1 files changed, 136 insertions, 0 deletions
diff --git a/webrtc/modules/video_processing/brightness_detection.cc b/webrtc/modules/video_processing/brightness_detection.cc
new file mode 100644
index 0000000000..7455cf9759
--- /dev/null
+++ b/webrtc/modules/video_processing/brightness_detection.cc
@@ -0,0 +1,136 @@
+/*
+ *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/modules/video_processing/brightness_detection.h"
+
+#include <math.h>
+
+#include "webrtc/modules/video_processing/include/video_processing.h"
+
+namespace webrtc {
+
+VPMBrightnessDetection::VPMBrightnessDetection() {
+  Reset();
+}
+
+VPMBrightnessDetection::~VPMBrightnessDetection() {}
+
+void VPMBrightnessDetection::Reset() {
+  frame_cnt_bright_ = 0;
+  frame_cnt_dark_ = 0;
+}
+
+int32_t VPMBrightnessDetection::ProcessFrame(
+    const VideoFrame& frame,
+    const VideoProcessing::FrameStats& stats) {
+  if (frame.IsZeroSize()) {
+    return VPM_PARAMETER_ERROR;
+  }
+  int width = frame.width();
+  int height = frame.height();
+
+  if (!VideoProcessing::ValidFrameStats(stats)) {
+    return VPM_PARAMETER_ERROR;
+  }
+
+  const uint8_t frame_cnt_alarm = 2;
+
+  // Get proportion in lowest bins.
+  uint8_t low_th = 20;
+  float prop_low = 0;
+  for (uint32_t i = 0; i < low_th; i++) {
+    prop_low += stats.hist[i];
+  }
+  prop_low /= stats.num_pixels;
+
+  // Get proportion in highest bins.
+  unsigned char high_th = 230;
+  float prop_high = 0;
+  for (uint32_t i = high_th; i < 256; i++) {
+    prop_high += stats.hist[i];
+  }
+  prop_high /= stats.num_pixels;
+
+  if (prop_high < 0.4) {
+    if (stats.mean < 90 || stats.mean > 170) {
+      // Standard deviation of Y
+      const uint8_t* buffer = frame.buffer(kYPlane);
+      float std_y = 0;
+      for (int h = 0; h < height; h += (1 << stats.sub_sampling_factor)) {
+        int row = h * width;
+        for (int w = 0; w < width; w += (1 << stats.sub_sampling_factor)) {
+          std_y +=
+              (buffer[w + row] - stats.mean) * (buffer[w + row] - stats.mean);
+        }
+      }
+      std_y = sqrt(std_y / stats.num_pixels);
+
+      // Get percentiles.
+      uint32_t sum = 0;
+      uint32_t median_y = 140;
+      uint32_t perc05 = 0;
+      uint32_t perc95 = 255;
+      float pos_perc05 = stats.num_pixels * 0.05f;
+      float pos_median = stats.num_pixels * 0.5f;
+      float posPerc95 = stats.num_pixels * 0.95f;
+      for (uint32_t i = 0; i < 256; i++) {
+        sum += stats.hist[i];
+        if (sum < pos_perc05)
+          perc05 = i;  // 5th perc.
+        if (sum < pos_median)
+          median_y = i;  // 50th perc.
+        if (sum < posPerc95)
+          perc95 = i;  // 95th perc.
+        else
+          break;
+      }
+
+      // Check if image is too dark
+      if ((std_y < 55) && (perc05 < 50)) {
+        if (median_y < 60 || stats.mean < 80 || perc95 < 130 ||
+            prop_low > 0.20) {
+          frame_cnt_dark_++;
+        } else {
+          frame_cnt_dark_ = 0;
+        }
+      } else {
+        frame_cnt_dark_ = 0;
+      }
+
+      // Check if image is too bright
+      if ((std_y < 52) && (perc95 > 200) && (median_y > 160)) {
+        if (median_y > 185 || stats.mean > 185 || perc05 > 140 ||
+            prop_high > 0.25) {
+          frame_cnt_bright_++;
+        } else {
+          frame_cnt_bright_ = 0;
+        }
+      } else {
+        frame_cnt_bright_ = 0;
+      }
+    } else {
+      frame_cnt_dark_ = 0;
+      frame_cnt_bright_ = 0;
+    }
+  } else {
+    frame_cnt_bright_++;
+    frame_cnt_dark_ = 0;
+  }
+
+  if (frame_cnt_dark_ > frame_cnt_alarm) {
+    return VideoProcessing::kDarkWarning;
+  } else if (frame_cnt_bright_ > frame_cnt_alarm) {
+    return VideoProcessing::kBrightWarning;
+  } else {
+    return VideoProcessing::kNoWarning;
+  }
+}
+
+}  // namespace webrtc