Lint enabled for webrtc/modules/video_coding folder.

webrtc/modules/video_coding/utility/frame_dropper.cc

 /*
  *  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_coding/utility/frame_dropper.h"
 
 #include "webrtc/system_wrappers/include/trace.h"
 
-namespace webrtc
-{
+namespace webrtc {
 
 const float kDefaultKeyFrameSizeAvgKBits = 0.9f;
 const float kDefaultKeyFrameRatio = 0.99f;
 const float kDefaultDropRatioAlpha = 0.9f;
 const float kDefaultDropRatioMax = 0.96f;
 const float kDefaultMaxTimeToDropFrames = 4.0f;  // In seconds.
 
 FrameDropper::FrameDropper()
-:
-_keyFrameSizeAvgKbits(kDefaultKeyFrameSizeAvgKBits),
-_keyFrameRatio(kDefaultKeyFrameRatio),
-_dropRatio(kDefaultDropRatioAlpha, kDefaultDropRatioMax),
-_enabled(true),
-_max_time_drops(kDefaultMaxTimeToDropFrames)
-{
-    Reset();
+    : _keyFrameSizeAvgKbits(kDefaultKeyFrameSizeAvgKBits),
+      _keyFrameRatio(kDefaultKeyFrameRatio),
+      _dropRatio(kDefaultDropRatioAlpha, kDefaultDropRatioMax),
+      _enabled(true),
+      _max_time_drops(kDefaultMaxTimeToDropFrames) {
+  Reset();
 }
 
 FrameDropper::FrameDropper(float max_time_drops)
-:
-_keyFrameSizeAvgKbits(kDefaultKeyFrameSizeAvgKBits),
-_keyFrameRatio(kDefaultKeyFrameRatio),
-_dropRatio(kDefaultDropRatioAlpha, kDefaultDropRatioMax),
-_enabled(true),
-_max_time_drops(max_time_drops)
-{
-    Reset();
-}
-
-void
-FrameDropper::Reset()
-{
-    _keyFrameRatio.Reset(0.99f);
-    _keyFrameRatio.Apply(1.0f, 1.0f/300.0f); // 1 key frame every 10th second in 30 fps
-    _keyFrameSizeAvgKbits.Reset(0.9f);
-    _keyFrameCount = 0;
+    : _keyFrameSizeAvgKbits(kDefaultKeyFrameSizeAvgKBits),
+      _keyFrameRatio(kDefaultKeyFrameRatio),
+      _dropRatio(kDefaultDropRatioAlpha, kDefaultDropRatioMax),
+      _enabled(true),
+      _max_time_drops(max_time_drops) {
+  Reset();
+}
+
+void FrameDropper::Reset() {
+  _keyFrameRatio.Reset(0.99f);
+  _keyFrameRatio.Apply(
+      1.0f, 1.0f / 300.0f);  // 1 key frame every 10th second in 30 fps
+  _keyFrameSizeAvgKbits.Reset(0.9f);
+  _keyFrameCount = 0;
+  _accumulator = 0.0f;
+  _accumulatorMax = 150.0f;  // assume 300 kb/s and 0.5 s window
+  _targetBitRate = 300.0f;
+  _incoming_frame_rate = 30;
+  _keyFrameSpreadFrames = 0.5f * _incoming_frame_rate;
+  _dropNext = false;
+  _dropRatio.Reset(0.9f);
+  _dropRatio.Apply(0.0f, 0.0f);  // Initialize to 0
+  _dropCount = 0;
+  _windowSize = 0.5f;
+  _wasBelowMax = true;
+  _fastMode = false;  // start with normal (non-aggressive) mode
+  // Cap for the encoder buffer level/accumulator, in secs.
+  _cap_buffer_size = 3.0f;
+  // Cap on maximum amount of dropped frames between kept frames, in secs.
+  _max_time_drops = 4.0f;
+}
+
+void FrameDropper::Enable(bool enable) {
+  _enabled = enable;
+}
+
+void FrameDropper::Fill(size_t frameSizeBytes, bool deltaFrame) {
+  if (!_enabled) {
+    return;
+  }
+  float frameSizeKbits = 8.0f * static_cast<float>(frameSizeBytes) / 1000.0f;
+  if (!deltaFrame &&
+      !_fastMode) {  // fast mode does not treat key-frames any different
+    _keyFrameSizeAvgKbits.Apply(1, frameSizeKbits);
+    _keyFrameRatio.Apply(1.0, 1.0);
+    if (frameSizeKbits > _keyFrameSizeAvgKbits.filtered()) {
+      // Remove the average key frame size since we
+      // compensate for key frames when adding delta
+      // frames.
