media/cast/framer/frame_id_map.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/cast/framer/frame_id_map.h"
   6
   7 #include "base/logging.h"
   8 #include "media/cast/rtp_receiver/rtp_receiver_defines.h"
   9
  10 namespace media {
  11 namespace cast {
  12
  13 FrameInfo::FrameInfo(uint32 frame_id,
  14                      uint32 referenced_frame_id,
  15                      uint16 max_packet_id,
  16                      bool key_frame)
  17     : is_key_frame_(key_frame),
  18       frame_id_(frame_id),
  19       referenced_frame_id_(referenced_frame_id),
  20       max_received_packet_id_(0) {
  21   // Create the set with all packets missing.
  22   for (uint16 i = 0; i <= max_packet_id; i++) {
  23     missing_packets_.insert(i);
  24   }
  25 }
  26
  27 FrameInfo::~FrameInfo() {}
  28
  29 PacketType FrameInfo::InsertPacket(uint16 packet_id) {
  30   if (missing_packets_.find(packet_id) == missing_packets_.end()) {
  31     return kDuplicatePacket;
  32   }
  33   // Update the last received packet id.
  34   if (IsNewerPacketId(packet_id, max_received_packet_id_)) {
  35     max_received_packet_id_ = packet_id;
  36   }
  37   missing_packets_.erase(packet_id);
  38   return missing_packets_.empty() ? kNewPacketCompletingFrame : kNewPacket;
  39 }
  40
  41 bool FrameInfo::Complete() const { return missing_packets_.empty(); }
  42
  43 void FrameInfo::GetMissingPackets(bool newest_frame,
  44                                   PacketIdSet* missing_packets) const {
  45   if (newest_frame) {
  46     // Missing packets capped by max_received_packet_id_.
  47     PacketIdSet::const_iterator it_after_last_received =
  48         missing_packets_.lower_bound(max_received_packet_id_);
  49     missing_packets->insert(missing_packets_.begin(), it_after_last_received);
  50   } else {
  51     missing_packets->insert(missing_packets_.begin(), missing_packets_.end());
  52   }
  53 }
  54
  55 FrameIdMap::FrameIdMap()
  56     : waiting_for_key_(true),
  57       last_released_frame_(kStartFrameId),
  58       newest_frame_id_(kStartFrameId) {}
  59
  60 FrameIdMap::~FrameIdMap() {}
  61
  62 PacketType FrameIdMap::InsertPacket(const RtpCastHeader& rtp_header) {
  63   uint32 frame_id = rtp_header.frame_id;
  64   uint32 reference_frame_id;
  65   reference_frame_id = rtp_header.reference_frame_id;
  66
  67   if (rtp_header.is_key_frame && waiting_for_key_) {
  68     last_released_frame_ = static_cast<uint32>(frame_id - 1);
  69     waiting_for_key_ = false;
  70   }
  71
  72   VLOG(3) << "InsertPacket frame:" << frame_id
  73           << " packet:" << static_cast<int>(rtp_header.packet_id)
  74           << " max packet:" << static_cast<int>(rtp_header.max_packet_id);
  75
  76   if (IsOlderFrameId(frame_id, last_released_frame_) && !waiting_for_key_) {
  77     return kTooOldPacket;
  78   }
  79
  80   // Update the last received frame id.
  81   if (IsNewerFrameId(frame_id, newest_frame_id_)) {
  82     newest_frame_id_ = frame_id;
  83   }
  84
  85   // Does this packet belong to a new frame?
  86   FrameMap::iterator it = frame_map_.find(frame_id);
  87   PacketType packet_type;
  88   if (it == frame_map_.end()) {
  89     // New frame.
  90     linked_ptr<FrameInfo> frame_info(new FrameInfo(frame_id,
  91                                                    reference_frame_id,
  92                                                    rtp_header.max_packet_id,
  93                                                    rtp_header.is_key_frame));
  94     std::pair<FrameMap::iterator, bool> retval =
  95         frame_map_.insert(std::make_pair(frame_id, frame_info));
  96
  97     packet_type = retval.first->second->InsertPacket(rtp_header.packet_id);
  98   } else {
  99     // Insert packet to existing frame.
 100     packet_type = it->second->InsertPacket(rtp_header.packet_id);
 101   }
 102   return packet_type;
 103 }
 104
 105 void FrameIdMap::RemoveOldFrames(uint32 frame_id) {
 106   FrameMap::iterator it = frame_map_.begin();
 107
 108   while (it != frame_map_.end()) {
 109     if (IsNewerFrameId(it->first, frame_id)) {
 110       ++it;
 111     } else {
 112       // Older or equal; erase.
