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      1 /*
      2  * libjingle
      3  * Copyright 2004 Google Inc.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions are met:
      7  *
      8  *  1. Redistributions of source code must retain the above copyright notice,
      9  *     this list of conditions and the following disclaimer.
     10  *  2. Redistributions in binary form must reproduce the above copyright notice,
     11  *     this list of conditions and the following disclaimer in the documentation
     12  *     and/or other materials provided with the distribution.
     13  *  3. The name of the author may not be used to endorse or promote products
     14  *     derived from this software without specific prior written permission.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
     19  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     20  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #include "talk/media/base/codec.h"
     29 
     30 #include <algorithm>
     31 #include <sstream>
     32 
     33 #include "webrtc/base/common.h"
     34 #include "webrtc/base/logging.h"
     35 #include "webrtc/base/stringencode.h"
     36 #include "webrtc/base/stringutils.h"
     37 
     38 namespace cricket {
     39 
     40 static const int kMaxStaticPayloadId = 95;
     41 const int kMaxPayloadId = 127;
     42 
     43 bool FeedbackParam::operator==(const FeedbackParam& other) const {
     44   return _stricmp(other.id().c_str(), id().c_str()) == 0 &&
     45       _stricmp(other.param().c_str(), param().c_str()) == 0;
     46 }
     47 
     48 bool FeedbackParams::operator==(const FeedbackParams& other) const {
     49   return params_ == other.params_;
     50 }
     51 
     52 bool FeedbackParams::Has(const FeedbackParam& param) const {
     53   return std::find(params_.begin(), params_.end(), param) != params_.end();
     54 }
     55 
     56 void FeedbackParams::Add(const FeedbackParam& param) {
     57   if (param.id().empty()) {
     58     return;
     59   }
     60   if (Has(param)) {
     61     // Param already in |this|.
     62     return;
     63   }
     64   params_.push_back(param);
     65   ASSERT(!HasDuplicateEntries());
     66 }
     67 
     68 void FeedbackParams::Intersect(const FeedbackParams& from) {
     69   std::vector<FeedbackParam>::iterator iter_to = params_.begin();
     70   while (iter_to != params_.end()) {
     71     if (!from.Has(*iter_to)) {
     72       iter_to = params_.erase(iter_to);
     73     } else {
     74       ++iter_to;
     75     }
     76   }
     77 }
     78 
     79 bool FeedbackParams::HasDuplicateEntries() const {
     80   for (std::vector<FeedbackParam>::const_iterator iter = params_.begin();
     81        iter != params_.end(); ++iter) {
     82     for (std::vector<FeedbackParam>::const_iterator found = iter + 1;
     83          found != params_.end(); ++found) {
     84       if (*found == *iter) {
     85         return true;
     86       }
     87     }
     88   }
     89   return false;
     90 }
     91 
     92 bool Codec::Matches(const Codec& codec) const {
     93   // Match the codec id/name based on the typical static/dynamic name rules.
     94   // Matching is case-insensitive.
     95   return (codec.id <= kMaxStaticPayloadId) ?
     96       (id == codec.id) : (_stricmp(name.c_str(), codec.name.c_str()) == 0);
     97 }
     98 
     99 bool Codec::GetParam(const std::string& name, std::string* out) const {
    100   CodecParameterMap::const_iterator iter = params.find(name);
    101   if (iter == params.end())
    102     return false;
    103   *out = iter->second;
    104   return true;
    105 }
    106 
    107 bool Codec::GetParam(const std::string& name, int* out) const {
    108   CodecParameterMap::const_iterator iter = params.find(name);
    109   if (iter == params.end())
    110     return false;
    111   return rtc::FromString(iter->second, out);
    112 }
    113 
    114 void Codec::SetParam(const std::string& name, const std::string& value) {
    115   params[name] = value;
    116 }
    117 
    118 void Codec::SetParam(const std::string& name, int value)  {
    119   params[name] = rtc::ToString(value);
    120 }
    121 
    122 bool Codec::RemoveParam(const std::string& name) {
    123   return params.erase(name) == 1;
    124 }
    125 
    126 void Codec::AddFeedbackParam(const FeedbackParam& param) {
    127   feedback_params.Add(param);
    128 }
    129 
    130 bool Codec::HasFeedbackParam(const FeedbackParam& param) const {
    131   return feedback_params.Has(param);
    132 }
    133 
    134 void Codec::IntersectFeedbackParams(const Codec& other) {
    135   feedback_params.Intersect(other.feedback_params);
    136 }
    137 
    138 bool AudioCodec::Matches(const AudioCodec& codec) const {
    139   // If a nonzero clockrate is specified, it must match the actual clockrate.
