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libtgvoip/controller/net/PacketReassembler.cpp
2020-01-28 12:34:24 +01:00

274 lines
6.9 KiB
C++

//
// Created by Grishka on 19.03.2018.
//
#include "PacketReassembler.h"
#include "tools/logging.h"
#include "controller/PrivateDefines.h"
#include "video/VideoFEC.h"
#include <assert.h>
#include <sstream>
#define NUM_OLD_PACKETS 3
#define NUM_FEC_PACKETS 10
using namespace tgvoip;
using namespace tgvoip::video;
PacketReassembler::PacketReassembler()
{
}
PacketReassembler::~PacketReassembler()
{
}
void PacketReassembler::Reset()
{
}
void PacketReassembler::AddFragment(Buffer pkt, unsigned int fragmentIndex, unsigned int fragmentCount, uint32_t pts, uint8_t _fseq, bool keyframe, uint16_t rotation)
{
for (std::unique_ptr<Packet> &packet : packets)
{
if (packet->timestamp == pts)
{
if (fragmentCount != packet->partCount)
{
LOGE("Received fragment total count %u inconsistent with previous %u", fragmentCount, packet->partCount);
return;
}
if (fragmentIndex >= packet->partCount)
{
LOGE("Received fragment index %u is greater than total %u", fragmentIndex, fragmentCount);
return;
}
packet->AddFragment(std::move(pkt), fragmentIndex);
return;
}
}
uint32_t fseq = (lastFrameSeq & 0xFFFFFF00) | (uint32_t)_fseq;
if ((uint8_t)lastFrameSeq > _fseq)
fseq += 256;
//LOGV("fseq: %u", (unsigned int)fseq);
/*if(pts<maxTimestamp){
LOGW("Received fragment doesn't belong here (ts=%u < maxTs=%u)", pts, maxTimestamp);
return;
}*/
if (lastFrameSeq > 3 && fseq < lastFrameSeq - 3)
{
LOGW("Packet too late (fseq=%u, lastFseq=%u)", fseq, lastFrameSeq);
return;
}
if (fragmentIndex >= fragmentCount)
{
LOGE("Received fragment index %u is out of bounds %u", fragmentIndex, fragmentCount);
return;
}
if (fragmentCount > 255)
{
LOGE("Received fragment total count too big %u", fragmentCount);
return;
}
maxTimestamp = std::max(maxTimestamp, pts);
packets.push_back(std::make_unique<Packet>(fseq, pts, fragmentCount, 0, keyframe, rotation));
packets[packets.size() - 1]->AddFragment(std::move(pkt), fragmentIndex);
while (packets.size() > 3)
{
std::unique_ptr<Packet> &_old = packets[0];
if (_old->receivedPartCount == _old->partCount)
{
std::unique_ptr<Packet> old = std::move(packets[0]);
packets.erase(packets.begin());
Buffer buffer = old->Reassemble();
callback(std::move(buffer), old->seq, old->isKeyframe, old->rotation);
oldPackets.push_back(std::move(old));
while (oldPackets.size() > NUM_OLD_PACKETS)
oldPackets.erase(oldPackets.begin());
}
else
{
LOGW("Packet %u not reassembled (%u of %u)", packets[0]->seq, packets[0]->receivedPartCount, packets[0]->partCount);
if (packets[0]->partCount - packets[0]->receivedPartCount == 1 && !waitingForFEC)
{
bool found = false;
for (FecPacket &fec : fecPackets)
{
if (packets[0]->seq <= fec.seq && packets[0]->seq > fec.seq - fec.prevFrameCount)
{
LOGI("Found FEC packet: %u %u", fec.seq, fec.prevFrameCount);
found = true;
TryDecodeFEC(fec);
packets.erase(packets.begin());
break;
}
}
if (!found)
{
waitingForFEC = true;
break;
}
}
else
{
waitingForFEC = false;
LOGE("unrecoverable packet loss");
std::unique_ptr<Packet> old = std::move(packets[0]);
packets.erase(packets.begin());
oldPackets.push_back(std::move(old));
while (oldPackets.size() > NUM_OLD_PACKETS)
oldPackets.erase(oldPackets.begin());
}
}
}
lastFrameSeq = fseq;
}
