media/cast/logging/encoding_event_subscriber.cc - chromium/src - Git at Google

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "media/cast/logging/encoding_event_subscriber.h"

 #include <stdint.h>

 #include <algorithm>
 #include <cstring>
 #include <utility>

 #include "base/logging.h"
 #include "base/numerics/safe_conversions.h"
 #include "media/cast/logging/proto/proto_utils.h"

 using google::protobuf::RepeatedPtrField;
 using media::cast::proto::AggregatedFrameEvent;
 using media::cast::proto::AggregatedPacketEvent;
 using media::cast::proto::BasePacketEvent;
 using media::cast::proto::LogMetadata;

 namespace {

 // A size limit on maps to keep lookups fast.
 const size_t kMaxMapSize = 200;

 // The smallest (oredered by RTP timestamp) |kNumMapEntriesToTransfer| entries
 // will be moved when the map size reaches |kMaxMapSize|.
 // Must be smaller than |kMaxMapSize|.
 const size_t kNumMapEntriesToTransfer = 100;

 template <typename ProtoPtr>
 bool IsRtpTimestampLessThan(const ProtoPtr& lhs, const ProtoPtr& rhs) {
   return lhs->relative_rtp_timestamp() < rhs->relative_rtp_timestamp();
 }

 BasePacketEvent* GetNewBasePacketEvent(AggregatedPacketEvent* event_proto,
     int packet_id, int size) {
   BasePacketEvent* base = event_proto->add_base_packet_event();
   base->set_packet_id(packet_id);
   base->set_size(size);
   return base;
 }

 }  // namespace

 namespace media {
 namespace cast {

 EncodingEventSubscriber::EncodingEventSubscriber(
     EventMediaType event_media_type,
     size_t max_frames)
     : event_media_type_(event_media_type), max_frames_(max_frames) {
   Reset();
 }

 EncodingEventSubscriber::~EncodingEventSubscriber() {
   DCHECK(thread_checker_.CalledOnValidThread());
 }

 void EncodingEventSubscriber::OnReceiveFrameEvent(
     const FrameEvent& frame_event) {
   DCHECK(thread_checker_.CalledOnValidThread());

   if (event_media_type_ != frame_event.media_type)
     return;

   const RtpTimeDelta relative_rtp_timestamp =
       GetRelativeRtpTimestamp(frame_event.rtp_timestamp);
   const uint32_t lower_32_bits = relative_rtp_timestamp.lower_32_bits();
   AggregatedFrameEvent* event_proto_ptr = nullptr;

   // Look up existing entry. If not found, create a new entry and add to map.
   auto it = frame_event_map_.find(relative_rtp_timestamp);
   if (it == frame_event_map_.end()) {
     if (!ShouldCreateNewProto(lower_32_bits))
       return;

     IncrementStoredProtoCount(lower_32_bits);
     auto event_proto = std::make_unique<AggregatedFrameEvent>();
     event_proto->set_relative_rtp_timestamp(lower_32_bits);
     event_proto_ptr = event_proto.get();
     frame_event_map_.insert(
         std::make_pair(relative_rtp_timestamp, std::move(event_proto)));
   } else {
     if (it->second->event_type_size() >= kMaxEventsPerProto) {
       DVLOG(2) << "Too many events in frame " << frame_event.rtp_timestamp
                << ". Using new frame event proto.";
       AddFrameEventToStorage(std::move(it->second));
       if (!ShouldCreateNewProto(lower_32_bits)) {
         frame_event_map_.erase(it);
         return;
       }

       IncrementStoredProtoCount(lower_32_bits);
       it->second = std::make_unique<AggregatedFrameEvent>();
       it->second->set_relative_rtp_timestamp(lower_32_bits);
     }
     event_proto_ptr = it->second.get();
   }

   event_proto_ptr->add_event_type(ToProtoEventType(frame_event.type));
   event_proto_ptr->add_event_timestamp_ms(
       (frame_event.timestamp - base::TimeTicks()).InMilliseconds());

