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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 const int kMaxPayloadId = 127;
     41 
     42 bool FeedbackParam::operator==(const FeedbackParam& other) const {
     43   return _stricmp(other.id().c_str(), id().c_str()) == 0 &&
     44       _stricmp(other.param().c_str(), param().c_str()) == 0;
     45 }
     46 
     47 bool FeedbackParams::operator==(const FeedbackParams& other) const {
     48   return params_ == other.params_;
     49 }
     50 
     51 bool FeedbackParams::Has(const FeedbackParam& param) const {
     52   return std::find(params_.begin(), params_.end(), param) != params_.end();
     53 }
     54 
     55 void FeedbackParams::Add(const FeedbackParam& param) {
     56   if (param.id().empty()) {
     57     return;
     58   }
     59   if (Has(param)) {
     60     // Param already in |this|.
     61     return;
     62   }
     63   params_.push_back(param);
     64   ASSERT(!HasDuplicateEntries());
     65 }
     66 
     67 void FeedbackParams::Intersect(const FeedbackParams& from) {
     68   std::vector<FeedbackParam>::iterator iter_to = params_.begin();
     69   while (iter_to != params_.end()) {
     70     if (!from.Has(*iter_to)) {
     71       iter_to = params_.erase(iter_to);
     72     } else {
     73       ++iter_to;
     74     }
     75   }
     76 }
     77 
     78 bool FeedbackParams::HasDuplicateEntries() const {
     79   for (std::vector<FeedbackParam>::const_iterator iter = params_.begin();
     80        iter != params_.end(); ++iter) {
     81     for (std::vector<FeedbackParam>::const_iterator found = iter + 1;
     82          found != params_.end(); ++found) {
     83       if (*found == *iter) {
     84         return true;
     85       }
     86     }
     87   }
     88   return false;
     89 }
     90 
     91 Codec::Codec(int id, const std::string& name, int clockrate, int preference)
     92     : id(id), name(name), clockrate(clockrate), preference(preference) {
     93 }
     94 
     95 Codec::Codec() : id(0), clockrate(0), preference(0) {
     96 }
     97 
     98 Codec::Codec(const Codec& c) = default;
     99 
    100 Codec::~Codec() = default;
    101 
    102 Codec& Codec::operator=(const Codec& c) {
    103   this->id = c.id;  // id is reserved in objective-c
    104   name = c.name;
    105   clockrate = c.clockrate;
    106   preference = c.preference;
    107   params = c.params;
    108   feedback_params = c.feedback_params;
    109   return *this;
    110 }
    111 
    112 bool Codec::operator==(const Codec& c) const {
    113   return this->id == c.id &&  // id is reserved in objective-c
    114          name == c.name && clockrate == c.clockrate &&
    115          preference == c.preference && params == c.params &&
    116          feedback_params == c.feedback_params;
    117 }
    118 
    119 bool Codec::Matches(const Codec& codec) const {
    120   // Match the codec id/name based on the typical static/dynamic name rules.
    121   // Matching is case-insensitive.
    122   const int kMaxStaticPayloadId = 95;
    123   return (codec.id <= kMaxStaticPayloadId) ?
