| // Copyright 2019 The Cobalt Authors. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "starboard/shared/starboard/player/filter/video_frame_cadence_pattern_generator.h" |
| |
| #include "starboard/common/log.h" |
| |
| namespace starboard { |
| namespace shared { |
| namespace starboard { |
| namespace player { |
| namespace filter { |
| |
| void VideoFrameCadencePatternGenerator::UpdateRefreshRateAndMaybeReset( |
| double refresh_rate) { |
| SB_DCHECK(refresh_rate > 0); |
| |
| if (refresh_rate == refresh_rate_) { |
| return; |
| } |
| |
| SB_LOG(WARNING) << "Refresh rate updated from " << refresh_rate_ << " to " |
| << refresh_rate; |
| |
| refresh_rate_ = refresh_rate; |
| frame_index_ = 0; |
| } |
| |
| void VideoFrameCadencePatternGenerator::UpdateFrameRate(double frame_rate) { |
| SB_DCHECK(frame_rate > 0); |
| |
| frame_rate_ = frame_rate; |
| } |
| |
| int VideoFrameCadencePatternGenerator::GetNumberOfTimesCurrentFrameDisplays() |
| const { |
| SB_DCHECK(refresh_rate_ != kInvalidRefreshRate); |
| SB_DCHECK(frame_rate_ != kInvalidFrameRate); |
| |
| int current_frame_display_times = 0; |
| |
| auto current_frame_time = frame_index_ / frame_rate_; |
| auto next_frame_time = (frame_index_ + 1) / frame_rate_; |
| |
| int refresh_ticks = |
| static_cast<int>(current_frame_time - 1 / refresh_rate_) * refresh_rate_; |
| |
| // The following loop should be able to terminate by itself without any |
| // constraints on the maximum iterations it can run. However, set a max |
| // number of iteration just in case, to avoid it loops infinitely. |
| const int kMaxFrameDisplayTimes = 120; |
| for (int i = 0; i < kMaxFrameDisplayTimes; ++i) { |
| double refresh_time = refresh_ticks / refresh_rate_; |
| if (refresh_time >= next_frame_time) { |
| break; |
| } |
| if (refresh_time >= current_frame_time) { |
| ++current_frame_display_times; |
| } |
| ++refresh_ticks; |
| } |
| |
| return current_frame_display_times; |
| } |
| |
| void VideoFrameCadencePatternGenerator::AdvanceToNextFrame() { |
| SB_DCHECK(refresh_rate_ != kInvalidRefreshRate); |
| SB_DCHECK(frame_rate_ != kInvalidFrameRate); |
| |
| ++frame_index_; |
| } |
| |
| void VideoFrameCadencePatternGenerator::Reset(double refresh_rate) { |
| SB_DCHECK(refresh_rate > 0); |
| |
| refresh_rate_ = refresh_rate; |
| frame_rate_ = kInvalidFrameRate; |
| frame_index_ = 0; |
| } |
| |
| } // namespace filter |
| } // namespace player |
| } // namespace starboard |
| } // namespace shared |
| } // namespace starboard |