media/base/video_adapter.cc - src/ - Git at Google

 /*
  *  Copyright (c) 2010 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 "media/base/video_adapter.h"

 #include <algorithm>
 #include <cmath>
 #include <cstdint>
 #include <cstdlib>
 #include <limits>
 #include <utility>

 #include "absl/types/optional.h"
 #include "media/base/video_common.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/logging.h"
 #include "rtc_base/strings/string_builder.h"
 #include "rtc_base/time_utils.h"
 #include "system_wrappers/include/field_trial.h"

 namespace {

 struct Fraction {
   int numerator;
   int denominator;

   void DivideByGcd() {
     int g = cricket::GreatestCommonDivisor(numerator, denominator);
     numerator /= g;
     denominator /= g;
   }

   // Determines number of output pixels if both width and height of an input of
   // `input_pixels` pixels is scaled with the fraction numerator / denominator.
   int scale_pixel_count(int input_pixels) {
     return (numerator * numerator * static_cast<int64_t>(input_pixels)) /
            (denominator * denominator);
   }
 };

 // Round `value_to_round` to a multiple of `multiple`. Prefer rounding upwards,
 // but never more than `max_value`.
 int roundUp(int value_to_round, int multiple, int max_value) {
   const int rounded_value =
       (value_to_round + multiple - 1) / multiple * multiple;
   return rounded_value <= max_value ? rounded_value
                                     : (max_value / multiple * multiple);
 }

 // Generates a scale factor that makes `input_pixels` close to `target_pixels`,
 // but no higher than `max_pixels`.
 Fraction FindScale(int input_width,
                    int input_height,
                    int target_pixels,
                    int max_pixels,
                    bool variable_start_scale_factor) {
   // This function only makes sense for a positive target.
   RTC_DCHECK_GT(target_pixels, 0);
   RTC_DCHECK_GT(max_pixels, 0);
   RTC_DCHECK_GE(max_pixels, target_pixels);

   const int input_pixels = input_width * input_height;

   // Don't scale up original.
   if (target_pixels >= input_pixels)
     return Fraction{1, 1};

   Fraction current_scale = Fraction{1, 1};
   Fraction best_scale = Fraction{1, 1};

   if (variable_start_scale_factor) {
     // Start scaling down by 2/3 depending on `input_width` and `input_height`.
     if (input_width % 3 == 0 && input_height % 3 == 0) {
       // 2/3 (then alternates 3/4, 2/3, 3/4,...).
       current_scale = Fraction{6, 6};
     }
     if (input_width % 9 == 0 && input_height % 9 == 0) {
       // 2/3, 2/3 (then alternates 3/4, 2/3, 3/4,...).
       current_scale = Fraction{36, 36};
     }
   }

   // The minimum (absolute) difference between the number of output pixels and
   // the target pixel count.
   int min_pixel_diff = std::numeric_limits<int>::max();
   if (input_pixels <= max_pixels) {
     // Start condition for 1/1 case, if it is less than max.
     min_pixel_diff = std::abs(input_pixels - target_pixels);
   }

   // Alternately scale down by 3/4 and 2/3. This results in fractions which are
   // effectively scalable. For instance, starting at 1280x720 will result in
   // the series (3/4) => 960x540, (1/2) => 640x360, (3/8) => 480x270,
   // (1/4) => 320x180, (3/16) => 240x125, (1/8) => 160x90.
   while (current_scale.scale_pixel_count(input_pixels) > target_pixels) {
     if (current_scale.numerator % 3 == 0 &&
         current_scale.denominator % 2 == 0) {
       // Multiply by 2/3.
       current_scale.numerator /= 3;
       current_scale.denominator /= 2;
     } else {
       // Multiply by 3/4.
       current_scale.numerator *= 3;
       current_scale.denominator *= 4;
     }

     int output_pixels = current_scale.scale_pixel_count(input_pixels);
     if (output_pixels <= max_pixels) {
       int diff = std::abs(target_pixels - output_pixels);
       if (diff < min_pixel_diff) {
         min_pixel_diff = diff;
         best_scale = current_scale;
       }
     }
   }
   best_scale.DivideByGcd();

   return best_scale;
 }

 absl::optional<std::pair<int, int>> Swap(
     const absl::optional<std::pair<int, int>>& in) {
   if (!in) {
     return absl::nullopt;
   }
   return std::make_pair(in->second, in->first);
 }