+      frameSizeKbits -= _keyFrameSizeAvgKbits.filtered();
+    } else {
+      // Shouldn't be negative, so zero is the lower bound.
+      frameSizeKbits = 0;
+    }
+    if (_keyFrameRatio.filtered() > 1e-5 &&
+        1 / _keyFrameRatio.filtered() < _keyFrameSpreadFrames) {
+      // We are sending key frames more often than our upper bound for
+      // how much we allow the key frame compensation to be spread
+      // out in time. Therefor we must use the key frame ratio rather
+      // than keyFrameSpreadFrames.
+      _keyFrameCount =
+          static_cast<int32_t>(1 / _keyFrameRatio.filtered() + 0.5);
+    } else {
+      // Compensate for the key frame the following frames
+      _keyFrameCount = static_cast<int32_t>(_keyFrameSpreadFrames + 0.5);
+    }
+  } else {
+    // Decrease the keyFrameRatio
+    _keyFrameRatio.Apply(1.0, 0.0);
+  }
+  // Change the level of the accumulator (bucket)
+  _accumulator += frameSizeKbits;
+  CapAccumulator();
+}
+
+void FrameDropper::Leak(uint32_t inputFrameRate) {
+  if (!_enabled) {
+    return;
+  }
+  if (inputFrameRate < 1) {
+    return;
+  }
+  if (_targetBitRate < 0.0f) {
+    return;
+  }
+  _keyFrameSpreadFrames = 0.5f * inputFrameRate;
+  // T is the expected bits per frame (target). If all frames were the same
+  // size,
+  // we would get T bits per frame. Notice that T is also weighted to be able to
+  // force a lower frame rate if wanted.
+  float T = _targetBitRate / inputFrameRate;
+  if (_keyFrameCount > 0) {
+    // Perform the key frame compensation
+    if (_keyFrameRatio.filtered() > 0 &&
+        1 / _keyFrameRatio.filtered() < _keyFrameSpreadFrames) {
+      T -= _keyFrameSizeAvgKbits.filtered() * _keyFrameRatio.filtered();
+    } else {
+      T -= _keyFrameSizeAvgKbits.filtered() / _keyFrameSpreadFrames;
+    }
+    _keyFrameCount--;
+  }
+  _accumulator -= T;
+  if (_accumulator < 0.0f) {
     _accumulator = 0.0f;
-    _accumulatorMax = 150.0f; // assume 300 kb/s and 0.5 s window
-    _targetBitRate = 300.0f;
-    _incoming_frame_rate = 30;
-    _keyFrameSpreadFrames = 0.5f * _incoming_frame_rate;
+  }
+  UpdateRatio();
+}
+
+void FrameDropper::UpdateNack(uint32_t nackBytes) {
+  if (!_enabled) {
+    return;
+  }
+  _accumulator += static_cast<float>(nackBytes) * 8.0f / 1000.0f;
+}
+
+void FrameDropper::FillBucket(float inKbits, float outKbits) {
+  _accumulator += (inKbits - outKbits);
+}
+
+void FrameDropper::UpdateRatio() {
+  if (_accumulator > 1.3f * _accumulatorMax) {
+    // Too far above accumulator max, react faster
+    _dropRatio.UpdateBase(0.8f);
+  } else {
+    // Go back to normal reaction
+    _dropRatio.UpdateBase(0.9f);
+  }
+  if (_accumulator > _accumulatorMax) {
+    // We are above accumulator max, and should ideally
+    // drop a frame. Increase the dropRatio and drop
+    // the frame later.
+    if (_wasBelowMax) {
+      _dropNext = true;
+    }
+    if (_fastMode) {
+      // always drop in aggressive mode
+      _dropNext = true;
+    }
+
+    _dropRatio.Apply(1.0f, 1.0f);
+    _dropRatio.UpdateBase(0.9f);
+  } else {
+    _dropRatio.Apply(1.0f, 0.0f);
+  }
+  _wasBelowMax = _accumulator < _accumulatorMax;
+}
+
+// This function signals when to drop frames to the caller. It makes use of the
+// dropRatio
+// to smooth out the drops over time.
