blob: ce8ab127124a628643fd8091c47bfea479769353 [file] [log] [blame]
/*
* Copyright (c) 2018 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 "modules/video_coding/utility/framerate_controller.h"
#include "rtc_base/checks.h"
namespace webrtc {
FramerateController::FramerateController(float target_framerate_fps)
: min_frame_interval_ms_(0), framerate_estimator_(1000.0, 1000.0) {
SetTargetRate(target_framerate_fps);
}
void FramerateController::SetTargetRate(float target_framerate_fps) {
if (target_framerate_fps_ != target_framerate_fps) {
framerate_estimator_.Reset();
if (last_timestamp_ms_) {
framerate_estimator_.Update(1, *last_timestamp_ms_);
}
const size_t target_frame_interval_ms = 1000 / target_framerate_fps;
target_framerate_fps_ = target_framerate_fps;
min_frame_interval_ms_ = 85 * target_frame_interval_ms / 100;
}
}
float FramerateController::GetTargetRate() {
return *target_framerate_fps_;
}
void FramerateController::Reset() {
framerate_estimator_.Reset();
last_timestamp_ms_.reset();
}
bool FramerateController::DropFrame(uint32_t timestamp_ms) const {
if (timestamp_ms < last_timestamp_ms_) {
// Timestamp jumps backward. We can't make adequate drop decision. Don't
// drop this frame. Stats will be reset in AddFrame().
return false;
}
if (Rate(timestamp_ms).value_or(*target_framerate_fps_) >
target_framerate_fps_) {
return true;
}
if (last_timestamp_ms_) {
const int64_t diff_ms =
static_cast<int64_t>(timestamp_ms) - *last_timestamp_ms_;
if (diff_ms < min_frame_interval_ms_) {
return true;
}
}
return false;
}
void FramerateController::AddFrame(uint32_t timestamp_ms) {
if (timestamp_ms < last_timestamp_ms_) {
// Timestamp jumps backward.
Reset();
}
framerate_estimator_.Update(1, timestamp_ms);
last_timestamp_ms_ = timestamp_ms;
}
absl::optional<float> FramerateController::Rate(uint32_t timestamp_ms) const {
return framerate_estimator_.Rate(timestamp_ms);
}
} // namespace webrtc