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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/session/media/ssrcmuxfilter.h"
     29 
     30 #include <algorithm>
     31 
     32 #include "talk/base/logging.h"
     33 #include "talk/media/base/rtputils.h"
     34 
     35 namespace cricket {
     36 
     37 static const uint32 kSsrc01 = 0x01;
     38 
     39 SsrcMuxFilter::SsrcMuxFilter() {
     40 }
     41 
     42 SsrcMuxFilter::~SsrcMuxFilter() {
     43 }
     44 
     45 bool SsrcMuxFilter::IsActive() const {
     46   return !streams_.empty();
     47 }
     48 
     49 bool SsrcMuxFilter::DemuxPacket(const char* data, size_t len, bool rtcp) {
     50   uint32 ssrc = 0;
     51   if (!rtcp) {
     52     GetRtpSsrc(data, len, &ssrc);
     53   } else {
     54     int pl_type = 0;
     55     if (!GetRtcpType(data, len, &pl_type)) return false;
     56     if (pl_type == kRtcpTypeSDES) {
     57       // SDES packet parsing not supported.
     58       LOG(LS_INFO) << "SDES packet received for demux.";
     59       return true;
     60     } else {
     61       if (!GetRtcpSsrc(data, len, &ssrc)) return false;
     62       if (ssrc == kSsrc01) {
     63         // SSRC 1 has a special meaning and indicates generic feedback on
     64         // some systems and should never be dropped.  If it is forwarded
     65         // incorrectly it will be ignored by lower layers anyway.
     66         return true;
     67       }
     68     }
     69   }
     70   return FindStream(ssrc);
     71 }
     72 
     73 bool SsrcMuxFilter::AddStream(const StreamParams& stream) {
     74   if (GetStreamBySsrc(streams_, stream.first_ssrc(), NULL)) {
     75       LOG(LS_WARNING) << "Stream already added to filter";
     76       return false;
     77   }
     78   streams_.push_back(stream);
     79   return true;
     80 }
     81 
     82 bool SsrcMuxFilter::RemoveStream(uint32 ssrc) {
     83   return RemoveStreamBySsrc(&streams_, ssrc);
     84 }
     85 
     86 bool SsrcMuxFilter::FindStream(uint32 ssrc) const {
     87   if (ssrc == 0) {
     88     return false;
     89   }
     90   return (GetStreamBySsrc(streams_, ssrc, NULL));
     91 }
     92 
     93 }  // namespace cricket
     94