[cheese] Enable cameras with only MJPEG output

[David King <davidk src gnome org>]

commit 5587daca748e9010f59250c5dcb8e8ea42266685
Author: Xℹ Ruoyao <xry111 mengyan1223 wang>
Date:   Mon Jan 6 20:16:37 2020 +0800

    Enable cameras with only MJPEG output
    
    This enables cameras like Sunplus Technology 1.3M Camera with vendor ID
    04fc and device ID 2802, which only outputs through image/jpeg and
    doesn't support raw output.

 libcheese/cheese-camera-device-monitor.c |  2 +-
 libcheese/cheese-camera-device.c         | 39 +++++++++++++++++++++++---------
 libcheese/cheese-camera-device.h         |  2 ++
 3 files changed, 31 insertions(+), 12 deletions(-)
---
diff --git a/libcheese/cheese-camera-device-monitor.c b/libcheese/cheese-camera-device-monitor.c
index 19f4ff0b..87c48ccb 100644
--- a/libcheese/cheese-camera-device-monitor.c
+++ b/libcheese/cheese-camera-device-monitor.c
@@ -296,7 +296,7 @@ initable_init (GInitable     *initable,
   gst_bus_add_watch (bus, cheese_camera_device_monitor_bus_func, monitor);
   gst_object_unref (bus);
 
-  caps = gst_caps_new_empty_simple ("video/x-raw");
+  caps = cheese_camera_device_supported_format_caps ();
   gst_device_monitor_add_filter (priv->monitor, "Video/Source", caps);
   gst_caps_unref (caps);
 
diff --git a/libcheese/cheese-camera-device.c b/libcheese/cheese-camera-device.c
index efcb0459..c6cc39ef 100644
--- a/libcheese/cheese-camera-device.c
+++ b/libcheese/cheese-camera-device.c
@@ -163,6 +163,27 @@ compare_formats (gconstpointer a, gconstpointer b)
   return (d->width * d->height - c->width * c->height);
 }
 
+static GstCaps *
+format_caps (const gchar * const formats[])
+{
+    GstCaps *filter;
+    gsize i;
+
+    filter = gst_caps_new_empty ();
+
+    for (i = 0; formats[i] != NULL; i++)
+    {
+        gst_caps_append (filter,
+                         gst_caps_new_simple (formats[i],
+                                              "framerate",
+                                              GST_TYPE_FRACTION_RANGE,
+                                              0, 1, CHEESE_MAXIMUM_RATE, 1,
+                                              NULL));
+    }
+
+    return filter;
+}
+
 /*
  * cheese_camera_device_filter_caps:
  * @device: the #CheeseCameraDevice
@@ -182,18 +203,8 @@ cheese_camera_device_filter_caps (CheeseCameraDevice *device,
 {
   GstCaps *filter;
   GstCaps *allowed;
-  gsize i;
-
-  filter = gst_caps_new_empty ();
 
-  for (i = 0; formats[i] != NULL; i++)
-  {
-    gst_caps_append (filter,
-                     gst_caps_new_simple (formats[i],
-                                          "framerate", GST_TYPE_FRACTION_RANGE,
-                                          0, 1, CHEESE_MAXIMUM_RATE, 1,
-                                          NULL));
-  }
+    filter = format_caps (formats);
 
   allowed = gst_caps_intersect (caps, filter);
 
@@ -935,3 +946,9 @@ cheese_camera_device_get_caps_for_format (CheeseCameraDevice *device,
 
     return result_caps;
 }
+
+GstCaps *
+cheese_camera_device_supported_format_caps (void)
+{
+    return format_caps (supported_formats);
+}
diff --git a/libcheese/cheese-camera-device.h b/libcheese/cheese-camera-device.h
index 4f5d819f..5e6b3ca5 100644
--- a/libcheese/cheese-camera-device.h
+++ b/libcheese/cheese-camera-device.h
@@ -75,6 +75,8 @@ GList *            cheese_camera_device_get_format_list (CheeseCameraDevice *dev
 const gchar *cheese_camera_device_get_name (CheeseCameraDevice *device);
 GstElement * cheese_camera_device_get_src (CheeseCameraDevice *device);
 
+GstCaps * cheese_camera_device_supported_format_caps (void);
+
 G_END_DECLS
 
 #endif /* CHEESE_CAMERA_DEVICE_H_ */