   if (frame_event.type == FRAME_CAPTURE_END) {
     if (frame_event.media_type == VIDEO_EVENT &&
         frame_event.width > 0 && frame_event.height > 0) {
       event_proto_ptr->set_width(frame_event.width);
       event_proto_ptr->set_height(frame_event.height);
     }
   } else if (frame_event.type == FRAME_ENCODED) {
     event_proto_ptr->set_encoded_frame_size(frame_event.size);
     if (frame_event.encoder_cpu_utilization >= 0.0) {
       event_proto_ptr->set_encoder_cpu_percent_utilized(
           base::saturated_cast<int32_t>(
               frame_event.encoder_cpu_utilization * 100.0 + 0.5));
     }
     if (frame_event.idealized_bitrate_utilization >= 0.0) {
       event_proto_ptr->set_idealized_bitrate_percent_utilized(
           base::saturated_cast<int32_t>(
               frame_event.idealized_bitrate_utilization * 100.0 + 0.5));
     }
     if (frame_event.media_type == VIDEO_EVENT) {
       event_proto_ptr->set_key_frame(frame_event.key_frame);
       event_proto_ptr->set_target_bitrate(frame_event.target_bitrate);
     }
   } else if (frame_event.type == FRAME_PLAYOUT) {
     event_proto_ptr->set_delay_millis(frame_event.delay_delta.InMilliseconds());
   }

   if (frame_event_map_.size() > kMaxMapSize)
     TransferFrameEvents(kNumMapEntriesToTransfer);

   DCHECK(frame_event_map_.size() <= kMaxMapSize);
   DCHECK(frame_event_storage_.size() <= max_frames_);
 }

 void EncodingEventSubscriber::OnReceivePacketEvent(
     const PacketEvent& packet_event) {
   DCHECK(thread_checker_.CalledOnValidThread());

   if (event_media_type_ != packet_event.media_type)
     return;

   const RtpTimeDelta relative_rtp_timestamp =
       GetRelativeRtpTimestamp(packet_event.rtp_timestamp);
   uint32_t lower_32_bits = relative_rtp_timestamp.lower_32_bits();
   auto it = packet_event_map_.find(relative_rtp_timestamp);
   BasePacketEvent* base_packet_event_proto = nullptr;

   // Look up existing entry. If not found, create a new entry and add to map.
   if (it == packet_event_map_.end()) {
     if (!ShouldCreateNewProto(lower_32_bits))
       return;

     IncrementStoredProtoCount(lower_32_bits);
     auto event_proto = std::make_unique<AggregatedPacketEvent>();
     event_proto->set_relative_rtp_timestamp(lower_32_bits);
     base_packet_event_proto = GetNewBasePacketEvent(
         event_proto.get(), packet_event.packet_id, packet_event.size);
     packet_event_map_.insert(
         std::make_pair(relative_rtp_timestamp, std::move(event_proto)));
   } else {
     // Found existing entry, now look up existing BasePacketEvent using packet
     // ID. If not found, create a new entry and add to proto.
     RepeatedPtrField<BasePacketEvent>* field =
         it->second->mutable_base_packet_event();
     for (RepeatedPtrField<BasePacketEvent>::pointer_iterator base_it =
              field->pointer_begin();
          base_it != field->pointer_end();
          ++base_it) {
       if ((*base_it)->packet_id() == packet_event.packet_id) {
         base_packet_event_proto = *base_it;
         break;
       }
     }
     if (!base_packet_event_proto) {
       if (it->second->base_packet_event_size() >= kMaxPacketsPerFrame) {
         DVLOG(3) << "Too many packets in AggregatedPacketEvent "
                  << packet_event.rtp_timestamp << ". "
                  << "Using new packet event proto.";
         AddPacketEventToStorage(std::move(it->second));
         if (!ShouldCreateNewProto(lower_32_bits)) {
           packet_event_map_.erase(it);
           return;
         }

         IncrementStoredProtoCount(lower_32_bits);
         it->second = std::make_unique<AggregatedPacketEvent>();
         it->second->set_relative_rtp_timestamp(lower_32_bits);
       }

       base_packet_event_proto = GetNewBasePacketEvent(
           it->second.get(), packet_event.packet_id, packet_event.size);
     } else if (base_packet_event_proto->event_type_size() >=
                kMaxEventsPerProto) {
       DVLOG(3) << "Too many events in packet "
                << packet_event.rtp_timestamp << ", "
                << packet_event.packet_id << ". Using new packet event proto.";
       AddPacketEventToStorage(std::move(it->second));
       if (!ShouldCreateNewProto(lower_32_bits)) {
         packet_event_map_.erase(it);
         return;
       }

