6a688f5265
Prevents downscaling below 160x90 or 90x160 to gain more quality. BUG=4625 R=mflodman@webrtc.org Review URL: https://codereview.webrtc.org/1160403004. Cr-Commit-Position: refs/heads/master@{#9480}
124 lines
3.4 KiB
C++
124 lines
3.4 KiB
C++
/*
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* Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "webrtc/modules/video_coding/utility/include/quality_scaler.h"
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namespace webrtc {
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static const int kMinFps = 10;
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static const int kMeasureSeconds = 5;
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static const int kFramedropPercentThreshold = 60;
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const int QualityScaler::kDefaultLowQpDenominator = 3;
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// Note that this is the same for width and height to permit 120x90 in both
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// portrait and landscape mode.
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const int QualityScaler::kDefaultMinDownscaleDimension = 90;
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QualityScaler::QualityScaler()
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: num_samples_(0),
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low_qp_threshold_(-1),
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downscale_shift_(0),
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min_width_(kDefaultMinDownscaleDimension),
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min_height_(kDefaultMinDownscaleDimension) {
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}
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void QualityScaler::Init(int low_qp_threshold) {
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ClearSamples();
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low_qp_threshold_ = low_qp_threshold;
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}
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void QualityScaler::SetMinResolution(int min_width, int min_height) {
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min_width_ = min_width;
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min_height_ = min_height;
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}
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// Report framerate(fps) to estimate # of samples.
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void QualityScaler::ReportFramerate(int framerate) {
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num_samples_ = static_cast<size_t>(
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kMeasureSeconds * (framerate < kMinFps ? kMinFps : framerate));
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}
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void QualityScaler::ReportQP(int qp) {
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framedrop_percent_.AddSample(0);
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average_qp_.AddSample(qp);
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}
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void QualityScaler::ReportDroppedFrame() {
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framedrop_percent_.AddSample(100);
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}
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QualityScaler::Resolution QualityScaler::GetScaledResolution(
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const VideoFrame& frame) {
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// Should be set through InitEncode -> Should be set by now.
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assert(low_qp_threshold_ >= 0);
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assert(num_samples_ > 0);
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Resolution res;
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res.width = frame.width();
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res.height = frame.height();
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// Update scale factor.
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int avg_drop = 0;
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int avg_qp = 0;
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if (framedrop_percent_.GetAverage(num_samples_, &avg_drop) &&
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avg_drop >= kFramedropPercentThreshold) {
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AdjustScale(false);
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} else if (average_qp_.GetAverage(num_samples_, &avg_qp) &&
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avg_qp <= low_qp_threshold_) {
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AdjustScale(true);
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}
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assert(downscale_shift_ >= 0);
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for (int shift = downscale_shift_;
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shift > 0 && (res.width >> 1 >= min_width_) &&
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(res.height >> 1 >= min_height_);
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--shift) {
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res.width >>= 1;
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res.height >>= 1;
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}
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return res;
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}
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const VideoFrame& QualityScaler::GetScaledFrame(const VideoFrame& frame) {
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Resolution res = GetScaledResolution(frame);
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if (res.width == frame.width())
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return frame;
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scaler_.Set(frame.width(),
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frame.height(),
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res.width,
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res.height,
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kI420,
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kI420,
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kScaleBox);
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if (scaler_.Scale(frame, &scaled_frame_) != 0)
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return frame;
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scaled_frame_.set_ntp_time_ms(frame.ntp_time_ms());
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scaled_frame_.set_timestamp(frame.timestamp());
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scaled_frame_.set_render_time_ms(frame.render_time_ms());
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return scaled_frame_;
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}
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void QualityScaler::ClearSamples() {
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framedrop_percent_.Reset();
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average_qp_.Reset();
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}
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void QualityScaler::AdjustScale(bool up) {
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downscale_shift_ += up ? -1 : 1;
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if (downscale_shift_ < 0)
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downscale_shift_ = 0;
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ClearSamples();
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}
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} // namespace webrtc
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