Cast: Reshuffle files under media/cast

media/cast/framer/cast_message_builder.cc

-// Copyright 2013 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/framer/cast_message_builder.h"
-
-#include "media/cast/cast_defines.h"
-
-namespace media {
-namespace cast {
-
-CastMessageBuilder::CastMessageBuilder(
-    base::TickClock* clock,
-    RtpPayloadFeedback* incoming_payload_feedback,
-    FrameIdMap* frame_id_map,
-    uint32 media_ssrc,
-    bool decoder_faster_than_max_frame_rate,
-    int max_unacked_frames)
-    : clock_(clock),
-      cast_feedback_(incoming_payload_feedback),
-      frame_id_map_(frame_id_map),
-      media_ssrc_(media_ssrc),
-      decoder_faster_than_max_frame_rate_(decoder_faster_than_max_frame_rate),
-      max_unacked_frames_(max_unacked_frames),
-      cast_msg_(media_ssrc),
-      slowing_down_ack_(false),
-      acked_last_frame_(true),
-      last_acked_frame_id_(kStartFrameId) {
-  cast_msg_.ack_frame_id_ = kStartFrameId;
-}
-
-CastMessageBuilder::~CastMessageBuilder() {}
-
-void CastMessageBuilder::CompleteFrameReceived(uint32 frame_id) {
-  DCHECK_GE(static_cast<int32>(frame_id - last_acked_frame_id_), 0);
-  VLOG(2) << "CompleteFrameReceived: " << frame_id;
-  if (last_update_time_.is_null()) {
-    // Our first update.
-    last_update_time_ = clock_->NowTicks();
-  }
-
-  if (!UpdateAckMessage(frame_id)) {
-    return;
-  }
-  BuildPacketList();
-
-  // Send cast message.
-  VLOG(2) << "Send cast message Ack:" << static_cast<int>(frame_id);
-  cast_feedback_->CastFeedback(cast_msg_);
-}
-
-bool CastMessageBuilder::UpdateAckMessage(uint32 frame_id) {
-  if (!decoder_faster_than_max_frame_rate_) {
-    int complete_frame_count = frame_id_map_->NumberOfCompleteFrames();
-    if (complete_frame_count > max_unacked_frames_) {
-      // We have too many frames pending in our framer; slow down ACK.
-      if (!slowing_down_ack_) {
-        slowing_down_ack_ = true;
-        ack_queue_.push_back(last_acked_frame_id_);
-      }
-    } else if (complete_frame_count <= 1) {
-      // We are down to one or less frames in our framer; ACK normally.
-      slowing_down_ack_ = false;
-      ack_queue_.clear();
-    }
-  }
-
-  if (slowing_down_ack_) {
-    // We are slowing down acknowledgment by acknowledging every other frame.
-    // Note: frame skipping and slowdown ACK is not supported at the same
-    // time; and it's not needed since we can skip frames to catch up.
-    if (!ack_queue_.empty() && ack_queue_.back() == frame_id) {
-      return false;
-    }
-    ack_queue_.push_back(frame_id);
-    if (!acked_last_frame_) {
-      ack_queue_.pop_front();
-    }
-    frame_id = ack_queue_.front();
-  }
-
-  acked_last_frame_ = false;
-  // Is it a new frame?
-  if (last_acked_frame_id_ == frame_id) {
-    return false;
-  }
-  acked_last_frame_ = true;
-  last_acked_frame_id_ = frame_id;
-  cast_msg_.ack_frame_id_ = last_acked_frame_id_;
-  cast_msg_.missing_frames_and_packets_.clear();
-  last_update_time_ = clock_->NowTicks();
-  return true;
-}
-
-bool CastMessageBuilder::TimeToSendNextCastMessage(
-    base::TimeTicks* time_to_send) {
-  // We haven't received any packets.
-  if (last_update_time_.is_null() && frame_id_map_->Empty())
-    return false;
-
-  *time_to_send = last_update_time_ + base::TimeDelta::FromMilliseconds(
-                                          kCastMessageUpdateIntervalMs);
-  return true;
-}
-
-void CastMessageBuilder::UpdateCastMessage() {
-  RtcpCastMessage message(media_ssrc_);
-  if (!UpdateCastMessageInternal(&message))
-    return;
-
-  // Send cast message.
-  cast_feedback_->CastFeedback(message);
-}
-
-void CastMessageBuilder::Reset() {
-  cast_msg_.ack_frame_id_ = kStartFrameId;
-  cast_msg_.missing_frames_and_packets_.clear();
-  time_last_nacked_map_.clear();
-}
-
-bool CastMessageBuilder::UpdateCastMessageInternal(RtcpCastMessage* message) {
-  if (last_update_time_.is_null()) {
-    if (!frame_id_map_->Empty()) {
-      // We have received packets.
-      last_update_time_ = clock_->NowTicks();
-    }
-    return false;
-  }
-  // Is it time to update the cast message?
-  base::TimeTicks now = clock_->NowTicks();
-  if (now - last_update_time_ <
-      base::TimeDelta::FromMilliseconds(kCastMessageUpdateIntervalMs)) {
-    return false;
-  }
-  last_update_time_ = now;
-
-  // Needed to cover when a frame is skipped.
-  UpdateAckMessage(last_acked_frame_id_);
-  BuildPacketList();
-  message->Copy(cast_msg_);
-  return true;
-}
-
-void CastMessageBuilder::BuildPacketList() {
-  base::TimeTicks now = clock_->NowTicks();
-
-  // Clear message NACK list.
-  cast_msg_.missing_frames_and_packets_.clear();
-
-  // Are we missing packets?
-  if (frame_id_map_->Empty())
-    return;
-
-  uint32 newest_frame_id = frame_id_map_->NewestFrameId();
-  uint32 next_expected_frame_id = cast_msg_.ack_frame_id_ + 1;
-
-  // Iterate over all frames.
-  for (; !IsNewerFrameId(next_expected_frame_id, newest_frame_id);
-       ++next_expected_frame_id) {
-    TimeLastNackMap::iterator it =
-        time_last_nacked_map_.find(next_expected_frame_id);
-    if (it != time_last_nacked_map_.end()) {
-      // We have sent a NACK in this frame before, make sure enough time have
-      // passed.
-      if (now - it->second <
-          base::TimeDelta::FromMilliseconds(kNackRepeatIntervalMs)) {
-        continue;
-      }
-    }
-
-    PacketIdSet missing;
-    if (frame_id_map_->FrameExists(next_expected_frame_id)) {
-      bool last_frame = (newest_frame_id == next_expected_frame_id);
-      frame_id_map_->GetMissingPackets(
-          next_expected_frame_id, last_frame, &missing);
-      if (!missing.empty()) {
-        time_last_nacked_map_[next_expected_frame_id] = now;
-        cast_msg_.missing_frames_and_packets_.insert(
-            std::make_pair(next_expected_frame_id, missing));
-      }
-    } else {
-      time_last_nacked_map_[next_expected_frame_id] = now;
-      missing.insert(kRtcpCastAllPacketsLost);
-      cast_msg_.missing_frames_and_packets_[next_expected_frame_id] = missing;
-    }
-  }
-}
-
-}  //  namespace cast
-}  //  namespace media