+bool FrameDropper::DropFrame() {
+  if (!_enabled) {
+    return false;
+  }
+  if (_dropNext) {
     _dropNext = false;
-    _dropRatio.Reset(0.9f);
-    _dropRatio.Apply(0.0f, 0.0f); // Initialize to 0
     _dropCount = 0;
-    _windowSize = 0.5f;
-    _wasBelowMax = true;
-    _fastMode = false; // start with normal (non-aggressive) mode
-    // Cap for the encoder buffer level/accumulator, in secs.
-    _cap_buffer_size = 3.0f;
-    // Cap on maximum amount of dropped frames between kept frames, in secs.
-    _max_time_drops = 4.0f;
-}
-
-void
-FrameDropper::Enable(bool enable)
-{
-    _enabled = enable;
-}
-
-void
-FrameDropper::Fill(size_t frameSizeBytes, bool deltaFrame)
-{
-    if (!_enabled)
-    {
-        return;
-    }
-    float frameSizeKbits = 8.0f * static_cast<float>(frameSizeBytes) / 1000.0f;
-    if (!deltaFrame && !_fastMode) // fast mode does not treat key-frames any different
-    {
-        _keyFrameSizeAvgKbits.Apply(1, frameSizeKbits);
-        _keyFrameRatio.Apply(1.0, 1.0);
-        if (frameSizeKbits > _keyFrameSizeAvgKbits.filtered())
-        {
-            // Remove the average key frame size since we
-            // compensate for key frames when adding delta
-            // frames.
-            frameSizeKbits -= _keyFrameSizeAvgKbits.filtered();
-        }
-        else
-        {
-            // Shouldn't be negative, so zero is the lower bound.
-            frameSizeKbits = 0;
-        }
-        if (_keyFrameRatio.filtered() > 1e-5 &&
-            1 / _keyFrameRatio.filtered() < _keyFrameSpreadFrames)
-        {
-            // We are sending key frames more often than our upper bound for
-            // how much we allow the key frame compensation to be spread
-            // out in time. Therefor we must use the key frame ratio rather
-            // than keyFrameSpreadFrames.
-            _keyFrameCount =
-                static_cast<int32_t>(1 / _keyFrameRatio.filtered() + 0.5);
-        }
-        else
-        {
-            // Compensate for the key frame the following frames
-            _keyFrameCount = static_cast<int32_t>(_keyFrameSpreadFrames + 0.5);
-        }
-    }
-    else
-    {
-        // Decrease the keyFrameRatio
-        _keyFrameRatio.Apply(1.0, 0.0);
-    }
-    // Change the level of the accumulator (bucket)
-    _accumulator += frameSizeKbits;
-    CapAccumulator();
-}
-
-void
-FrameDropper::Leak(uint32_t inputFrameRate)
-{
-    if (!_enabled)
-    {
-        return;
-    }
-    if (inputFrameRate < 1)
-    {
-        return;
-    }
-    if (_targetBitRate < 0.0f)
-    {
-        return;
-    }
-    _keyFrameSpreadFrames = 0.5f * inputFrameRate;
-    // T is the expected bits per frame (target). If all frames were the same size,
-    // we would get T bits per frame. Notice that T is also weighted to be able to
-    // force a lower frame rate if wanted.
-    float T = _targetBitRate / inputFrameRate;
-    if (_keyFrameCount > 0)
-    {
-        // Perform the key frame compensation
-        if (_keyFrameRatio.filtered() > 0 &&
-            1 / _keyFrameRatio.filtered() < _keyFrameSpreadFrames)
-        {
-            T -= _keyFrameSizeAvgKbits.filtered() * _keyFrameRatio.filtered();
-        }
-        else
-        {
-            T -= _keyFrameSizeAvgKbits.filtered() / _keyFrameSpreadFrames;
-        }
-        _keyFrameCount--;
-    }
-    _accumulator -= T;
-    if (_accumulator < 0.0f)
-    {
-        _accumulator = 0.0f;
-    }
-    UpdateRatio();
-}
-
-void
-FrameDropper::UpdateNack(uint32_t nackBytes)
-{
-    if (!_enabled)
-    {
-        return;
-    }
-    _accumulator += static_cast<float>(nackBytes) * 8.0f / 1000.0f;
-}
-
-void
-FrameDropper::FillBucket(float inKbits, float outKbits)
-{
-    _accumulator += (inKbits - outKbits);
-}
-
-void
-FrameDropper::UpdateRatio()
-{
-    if (_accumulator > 1.3f * _accumulatorMax)
-    {
-        // Too far above accumulator max, react faster
-        _dropRatio.UpdateBase(0.8f);
-    }
-    else
-    {
-        // Go back to normal reaction
-        _dropRatio.UpdateBase(0.9f);
-    }
-    if (_accumulator > _accumulatorMax)
-    {
-        // We are above accumulator max, and should ideally
-        // drop a frame. Increase the dropRatio and drop
-        // the frame later.
