v4l2: ignore devices without suitable pixel format

Author: EmmanuelP

src/arvv4l2device.c

@@ -99,6 +99,19 @@ G_DEFINE_TYPE_WITH_CODE (ArvV4l2Device, arv_v4l2_device, ARV_TYPE_DEVICE, G_ADD_
 
 /* ArvV4l2Device implemenation */
 
+ArvPixelFormat
+arv_pixel_format_from_v4l2 (guint32 v4l2_pixel_format)
+{
+        unsigned int i;
+
+        for (i = 0; i < G_N_ELEMENTS(pixel_format_map); i++) {
+                if (v4l2_pixel_format == pixel_format_map[i].v4l2)
+                        return pixel_format_map[i].genicam;
+        }
+
+        return 0;
+}
+
 /* ArvDevice implemenation */
 
 static ArvStream *
@@ -547,7 +560,7 @@ arv_v4l2_device_constructed (GObject *self)
                                        "  <DisplayName>Pixel format</DisplayName>\n");
 
         for (i = 0; TRUE; i++) {
-                int j, k;
+                int j;
                 struct v4l2_fmtdesc format = {0};
                 guint32 genicam_pixel_format = 0;
 
@@ -558,10 +571,7 @@ arv_v4l2_device_constructed (GObject *self)
 
                 arv_info_device ("Found format %s", format.description);
 
-                for (k = 0; k < G_N_ELEMENTS(pixel_format_map); k++) {
-                        if (format.pixelformat == pixel_format_map[k].v4l2)
-                                genicam_pixel_format = pixel_format_map[k].genicam;
-                }
+                genicam_pixel_format = arv_pixel_format_from_v4l2(format.pixelformat);
 
                 g_array_insert_val (priv->pixel_formats, i, genicam_pixel_format);
 

src/arvv4l2deviceprivate.h

@@ -31,9 +31,11 @@
 
 G_BEGIN_DECLS
 
+ArvPixelFormat  arv_pixel_format_from_v4l2              (guint32 v4l2_pixel_format);
+
 gboolean        arv_v4l2_device_set_image_format        (ArvV4l2Device *device);
 gboolean        arv_v4l2_device_get_image_format        (ArvV4l2Device *device,
-                                                         guint32 *payload_size, guint32 *pixel_format,
+                                                         guint32 *payload_size, ArvPixelFormat *pixel_format,
                                                          guint32 *width, guint32 *height, guint32 *bytes_per_line);
 int             arv_v4l2_device_get_fd                  (ArvV4l2Device *v4l2_device);
 

src/arvv4l2interface.c

@@ -29,7 +29,7 @@
 #include <arvv4l2deviceprivate.h>
 #include <arvinterfaceprivate.h>
 #include <arvv4l2device.h>
-#include <arvdebug.h>
+#include <arvdebugprivate.h>
 #include <gudev/gudev.h>
 #include <libv4l2.h>
 #include <linux/videodev2.h>
@@ -75,22 +75,46 @@ arv_v4l2_interface_device_infos_new (const char *device_file, const char *name)
 			if (v4l2_ioctl (fd, VIDIOC_QUERYCAP, &cap) != -1 &&
 			    ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) != 0) &&
 			    ((cap.capabilities & V4L2_CAP_STREAMING) != 0)) {
-				infos = g_new0 (ArvV4l2InterfaceDeviceInfos, 1);
-
-				infos->ref_count = 1;
-				infos->id = g_strdup_printf ("%s-%s", (char *) cap.card, name);
-				infos->bus = g_strdup ((char *) cap.bus_info);
-				infos->device_file = g_strdup (device_file);
-				infos->version = g_strdup_printf ("%d.%d.%d",
-								  (cap.version >> 16) & 0xff,
-								  (cap.version >>  8) & 0xff,
-								  (cap.version >>  0) & 0xff);
-
-				return infos;
-			}
-			v4l2_close (fd);
-		}
-	}
+                                unsigned int i;
+                                gboolean found = FALSE;
+
+                                for (i = 0; TRUE; i++) {
+                                        struct v4l2_fmtdesc format = {0};
+
+                                        format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+                                        format.index = i;
+                                        if (v4l2_ioctl(fd, VIDIOC_ENUM_FMT, &format) == -1)
+                                                break;
+
+                                        if (arv_pixel_format_from_v4l2(format.pixelformat) != 0) {
+                                                found = TRUE;
+                                                break;
+                                        }
+                                }
+
+                                if (found) {
+                                        infos = g_new0 (ArvV4l2InterfaceDeviceInfos, 1);
+
+                                        infos->ref_count = 1;
+                                        infos->id = g_strdup_printf ("%s-%s", (char *) cap.card, name);
+                                        infos->bus = g_strdup ((char *) cap.bus_info);
+                                        infos->device_file = g_strdup (device_file);
+                                        infos->version = g_strdup_printf ("%d.%d.%d",
+                                                                          (cap.version >> 16) & 0xff,
+                                                                          (cap.version >>  8) & 0xff,
+                                                                          (cap.version >>  0) & 0xff);
+
+                                        v4l2_close (fd);
+
+                                        return infos;
+                                }
+
+                                arv_warning_interface ("No suitable pixel format found for v4l2 device '%s'",
+                                                       device_file);
+                        }
+                        v4l2_close (fd);
+                }
+        }
 
 	return NULL;
 }