 }  // namespace

 namespace cricket {

 VideoAdapter::VideoAdapter(int source_resolution_alignment)
     : frames_in_(0),
       frames_out_(0),
       frames_scaled_(0),
       adaption_changes_(0),
       previous_width_(0),
       previous_height_(0),
       variable_start_scale_factor_(!webrtc::field_trial::IsDisabled(
           "WebRTC-Video-VariableStartScaleFactor")),
       source_resolution_alignment_(source_resolution_alignment),
       resolution_alignment_(source_resolution_alignment),
       resolution_request_target_pixel_count_(std::numeric_limits<int>::max()),
       resolution_request_max_pixel_count_(std::numeric_limits<int>::max()),
       max_framerate_request_(std::numeric_limits<int>::max()) {}

 VideoAdapter::VideoAdapter() : VideoAdapter(1) {}

 VideoAdapter::~VideoAdapter() {}

 bool VideoAdapter::DropFrame(int64_t in_timestamp_ns) {
   int max_fps = max_framerate_request_;
   if (output_format_request_.max_fps)
     max_fps = std::min(max_fps, *output_format_request_.max_fps);

   framerate_controller_.SetMaxFramerate(max_fps);
   return framerate_controller_.ShouldDropFrame(in_timestamp_ns);
 }

 bool VideoAdapter::AdaptFrameResolution(int in_width,
                                         int in_height,
                                         int64_t in_timestamp_ns,
                                         int* cropped_width,
                                         int* cropped_height,
                                         int* out_width,
                                         int* out_height) {
   webrtc::MutexLock lock(&mutex_);
   ++frames_in_;

   // The max output pixel count is the minimum of the requests from
   // OnOutputFormatRequest and OnResolutionFramerateRequest.
   int max_pixel_count = resolution_request_max_pixel_count_;

   // Select target aspect ratio and max pixel count depending on input frame
   // orientation.
   absl::optional<std::pair<int, int>> target_aspect_ratio;
   if (in_width > in_height) {
     target_aspect_ratio = output_format_request_.target_landscape_aspect_ratio;
     if (output_format_request_.max_landscape_pixel_count)
       max_pixel_count = std::min(
           max_pixel_count, *output_format_request_.max_landscape_pixel_count);
   } else {
     target_aspect_ratio = output_format_request_.target_portrait_aspect_ratio;
     if (output_format_request_.max_portrait_pixel_count)
       max_pixel_count = std::min(
           max_pixel_count, *output_format_request_.max_portrait_pixel_count);
   }

   int target_pixel_count =
       std::min(resolution_request_target_pixel_count_, max_pixel_count);

   // Drop the input frame if necessary.
   if (max_pixel_count <= 0 || DropFrame(in_timestamp_ns)) {
     // Show VAdapt log every 90 frames dropped. (3 seconds)
     if ((frames_in_ - frames_out_) % 90 == 0) {
       // TODO(fbarchard): Reduce to LS_VERBOSE when adapter info is not needed
       // in default calls.
       RTC_LOG(LS_INFO) << "VAdapt Drop Frame: scaled " << frames_scaled_
                        << " / out " << frames_out_ << " / in " << frames_in_
                        << " Changes: " << adaption_changes_
                        << " Input: " << in_width << "x" << in_height
                        << " timestamp: " << in_timestamp_ns
                        << " Output fps: " << max_framerate_request_ << "/"
                        << output_format_request_.max_fps.value_or(-1)
                        << " alignment: " << resolution_alignment_;
     }

     // Drop frame.
     return false;
   }

   // Calculate how the input should be cropped.
   if (!target_aspect_ratio || target_aspect_ratio->first <= 0 ||
       target_aspect_ratio->second <= 0) {
     *cropped_width = in_width;
     *cropped_height = in_height;
   } else {
     const float requested_aspect =
         target_aspect_ratio->first /
         static_cast<float>(target_aspect_ratio->second);
     *cropped_width =
         std::min(in_width, static_cast<int>(in_height * requested_aspect));
     *cropped_height =
         std::min(in_height, static_cast<int>(in_width / requested_aspect));
   }
   const Fraction scale =
       FindScale(*cropped_width, *cropped_height, target_pixel_count,
                 max_pixel_count, variable_start_scale_factor_);
   // Adjust cropping slightly to get correctly aligned output size and a perfect
   // scale factor.
   *cropped_width = roundUp(*cropped_width,
                            scale.denominator * resolution_alignment_, in_width);
   *cropped_height = roundUp(
       *cropped_height, scale.denominator * resolution_alignment_, in_height);
   RTC_DCHECK_EQ(0, *cropped_width % scale.denominator);
   RTC_DCHECK_EQ(0, *cropped_height % scale.denominator);

