Add h264 and opus streaming support to libdatachannel

src/h264packetizationhandler.cpp

@@ -0,0 +1,164 @@
+/*
+ * libdatachannel client example
+ * Copyright (c) 2020 Filip Klembara (in2core)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "h264packetizationhandler.hpp"
+
+#if RTC_ENABLE_MEDIA
+
+using namespace rtc;
+using namespace std;
+
+typedef enum {
+    NUSM_noMatch,
+    NUSM_firstZero,
+    NUSM_secondZero,
+    NUSM_thirdZero,
+    NUSM_shortMatch,
+    NUSM_longMatch
+} NalUnitStartSequenceMatch;
+
+NalUnitStartSequenceMatch StartSequenceMatchSucc(NalUnitStartSequenceMatch match, byte _byte, H264PacketizationHandler::Separator separator) {
+    assert(separator != H264PacketizationHandler::Separator::Length);
+    auto byte = (uint8_t) _byte;
+    auto detectShort = separator == H264PacketizationHandler::Separator::ShortStartSequence || separator == H264PacketizationHandler::Separator::StartSequence;
+    auto detectLong = separator == H264PacketizationHandler::Separator::LongStartSequence || separator == H264PacketizationHandler::Separator::StartSequence;
+    switch (match) {
+        case NUSM_noMatch:
+            if (byte == 0x00) {
+                return NUSM_firstZero;
+            }
+            break;
+        case NUSM_firstZero:
+            if (byte == 0x00) {
+                return NUSM_secondZero;
+            }
+            break;
+        case NUSM_secondZero:
+            if (byte == 0x00 && detectLong) {
+                return NUSM_thirdZero;
+            } else if (byte == 0x01 && detectShort) {
+                return NUSM_shortMatch;
+            }
+            break;
+        case NUSM_thirdZero:
+            if (byte == 0x01 && detectLong) {
+                return NUSM_longMatch;
+            }
+            break;
+        case NUSM_shortMatch:
+            return NUSM_shortMatch;
+        case NUSM_longMatch:
+            return NUSM_longMatch;
+    }
+    return NUSM_noMatch;
+}
+
+message_ptr H264PacketizationHandler::incoming(message_ptr ptr) {
+    return ptr;
+}
+
+shared_ptr<NalUnits> H264PacketizationHandler::splitMessage(rtc::message_ptr message) {
+    auto nalus = make_shared<NalUnits>();
+    if (separator == Separator::Length) {
+        unsigned long long index = 0;
+        while (index < message->size()) {
+            assert(index + 4 < message->size());
+            if (index + 4 >= message->size()) {
+                LOG_WARNING << "Invalid NAL Unit data (incomplete length), ignoring!";
+                break;
+            }
+            auto lengthPtr = (uint32_t *) (message->data() + index);
+            uint32_t length = ntohl(*lengthPtr);
+            auto naluStartIndex = index + 4;
+            auto naluEndIndex = naluStartIndex + length;
+
+            assert(naluEndIndex <= message->size());
+            if (naluEndIndex > message->size()) {
+                LOG_WARNING << "Invalid NAL Unit data (incomplete unit), ignoring!";
+                break;
+            }
+            nalus->push_back(NalUnit(message->begin() + naluStartIndex, message->begin() + naluEndIndex));
+            index = naluEndIndex;
+        }
+    } else {
+        NalUnitStartSequenceMatch match = NUSM_noMatch;
+        unsigned long long index = 0;
+        while (index < message->size()) {
+            match = StartSequenceMatchSucc(match, (*message)[index++], separator);
+            if (match == NUSM_longMatch || match == NUSM_shortMatch) {
+                match = NUSM_noMatch;
+                break;
+            }
+        }
+        index++;
+        unsigned long long naluStartIndex = index;
+
+        while (index < message->size()) {
+            match = StartSequenceMatchSucc(match, (*message)[index], separator);
+            if (match == NUSM_longMatch || match == NUSM_shortMatch) {
+                auto sequenceLength = match == NUSM_longMatch ? 4 : 3;
+                unsigned long long naluEndIndex = index - sequenceLength;
+                match = NUSM_noMatch;
+                nalus->push_back(NalUnit(message->begin() + naluStartIndex, message->begin() + naluEndIndex + 1));
+                naluStartIndex = index + 1;
+            }
+            index++;
+        }
+        nalus->push_back(NalUnit(message->begin() + naluStartIndex, message->end()));
+    }
+    return nalus;
+}
+
+message_ptr H264PacketizationHandler::outgoing(message_ptr ptr) {
+    if (ptr->type == Message::Binary) {
+        auto nalus = splitMessage(ptr);
+        auto fragments = nalus->generateFragments(maximumFragmentSize);
+
+         auto lastPacket = withStatsRecording<message_ptr>([fragments, this](function<void (message_ptr)> addToReport) {
+             for(unsigned long long index = 0; index < fragments.size() - 1; index++) {
+                 auto packet = packetizer->packetize(fragments[index], false);
+
+                 addToReport(packet);
+
+                 outgoingCallback(std::move(packet));
+             }
+             // packet is last, marker must be set
+             auto lastPacket = packetizer->packetize(fragments[fragments.size() - 1], true);
+             addToReport(lastPacket);
+             return lastPacket;
+         });
+        return lastPacket;
+    }
+    return ptr;
+}
+
+H264PacketizationHandler::H264PacketizationHandler(Separator separator,
+                                                   std::shared_ptr<H264RTPPacketizer> packetizer,
+                                                   uint16_t maximumFragmentSize):
+        RtcpHandler(),
+        rtc::RTCPSenderReportable(packetizer->rtpConfig),
+        packetizer(packetizer),
+        maximumFragmentSize(maximumFragmentSize),
+        separator(separator) {
+
+    senderReportOutgoingCallback = [this](message_ptr msg) {
+        outgoingCallback(msg);
+    };
+}
+
+#endif /* RTC_ENABLE_MEDIA */