    140   // If a nonzero bitrate is specified, it must match the actual bitrate,
    141   // unless the codec is VBR (0), where we just force the supplied value.
    142   // The number of channels must match exactly, with the exception
    143   // that channels=0 is treated synonymously as channels=1, per RFC
    144   // 4566 section 6: " [The channels] parameter is OPTIONAL and may be
    145   // omitted if the number of channels is one."
    146   // Preference is ignored.
    147   // TODO(juberti): Treat a zero clockrate as 8000Hz, the RTP default clockrate.
    148   return Codec::Matches(codec) &&
    149       ((codec.clockrate == 0 /*&& clockrate == 8000*/) ||
    150           clockrate == codec.clockrate) &&
    151       (codec.bitrate == 0 || bitrate <= 0 || bitrate == codec.bitrate) &&
    152       ((codec.channels < 2 && channels < 2) || channels == codec.channels);
    153 }
    154 
    155 std::string AudioCodec::ToString() const {
    156   std::ostringstream os;
    157   os << "AudioCodec[" << id << ":" << name << ":" << clockrate << ":" << bitrate
    158      << ":" << channels << ":" << preference << "]";
    159   return os.str();
    160 }
    161 
    162 std::string VideoCodec::ToString() const {
    163   std::ostringstream os;
    164   os << "VideoCodec[" << id << ":" << name << ":" << width << ":" << height
    165      << ":" << framerate << ":" << preference << "]";
    166   return os.str();
    167 }
    168 
    169 VideoCodec VideoCodec::CreateRtxCodec(int rtx_payload_type,
    170                                       int associated_payload_type) {
    171   VideoCodec rtx_codec(rtx_payload_type, kRtxCodecName, 0, 0, 0, 0);
    172   rtx_codec.SetParam(kCodecParamAssociatedPayloadType, associated_payload_type);
    173   return rtx_codec;
    174 }
    175 
    176 VideoCodec::CodecType VideoCodec::GetCodecType() const {
    177   const char* payload_name = name.c_str();
    178   if (_stricmp(payload_name, kRedCodecName) == 0) {
    179     return CODEC_RED;
    180   }
    181   if (_stricmp(payload_name, kUlpfecCodecName) == 0) {
    182     return CODEC_ULPFEC;
    183   }
    184   if (_stricmp(payload_name, kRtxCodecName) == 0) {
    185     return CODEC_RTX;
    186   }
    187 
    188   return CODEC_VIDEO;
    189 }
    190 
    191 bool VideoCodec::ValidateCodecFormat() const {
    192   if (id < 0 || id > 127) {
    193     LOG(LS_ERROR) << "Codec with invalid payload type: " << ToString();
    194     return false;
    195   }
    196   if (GetCodecType() != CODEC_VIDEO) {
    197     return true;
    198   }
    199 
    200   // Video validation from here on.
    201 
    202   if (width <= 0 || height <= 0) {
    203     LOG(LS_ERROR) << "Codec with invalid dimensions: " << ToString();
    204     return false;
    205   }
    206   int min_bitrate = -1;
    207   int max_bitrate = -1;
    208   if (GetParam(kCodecParamMinBitrate, &min_bitrate) &&
    209       GetParam(kCodecParamMaxBitrate, &max_bitrate)) {
    210     if (max_bitrate < min_bitrate) {
    211       LOG(LS_ERROR) << "Codec with max < min bitrate: " << ToString();
    212       return false;
    213     }
    214   }
    215   return true;
    216 }
    217 
    218 std::string DataCodec::ToString() const {
    219   std::ostringstream os;
    220   os << "DataCodec[" << id << ":" << name << "]";
    221   return os.str();
    222 }
    223 
    224 }  // namespace cricket
    225