   // Calculate final output size.
   *out_width = *cropped_width / scale.denominator * scale.numerator;
   *out_height = *cropped_height / scale.denominator * scale.numerator;
   RTC_DCHECK_EQ(0, *out_width % resolution_alignment_);
   RTC_DCHECK_EQ(0, *out_height % resolution_alignment_);

   ++frames_out_;
   if (scale.numerator != scale.denominator)
     ++frames_scaled_;

   if (previous_width_ &&
       (previous_width_ != *out_width || previous_height_ != *out_height)) {
     ++adaption_changes_;
     RTC_LOG(LS_INFO) << "Frame size changed: scaled " << frames_scaled_
                      << " / out " << frames_out_ << " / in " << frames_in_
                      << " Changes: " << adaption_changes_
                      << " Input: " << in_width << "x" << in_height
                      << " Scale: " << scale.numerator << "/"
                      << scale.denominator << " Output: " << *out_width << "x"
                      << *out_height << " fps: " << max_framerate_request_ << "/"
                      << output_format_request_.max_fps.value_or(-1)
                      << " alignment: " << resolution_alignment_;
   }

   previous_width_ = *out_width;
   previous_height_ = *out_height;

   return true;
 }

 void VideoAdapter::OnOutputFormatRequest(
     const absl::optional<VideoFormat>& format) {
   absl::optional<std::pair<int, int>> target_aspect_ratio;
   absl::optional<int> max_pixel_count;
   absl::optional<int> max_fps;
   if (format) {
     target_aspect_ratio = std::make_pair(format->width, format->height);
     max_pixel_count = format->width * format->height;
     if (format->interval > 0)
       max_fps = rtc::kNumNanosecsPerSec / format->interval;
   }
   OnOutputFormatRequest(target_aspect_ratio, max_pixel_count, max_fps);
 }

 void VideoAdapter::OnOutputFormatRequest(
     const absl::optional<std::pair<int, int>>& target_aspect_ratio,
     const absl::optional<int>& max_pixel_count,
     const absl::optional<int>& max_fps) {
   absl::optional<std::pair<int, int>> target_landscape_aspect_ratio;
   absl::optional<std::pair<int, int>> target_portrait_aspect_ratio;
   if (target_aspect_ratio && target_aspect_ratio->first > 0 &&
       target_aspect_ratio->second > 0) {
     // Maintain input orientation.
     const int max_side =
         std::max(target_aspect_ratio->first, target_aspect_ratio->second);
     const int min_side =
         std::min(target_aspect_ratio->first, target_aspect_ratio->second);
     target_landscape_aspect_ratio = std::make_pair(max_side, min_side);
     target_portrait_aspect_ratio = std::make_pair(min_side, max_side);
   }
   OnOutputFormatRequest(target_landscape_aspect_ratio, max_pixel_count,
                         target_portrait_aspect_ratio, max_pixel_count, max_fps);
 }

 void VideoAdapter::OnOutputFormatRequest(
     const absl::optional<std::pair<int, int>>& target_landscape_aspect_ratio,
     const absl::optional<int>& max_landscape_pixel_count,
     const absl::optional<std::pair<int, int>>& target_portrait_aspect_ratio,
     const absl::optional<int>& max_portrait_pixel_count,
     const absl::optional<int>& max_fps) {
   webrtc::MutexLock lock(&mutex_);

   OutputFormatRequest request = {
       .target_landscape_aspect_ratio = target_landscape_aspect_ratio,
       .max_landscape_pixel_count = max_landscape_pixel_count,
       .target_portrait_aspect_ratio = target_portrait_aspect_ratio,
       .max_portrait_pixel_count = max_portrait_pixel_count,
       .max_fps = max_fps};

   if (stashed_output_format_request_) {
     // Save the output format request for later use in case the encoder making
     // this call would become active, because currently all active encoders use
     // requested_resolution instead.
     stashed_output_format_request_ = request;
     RTC_LOG(LS_INFO) << "Stashing OnOutputFormatRequest: "
                      << stashed_output_format_request_->ToString();
   } else {
     output_format_request_ = request;
     RTC_LOG(LS_INFO) << "Setting output_format_request_: "
                      << output_format_request_.ToString();
   }

   framerate_controller_.Reset();
 }

 void VideoAdapter::OnSinkWants(const rtc::VideoSinkWants& sink_wants) {
   webrtc::MutexLock lock(&mutex_);
   resolution_request_max_pixel_count_ = sink_wants.max_pixel_count;
   resolution_request_target_pixel_count_ =
       sink_wants.target_pixel_count.value_or(
           resolution_request_max_pixel_count_);
   max_framerate_request_ = sink_wants.max_framerate_fps;
   resolution_alignment_ = cricket::LeastCommonMultiple(
       source_resolution_alignment_, sink_wants.resolution_alignment);

   if (!sink_wants.aggregates) {
     RTC_LOG(LS_WARNING)
         << "These should always be created by VideoBroadcaster!";
     return;
   }