       IncrementStoredProtoCount(lower_32_bits);
       it->second = std::make_unique<AggregatedPacketEvent>();
       it->second->set_relative_rtp_timestamp(lower_32_bits);
       base_packet_event_proto = GetNewBasePacketEvent(
           it->second.get(), packet_event.packet_id, packet_event.size);
     }
   }

   base_packet_event_proto->add_event_type(
       ToProtoEventType(packet_event.type));
   base_packet_event_proto->add_event_timestamp_ms(
       (packet_event.timestamp - base::TimeTicks()).InMilliseconds());

   // |base_packet_event_proto| could have been created with a receiver event
   // which does not have the packet size and we would need to overwrite it when
   // we see a sender event, which does have the packet size.
   if (packet_event.size > 0) {
     base_packet_event_proto->set_size(packet_event.size);
   }

   if (packet_event_map_.size() > kMaxMapSize)
     TransferPacketEvents(kNumMapEntriesToTransfer);

   DCHECK(packet_event_map_.size() <= kMaxMapSize);
   DCHECK(packet_event_storage_.size() <= max_frames_);
 }

 void EncodingEventSubscriber::GetEventsAndReset(LogMetadata* metadata,
     FrameEventList* frame_events, PacketEventList* packet_events) {
   DCHECK(thread_checker_.CalledOnValidThread());

   // Flush all events.
   TransferFrameEvents(frame_event_map_.size());
   TransferPacketEvents(packet_event_map_.size());
   std::sort(frame_event_storage_.begin(), frame_event_storage_.end(),
             &IsRtpTimestampLessThan<std::unique_ptr<AggregatedFrameEvent>>);
   std::sort(packet_event_storage_.begin(), packet_event_storage_.end(),
             &IsRtpTimestampLessThan<std::unique_ptr<AggregatedPacketEvent>>);

   metadata->set_is_audio(event_media_type_ == AUDIO_EVENT);
   metadata->set_first_rtp_timestamp(first_rtp_timestamp_.lower_32_bits());
   metadata->set_num_frame_events(frame_event_storage_.size());
   metadata->set_num_packet_events(packet_event_storage_.size());
   metadata->set_reference_timestamp_ms_at_unix_epoch(
       (base::TimeTicks::UnixEpoch() - base::TimeTicks()).InMilliseconds());
   frame_events->swap(frame_event_storage_);
   packet_events->swap(packet_event_storage_);
   Reset();
 }

 void EncodingEventSubscriber::TransferFrameEvents(size_t max_num_entries) {
   DCHECK(frame_event_map_.size() >= max_num_entries);

   auto it = frame_event_map_.begin();
   for (size_t i = 0;
        i < max_num_entries && it != frame_event_map_.end();
        i++, ++it) {
     AddFrameEventToStorage(std::move(it->second));
   }

   frame_event_map_.erase(frame_event_map_.begin(), it);
 }

 void EncodingEventSubscriber::TransferPacketEvents(size_t max_num_entries) {
   auto it = packet_event_map_.begin();
   for (size_t i = 0;
        i < max_num_entries && it != packet_event_map_.end();
        i++, ++it) {
     AddPacketEventToStorage(std::move(it->second));
   }

   packet_event_map_.erase(packet_event_map_.begin(), it);
 }

 void EncodingEventSubscriber::AddFrameEventToStorage(
     std::unique_ptr<AggregatedFrameEvent> frame_event_proto) {
   if (frame_event_storage_.size() >= max_frames_) {
     auto& entry = frame_event_storage_[frame_event_storage_index_];
     DecrementStoredProtoCount(entry->relative_rtp_timestamp());
     entry = std::move(frame_event_proto);
   } else {
     frame_event_storage_.push_back(std::move(frame_event_proto));
   }

   frame_event_storage_index_ = (frame_event_storage_index_ + 1) % max_frames_;
 }

 void EncodingEventSubscriber::AddPacketEventToStorage(
     std::unique_ptr<AggregatedPacketEvent> packet_event_proto) {
   if (packet_event_storage_.size() >= max_frames_) {
     auto& entry = packet_event_storage_[packet_event_storage_index_];
     DecrementStoredProtoCount(entry->relative_rtp_timestamp());
     entry = std::move(packet_event_proto);
   } else {
     packet_event_storage_.push_back(std::move(packet_event_proto));
   }

   packet_event_storage_index_ = (packet_event_storage_index_ + 1) % max_frames_;
 }