void PacketReassembler::AddFEC(Buffer data, uint8_t _fseq, unsigned int frameCount, unsigned int fecScheme)
{
uint32_t fseq = (lastFrameSeq & 0xFFFFFF00) | (uint32_t)_fseq;
std::ostringstream _s;
for (unsigned int i = 0; i < frameCount; i++)
{
_s << (fseq - i);
_s << " ";
}
//LOGV("Received FEC packet: len %u, scheme %u, frames %s", (unsigned int)data.Length(), fecScheme, _s.str().c_str());
FecPacket fec{
fseq,
frameCount,
fecScheme,
std::move(data)};
if (waitingForFEC)
{
if (packets[0]->seq <= fec.seq && packets[0]->seq > fec.seq - fec.prevFrameCount)
{
LOGI("Found FEC packet: %u %u", fec.seq, fec.prevFrameCount);
TryDecodeFEC(fec);
packets.erase(packets.begin());
waitingForFEC = false;
}
}
fecPackets.push_back(std::move(fec));
while (fecPackets.size() > NUM_FEC_PACKETS)
fecPackets.erase(fecPackets.begin());
}
void PacketReassembler::SetCallback(std::function<void(Buffer packet, uint32_t pts, bool keyframe, uint16_t rotation)> callback)
{
this->callback = callback;
}
bool PacketReassembler::TryDecodeFEC(PacketReassembler::FecPacket &fec)
{
LOGI("Decoding FEC");
std::vector<Buffer> packetsForRecovery;
for (std::unique_ptr<Packet> &p : oldPackets)
{
if (p->seq <= fec.seq && p->seq > fec.seq - fec.prevFrameCount)
{
LOGD("Adding frame %u from old", p->seq);
for (uint32_t i = 0; i < p->partCount; i++)
{
packetsForRecovery.push_back(i < p->parts.size() ? Buffer::CopyOf(p->parts[i]) : Buffer());
}
}
}
for (std::unique_ptr<Packet> &p : packets)
{
if (p->seq <= fec.seq && p->seq > fec.seq - fec.prevFrameCount)
{
LOGD("Adding frame %u from pending", p->seq);
for (uint32_t i = 0; i < p->partCount; i++)
{
//LOGV("[%u] size %u", i, p.parts[i].Length());
packetsForRecovery.push_back(i < p->parts.size() ? Buffer::CopyOf(p->parts[i]) : Buffer());
}
}
}
if (fec.fecScheme == FEC_SCHEME_XOR)
{
Buffer recovered = ParityFEC::Decode(packetsForRecovery, fec.data);
LOGI("Recovered packet size %u", (unsigned int)recovered.Length());
if (!recovered.IsEmpty())
{
std::unique_ptr<Packet> &pkt = packets[0];
if (pkt->parts.size() < pkt->partCount)
{
pkt->parts.push_back(std::move(recovered));
}
else
{
for (Buffer &b : pkt->parts)
{
if (b.IsEmpty())
{
b = std::move(recovered);
break;
}
}
}
pkt->receivedPartCount++;
callback(pkt->Reassemble(), pkt->seq, pkt->isKeyframe, pkt->rotation);
}
}
return false;
}
#pragma mark - Packet
void PacketReassembler::Packet::AddFragment(Buffer pkt, uint32_t fragmentIndex)
{
//LOGV("Add fragment %u/%u to packet %u", fragmentIndex, partCount, timestamp);
if (parts.size() == fragmentIndex)
{
parts.push_back(std::move(pkt));
//LOGV("add1");
}
else if (parts.size() > fragmentIndex)
{
assert(parts[fragmentIndex].IsEmpty());
parts[fragmentIndex] = std::move(pkt);
//LOGV("add2");
}
else
{
while (parts.size() < fragmentIndex)
parts.push_back(Buffer());
parts.push_back(std::move(pkt));
//LOGV("add3");
}
receivedPartCount++;
//assert(parts.size()>=receivedPartCount);
if (parts.size() < receivedPartCount)
LOGW("Received %u parts but parts.size is %u", (unsigned int)receivedPartCount, (unsigned int)parts.size());
}
Buffer PacketReassembler::Packet::Reassemble()
{
assert(partCount == receivedPartCount);
assert(parts.size() == partCount);
if (partCount == 1)
{
return Buffer::CopyOf(parts[0]);
}
BufferOutputStream out(10240);
for (unsigned int i = 0; i < partCount; i++)
{
out.WriteBytes(parts[i]);
//parts[i]=Buffer();
}
return Buffer(std::move(out));
}