   // If requested_resolution is used, and there are no active encoders
   // that are NOT using requested_resolution (aka newapi), then override
   // calls to OnOutputFormatRequest and use values from requested_resolution
   // instead (combined with qualityscaling based on pixel counts above).
   if (!sink_wants.requested_resolution) {
     if (stashed_output_format_request_) {
       // because current active_output_format_request is based on
       // requested_resolution logic, while current encoder(s) doesn't want that,
       // we have to restore the stashed request.
       RTC_LOG(LS_INFO) << "Unstashing OnOutputFormatRequest: "
                        << stashed_output_format_request_->ToString();
       output_format_request_ = *stashed_output_format_request_;
       stashed_output_format_request_.reset();
     }
     return;
   }

   if (sink_wants.aggregates->any_active_without_requested_resolution) {
     return;
   }

   if (!stashed_output_format_request_) {
     // The active output format request is about to be rewritten by
     // request_resolution. We need to save it for later use in case the encoder
     // which doesn't use request_resolution logic become active in the future.
     stashed_output_format_request_ = output_format_request_;
     RTC_LOG(LS_INFO) << "Stashing OnOutputFormatRequest: "
                      << stashed_output_format_request_->ToString();
   }

   auto res = *sink_wants.requested_resolution;
   auto pixel_count = res.width * res.height;
   output_format_request_.target_landscape_aspect_ratio =
       std::make_pair(res.width, res.height);
   output_format_request_.max_landscape_pixel_count = pixel_count;
   output_format_request_.target_portrait_aspect_ratio =
       std::make_pair(res.height, res.width);
   output_format_request_.max_portrait_pixel_count = pixel_count;
   output_format_request_.max_fps = max_framerate_request_;
   RTC_LOG(LS_INFO) << "Setting output_format_request_ based on sink_wants: "
                    << output_format_request_.ToString();
 }

 int VideoAdapter::GetTargetPixels() const {
   webrtc::MutexLock lock(&mutex_);
   return resolution_request_target_pixel_count_;
 }

 float VideoAdapter::GetMaxFramerate() const {
   webrtc::MutexLock lock(&mutex_);
   // Minimum of `output_format_request_.max_fps` and `max_framerate_request_` is
   // used to throttle frame-rate.
   int framerate =
       std::min(max_framerate_request_,
                output_format_request_.max_fps.value_or(max_framerate_request_));
   if (framerate == std::numeric_limits<int>::max()) {
     return std::numeric_limits<float>::infinity();
   } else {
     return max_framerate_request_;
   }
 }

 std::string VideoAdapter::OutputFormatRequest::ToString() const {
   rtc::StringBuilder oss;
   oss << "[ ";
   if (target_landscape_aspect_ratio == Swap(target_portrait_aspect_ratio) &&
       max_landscape_pixel_count == max_portrait_pixel_count) {
     if (target_landscape_aspect_ratio) {
       oss << target_landscape_aspect_ratio->first << "x"
           << target_landscape_aspect_ratio->second;
     } else {
       oss << "unset-resolution";
     }
     if (max_landscape_pixel_count) {
       oss << " max_pixel_count: " << *max_landscape_pixel_count;
     }
   } else {
     oss << "[ landscape: ";
     if (target_landscape_aspect_ratio) {
       oss << target_landscape_aspect_ratio->first << "x"
           << target_landscape_aspect_ratio->second;
     } else {
       oss << "unset";
     }
     if (max_landscape_pixel_count) {
       oss << " max_pixel_count: " << *max_landscape_pixel_count;
     }
     oss << " ] [ portrait: ";
     if (target_portrait_aspect_ratio) {
       oss << target_portrait_aspect_ratio->first << "x"
           << target_portrait_aspect_ratio->second;
     }
     if (max_portrait_pixel_count) {
       oss << " max_pixel_count: " << *max_portrait_pixel_count;
     }
     oss << " ]";
   }
   oss << " max_fps: ";
   if (max_fps) {
     oss << *max_fps;
   } else {
     oss << "unset";
   }
   oss << " ]";
   return oss.Release();
 }