 bool EncodingEventSubscriber::ShouldCreateNewProto(
     uint32_t relative_rtp_timestamp_lower_32_bits) const {
   auto it = stored_proto_counts_.find(relative_rtp_timestamp_lower_32_bits);
   int proto_count = it == stored_proto_counts_.end() ? 0 : it->second;
   DVLOG_IF(2, proto_count >= kMaxProtosPerFrame)
       << relative_rtp_timestamp_lower_32_bits
       << " already reached max number of protos.";
   return proto_count < kMaxProtosPerFrame;
 }

 void EncodingEventSubscriber::IncrementStoredProtoCount(
     uint32_t relative_rtp_timestamp_lower_32_bits) {
   stored_proto_counts_[relative_rtp_timestamp_lower_32_bits]++;
   DCHECK_LE(stored_proto_counts_[relative_rtp_timestamp_lower_32_bits],
             kMaxProtosPerFrame)
       << relative_rtp_timestamp_lower_32_bits
       << " exceeded max number of event protos.";
 }

 void EncodingEventSubscriber::DecrementStoredProtoCount(
     uint32_t relative_rtp_timestamp_lower_32_bits) {
   auto it = stored_proto_counts_.find(relative_rtp_timestamp_lower_32_bits);
   DCHECK(it != stored_proto_counts_.end())
       << "no event protos for " << relative_rtp_timestamp_lower_32_bits;
   if (it->second > 1)
     it->second--;
   else
     stored_proto_counts_.erase(it);
 }

 RtpTimeDelta EncodingEventSubscriber::GetRelativeRtpTimestamp(
     RtpTimeTicks rtp_timestamp) {
   if (!seen_first_rtp_timestamp_) {
     seen_first_rtp_timestamp_ = true;
     first_rtp_timestamp_ = rtp_timestamp;
   }

   return rtp_timestamp - first_rtp_timestamp_;
 }

 void EncodingEventSubscriber::Reset() {
   frame_event_map_.clear();
   frame_event_storage_.clear();
   frame_event_storage_index_ = 0;
   packet_event_map_.clear();
   packet_event_storage_.clear();
   packet_event_storage_index_ = 0;
   stored_proto_counts_.clear();
   seen_first_rtp_timestamp_ = false;
   first_rtp_timestamp_ = RtpTimeTicks();
 }

 }  // namespace cast
 }  // namespace media
	// Copyright 2014 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "media/cast/logging/encoding_event_subscriber.h"

	#include <stdint.h>

	#include <algorithm>
	#include <cstring>
	#include <utility>

	#include "base/logging.h"
	#include "base/numerics/safe_conversions.h"
	#include "media/cast/logging/proto/proto_utils.h"

	using google::protobuf::RepeatedPtrField;
	using media::cast::proto::AggregatedFrameEvent;
	using media::cast::proto::AggregatedPacketEvent;
	using media::cast::proto::BasePacketEvent;
	using media::cast::proto::LogMetadata;

	namespace {

	// A size limit on maps to keep lookups fast.
	const size_t kMaxMapSize = 200;

	// The smallest (oredered by RTP timestamp) \|kNumMapEntriesToTransfer\| entries
	// will be moved when the map size reaches \|kMaxMapSize\|.
	// Must be smaller than \|kMaxMapSize\|.
	const size_t kNumMapEntriesToTransfer = 100;

	template <typename ProtoPtr>
	bool IsRtpTimestampLessThan(const ProtoPtr& lhs, const ProtoPtr& rhs) {
	return lhs->relative_rtp_timestamp() < rhs->relative_rtp_timestamp();
	}

	BasePacketEvent* GetNewBasePacketEvent(AggregatedPacketEvent* event_proto,
	int packet_id, int size) {
	BasePacketEvent* base = event_proto->add_base_packet_event();
	base->set_packet_id(packet_id);
	base->set_size(size);
	return base;
	}

	} // namespace

	namespace media {
	namespace cast {

	EncodingEventSubscriber::EncodingEventSubscriber(
	EventMediaType event_media_type,
	size_t max_frames)
	: event_media_type_(event_media_type), max_frames_(max_frames) {
	Reset();
	}

	EncodingEventSubscriber::~EncodingEventSubscriber() {
	DCHECK(thread_checker_.CalledOnValidThread());
	}

	void EncodingEventSubscriber::OnReceiveFrameEvent(
	const FrameEvent& frame_event) {
	DCHECK(thread_checker_.CalledOnValidThread());

	if (event_media_type_ != frame_event.media_type)
	return;

	const RtpTimeDelta relative_rtp_timestamp =
	GetRelativeRtpTimestamp(frame_event.rtp_timestamp);
	const uint32_t lower_32_bits = relative_rtp_timestamp.lower_32_bits();
	AggregatedFrameEvent* event_proto_ptr = nullptr;

