[cheese/wip/hans-fixes: 14/35] cheese-camera-device: Make get_best_format smarter

[David King <davidk src gnome org>]

commit eaa2c2c545c7bc63d8f871f4bf6cd01e9408b902
Author: Hans de Goede <hdegoede redhat com>
Date:   Thu Jun 13 11:07:37 2013 +0200

    cheese-camera-device: Make get_best_format smarter
    
    If we've a device which can do 1600x900 at 10 fps and 1280x800 @ 25 fps,
    then 1600x900 is not really the best format, as 10 fps leads to a bad
    user experience.
    
    So this patch makes get_best_format return the highest resolution at which
    the device can do atleast 15 fps.
    
    Since some (older) cameras may have something like 640x480 @ 10 fps and
    320x240 @ 30 fps as modes, there is an additional check that the mode
    must also have a width of at least 640 pixels.
    
    If no mode matching the widh >= 640 && frame_rate >= 15 criteria is found,
    get_best_format will behave as before as simply return the highest resolution
    mode.
    
    Signed-off-by: Hans de Goede <hdegoede redhat com>

 libcheese/cheese-camera-device.c |   24 ++++++++++++++++++++----
 1 files changed, 20 insertions(+), 4 deletions(-)
---
diff --git a/libcheese/cheese-camera-device.c b/libcheese/cheese-camera-device.c
index c23069d..402bbb8 100644
--- a/libcheese/cheese-camera-device.c
+++ b/libcheese/cheese-camera-device.c
@@ -935,14 +935,30 @@ cheese_camera_device_get_device_node (CheeseCameraDevice *device)
 CheeseVideoFormat *
 cheese_camera_device_get_best_format (CheeseCameraDevice *device)
 {
-  CheeseVideoFormat *format;
+  CheeseVideoFormatFull *format = NULL;
+  GList *l;
 
   g_return_val_if_fail (CHEESE_IS_CAMERA_DEVICE (device), NULL);
 
-  format = g_boxed_copy (CHEESE_TYPE_VIDEO_FORMAT, device->priv->formats->data);
+  /* First check for the highest res with width >= 640 and fps >= 15 */
+  for (l = device->priv->formats; l != NULL; l = l->next)
+  {
+    CheeseVideoFormatFull *item = l->data;
+    float frame_rate = (float)item->fr_numerator / (float)item->fr_denominator;
+    if (item->width >= 640 && frame_rate >= 15)
+    {
+      format = item;
+      break;
+    }
+  }
+  /* Else simply return the highest res */
+  if (!format)
+    format = device->priv->formats->data;
+
+  GST_INFO ("%dx%d %d/%d", format->width, format->height,
+            format->fr_numerator, format->fr_denominator);
 
-  GST_INFO ("%dx%d", format->width, format->height);
-  return format;
+  return g_boxed_copy (CHEESE_TYPE_VIDEO_FORMAT, format);;
 }
 
 /**