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      1 /* libjingle
      2  * Copyright 2012, Google Inc.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are met:
      6  *
      7  *  1. Redistributions of source code must retain the above copyright notice,
      8  *     this list of conditions and the following disclaimer.
      9  *  2. Redistributions in binary form must reproduce the above copyright notice,
     10  *     this list of conditions and the following disclaimer in the documentation
     11  *     and/or other materials provided with the distribution.
     12  *  3. The name of the author may not be used to endorse or promote products
     13  *     derived from this software without specific prior written permission.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     16  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     17  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
     18  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     19  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     21  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     22  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     23  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     24  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 
     27 #include "talk/app/webrtc/jsepsessiondescription.h"
     28 
     29 #include "talk/app/webrtc/webrtcsdp.h"
     30 #include "talk/base/stringencode.h"
     31 #include "talk/session/media/mediasession.h"
     32 
     33 using talk_base::scoped_ptr;
     34 using cricket::SessionDescription;
     35 
     36 namespace webrtc {
     37 
     38 static const char* kSupportedTypes[] = {
     39     JsepSessionDescription::kOffer,
     40     JsepSessionDescription::kPrAnswer,
     41     JsepSessionDescription::kAnswer
     42 };
     43 
     44 static bool IsTypeSupported(const std::string& type) {
     45   bool type_supported = false;
     46   for (size_t i = 0; i < ARRAY_SIZE(kSupportedTypes); ++i) {
     47     if (kSupportedTypes[i] == type) {
     48       type_supported = true;
     49       break;
     50     }
     51   }
     52   return type_supported;
     53 }
     54 
     55 const char SessionDescriptionInterface::kOffer[] = "offer";
     56 const char SessionDescriptionInterface::kPrAnswer[] = "pranswer";
     57 const char SessionDescriptionInterface::kAnswer[] = "answer";
     58 
     59 const int JsepSessionDescription::kDefaultVideoCodecId = 100;
     60 const int JsepSessionDescription::kDefaultVideoCodecFramerate = 30;
     61 const char JsepSessionDescription::kDefaultVideoCodecName[] = "VP8";
     62 const int JsepSessionDescription::kMaxVideoCodecWidth = 1280;
     63 const int JsepSessionDescription::kMaxVideoCodecHeight = 720;
     64 const int JsepSessionDescription::kDefaultVideoCodecPreference = 1;
     65 
     66 SessionDescriptionInterface* CreateSessionDescription(const std::string& type,
     67                                                       const std::string& sdp) {
     68   return CreateSessionDescription(type, sdp, NULL);
     69 }
     70 
     71 SessionDescriptionInterface* CreateSessionDescription(const std::string& type,
     72                                                       const std::string& sdp,
     73                                                       SdpParseError* error) {
     74   if (!IsTypeSupported(type)) {
     75     return NULL;
     76   }
     77 
     78   JsepSessionDescription* jsep_desc = new JsepSessionDescription(type);
     79   if (!jsep_desc->Initialize(sdp, error)) {
     80     delete jsep_desc;
     81     return NULL;
     82   }
     83   return jsep_desc;
     84 }
     85 
     86 JsepSessionDescription::JsepSessionDescription(const std::string& type)
     87     : type_(type) {
     88 }
     89 
     90 JsepSessionDescription::~JsepSessionDescription() {}
     91 
     92 bool JsepSessionDescription::Initialize(
     93     cricket::SessionDescription* description,
     94     const std::string& session_id,
     95     const std::string& session_version) {
     96   if (!description)
     97     return false;
     98 
     99   session_id_ = session_id;
    100   session_version_ = session_version;
    101   description_.reset(description);
    102   candidate_collection_.resize(number_of_mediasections());
    103   return true;
    104 }
    105 
    106 bool JsepSessionDescription::Initialize(const std::string& sdp,
    107                                         SdpParseError* error) {
    108   return SdpDeserialize(sdp, this, error);
    109 }
    110 
    111 bool JsepSessionDescription::AddCandidate(
    112     const IceCandidateInterface* candidate) {
    113   if (!candidate || candidate->sdp_mline_index() < 0)
    114     return false;
    115   size_t mediasection_index = 0;
    116   if (!GetMediasectionIndex(candidate, &mediasection_index)) {
    117     return false;
    118   }
    119   if (mediasection_index >= number_of_mediasections())
    120     return false;
    121   if (candidate_collection_[mediasection_index].HasCandidate(candidate)) {
    122     return true;  // Silently ignore this candidate if we already have it.
    123   }
    124   const std::string content_name =
    125       description_->contents()[mediasection_index].name;
    126   const cricket::TransportInfo* transport_info =
    127       description_->GetTransportInfoByName(content_name);
    128   if (!transport_info) {
    129     return false;
    130   }
    131 
    132   cricket::Candidate updated_candidate = candidate->candidate();
    133   if (updated_candidate.username().empty()) {
    134     updated_candidate.set_username(transport_info->description.ice_ufrag);
    135   }
    136   if (updated_candidate.password().empty()) {
    137     updated_candidate.set_password(transport_info->description.ice_pwd);
    138   }
    139 
    140   candidate_collection_[mediasection_index].add(
    141        new JsepIceCandidate(candidate->sdp_mid(),
    142                             static_cast<int>(mediasection_index),
    143                             updated_candidate));
    144   return true;
    145 }
    146 
    147 size_t JsepSessionDescription::number_of_mediasections() const {
    148   if (!description_)
    149     return 0;
    150   return description_->contents().size();
    151 }
    152 
    153 const IceCandidateCollection* JsepSessionDescription::candidates(
    154     size_t mediasection_index) const {
    155   if (mediasection_index >= candidate_collection_.size())
    156     return NULL;
    157   return &candidate_collection_[mediasection_index];
    158 }
    159 
    160 bool JsepSessionDescription::ToString(std::string* out) const {
    161   if (!description_ || !out)
    162     return false;
    163   *out = SdpSerialize(*this);
    164   return !out->empty();
    165 }
    166 
    167 bool JsepSessionDescription::GetMediasectionIndex(
    168     const IceCandidateInterface* candidate,
    169     size_t* index) {
    170   if (!candidate || !index) {
    171     return false;
    172   }
    173   *index = static_cast<size_t>(candidate->sdp_mline_index());
    174   if (description_ && !candidate->sdp_mid().empty()) {
    175     bool found = false;
    176     // Try to match the sdp_mid with content name.
    177     for (size_t i = 0; i < description_->contents().size(); ++i) {
    178       if (candidate->sdp_mid() == description_->contents().at(i).name) {
    179         *index = i;
    180         found = true;
    181         break;
    182       }
    183     }
    184     if (!found) {
    185       // If the sdp_mid is presented but we can't find a match, we consider
    186       // this as an error.
    187       return false;
    188     }
    189   }
    190   return true;
    191 }
    192 
    193 }  // namespace webrtc
    194