 }  // namespace cricket
	/*
	* Copyright (c) 2010 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 "media/base/video_adapter.h"

	#include <algorithm>
	#include <cmath>
	#include <cstdint>
	#include <cstdlib>
	#include <limits>
	#include <utility>

	#include "absl/types/optional.h"
	#include "media/base/video_common.h"
	#include "rtc_base/checks.h"
	#include "rtc_base/logging.h"
	#include "rtc_base/strings/string_builder.h"
	#include "rtc_base/time_utils.h"
	#include "system_wrappers/include/field_trial.h"

	namespace {

	struct Fraction {
	int numerator;
	int denominator;

	void DivideByGcd() {
	int g = cricket::GreatestCommonDivisor(numerator, denominator);
	numerator /= g;
	denominator /= g;
	}

	// Determines number of output pixels if both width and height of an input of
	// `input_pixels` pixels is scaled with the fraction numerator / denominator.
	int scale_pixel_count(int input_pixels) {
	return (numerator * numerator * static_cast<int64_t>(input_pixels)) /
	(denominator * denominator);
	}
	};

	// Round `value_to_round` to a multiple of `multiple`. Prefer rounding upwards,
	// but never more than `max_value`.
	int roundUp(int value_to_round, int multiple, int max_value) {
	const int rounded_value =
	(value_to_round + multiple - 1) / multiple * multiple;
	return rounded_value <= max_value ? rounded_value
	: (max_value / multiple * multiple);
	}

	// Generates a scale factor that makes `input_pixels` close to `target_pixels`,
	// but no higher than `max_pixels`.
	Fraction FindScale(int input_width,
	int input_height,
	int target_pixels,
	int max_pixels,
	bool variable_start_scale_factor) {
	// This function only makes sense for a positive target.
	RTC_DCHECK_GT(target_pixels, 0);
	RTC_DCHECK_GT(max_pixels, 0);
	RTC_DCHECK_GE(max_pixels, target_pixels);

	const int input_pixels = input_width * input_height;

	// Don't scale up original.
	if (target_pixels >= input_pixels)
	return Fraction{1, 1};

	Fraction current_scale = Fraction{1, 1};
	Fraction best_scale = Fraction{1, 1};

	if (variable_start_scale_factor) {
	// Start scaling down by 2/3 depending on `input_width` and `input_height`.
	if (input_width % 3 == 0 && input_height % 3 == 0) {
	// 2/3 (then alternates 3/4, 2/3, 3/4,...).
	current_scale = Fraction{6, 6};
	}
	if (input_width % 9 == 0 && input_height % 9 == 0) {
	// 2/3, 2/3 (then alternates 3/4, 2/3, 3/4,...).
	current_scale = Fraction{36, 36};
	}
	}

	// The minimum (absolute) difference between the number of output pixels and
	// the target pixel count.
	int min_pixel_diff = std::numeric_limits<int>::max();
	if (input_pixels <= max_pixels) {
	// Start condition for 1/1 case, if it is less than max.
	min_pixel_diff = std::abs(input_pixels - target_pixels);
	}

	// Alternately scale down by 3/4 and 2/3. This results in fractions which are
	// effectively scalable. For instance, starting at 1280x720 will result in
	// the series (3/4) => 960x540, (1/2) => 640x360, (3/8) => 480x270,
	// (1/4) => 320x180, (3/16) => 240x125, (1/8) => 160x90.
	while (current_scale.scale_pixel_count(input_pixels) > target_pixels) {
	if (current_scale.numerator % 3 == 0 &&
	current_scale.denominator % 2 == 0) {
	// Multiply by 2/3.
	current_scale.numerator /= 3;
	current_scale.denominator /= 2;
	} else {
	// Multiply by 3/4.
	current_scale.numerator *= 3;
	current_scale.denominator *= 4;
	}

	int output_pixels = current_scale.scale_pixel_count(input_pixels);
	if (output_pixels <= max_pixels) {
	int diff = std::abs(target_pixels - output_pixels);
	if (diff < min_pixel_diff) {
	min_pixel_diff = diff;
	best_scale = current_scale;
	}
	}
	}
	best_scale.DivideByGcd();

	return best_scale;
	}

	absl::optional<std::pair<int, int>> Swap(
	const absl::optional<std::pair<int, int>>& in) {
	if (!in) {
	return absl::nullopt;
	}
	return std::make_pair(in->second, in->first);
	}

