src/third_party/webrtc/modules/audio_coding/neteq4/tools/packet.cc

   1 /*
   2  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
   3  *
   4  *  Use of this source code is governed by a BSD-style license
   5  *  that can be found in the LICENSE file in the root of the source
   6  *  tree. An additional intellectual property rights grant can be found
   7  *  in the file PATENTS.  All contributing project authors may
   8  *  be found in the AUTHORS file in the root of the source tree.
   9  */
  10
  11 #include "webrtc/modules/audio_coding/neteq4/tools/packet.h"
  12 #include "webrtc/modules/rtp_rtcp/interface/rtp_header_parser.h"
  13
  14 namespace webrtc {
  15 namespace test {
  16
  17 Packet::Packet(uint8_t* packet_memory,
  18                size_t allocated_bytes,
  19                double time_ms,
  20                const RtpHeaderParser& parser)
  21     : payload_memory_(packet_memory),
  22       payload_(NULL),
  23       packet_length_bytes_(allocated_bytes),
  24       payload_length_bytes_(0),
  25       virtual_packet_length_bytes_(allocated_bytes),
  26       virtual_payload_length_bytes_(0),
  27       time_ms_(time_ms) {
  28   valid_header_ = ParseHeader(parser);
  29 }
  30
  31 Packet::Packet(uint8_t* packet_memory,
  32                size_t allocated_bytes,
  33                size_t virtual_packet_length_bytes,
  34                double time_ms,
  35                const RtpHeaderParser& parser)
  36     : payload_memory_(packet_memory),
  37       payload_(NULL),
  38       packet_length_bytes_(allocated_bytes),
  39       payload_length_bytes_(0),
  40       virtual_packet_length_bytes_(virtual_packet_length_bytes),
  41       virtual_payload_length_bytes_(0),
  42       time_ms_(time_ms) {
  43   valid_header_ = ParseHeader(parser);
  44 }
  45
  46 Packet::Packet(uint8_t* packet_memory, size_t allocated_bytes, double time_ms)
  47     : payload_memory_(packet_memory),
  48       payload_(NULL),
  49       packet_length_bytes_(allocated_bytes),
  50       payload_length_bytes_(0),
  51       virtual_packet_length_bytes_(allocated_bytes),
  52       virtual_payload_length_bytes_(0),
  53       time_ms_(time_ms) {
  54   scoped_ptr<RtpHeaderParser> parser(RtpHeaderParser::Create());
  55   valid_header_ = ParseHeader(*parser);
  56 }
  57
  58 Packet::Packet(uint8_t* packet_memory,
  59                size_t allocated_bytes,
  60                size_t virtual_packet_length_bytes,
  61                double time_ms)
  62     : payload_memory_(packet_memory),
  63       payload_(NULL),
  64       packet_length_bytes_(allocated_bytes),
  65       payload_length_bytes_(0),
  66       virtual_packet_length_bytes_(virtual_packet_length_bytes),
  67       virtual_payload_length_bytes_(0),
  68       time_ms_(time_ms) {
  69   scoped_ptr<RtpHeaderParser> parser(RtpHeaderParser::Create());
  70   valid_header_ = ParseHeader(*parser);
  71 }
  72
  73 bool Packet::ExtractRedHeaders(std::list<RTPHeader*>* headers) const {
  74   //
  75   //  0                   1                    2                   3
  76   //  0 1 2 3 4 5 6 7 8 9 0 1 2 3  4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  77   // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  78   // |1|   block PT  |  timestamp offset         |   block length    |
  79   // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  80   // |1|    ...                                                      |
  81   // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  82   // |0|   block PT  |
  83   // +-+-+-+-+-+-+-+-+
  84   //
  85
  86   assert(payload_);
  87   const uint8_t* payload_ptr = payload_;
  88   const uint8_t* payload_end_ptr = payload_ptr + payload_length_bytes_;
  89
  90   // Find all RED headers with the extension bit set to 1. That is, all headers
  91   // but the last one.
  92   while ((payload_ptr < payload_end_ptr) && (*payload_ptr & 0x80)) {
  93     RTPHeader* header = new RTPHeader;
  94     CopyToHeader(header);
  95     header->payloadType = payload_ptr[0] & 0x7F;
  96     uint32_t offset = (payload_ptr[1] << 6) + ((payload_ptr[2] & 0xFC) >> 2);
  97     header->timestamp -= offset;
  98     headers->push_front(header);
  99     payload_ptr += 4;
 100   }
 101   // Last header.
 102   assert(payload_ptr < payload_end_ptr);
 103   if (payload_ptr >= payload_end_ptr) {
 104     return false;  // Payload too short.
 105   }
 106   RTPHeader* header = new RTPHeader;
 107   CopyToHeader(header);
 108   header->payloadType = payload_ptr[0] & 0x7F;
 109   headers->push_front(header);
 110   return true;
 111 }
 112
 113 void Packet::DeleteRedHeaders(std::list<RTPHeader*>* headers) {
 114   while (!headers->empty()) {
 115     delete headers->front();
 116     headers->pop_front();
 117   }
 118 }
 119
 120 bool Packet::ParseHeader(const RtpHeaderParser& parser) {
 121   bool valid_header = parser.Parse(
 122       payload_memory_.get(), static_cast<int>(packet_length_bytes_), &header_);
 123   assert(valid_header);
 124   if (!valid_header) {
 125     return false;
 126   }
 127   assert(header_.headerLength <= packet_length_bytes_);
 128   payload_ = &payload_memory_[header_.headerLength];
 129   assert(packet_length_bytes_ >= header_.headerLength);
 130   payload_length_bytes_ = packet_length_bytes_ - header_.headerLength;
 131   assert(virtual_packet_length_bytes_ >= header_.headerLength);
 132   virtual_payload_length_bytes_ =
 133       virtual_packet_length_bytes_ - header_.headerLength;
 134   return true;
 135 }
 136
 137 void Packet::CopyToHeader(RTPHeader* destination) const {
 138   destination->markerBit = header_.markerBit;
 139   destination->payloadType = header_.payloadType;
 140   destination->sequenceNumber = header_.sequenceNumber;
 141   destination->timestamp = header_.timestamp;
 142   destination->ssrc = header_.ssrc;
 143   destination->numCSRCs = header_.numCSRCs;
 144   destination->paddingLength = header_.paddingLength;
 145   destination->headerLength = header_.headerLength;
 146   destination->payload_type_frequency = header_.payload_type_frequency;
 147   memcpy(&destination->arrOfCSRCs,
 148          &header_.arrOfCSRCs,
 149          sizeof(header_.arrOfCSRCs));
 150   memcpy(
 151       &destination->extension, &header_.extension, sizeof(header_.extension));
 152 }
 153
 154 }  // namespace test
 155 }  // namespace webrtc