-        if (_wasBelowMax)
-        {
-            _dropNext = true;
-        }
-        if (_fastMode)
-        {
-            // always drop in aggressive mode
-            _dropNext = true;
-        }
-
-        _dropRatio.Apply(1.0f, 1.0f);
-        _dropRatio.UpdateBase(0.9f);
-    }
-    else
-    {
-        _dropRatio.Apply(1.0f, 0.0f);
-    }
-    _wasBelowMax = _accumulator < _accumulatorMax;
-}
-
-// This function signals when to drop frames to the caller. It makes use of the dropRatio
-// to smooth out the drops over time.
-bool
-FrameDropper::DropFrame()
-{
-    if (!_enabled)
-    {
+  }
+
+  if (_dropRatio.filtered() >= 0.5f) {  // Drops per keep
+    // limit is the number of frames we should drop between each kept frame
+    // to keep our drop ratio. limit is positive in this case.
+    float denom = 1.0f - _dropRatio.filtered();
+    if (denom < 1e-5) {
+      denom = 1e-5;
+    }
+    int32_t limit = static_cast<int32_t>(1.0f / denom - 1.0f + 0.5f);
+    // Put a bound on the max amount of dropped frames between each kept
+    // frame, in terms of frame rate and window size (secs).
+    int max_limit = static_cast<int>(_incoming_frame_rate * _max_time_drops);
+    if (limit > max_limit) {
+      limit = max_limit;
+    }
+    if (_dropCount < 0) {
+      // Reset the _dropCount since it was negative and should be positive.
+      if (_dropRatio.filtered() > 0.4f) {
+        _dropCount = -_dropCount;
+      } else {
+        _dropCount = 0;
+      }
+    }
+    if (_dropCount < limit) {
+      // As long we are below the limit we should drop frames.
+      _dropCount++;
+      return true;
+    } else {
+      // Only when we reset _dropCount a frame should be kept.
+      _dropCount = 0;
+      return false;
+    }
+  } else if (_dropRatio.filtered() > 0.0f &&
+             _dropRatio.filtered() < 0.5f) {  // Keeps per drop
+    // limit is the number of frames we should keep between each drop
+    // in order to keep the drop ratio. limit is negative in this case,
+    // and the _dropCount is also negative.
+    float denom = _dropRatio.filtered();
+    if (denom < 1e-5) {
+      denom = 1e-5;
+    }
+    int32_t limit = -static_cast<int32_t>(1.0f / denom - 1.0f + 0.5f);
+    if (_dropCount > 0) {
+      // Reset the _dropCount since we have a positive
+      // _dropCount, and it should be negative.
+      if (_dropRatio.filtered() < 0.6f) {
+        _dropCount = -_dropCount;
+      } else {
+        _dropCount = 0;
+      }
+    }
+    if (_dropCount > limit) {
+      if (_dropCount == 0) {
+        // Drop frames when we reset _dropCount.
+        _dropCount--;
+        return true;
+      } else {
+        // Keep frames as long as we haven't reached limit.
+        _dropCount--;
         return false;
-    }
-    if (_dropNext)
-    {
-        _dropNext = false;
-        _dropCount = 0;
-    }
-
-    if (_dropRatio.filtered() >= 0.5f) // Drops per keep
-    {
-        // limit is the number of frames we should drop between each kept frame
-        // to keep our drop ratio. limit is positive in this case.
-        float denom = 1.0f - _dropRatio.filtered();
-        if (denom < 1e-5)
-        {
-            denom = (float)1e-5;
-        }
-        int32_t limit = static_cast<int32_t>(1.0f / denom - 1.0f + 0.5f);
-        // Put a bound on the max amount of dropped frames between each kept
-        // frame, in terms of frame rate and window size (secs).
-        int max_limit = static_cast<int>(_incoming_frame_rate *
-                                         _max_time_drops);
-        if (limit > max_limit) {
-          limit = max_limit;
-        }
-        if (_dropCount < 0)
-        {
-            // Reset the _dropCount since it was negative and should be positive.