	} // namespace

	namespace cricket {

	VideoAdapter::VideoAdapter(int source_resolution_alignment)
	: frames_in_(0),
	frames_out_(0),
	frames_scaled_(0),
	adaption_changes_(0),
	previous_width_(0),
	previous_height_(0),
	variable_start_scale_factor_(!webrtc::field_trial::IsDisabled(
	"WebRTC-Video-VariableStartScaleFactor")),
	source_resolution_alignment_(source_resolution_alignment),
	resolution_alignment_(source_resolution_alignment),
	resolution_request_target_pixel_count_(std::numeric_limits<int>::max()),
	resolution_request_max_pixel_count_(std::numeric_limits<int>::max()),
	max_framerate_request_(std::numeric_limits<int>::max()) {}

	VideoAdapter::VideoAdapter() : VideoAdapter(1) {}

	VideoAdapter::~VideoAdapter() {}

	bool VideoAdapter::DropFrame(int64_t in_timestamp_ns) {
	int max_fps = max_framerate_request_;
	if (output_format_request_.max_fps)
	max_fps = std::min(max_fps, *output_format_request_.max_fps);

	framerate_controller_.SetMaxFramerate(max_fps);
	return framerate_controller_.ShouldDropFrame(in_timestamp_ns);
	}

	bool VideoAdapter::AdaptFrameResolution(int in_width,
	int in_height,
	int64_t in_timestamp_ns,
	int* cropped_width,
	int* cropped_height,
	int* out_width,
	int* out_height) {
	webrtc::MutexLock lock(&mutex_);
	++frames_in_;

	// The max output pixel count is the minimum of the requests from
	// OnOutputFormatRequest and OnResolutionFramerateRequest.
	int max_pixel_count = resolution_request_max_pixel_count_;

	// Select target aspect ratio and max pixel count depending on input frame
	// orientation.
	absl::optional<std::pair<int, int>> target_aspect_ratio;
	if (in_width > in_height) {
	target_aspect_ratio = output_format_request_.target_landscape_aspect_ratio;
	if (output_format_request_.max_landscape_pixel_count)
	max_pixel_count = std::min(
	max_pixel_count, *output_format_request_.max_landscape_pixel_count);
	} else {
	target_aspect_ratio = output_format_request_.target_portrait_aspect_ratio;
	if (output_format_request_.max_portrait_pixel_count)
	max_pixel_count = std::min(
	max_pixel_count, *output_format_request_.max_portrait_pixel_count);
	}

	int target_pixel_count =
	std::min(resolution_request_target_pixel_count_, max_pixel_count);

	// Drop the input frame if necessary.
	if (max_pixel_count <= 0 \|\| DropFrame(in_timestamp_ns)) {
	// Show VAdapt log every 90 frames dropped. (3 seconds)
	if ((frames_in_ - frames_out_) % 90 == 0) {
	// TODO(fbarchard): Reduce to LS_VERBOSE when adapter info is not needed
	// in default calls.
	RTC_LOG(LS_INFO) << "VAdapt Drop Frame: scaled " << frames_scaled_
	<< " / out " << frames_out_ << " / in " << frames_in_
	<< " Changes: " << adaption_changes_
	<< " Input: " << in_width << "x" << in_height
	<< " timestamp: " << in_timestamp_ns
	<< " Output fps: " << max_framerate_request_ << "/"
	<< output_format_request_.max_fps.value_or(-1)
	<< " alignment: " << resolution_alignment_;
	}

	// Drop frame.
	return false;
	}

	// Calculate how the input should be cropped.
	if (!target_aspect_ratio \|\| target_aspect_ratio->first <= 0 \|\|
	target_aspect_ratio->second <= 0) {
	*cropped_width = in_width;
	*cropped_height = in_height;
	} else {
	const float requested_aspect =
	target_aspect_ratio->first /
	static_cast<float>(target_aspect_ratio->second);
	*cropped_width =
	std::min(in_width, static_cast<int>(in_height * requested_aspect));
	*cropped_height =
	std::min(in_height, static_cast<int>(in_width / requested_aspect));
	}
	const Fraction scale =
	FindScale(cropped_width, cropped_height, target_pixel_count,
	max_pixel_count, variable_start_scale_factor_);
	// Adjust cropping slightly to get correctly aligned output size and a perfect
	// scale factor.
	cropped_width = roundUp(cropped_width,
	scale.denominator * resolution_alignment_, in_width);
	*cropped_height = roundUp(
	cropped_height, scale.denominator resolution_alignment_, in_height);
	RTC_DCHECK_EQ(0, *cropped_width % scale.denominator);
	RTC_DCHECK_EQ(0, *cropped_height % scale.denominator);

