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 uint32 FrameIdMap::LastContinuousFrame() const {
 141   uint32 last_continuous_frame_id = last_released_frame_;
 142   uint32 next_expected_frame = last_released_frame_;
 143
 144   FrameMap::const_iterator it;
 145
 146   do {
 147     next_expected_frame++;
 148     it = frame_map_.find(next_expected_frame);
 149     if (it == frame_map_.end())
 150       break;
 151     if (!it->second->Complete())
 152       break;
 153
 154     // We found the next continuous frame.
 155     last_continuous_frame_id = it->first;
 156   } while (next_expected_frame != newest_frame_id_);
 157   return last_continuous_frame_id;
 158 }
 159
 160 bool FrameIdMap::NextAudioFrameAllowingMissingFrames(uint32* frame_id) const {
 161   // First check if we have continuous frames.
 162   if (NextContinuousFrame(frame_id))
 163     return true;
 164
 165   // Find the oldest frame.
 166   FrameMap::const_iterator it_best_match = frame_map_.end();
 167   FrameMap::const_iterator it;
 168
 169   // Find first complete frame.
 170   for (it = frame_map_.begin(); it != frame_map_.end(); ++it) {
 171     if (it->second->Complete()) {
 172       it_best_match = it;
 173       break;
 174     }
 175   }
 176   if (it_best_match == frame_map_.end())
 177     return false;  // No complete frame.
 178
 179   ++it;
 180   for (; it != frame_map_.end(); ++it) {
 181     if (it->second->Complete() &&
 182         IsOlderFrameId(it->first, it_best_match->first)) {
 183       it_best_match = it;
 184     }
 185   }
 186   *frame_id = it_best_match->first;
 187   return true;
 188 }
 189
 190 bool FrameIdMap::NextVideoFrameAllowingSkippingFrames(uint32* frame_id) const {
 191   // Find the oldest decodable frame.
 192   FrameMap::const_iterator it_best_match = frame_map_.end();
 193   FrameMap::const_iterator it;
 194   for (it = frame_map_.begin(); it != frame_map_.end(); ++it) {
 195     if (it->second->Complete() && DecodableVideoFrame(it->second.get())) {
 196       it_best_match = it;
 197     }
 198   }
 199   if (it_best_match == frame_map_.end())
 200     return false;
 201
 202   *frame_id = it_best_match->first;
 203   return true;
 204 }
 205
 206 bool FrameIdMap::Empty() const { return frame_map_.empty(); }
 207
 208 int FrameIdMap::NumberOfCompleteFrames() const {
 209   int count = 0;
 210   FrameMap::const_iterator it;
 211   for (it = frame_map_.begin(); it != frame_map_.end(); ++it) {
 212     if (it->second->Complete()) {
 213       ++count;
 214     }
 215   }
 216   return count;
 217 }
 218
 219 bool FrameIdMap::FrameExists(uint32 frame_id) const {
 220   return frame_map_.end() != frame_map_.find(frame_id);
 221 }
 222
 223 void FrameIdMap::GetMissingPackets(uint32 frame_id,
 224                                    bool last_frame,
 225                                    PacketIdSet* missing_packets) const {
 226   FrameMap::const_iterator it = frame_map_.find(frame_id);
 227   if (it == frame_map_.end())
 228     return;
 229
 230   it->second->GetMissingPackets(last_frame, missing_packets);
 231 }
 232
 233 bool FrameIdMap::ContinuousFrame(FrameInfo* frame) const {
 234   DCHECK(frame);
 235   if (waiting_for_key_ && !frame->is_key_frame())
 236     return false;
 237   return static_cast<uint32>(last_released_frame_ + 1) == frame->frame_id();
 238 }
 239
 240 bool FrameIdMap::DecodableVideoFrame(FrameInfo* frame) const {
 241   if (frame->is_key_frame())
 242     return true;
 243   if (waiting_for_key_ && !frame->is_key_frame())
 244     return false;
 245
 246   // Current frame is not necessarily referencing the last frame.
 247   // Do we have the reference frame?
 248   if (IsOlderFrameId(frame->referenced_frame_id(), last_released_frame_)) {
 249     return true;
 250   }
 251   return frame->referenced_frame_id() == last_released_frame_;
 252 }
 253
 254 }  //  namespace cast
 255 }  //  namespace media