	// Look up existing entry. If not found, create a new entry and add to map.
	auto it = frame_event_map_.find(relative_rtp_timestamp);
	if (it == frame_event_map_.end()) {
	if (!ShouldCreateNewProto(lower_32_bits))
	return;

	IncrementStoredProtoCount(lower_32_bits);
	auto event_proto = std::make_unique<AggregatedFrameEvent>();
	event_proto->set_relative_rtp_timestamp(lower_32_bits);
	event_proto_ptr = event_proto.get();
	frame_event_map_.insert(
	std::make_pair(relative_rtp_timestamp, std::move(event_proto)));
	} else {
	if (it->second->event_type_size() >= kMaxEventsPerProto) {
	DVLOG(2) << "Too many events in frame " << frame_event.rtp_timestamp
	<< ". Using new frame event proto.";
	AddFrameEventToStorage(std::move(it->second));
	if (!ShouldCreateNewProto(lower_32_bits)) {
	frame_event_map_.erase(it);
	return;
	}

	IncrementStoredProtoCount(lower_32_bits);
	it->second = std::make_unique<AggregatedFrameEvent>();
	it->second->set_relative_rtp_timestamp(lower_32_bits);
	}
	event_proto_ptr = it->second.get();
	}

	event_proto_ptr->add_event_type(ToProtoEventType(frame_event.type));
	event_proto_ptr->add_event_timestamp_ms(
	(frame_event.timestamp - base::TimeTicks()).InMilliseconds());

	if (frame_event.type == FRAME_CAPTURE_END) {
	if (frame_event.media_type == VIDEO_EVENT &&
	frame_event.width > 0 && frame_event.height > 0) {
	event_proto_ptr->set_width(frame_event.width);
	event_proto_ptr->set_height(frame_event.height);
	}
	} else if (frame_event.type == FRAME_ENCODED) {
	event_proto_ptr->set_encoded_frame_size(frame_event.size);
	if (frame_event.encoder_cpu_utilization >= 0.0) {
	event_proto_ptr->set_encoder_cpu_percent_utilized(
	base::saturated_cast<int32_t>(
	frame_event.encoder_cpu_utilization * 100.0 + 0.5));
	}
	if (frame_event.idealized_bitrate_utilization >= 0.0) {
	event_proto_ptr->set_idealized_bitrate_percent_utilized(
	base::saturated_cast<int32_t>(
	frame_event.idealized_bitrate_utilization * 100.0 + 0.5));
	}
	if (frame_event.media_type == VIDEO_EVENT) {
	event_proto_ptr->set_key_frame(frame_event.key_frame);
	event_proto_ptr->set_target_bitrate(frame_event.target_bitrate);
	}
	} else if (frame_event.type == FRAME_PLAYOUT) {
	event_proto_ptr->set_delay_millis(frame_event.delay_delta.InMilliseconds());
	}

	if (frame_event_map_.size() > kMaxMapSize)
	TransferFrameEvents(kNumMapEntriesToTransfer);

	DCHECK(frame_event_map_.size() <= kMaxMapSize);
	DCHECK(frame_event_storage_.size() <= max_frames_);
	}

	void EncodingEventSubscriber::OnReceivePacketEvent(
	const PacketEvent& packet_event) {
	DCHECK(thread_checker_.CalledOnValidThread());

	if (event_media_type_ != packet_event.media_type)
	return;

	const RtpTimeDelta relative_rtp_timestamp =
	GetRelativeRtpTimestamp(packet_event.rtp_timestamp);
	uint32_t lower_32_bits = relative_rtp_timestamp.lower_32_bits();
	auto it = packet_event_map_.find(relative_rtp_timestamp);
	BasePacketEvent* base_packet_event_proto = nullptr;

	// Look up existing entry. If not found, create a new entry and add to map.
	if (it == packet_event_map_.end()) {
	if (!ShouldCreateNewProto(lower_32_bits))
	return;