	// Calculate final output size.
	out_width = cropped_width / scale.denominator * scale.numerator;
	out_height = cropped_height / scale.denominator * scale.numerator;
	RTC_DCHECK_EQ(0, *out_width % resolution_alignment_);
	RTC_DCHECK_EQ(0, *out_height % resolution_alignment_);

	++frames_out_;
	if (scale.numerator != scale.denominator)
	++frames_scaled_;

	if (previous_width_ &&
	(previous_width_ != out_width \|\| previous_height_ != out_height)) {
	++adaption_changes_;
	RTC_LOG(LS_INFO) << "Frame size changed: scaled " << frames_scaled_
	<< " / out " << frames_out_ << " / in " << frames_in_
	<< " Changes: " << adaption_changes_
	<< " Input: " << in_width << "x" << in_height
	<< " Scale: " << scale.numerator << "/"
	<< scale.denominator << " Output: " << *out_width << "x"
	<< *out_height << " fps: " << max_framerate_request_ << "/"
	<< output_format_request_.max_fps.value_or(-1)
	<< " alignment: " << resolution_alignment_;
	}

	previous_width_ = *out_width;
	previous_height_ = *out_height;

	return true;
	}

	void VideoAdapter::OnOutputFormatRequest(
	const absl::optional<VideoFormat>& format) {
	absl::optional<std::pair<int, int>> target_aspect_ratio;
	absl::optional<int> max_pixel_count;
	absl::optional<int> max_fps;
	if (format) {
	target_aspect_ratio = std::make_pair(format->width, format->height);
	max_pixel_count = format->width * format->height;
	if (format->interval > 0)
	max_fps = rtc::kNumNanosecsPerSec / format->interval;
	}
	OnOutputFormatRequest(target_aspect_ratio, max_pixel_count, max_fps);
	}

	void VideoAdapter::OnOutputFormatRequest(
	const absl::optional<std::pair<int, int>>& target_aspect_ratio,
	const absl::optional<int>& max_pixel_count,
	const absl::optional<int>& max_fps) {
	absl::optional<std::pair<int, int>> target_landscape_aspect_ratio;
	absl::optional<std::pair<int, int>> target_portrait_aspect_ratio;
	if (target_aspect_ratio && target_aspect_ratio->first > 0 &&
	target_aspect_ratio->second > 0) {
	// Maintain input orientation.
	const int max_side =
	std::max(target_aspect_ratio->first, target_aspect_ratio->second);
	const int min_side =
	std::min(target_aspect_ratio->first, target_aspect_ratio->second);
	target_landscape_aspect_ratio = std::make_pair(max_side, min_side);
	target_portrait_aspect_ratio = std::make_pair(min_side, max_side);
	}
	OnOutputFormatRequest(target_landscape_aspect_ratio, max_pixel_count,
	target_portrait_aspect_ratio, max_pixel_count, max_fps);
	}

	void VideoAdapter::OnOutputFormatRequest(
	const absl::optional<std::pair<int, int>>& target_landscape_aspect_ratio,
	const absl::optional<int>& max_landscape_pixel_count,
	const absl::optional<std::pair<int, int>>& target_portrait_aspect_ratio,
	const absl::optional<int>& max_portrait_pixel_count,
	const absl::optional<int>& max_fps) {
	webrtc::MutexLock lock(&mutex_);

	OutputFormatRequest request = {
	.target_landscape_aspect_ratio = target_landscape_aspect_ratio,
	.max_landscape_pixel_count = max_landscape_pixel_count,
	.target_portrait_aspect_ratio = target_portrait_aspect_ratio,
	.max_portrait_pixel_count = max_portrait_pixel_count,
	.max_fps = max_fps};

	if (stashed_output_format_request_) {
	// Save the output format request for later use in case the encoder making
	// this call would become active, because currently all active encoders use
	// requested_resolution instead.
	stashed_output_format_request_ = request;
	RTC_LOG(LS_INFO) << "Stashing OnOutputFormatRequest: "
	<< stashed_output_format_request_->ToString();
	} else {
	output_format_request_ = request;
	RTC_LOG(LS_INFO) << "Setting output_format_request_: "
	<< output_format_request_.ToString();
	}

	framerate_controller_.Reset();
	}

	void VideoAdapter::OnSinkWants(const rtc::VideoSinkWants& sink_wants) {
	webrtc::MutexLock lock(&mutex_);
	resolution_request_max_pixel_count_ = sink_wants.max_pixel_count;
	resolution_request_target_pixel_count_ =
	sink_wants.target_pixel_count.value_or(
	resolution_request_max_pixel_count_);
	max_framerate_request_ = sink_wants.max_framerate_fps;
	resolution_alignment_ = cricket::LeastCommonMultiple(
	source_resolution_alignment_, sink_wants.resolution_alignment);

	if (!sink_wants.aggregates) {
	RTC_LOG(LS_WARNING)
	<< "These should always be created by VideoBroadcaster!";
	return;
	}

