ahc2src: implement ev_compensation

Signed-off-by: Justin Kim <justin.kim@collabora.com>

sys/androidmedia/gstahc2src.c

@@ -24,6 +24,7 @@
 
 #include "gstahc2src.h"
 
+#include <math.h>
 #include <stdbool.h>
 #include <gst/base/base.h>
 #include <gst/video/video.h>
@@ -214,6 +215,123 @@ gst_ahc2_src_get_capabilities (GstPhotography * photo)
   return caps;
 }
 
+static gboolean
+gst_ahc2_src_get_ev_compensation (GstPhotography * photo, gfloat * ev_comp)
+{
+  GstAHC2Src *self = GST_AHC2_SRC (photo);
+  GstAHC2SrcPrivate *priv = GST_AHC2_SRC_GET_PRIVATE (self);
+
+  ACameraMetadata* metadata = NULL;
+  ACameraMetadata_const_entry entry;
+  gint ev;
+  ACameraMetadata_rational ev_step;
+  gboolean ret = FALSE;
+
+  g_return_val_if_fail (priv->camera_manager != NULL, FALSE);
+  g_return_val_if_fail (priv->camera_id_list != NULL, FALSE);
+  g_return_val_if_fail (priv->camera_index < priv->camera_id_list->numCameras,
+      FALSE);
+  g_return_val_if_fail (priv->capture_request != NULL, FALSE);
+
+  if (ACameraManager_getCameraCharacteristics (priv->camera_manager,
+      priv->camera_id_list->cameraIds[priv->camera_index],
+      &metadata) != ACAMERA_OK) {
+    GST_ERROR_OBJECT (self, "Failed to get metadata object");
+    goto out;
+  }
+
+  if (ACameraMetadata_getConstEntry (metadata,
+      ACAMERA_CONTROL_AE_COMPENSATION_STEP, &entry) != ACAMERA_OK) {
+    GST_WARNING_OBJECT (self, "Failed to get EV STEP");
+    goto out;
+  }
+
+  ev_step = entry.data.r[0];
+ 
+  if (ACaptureRequest_getConstEntry (priv->capture_request,
+      ACAMERA_CONTROL_AE_EXPOSURE_COMPENSATION, &entry) != ACAMERA_OK) {
+    GST_WARNING_OBJECT (self, "Failed to get EV COMPENSATION");
+    goto out;
+  }
+
+  ev = entry.data.i32[0];
+
+  *ev_comp = (gfloat) (ev * ev_step.numerator / ev_step.denominator);
+
+  ret = TRUE;
+out:
+  g_clear_pointer (&metadata, (GDestroyNotify) ACameraMetadata_free);
+  return ret;
+}
+
+static gboolean
+gst_ahc2_src_set_ev_compensation (GstPhotography * photo, gfloat ev_comp)
+{
+  GstAHC2Src *self = GST_AHC2_SRC (photo);
+  GstAHC2SrcPrivate *priv = GST_AHC2_SRC_GET_PRIVATE (self);
+
+  ACameraMetadata* metadata = NULL;
+  ACameraMetadata_const_entry entry;
+  gint ev, ev_min, ev_max;
+  ACameraMetadata_rational ev_step;
+  gboolean ret = FALSE;
+
+  g_return_val_if_fail (priv->camera_manager != NULL, FALSE);
+  g_return_val_if_fail (priv->camera_id_list != NULL, FALSE);
+  g_return_val_if_fail (priv->camera_index < priv->camera_id_list->numCameras,
+      FALSE);
+  g_return_val_if_fail (priv->capture_request != NULL, FALSE);
+
+  if (ACameraManager_getCameraCharacteristics (priv->camera_manager,
+      priv->camera_id_list->cameraIds[priv->camera_index],
+      &metadata) != ACAMERA_OK) {
+    GST_ERROR_OBJECT (self, "Failed to get metadata object");
+    goto out;
+  }
+
+  if (ACameraMetadata_getConstEntry (metadata,
+      ACAMERA_CONTROL_AE_COMPENSATION_STEP, &entry) != ACAMERA_OK) {
+    GST_WARNING_OBJECT (self, "Failed to get EV STEP");
+    goto out;
+  }
+
+  ev_step = entry.data.r[0];
+
+  if (ACameraMetadata_getConstEntry (metadata,
+      ACAMERA_CONTROL_AE_COMPENSATION_RANGE, &entry) != ACAMERA_OK) {
+    GST_WARNING_OBJECT (self, "Failed to get EV RANGE");
+    goto out;
+  }
+
+  ev_min = entry.data.i32[0];
+  ev_max = entry.data.i32[1];
+
+  ev = (gint) round (ev_comp / ev_step.numerator * ev_step.denominator);
+
+  if (ev < ev_min) {
+    GST_WARNING_OBJECT (self, "converted EV(%d) is less than min(%d)", ev, ev_min);
+    ev = ev_min;
+  }
+
+  if (ev > ev_max) {
+    GST_WARNING_OBJECT (self, "converted EV(%d) is greater than max(%d)", ev, ev_max);
+    ev = ev_max;
+  }
+
+  ACameraCaptureSession_stopRepeating (priv->camera_capture_session);
+
+  ACaptureRequest_setEntry_i32 (priv->capture_request,
+      ACAMERA_CONTROL_AE_EXPOSURE_COMPENSATION, 1, &ev);
+
+  ACameraCaptureSession_setRepeatingRequest (priv->camera_capture_session,
+    NULL, 1, &priv->capture_request, NULL);
+
+  ret = TRUE;
+out:
+  g_clear_pointer (&metadata, (GDestroyNotify) ACameraMetadata_free);
+  return ret;
+}
+
 static gboolean
 gst_ahc2_src_get_white_balance_mode (GstPhotography * photo,
     GstPhotographyWhiteBalanceMode * mode)
@@ -747,6 +865,11 @@ gst_ahc2_src_set_property (GObject * object,
     case PROP_MAX_IMAGES:
       priv->max_images = g_value_get_int (value);
       break;
+    case PROP_EV_COMPENSATION: {
+      gfloat ev = g_value_get_float (value);
+      gst_ahc2_src_set_ev_compensation (GST_PHOTOGRAPHY (self), ev);
+      break;
+    }
     case PROP_WHITE_BALANCE_MODE: {
       GstPhotographyWhiteBalanceMode wb = g_value_get_enum (value);
       gst_ahc2_src_set_white_balance_mode (GST_PHOTOGRAPHY (self), wb);
@@ -783,6 +906,14 @@ gst_ahc2_src_get_property (GObject * object,
 
       break;
     }
+    case PROP_EV_COMPENSATION: {
+      gfloat ev;
+
+      if (gst_ahc2_src_get_ev_compensation (GST_PHOTOGRAPHY (self), &ev))
+        g_value_set_float (value, ev);
+
+      break;
+    }
     case PROP_WHITE_BALANCE_MODE: {
       GstPhotographyWhiteBalanceMode wb;
       if (gst_ahc2_src_get_white_balance_mode (GST_PHOTOGRAPHY (self), &wb))
@@ -1244,6 +1375,9 @@ gst_ahc2_src_photography_init (gpointer g_iface, gpointer iface_data)
 
   iface->get_white_balance_mode = gst_ahc2_src_get_white_balance_mode;
   iface->set_white_balance_mode = gst_ahc2_src_set_white_balance_mode;
+
+  iface->get_ev_compensation = gst_ahc2_src_get_ev_compensation;
+  iface->set_ev_compensation = gst_ahc2_src_set_ev_compensation;
 }
 
 static gboolean