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/*
* Copyright (c) 2012 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/media_optimization.h"
#include <limits>
#include "modules/video_coding/utility/frame_dropper.h"
#include "system_wrappers/include/clock.h"
namespace webrtc {
namespace media_optimization {
namespace {
const int64_t kFrameHistoryWinMs = 2000;
} // namespace
MediaOptimization::MediaOptimization(Clock* clock)
: clock_(clock),
max_bit_rate_(0),
max_frame_rate_(0),
frame_dropper_(new FrameDropper),
incoming_frame_rate_(0) {
memset(incoming_frame_times_, -1, sizeof(incoming_frame_times_));
}
MediaOptimization::~MediaOptimization(void) {}
void MediaOptimization::Reset() {
rtc::CritScope lock(&crit_sect_);
memset(incoming_frame_times_, -1, sizeof(incoming_frame_times_));
incoming_frame_rate_ = 0.0;
frame_dropper_->Reset();
frame_dropper_->SetRates(0, 0);
max_bit_rate_ = 0;
max_frame_rate_ = 0;
}
void MediaOptimization::SetEncodingData(int32_t max_bit_rate,
uint32_t target_bitrate,
uint32_t max_frame_rate) {
rtc::CritScope lock(&crit_sect_);
// Everything codec specific should be reset here since the codec has changed.
max_bit_rate_ = max_bit_rate;
max_frame_rate_ = static_cast<float>(max_frame_rate);
float target_bitrate_kbps = static_cast<float>(target_bitrate) / 1000.0f;
frame_dropper_->Reset();
frame_dropper_->SetRates(target_bitrate_kbps, max_frame_rate_);
}
uint32_t MediaOptimization::SetTargetRates(uint32_t target_bitrate) {
rtc::CritScope lock(&crit_sect_);
// Cap target video bitrate to codec maximum.
int video_target_bitrate = target_bitrate;
if (max_bit_rate_ > 0 && video_target_bitrate > max_bit_rate_) {
video_target_bitrate = max_bit_rate_;
}
float target_video_bitrate_kbps =
static_cast<float>(video_target_bitrate) / 1000.0f;
float framerate = incoming_frame_rate_;
if (framerate == 0.0) {
// No framerate estimate available, use configured max framerate instead.
framerate = max_frame_rate_;
}
frame_dropper_->SetRates(target_video_bitrate_kbps, framerate);
return video_target_bitrate;
}
uint32_t MediaOptimization::InputFrameRate() {
rtc::CritScope lock(&crit_sect_);
return InputFrameRateInternal();
}
uint32_t MediaOptimization::InputFrameRateInternal() {
ProcessIncomingFrameRate(clock_->TimeInMilliseconds());
uint32_t framerate = static_cast<uint32_t>(std::min<float>(
std::numeric_limits<uint32_t>::max(), incoming_frame_rate_ + 0.5f));
return framerate;
}
void MediaOptimization::UpdateWithEncodedData(
const size_t encoded_image_length,
const FrameType encoded_image_frametype) {
size_t encoded_length = encoded_image_length;
rtc::CritScope lock(&crit_sect_);
if (encoded_length > 0) {
const bool delta_frame = encoded_image_frametype != kVideoFrameKey;
frame_dropper_->Fill(encoded_length, delta_frame);
}
}
void MediaOptimization::EnableFrameDropper(bool enable) {
rtc::CritScope lock(&crit_sect_);
frame_dropper_->Enable(enable);
}
bool MediaOptimization::DropFrame() {
rtc::CritScope lock(&crit_sect_);
UpdateIncomingFrameRate();
// Leak appropriate number of bytes.
frame_dropper_->Leak((uint32_t)(InputFrameRateInternal() + 0.5f));
return frame_dropper_->DropFrame();
}
void MediaOptimization::UpdateIncomingFrameRate() {
int64_t now = clock_->TimeInMilliseconds();
if (incoming_frame_times_[0] == 0) {
// No shifting if this is the first time.
} else {
// Shift all times one step.
for (int32_t i = (kFrameCountHistorySize - 2); i >= 0; i--) {
incoming_frame_times_[i + 1] = incoming_frame_times_[i];
}
}
incoming_frame_times_[0] = now;
ProcessIncomingFrameRate(now);
}
// Allowing VCM to keep track of incoming frame rate.
void MediaOptimization::ProcessIncomingFrameRate(int64_t now) {
int32_t num = 0;
int32_t nr_of_frames = 0;
for (num = 1; num < (kFrameCountHistorySize - 1); ++num) {
if (incoming_frame_times_[num] <= 0 ||
// Don't use data older than 2 s.
now - incoming_frame_times_[num] > kFrameHistoryWinMs) {
break;
} else {
nr_of_frames++;
}
}
if (num > 1) {
const int64_t diff =
incoming_frame_times_[0] - incoming_frame_times_[num - 1];
incoming_frame_rate_ = 0.0; // No frame rate estimate available.
if (diff > 0) {
incoming_frame_rate_ = nr_of_frames * 1000.0f / static_cast<float>(diff);
}
}
}
} // namespace media_optimization
} // namespace webrtc
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