	IncrementStoredProtoCount(lower_32_bits);
	auto event_proto = std::make_unique<AggregatedPacketEvent>();
	event_proto->set_relative_rtp_timestamp(lower_32_bits);
	base_packet_event_proto = GetNewBasePacketEvent(
	event_proto.get(), packet_event.packet_id, packet_event.size);
	packet_event_map_.insert(
	std::make_pair(relative_rtp_timestamp, std::move(event_proto)));
	} else {
	// Found existing entry, now look up existing BasePacketEvent using packet
	// ID. If not found, create a new entry and add to proto.
	RepeatedPtrField<BasePacketEvent>* field =
	it->second->mutable_base_packet_event();
	for (RepeatedPtrField<BasePacketEvent>::pointer_iterator base_it =
	field->pointer_begin();
	base_it != field->pointer_end();
	++base_it) {
	if ((*base_it)->packet_id() == packet_event.packet_id) {
	base_packet_event_proto = *base_it;
	break;
	}
	}
	if (!base_packet_event_proto) {
	if (it->second->base_packet_event_size() >= kMaxPacketsPerFrame) {
	DVLOG(3) << "Too many packets in AggregatedPacketEvent "
	<< packet_event.rtp_timestamp << ". "
	<< "Using new packet event proto.";
	AddPacketEventToStorage(std::move(it->second));
	if (!ShouldCreateNewProto(lower_32_bits)) {
	packet_event_map_.erase(it);
	return;
	}

	IncrementStoredProtoCount(lower_32_bits);
	it->second = std::make_unique<AggregatedPacketEvent>();
	it->second->set_relative_rtp_timestamp(lower_32_bits);
	}

	base_packet_event_proto = GetNewBasePacketEvent(
	it->second.get(), packet_event.packet_id, packet_event.size);
	} else if (base_packet_event_proto->event_type_size() >=
	kMaxEventsPerProto) {
	DVLOG(3) << "Too many events in packet "
	<< packet_event.rtp_timestamp << ", "
	<< packet_event.packet_id << ". Using new packet event proto.";
	AddPacketEventToStorage(std::move(it->second));
	if (!ShouldCreateNewProto(lower_32_bits)) {
	packet_event_map_.erase(it);
	return;
	}

	IncrementStoredProtoCount(lower_32_bits);
	it->second = std::make_unique<AggregatedPacketEvent>();
	it->second->set_relative_rtp_timestamp(lower_32_bits);
	base_packet_event_proto = GetNewBasePacketEvent(
	it->second.get(), packet_event.packet_id, packet_event.size);
	}
	}

	base_packet_event_proto->add_event_type(
	ToProtoEventType(packet_event.type));
	base_packet_event_proto->add_event_timestamp_ms(
	(packet_event.timestamp - base::TimeTicks()).InMilliseconds());

	// \|base_packet_event_proto\| could have been created with a receiver event
	// which does not have the packet size and we would need to overwrite it when
	// we see a sender event, which does have the packet size.
	if (packet_event.size > 0) {
	base_packet_event_proto->set_size(packet_event.size);
	}

	if (packet_event_map_.size() > kMaxMapSize)
	TransferPacketEvents(kNumMapEntriesToTransfer);

	DCHECK(packet_event_map_.size() <= kMaxMapSize);
	DCHECK(packet_event_storage_.size() <= max_frames_);
	}

	void EncodingEventSubscriber::GetEventsAndReset(LogMetadata* metadata,
	FrameEventList* frame_events, PacketEventList* packet_events) {
	DCHECK(thread_checker_.CalledOnValidThread());

	// Flush all events.
	TransferFrameEvents(frame_event_map_.size());
	TransferPacketEvents(packet_event_map_.size());
	std::sort(frame_event_storage_.begin(), frame_event_storage_.end(),
	&IsRtpTimestampLessThan<std::unique_ptr<AggregatedFrameEvent>>);
	std::sort(packet_event_storage_.begin(), packet_event_storage_.end(),
	&IsRtpTimestampLessThan<std::unique_ptr<AggregatedPacketEvent>>);

	metadata->set_is_audio(event_media_type_ == AUDIO_EVENT);
	metadata->set_first_rtp_timestamp(first_rtp_timestamp_.lower_32_bits());
	metadata->set_num_frame_events(frame_event_storage_.size());
	metadata->set_num_packet_events(packet_event_storage_.size());
	metadata->set_reference_timestamp_ms_at_unix_epoch(
	(base::TimeTicks::UnixEpoch() - base::TimeTicks()).InMilliseconds());
	frame_events->swap(frame_event_storage_);
	packet_events->swap(packet_event_storage_);
	Reset();
	}

