1 /*
2  *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef WEBRTC_MODULES_VIDEO_PROCESSING_DEFLICKERING_H_
12 #define WEBRTC_MODULES_VIDEO_PROCESSING_DEFLICKERING_H_
13 
14 #include <string.h>  // NULL
15 
16 #include "webrtc/modules/video_processing/include/video_processing.h"
17 #include "webrtc/typedefs.h"
18 
19 namespace webrtc {
20 
21 class VPMDeflickering {
22  public:
23   VPMDeflickering();
24   ~VPMDeflickering();
25 
26   void Reset();
27   int32_t ProcessFrame(VideoFrame* frame, VideoProcessing::FrameStats* stats);
28 
29  private:
30   int32_t PreDetection(uint32_t timestamp,
31                        const VideoProcessing::FrameStats& stats);
32 
33   int32_t DetectFlicker();
34 
35   enum { kMeanBufferLength = 32 };
36   enum { kFrameHistory_size = 15 };
37   enum { kNumProbs = 12 };
38   enum { kNumQuants = kNumProbs + 2 };
39   enum { kMaxOnlyLength = 5 };
40 
41   uint32_t mean_buffer_length_;
42   uint8_t detection_state_;  // 0: No flickering
43                              // 1: Flickering detected
44                              // 2: In flickering
45   int32_t mean_buffer_[kMeanBufferLength];
46   uint32_t timestamp_buffer_[kMeanBufferLength];
47   uint32_t frame_rate_;
48   static const uint16_t prob_uw16_[kNumProbs];
49   static const uint16_t weight_uw16_[kNumQuants - kMaxOnlyLength];
50   uint8_t quant_hist_uw8_[kFrameHistory_size][kNumQuants];
51 };
52 
53 }  // namespace webrtc
54 
55 #endif  // WEBRTC_MODULES_VIDEO_PROCESSING_DEFLICKERING_H_
56