    124       (id == codec.id) : (_stricmp(name.c_str(), codec.name.c_str()) == 0);
    125 }
    126 
    127 bool Codec::GetParam(const std::string& name, std::string* out) const {
    128   CodecParameterMap::const_iterator iter = params.find(name);
    129   if (iter == params.end())
    130     return false;
    131   *out = iter->second;
    132   return true;
    133 }
    134 
    135 bool Codec::GetParam(const std::string& name, int* out) const {
    136   CodecParameterMap::const_iterator iter = params.find(name);
    137   if (iter == params.end())
    138     return false;
    139   return rtc::FromString(iter->second, out);
    140 }
    141 
    142 void Codec::SetParam(const std::string& name, const std::string& value) {
    143   params[name] = value;
    144 }
    145 
    146 void Codec::SetParam(const std::string& name, int value)  {
    147   params[name] = rtc::ToString(value);
    148 }
    149 
    150 bool Codec::RemoveParam(const std::string& name) {
    151   return params.erase(name) == 1;
    152 }
    153 
    154 void Codec::AddFeedbackParam(const FeedbackParam& param) {
    155   feedback_params.Add(param);
    156 }
    157 
    158 bool Codec::HasFeedbackParam(const FeedbackParam& param) const {
    159   return feedback_params.Has(param);
    160 }
    161 
    162 void Codec::IntersectFeedbackParams(const Codec& other) {
    163   feedback_params.Intersect(other.feedback_params);
    164 }
    165 
    166 AudioCodec::AudioCodec(int id,
    167                        const std::string& name,
    168                        int clockrate,
    169                        int bitrate,
    170                        size_t channels,
    171                        int preference)
    172     : Codec(id, name, clockrate, preference),
    173       bitrate(bitrate),
    174       channels(channels) {
    175 }
    176 
    177 AudioCodec::AudioCodec() : Codec(), bitrate(0), channels(0) {
    178 }
    179 
    180 AudioCodec::AudioCodec(const AudioCodec& c) = default;
    181 
    182 AudioCodec& AudioCodec::operator=(const AudioCodec& c) {
    183   Codec::operator=(c);
    184   bitrate = c.bitrate;
    185   channels = c.channels;
    186   return *this;
    187 }
    188 
    189 bool AudioCodec::operator==(const AudioCodec& c) const {
    190   return bitrate == c.bitrate && channels == c.channels && Codec::operator==(c);
    191 }
    192 
    193 bool AudioCodec::Matches(const AudioCodec& codec) const {
    194   // If a nonzero clockrate is specified, it must match the actual clockrate.
    195   // If a nonzero bitrate is specified, it must match the actual bitrate,
    196   // unless the codec is VBR (0), where we just force the supplied value.
    197   // The number of channels must match exactly, with the exception
    198   // that channels=0 is treated synonymously as channels=1, per RFC
    199   // 4566 section 6: " [The channels] parameter is OPTIONAL and may be
    200   // omitted if the number of channels is one."
    201   // Preference is ignored.
    202   // TODO(juberti): Treat a zero clockrate as 8000Hz, the RTP default clockrate.
    203   return Codec::Matches(codec) &&
    204       ((codec.clockrate == 0 /*&& clockrate == 8000*/) ||
    205           clockrate == codec.clockrate) &&
    206       (codec.bitrate == 0 || bitrate <= 0 || bitrate == codec.bitrate) &&
    207       ((codec.channels < 2 && channels < 2) || channels == codec.channels);
    208 }
    209 
    210 std::string AudioCodec::ToString() const {
    211   std::ostringstream os;
    212   os << "AudioCodec[" << id << ":" << name << ":" << clockrate << ":" << bitrate
    213      << ":" << channels << ":" << preference << "]";
    214   return os.str();
    215 }
    216 
    217 std::string VideoCodec::ToString() const {
    218   std::ostringstream os;
    219   os << "VideoCodec[" << id << ":" << name << ":" << width << ":" << height
    220      << ":" << framerate << ":" << preference << "]";
    221   return os.str();
    222 }
    223 
    224 VideoCodec::VideoCodec(int id,
    225                        const std::string& name,
    226                        int width,
    227                        int height,