	void EncodingEventSubscriber::TransferFrameEvents(size_t max_num_entries) {
	DCHECK(frame_event_map_.size() >= max_num_entries);

	auto it = frame_event_map_.begin();
	for (size_t i = 0;
	i < max_num_entries && it != frame_event_map_.end();
	i++, ++it) {
	AddFrameEventToStorage(std::move(it->second));
	}

	frame_event_map_.erase(frame_event_map_.begin(), it);
	}

	void EncodingEventSubscriber::TransferPacketEvents(size_t max_num_entries) {
	auto it = packet_event_map_.begin();
	for (size_t i = 0;
	i < max_num_entries && it != packet_event_map_.end();
	i++, ++it) {
	AddPacketEventToStorage(std::move(it->second));
	}

	packet_event_map_.erase(packet_event_map_.begin(), it);
	}

	void EncodingEventSubscriber::AddFrameEventToStorage(
	std::unique_ptr<AggregatedFrameEvent> frame_event_proto) {
	if (frame_event_storage_.size() >= max_frames_) {
	auto& entry = frame_event_storage_[frame_event_storage_index_];
	DecrementStoredProtoCount(entry->relative_rtp_timestamp());
	entry = std::move(frame_event_proto);
	} else {
	frame_event_storage_.push_back(std::move(frame_event_proto));
	}

	frame_event_storage_index_ = (frame_event_storage_index_ + 1) % max_frames_;
	}

	void EncodingEventSubscriber::AddPacketEventToStorage(
	std::unique_ptr<AggregatedPacketEvent> packet_event_proto) {
	if (packet_event_storage_.size() >= max_frames_) {
	auto& entry = packet_event_storage_[packet_event_storage_index_];
	DecrementStoredProtoCount(entry->relative_rtp_timestamp());
	entry = std::move(packet_event_proto);
	} else {
	packet_event_storage_.push_back(std::move(packet_event_proto));
	}

	packet_event_storage_index_ = (packet_event_storage_index_ + 1) % max_frames_;
	}

	bool EncodingEventSubscriber::ShouldCreateNewProto(
	uint32_t relative_rtp_timestamp_lower_32_bits) const {
	auto it = stored_proto_counts_.find(relative_rtp_timestamp_lower_32_bits);
	int proto_count = it == stored_proto_counts_.end() ? 0 : it->second;
	DVLOG_IF(2, proto_count >= kMaxProtosPerFrame)
	<< relative_rtp_timestamp_lower_32_bits
	<< " already reached max number of protos.";
	return proto_count < kMaxProtosPerFrame;
	}

	void EncodingEventSubscriber::IncrementStoredProtoCount(
	uint32_t relative_rtp_timestamp_lower_32_bits) {
	stored_proto_counts_[relative_rtp_timestamp_lower_32_bits]++;
	DCHECK_LE(stored_proto_counts_[relative_rtp_timestamp_lower_32_bits],
	kMaxProtosPerFrame)
	<< relative_rtp_timestamp_lower_32_bits
	<< " exceeded max number of event protos.";
	}

	void EncodingEventSubscriber::DecrementStoredProtoCount(
	uint32_t relative_rtp_timestamp_lower_32_bits) {
	auto it = stored_proto_counts_.find(relative_rtp_timestamp_lower_32_bits);
	DCHECK(it != stored_proto_counts_.end())
	<< "no event protos for " << relative_rtp_timestamp_lower_32_bits;
	if (it->second > 1)
	it->second--;
	else
	stored_proto_counts_.erase(it);
	}

	RtpTimeDelta EncodingEventSubscriber::GetRelativeRtpTimestamp(
	RtpTimeTicks rtp_timestamp) {
	if (!seen_first_rtp_timestamp_) {
	seen_first_rtp_timestamp_ = true;
	first_rtp_timestamp_ = rtp_timestamp;
	}

	return rtp_timestamp - first_rtp_timestamp_;
	}

	void EncodingEventSubscriber::Reset() {
	frame_event_map_.clear();
	frame_event_storage_.clear();
	frame_event_storage_index_ = 0;
	packet_event_map_.clear();
	packet_event_storage_.clear();
	packet_event_storage_index_ = 0;
	stored_proto_counts_.clear();
	seen_first_rtp_timestamp_ = false;
	first_rtp_timestamp_ = RtpTimeTicks();
	}

	} // namespace cast
	} // namespace media