	// If requested_resolution is used, and there are no active encoders
	// that are NOT using requested_resolution (aka newapi), then override
	// calls to OnOutputFormatRequest and use values from requested_resolution
	// instead (combined with qualityscaling based on pixel counts above).
	if (!sink_wants.requested_resolution) {
	if (stashed_output_format_request_) {
	// because current active_output_format_request is based on
	// requested_resolution logic, while current encoder(s) doesn't want that,
	// we have to restore the stashed request.
	RTC_LOG(LS_INFO) << "Unstashing OnOutputFormatRequest: "
	<< stashed_output_format_request_->ToString();
	output_format_request_ = *stashed_output_format_request_;
	stashed_output_format_request_.reset();
	}
	return;
	}

	if (sink_wants.aggregates->any_active_without_requested_resolution) {
	return;
	}

	if (!stashed_output_format_request_) {
	// The active output format request is about to be rewritten by
	// request_resolution. We need to save it for later use in case the encoder
	// which doesn't use request_resolution logic become active in the future.
	stashed_output_format_request_ = output_format_request_;
	RTC_LOG(LS_INFO) << "Stashing OnOutputFormatRequest: "
	<< stashed_output_format_request_->ToString();
	}

	auto res = *sink_wants.requested_resolution;
	auto pixel_count = res.width * res.height;
	output_format_request_.target_landscape_aspect_ratio =
	std::make_pair(res.width, res.height);
	output_format_request_.max_landscape_pixel_count = pixel_count;
	output_format_request_.target_portrait_aspect_ratio =
	std::make_pair(res.height, res.width);
	output_format_request_.max_portrait_pixel_count = pixel_count;
	output_format_request_.max_fps = max_framerate_request_;
	RTC_LOG(LS_INFO) << "Setting output_format_request_ based on sink_wants: "
	<< output_format_request_.ToString();
	}

	int VideoAdapter::GetTargetPixels() const {
	webrtc::MutexLock lock(&mutex_);
	return resolution_request_target_pixel_count_;
	}

	float VideoAdapter::GetMaxFramerate() const {
	webrtc::MutexLock lock(&mutex_);
	// Minimum of `output_format_request_.max_fps` and `max_framerate_request_` is
	// used to throttle frame-rate.
	int framerate =
	std::min(max_framerate_request_,
	output_format_request_.max_fps.value_or(max_framerate_request_));
	if (framerate == std::numeric_limits<int>::max()) {
	return std::numeric_limits<float>::infinity();
	} else {
	return max_framerate_request_;
	}
	}

	std::string VideoAdapter::OutputFormatRequest::ToString() const {
	rtc::StringBuilder oss;
	oss << "[ ";
	if (target_landscape_aspect_ratio == Swap(target_portrait_aspect_ratio) &&
	max_landscape_pixel_count == max_portrait_pixel_count) {
	if (target_landscape_aspect_ratio) {
	oss << target_landscape_aspect_ratio->first << "x"
	<< target_landscape_aspect_ratio->second;
	} else {
	oss << "unset-resolution";
	}
	if (max_landscape_pixel_count) {
	oss << " max_pixel_count: " << *max_landscape_pixel_count;
	}
	} else {
	oss << "[ landscape: ";
	if (target_landscape_aspect_ratio) {
	oss << target_landscape_aspect_ratio->first << "x"
	<< target_landscape_aspect_ratio->second;
	} else {
	oss << "unset";
	}
	if (max_landscape_pixel_count) {
	oss << " max_pixel_count: " << *max_landscape_pixel_count;
	}
	oss << " ] [ portrait: ";
	if (target_portrait_aspect_ratio) {
	oss << target_portrait_aspect_ratio->first << "x"
	<< target_portrait_aspect_ratio->second;
	}
	if (max_portrait_pixel_count) {
	oss << " max_pixel_count: " << *max_portrait_pixel_count;
	}
	oss << " ]";
	}
	oss << " max_fps: ";
	if (max_fps) {
	oss << *max_fps;
	} else {
	oss << "unset";
	}
	oss << " ]";
	return oss.Release();
	}

	} // namespace cricket