 113       frame_map_.erase(it++);
 114     }
 115   }
 116   last_released_frame_ = frame_id;
 117 }
 118
 119 void FrameIdMap::Clear() {
 120   frame_map_.clear();
 121   waiting_for_key_ = true;
 122   last_released_frame_ = kStartFrameId;
 123   newest_frame_id_ = kStartFrameId;
 124 }
 125
 126 uint32 FrameIdMap::NewestFrameId() const { return newest_frame_id_; }
 127
 128 bool FrameIdMap::NextContinuousFrame(uint32* frame_id) const {
 129   FrameMap::const_iterator it;
 130
 131   for (it = frame_map_.begin(); it != frame_map_.end(); ++it) {
 132     if (it->second->Complete() && ContinuousFrame(it->second.get())) {
 133       *frame_id = it->first;
 134       return true;
 135     }
 136   }
 137   return false;
 138 }
 139
 140 bool FrameIdMap::HaveMultipleDecodableFrames() const {
 141   // Find the oldest decodable frame.
 142   FrameMap::const_iterator it;
 143   bool found_one = false;
 144   for (it = frame_map_.begin(); it != frame_map_.end(); ++it) {
 145     if (it->second->Complete() && DecodableFrame(it->second.get())) {
 146       if (found_one) {
 147         return true;
 148       } else {
 149         found_one = true;
 150       }
 151     }
 152   }
 153   return false;
 154 }
 155
 156 uint32 FrameIdMap::LastContinuousFrame() const {
 157   uint32 last_continuous_frame_id = last_released_frame_;
 158   uint32 next_expected_frame = last_released_frame_;
 159
 160   FrameMap::const_iterator it;
 161
 162   do {
 163     next_expected_frame++;
 164     it = frame_map_.find(next_expected_frame);
 165     if (it == frame_map_.end())
 166       break;
 167     if (!it->second->Complete())
 168       break;
 169
 170     // We found the next continuous frame.
 171     last_continuous_frame_id = it->first;
 172   } while (next_expected_frame != newest_frame_id_);
 173   return last_continuous_frame_id;
 174 }
 175
 176 bool FrameIdMap::NextFrameAllowingSkippingFrames(uint32* frame_id) const {
 177   // Find the oldest decodable frame.
 178   FrameMap::const_iterator it_best_match = frame_map_.end();
 179   FrameMap::const_iterator it;
 180   for (it = frame_map_.begin(); it != frame_map_.end(); ++it) {
 181     if (it->second->Complete() && DecodableFrame(it->second.get())) {
 182       if (it_best_match == frame_map_.end() ||
 183           IsOlderFrameId(it->first, it_best_match->first)) {
 184         it_best_match = it;
 185       }
 186     }
 187   }
 188   if (it_best_match == frame_map_.end())
 189     return false;
 190
 191   *frame_id = it_best_match->first;
 192   return true;
 193 }
 194
 195 bool FrameIdMap::Empty() const { return frame_map_.empty(); }
 196
 197 int FrameIdMap::NumberOfCompleteFrames() const {
 198   int count = 0;
 199   FrameMap::const_iterator it;
 200   for (it = frame_map_.begin(); it != frame_map_.end(); ++it) {
 201     if (it->second->Complete()) {
 202       ++count;
 203     }
 204   }
 205   return count;
 206 }
 207
 208 bool FrameIdMap::FrameExists(uint32 frame_id) const {
 209   return frame_map_.end() != frame_map_.find(frame_id);
 210 }
 211
 212 void FrameIdMap::GetMissingPackets(uint32 frame_id,
 213                                    bool last_frame,
 214                                    PacketIdSet* missing_packets) const {
 215   FrameMap::const_iterator it = frame_map_.find(frame_id);
 216   if (it == frame_map_.end())
 217     return;
 218
 219   it->second->GetMissingPackets(last_frame, missing_packets);
 220 }
 221
 222 bool FrameIdMap::ContinuousFrame(FrameInfo* frame) const {
 223   DCHECK(frame);
 224   if (waiting_for_key_ && !frame->is_key_frame())
 225     return false;
 226   return static_cast<uint32>(last_released_frame_ + 1) == frame->frame_id();
 227 }
 228
 229 bool FrameIdMap::DecodableFrame(FrameInfo* frame) const {
 230   if (frame->is_key_frame())
 231     return true;
 232   if (waiting_for_key_ && !frame->is_key_frame())
 233     return false;
 234   // Self-reference?
 235   if (frame->referenced_frame_id() == frame->frame_id())
 236     return true;
 237
 238   // Current frame is not necessarily referencing the last frame.
 239   // Do we have the reference frame?
 240   if (IsOlderFrameId(frame->referenced_frame_id(), last_released_frame_)) {
 241     return true;
 242   }
 243   return frame->referenced_frame_id() == last_released_frame_;
 244 }
 245
 246 }  //  namespace cast
 247 }  //  namespace media