP_AUDIO);
+        check_cap(V4L2_CAP_RADIO);
+        check_cap(V4L2_CAP_READWRITE);
+        check_cap(V4L2_CAP_ASYNCIO);
+        check_cap(V4L2_CAP_STREAMING);
+    }
+    else
+    {
+        cerr << "Could not open device '" << device << "'" << endl;
+    }
+}
+
+WebcamTracker::~WebcamTracker()
+{
+    if (m_open)
+    {
+        close(m_fd);
+    }
 }

WebcamTracker.h

@@ -0,0 +1,19 @@
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdlib.h>                 /* exit() */
+#include <sys/ioctl.h>              /* ioctl() */
+#include <libv4lconvert.h>
+#include <iostream>
+
+class WebcamTracker
+{
+    public:
+        WebcamTracker(const char * device);
+        ~WebcamTracker();
+
+    protected:
+        bool    m_open;
+        int     m_fd;
+};