RTPPacket* FECDecoder::Recover() { BYTE aux[8]; QWORD lostMask = 0; //Check we have media pacekts if (!medias.size()) //Exit return NULL; //Get First packet RTPPacket* first = medias.begin()->second; //Get the SSRC DWORD ssrc = first->GetSSRC(); //Get first media packet DWORD minSeq = first->GetExtSeqNum(); //Iterator on seq DWORD lastSeq = minSeq; //Set to 0 memset(aux,0,8); //Create writter BitWritter w(aux,8); //vector of lost pacekt seq std::vector<DWORD> losts; //For each media packet for (RTPOrderedPackets::iterator it=medias.begin();it!=medias.end();++it) { //Get seq DWORD cur = it->first; //Insert lost for (DWORD i=lastSeq+1;i<cur;++i) { //set mask bit to not present w.Put(1,0); //Add to the vecotr losts.push_back(i); } //Set last seq lastSeq = cur; //set mask bit to present w.Put(1,1); } //End it w.Flush(); //Get mask lostMask = get8(aux,0); //Check we have lost pacekts if (!losts.size()) //Exit return NULL; //For each lost packet for(std::vector<DWORD>::iterator it=losts.begin();it!=losts.end();++it) { //Get lost packet sequence DWORD seq = *it; //Search FEC packets associated this media packet for (FECOrderedData::iterator it2 = codes.begin();it2!=codes.end();++it2) { //Get FEC packet FECData *fec = it2->second; //Check if it is associated with this media pacekt in level 0 if (!fec->IsProtectedAtLevel0(seq)) //Next continue; //Get the seq difference between fec data and the media // fec seq has to be <= media seq it fec data protect media data) DWORD diff = seq-fec->GetBaseExtSeq(); //Shit mask of the lost packets to check the present ones from the base seq QWORD mediaMask = lostMask << (fec->GetBaseExtSeq()-minSeq); //Remove lost packet bit from the fec mask QWORD fecMask = fec->GetLevel0Mask() & ~(((QWORD)1)<<(64-diff-1)); //Compare needed pacekts with actual pacekts, to check if we have all of them except the missing if ((fecMask & mediaMask) == fecMask) { //Rocovered media data BYTE recovered[MTU+SRTP_MAX_TRAILER_LEN] ZEROALIGNEDTO32; //Get attributes bool p = fec->GetRecoveryP(); bool x = fec->GetRecoveryX(); BYTE cc = fec->GetRecoveryCC(); bool m = fec->GetRecoveryM(); BYTE pt = fec->GetRecoveryType(); DWORD ts = fec->GetRecoveryTimestamp(); WORD l = fec->GetRecoveryLength(); //Get protection length DWORD level0Size = fec->GetLevel0Size(); //Ensure there is enought size if (level0Size>MTU) { //Error Error("-FEC level 0 data size too big [%d]\n",level0Size); //Skip this one continue; } //Copy data memcpy(recovered,fec->GetLevel0Data(),level0Size); //Set value in temp buffer set8(aux,0,fecMask); //Get bit reader BitReader r(aux,8); //Read all media packet while(r.Left()) { //If the media packet is used to reconstrud the packet if (r.Get(1)) { //Get media packet RTPPacket* media = medias[fec->GetBaseExtSeq()+r.GetPos()-1]; //Calculate receovered attributes p ^= media->GetP(); x ^= media->GetX(); cc ^= media->GetCC(); m ^= media->GetMark(); pt ^= media->GetType(); ts ^= media->GetTimestamp(); l ^= media->GetMediaLength(); //Get data BYTE *payload = media->GetMediaData(); //Calculate the xor for (int i=0;i<fmin(media->GetMediaLength(),level0Size);++i) //XOR recovered[i] ^= payload[i]; } } //Create new video packet RTPPacket* packet = new RTPPacket(MediaFrame::Video,pt); //Set values packet->SetP(p); packet->SetX(x); packet->SetMark(m); packet->SetTimestamp(ts); //Set sequence number packet->SetSeqNum(seq); //Set seq cycles packet->SetSeqCycles(fec->GetBaseSeqCylcles()); //Set ssrc packet->SetSSRC(ssrc); //Set payload and recovered length if (!packet->SetPayloadWithExtensionData(recovered,l)) { //Delete packet delete(packet); //Error Error("-FEC payload of recovered packet to big [%u]\n",(unsigned int)l); //Skip continue; } Debug("-recovered packet len:%u ts:%u pts:%u seq:%d\n",l,ts,packet->GetTimestamp() ,packet->GetSeqNum()); //Append the packet to the media packet list if (AddPacket(packet)) //Return it if contained media return packet; else //Discard and continue delete(packet); } } } //Nothing found return NULL; }
int RTPPacketProcessor::ProcessRTPBlock(unsigned char *data,int len,unsigned long ip,int port,bool *collis,bool acceptlocalpackets,double localtsunit) { int status; RTPPacket *packet; *collis = false; if (!initialized) { delete [] data; return ERR_RTP_PACKETPROCESSORNOTINITIALIZED; } if ((status = GetRTPData(data,len,&packet)) < 0) { delete [] data; return status; } if (packet != NULL) // valid packet { // check for collision with local ssrc and process further if (contribsrcs->GetLocalSSRC() == htonl(packet->GetSSRC())) { // collision with local ssrc if (ip == conn->GetLocalIP() && port == conn->GetSendPort()) { if (!acceptlocalpackets) { delete packet; return 0; } } else { if (handlers->handlers[RTP_EXCEPTION_LOCALSSRCCOLLISION].handler != NULL) CallLocalSSRCCollHandler(packet->GetSSRC(),ip,true,port); delete packet; *collis = true; return 0; } } status = sources->ProcessPacket(packet,ip,port,localtsunit); if (status < 0) { delete packet; /* On a collision we still want other data to be processed, so we will not count this as an error */ if (status == ERR_RTP_COLLISIONBETWEENSSRCS) return 0; return status; } } else // invalid packet delete [] data; return 0; }