datachannel-sys 0.18.0

/**
 * Copyright (c) 2020 Filip Klembara (in2core)
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */

#if RTC_ENABLE_MEDIA

#include "rtcpsrreporter.hpp"

#include <cassert>
#include <chrono>
#include <cmath>

namespace {

uint64_t ntp_time() {
	const auto now = std::chrono::system_clock::now();
	const double secs = std::chrono::duration<double>(now.time_since_epoch()).count();
	// Assume the epoch is 01/01/1970 and adds the number of seconds between 1900 and 1970
	return uint64_t(std::floor((secs + 2208988800.) * double(uint64_t(1) << 32)));
}

} // namespace

namespace rtc {

ChainedOutgoingProduct RtcpSrReporter::processOutgoingBinaryMessage(ChainedMessagesProduct messages,
                                                                    message_ptr control) {
	if (std::exchange(mNeedsToReport, false)) {
		auto timestamp = rtpConfig->timestamp;
		auto sr = getSenderReport(timestamp);
		if (control) {
			control->insert(control->end(), sr->begin(), sr->end());
		} else {
			control = sr;
		}
	}
	for (auto message : *messages) {
		auto rtp = reinterpret_cast<RtpHeader *>(message->data());
		addToReport(rtp, uint32_t(message->size()));
	}
	return {messages, control};
}

void RtcpSrReporter::addToReport(RtpHeader *rtp, uint32_t rtpSize) {
	mPacketCount += 1;
	assert(!rtp->padding());
	mPayloadOctets += rtpSize - uint32_t(rtp->getSize());
}

RtcpSrReporter::RtcpSrReporter(shared_ptr<RtpPacketizationConfig> rtpConfig)
    : MediaHandlerElement(), rtpConfig(rtpConfig) {
	mLastReportedTimestamp = rtpConfig->timestamp;
}

message_ptr RtcpSrReporter::getSenderReport(uint32_t timestamp) {
	auto srSize = RtcpSr::Size(0);
	auto msg = make_message(srSize + RtcpSdes::Size({{uint8_t(rtpConfig->cname.size())}}),
	                        Message::Control);
	auto sr = reinterpret_cast<RtcpSr *>(msg->data());
	sr->setNtpTimestamp(ntp_time());
	sr->setRtpTimestamp(timestamp);
	sr->setPacketCount(mPacketCount);
	sr->setOctetCount(mPayloadOctets);
	sr->preparePacket(rtpConfig->ssrc, 0);

	auto sdes = reinterpret_cast<RtcpSdes *>(msg->data() + srSize);
	auto chunk = sdes->getChunk(0);
	chunk->setSSRC(rtpConfig->ssrc);
	auto item = chunk->getItem(0);
	item->type = 1;
	item->setText(rtpConfig->cname);
	sdes->preparePacket(1);

	mLastReportedTimestamp = timestamp;
	return msg;
}

void RtcpSrReporter::setNeedsToReport() {
	mNeedsToReport = true;
}

void RtcpSrReporter::startRecording() {
	// Dummy
}

uint32_t RtcpSrReporter::lastReportedTimestamp() const {
	return mLastReportedTimestamp;
}

} // namespace rtc

#endif /* RTC_ENABLE_MEDIA */