diff options
Diffstat (limited to 'webrtc/modules/video_coding/utility/frame_dropper.cc')
| -rw-r--r-- | webrtc/modules/video_coding/utility/frame_dropper.cc | 529 |
1 files changed, 227 insertions, 302 deletions
diff --git a/webrtc/modules/video_coding/utility/frame_dropper.cc b/webrtc/modules/video_coding/utility/frame_dropper.cc index 5262c5b88a..a0aa67be4e 100644 --- a/webrtc/modules/video_coding/utility/frame_dropper.cc +++ b/webrtc/modules/video_coding/utility/frame_dropper.cc @@ -8,12 +8,11 @@ * be found in the AUTHORS file in the root of the source tree. */ -#include "webrtc/modules/video_coding/utility/include/frame_dropper.h" +#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; @@ -22,339 +21,266 @@ 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(); + : _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::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::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); - } +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; } - else - { - // Decrease the keyFrameRatio - _keyFrameRatio.Apply(1.0, 0.0); + 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); } - // Change the level of the accumulator (bucket) - _accumulator += frameSizeKbits; - CapAccumulator(); + } 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; +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; } - UpdateRatio(); + _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::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::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); +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; } - else - { - // Go back to normal reaction - _dropRatio.UpdateBase(0.9f); + if (_fastMode) { + // always drop in aggressive mode + _dropNext = true; } - 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; + _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 +// 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; +bool FrameDropper::DropFrame() { + if (!_enabled) { + 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 = 1e-5f; + } + 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 (_dropNext) - { - _dropNext = false; + 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 (_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; - } + 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; - } + } 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-5f; } - _dropCount = 0; - return false; + 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; + // 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; +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()); +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. @@ -366,5 +292,4 @@ void FrameDropper::CapAccumulator() { _accumulator = max_accumulator; } } - -} +} // namespace webrtc |