-            if (_dropRatio.filtered() > 0.4f)
-            {
-                _dropCount = -_dropCount;
-            }
-            else
-            {
-                _dropCount = 0;
-            }
-        }
-        if (_dropCount < limit)
-        {
-            // As long we are below the limit we should drop frames.
-            _dropCount++;
-            return true;
-        }
-        else
-        {
-            // Only when we reset _dropCount a frame should be kept.
-            _dropCount = 0;
-            return false;
-        }
-    }
-    else if (_dropRatio.filtered() > 0.0f &&
-        _dropRatio.filtered() < 0.5f) // Keeps per drop
-    {
-        // limit is the number of frames we should keep between each drop
-        // in order to keep the drop ratio. limit is negative in this case,
-        // and the _dropCount is also negative.
-        float denom = _dropRatio.filtered();
-        if (denom < 1e-5)
-        {
-            denom = (float)1e-5;
-        }
-        int32_t limit = -static_cast<int32_t>(1.0f / denom - 1.0f + 0.5f);
-        if (_dropCount > 0)
-        {
-            // Reset the _dropCount since we have a positive
-            // _dropCount, and it should be negative.
-            if (_dropRatio.filtered() < 0.6f)
-            {
-                _dropCount = -_dropCount;
-            }
-            else
-            {
-                _dropCount = 0;
-            }
-        }
-        if (_dropCount > limit)
-        {
-            if (_dropCount == 0)
-            {
-                // Drop frames when we reset _dropCount.
-                _dropCount--;
-                return true;
-            }
-            else
-            {
-                // Keep frames as long as we haven't reached limit.
-                _dropCount--;
-                return false;
-            }
-        }
-        else
-        {
-            _dropCount = 0;
-            return false;
-        }
-    }
-    _dropCount = 0;
-    return false;
-
-    // A simpler version, unfiltered and quicker
-    //bool dropNext = _dropNext;
-    //_dropNext = false;
-    //return dropNext;
-}
-
-void
-FrameDropper::SetRates(float bitRate, float incoming_frame_rate)
-{
-    // Bit rate of -1 means infinite bandwidth.
-    _accumulatorMax = bitRate * _windowSize; // bitRate * windowSize (in seconds)
-    if (_targetBitRate > 0.0f && bitRate < _targetBitRate && _accumulator > _accumulatorMax)
-    {
-        // Rescale the accumulator level if the accumulator max decreases
-        _accumulator = bitRate / _targetBitRate * _accumulator;
-    }
-    _targetBitRate = bitRate;
-    CapAccumulator();
-    _incoming_frame_rate = incoming_frame_rate;
-}
-
-float
-FrameDropper::ActualFrameRate(uint32_t inputFrameRate) const
-{
-    if (!_enabled)
-    {
-        return static_cast<float>(inputFrameRate);
-    }
-    return inputFrameRate * (1.0f - _dropRatio.filtered());
+      }
+    } else {
+      _dropCount = 0;
+      return false;
+    }
+  }
+  _dropCount = 0;
+  return false;
+
+  // A simpler version, unfiltered and quicker
+  // bool dropNext = _dropNext;
+  // _dropNext = false;
+  // return dropNext;
+}
+
+void FrameDropper::SetRates(float bitRate, float incoming_frame_rate) {
+  // Bit rate of -1 means infinite bandwidth.
+  _accumulatorMax = bitRate * _windowSize;  // bitRate * windowSize (in seconds)
+  if (_targetBitRate > 0.0f && bitRate < _targetBitRate &&
+      _accumulator > _accumulatorMax) {
+    // Rescale the accumulator level if the accumulator max decreases
+    _accumulator = bitRate / _targetBitRate * _accumulator;
+  }
+  _targetBitRate = bitRate;
+  CapAccumulator();
+  _incoming_frame_rate = incoming_frame_rate;
+}
+
+float FrameDropper::ActualFrameRate(uint32_t inputFrameRate) const {
+  if (!_enabled) {
+    return static_cast<float>(inputFrameRate);
+  }
+  return inputFrameRate * (1.0f - _dropRatio.filtered());
 }
 
 // Put a cap on the accumulator, i.e., don't let it grow beyond some level.
 // This is a temporary fix for screencasting where very large frames from
 // encoder will cause very slow response (too many frame drops).
 void FrameDropper::CapAccumulator() {
   float max_accumulator = _targetBitRate * _cap_buffer_size;
   if (_accumulator > max_accumulator) {
     _accumulator = max_accumulator;
   }
 }
-
-}
+}  // namespace webrtc