    228                        int framerate,
    229                        int preference)
    230     : Codec(id, name, kVideoCodecClockrate, preference),
    231       width(width),
    232       height(height),
    233       framerate(framerate) {
    234 }
    235 
    236 VideoCodec::VideoCodec(int id, const std::string& name)
    237     : Codec(id, name, kVideoCodecClockrate, 0),
    238       width(0),
    239       height(0),
    240       framerate(0) {
    241 }
    242 
    243 VideoCodec::VideoCodec() : Codec(), width(0), height(0), framerate(0) {
    244   clockrate = kVideoCodecClockrate;
    245 }
    246 
    247 VideoCodec::VideoCodec(const VideoCodec& c) = default;
    248 
    249 VideoCodec& VideoCodec::operator=(const VideoCodec& c) {
    250   Codec::operator=(c);
    251   width = c.width;
    252   height = c.height;
    253   framerate = c.framerate;
    254   return *this;
    255 }
    256 
    257 bool VideoCodec::operator==(const VideoCodec& c) const {
    258   return width == c.width && height == c.height && framerate == c.framerate &&
    259          Codec::operator==(c);
    260 }
    261 
    262 VideoCodec VideoCodec::CreateRtxCodec(int rtx_payload_type,
    263                                       int associated_payload_type) {
    264   VideoCodec rtx_codec(rtx_payload_type, kRtxCodecName, 0, 0, 0, 0);
    265   rtx_codec.SetParam(kCodecParamAssociatedPayloadType, associated_payload_type);
    266   return rtx_codec;
    267 }
    268 
    269 VideoCodec::CodecType VideoCodec::GetCodecType() const {
    270   const char* payload_name = name.c_str();
    271   if (_stricmp(payload_name, kRedCodecName) == 0) {
    272     return CODEC_RED;
    273   }
    274   if (_stricmp(payload_name, kUlpfecCodecName) == 0) {
    275     return CODEC_ULPFEC;
    276   }
    277   if (_stricmp(payload_name, kRtxCodecName) == 0) {
    278     return CODEC_RTX;
    279   }
    280 
    281   return CODEC_VIDEO;
    282 }
    283 
    284 bool VideoCodec::ValidateCodecFormat() const {
    285   if (id < 0 || id > 127) {
    286     LOG(LS_ERROR) << "Codec with invalid payload type: " << ToString();
    287     return false;
    288   }
    289   if (GetCodecType() != CODEC_VIDEO) {
    290     return true;
    291   }
    292 
    293   // Video validation from here on.
    294 
    295   if (width <= 0 || height <= 0) {
    296     LOG(LS_ERROR) << "Codec with invalid dimensions: " << ToString();
    297     return false;
    298   }
    299   int min_bitrate = -1;
    300   int max_bitrate = -1;
    301   if (GetParam(kCodecParamMinBitrate, &min_bitrate) &&
    302       GetParam(kCodecParamMaxBitrate, &max_bitrate)) {
    303     if (max_bitrate < min_bitrate) {
    304       LOG(LS_ERROR) << "Codec with max < min bitrate: " << ToString();
    305       return false;
    306     }
    307   }
    308   return true;
    309 }
    310 
    311 DataCodec::DataCodec(int id, const std::string& name, int preference)
    312     : Codec(id, name, kDataCodecClockrate, preference) {
    313 }
    314 
    315 DataCodec::DataCodec() : Codec() {
    316   clockrate = kDataCodecClockrate;
    317 }
    318 
    319 DataCodec::DataCodec(const DataCodec& c) = default;
    320 
    321 DataCodec& DataCodec::operator=(const DataCodec& c) = default;
    322 
    323 std::string DataCodec::ToString() const {
    324   std::ostringstream os;
    325   os << "DataCodec[" << id << ":" << name << "]";
    326   return os.str();
    327 }
    328 
    329 bool HasNack(const VideoCodec& codec) {
    330   return codec.HasFeedbackParam(
    331       FeedbackParam(kRtcpFbParamNack, kParamValueEmpty));
    332 }
    333 
    334 bool HasRemb(const VideoCodec& codec) {
    335   return codec.HasFeedbackParam(
    336       FeedbackParam(kRtcpFbParamRemb, kParamValueEmpty));
    337 }
    338 
    339 bool HasTransportCc(const VideoCodec& codec) {
    340   return codec.HasFeedbackParam(
    341       FeedbackParam(kRtcpFbParamTransportCc, kParamValueEmpty));
    342 }
    343 
    344 bool CodecNamesEq(const std::string& name1, const std::string& name2) {
    345   return _stricmp(name1.c_str(), name2.c_str()) == 0;
    346 }
    347 
    348 }  // namespace cricket
    349