/**********
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This library is free software; you can redistribute it and/or modify it under
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the terms of the GNU Lesser General Public License as published by the
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Free Software Foundation; either version 3 of the License, or (at your
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option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)
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This library is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
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more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this library; if not, write to the Free Software Foundation, Inc.,
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51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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**********/
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// "liveMedia"
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// Copyright (c) 1996-2017 Live Networks, Inc. All rights reserved.
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// RTP sink for T.140 text (RFC 2793)
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// C++ header
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#ifndef _T140_TEXT_RTP_SINK_HH
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#define _T140_TEXT_RTP_SINK_HH
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#ifndef _TEXT_RTP_SINK_HH
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#include "TextRTPSink.hh"
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#endif
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#ifndef _FRAMED_FILTER_HH
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#include "FramedFilter.hh"
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#endif
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class T140IdleFilter;
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class T140TextRTPSink: public TextRTPSink {
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public:
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static T140TextRTPSink* createNew(UsageEnvironment& env, Groupsock* RTPgs, unsigned char rtpPayloadFormat);
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protected:
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T140TextRTPSink(UsageEnvironment& env, Groupsock* RTPgs, unsigned char rtpPayloadFormat);
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// called only by createNew()
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virtual ~T140TextRTPSink();
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protected: // redefined virtual functions:
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virtual Boolean continuePlaying();
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virtual void doSpecialFrameHandling(unsigned fragmentationOffset,
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unsigned char* frameStart,
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unsigned numBytesInFrame,
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struct timeval framePresentationTime,
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unsigned numRemainingBytes);
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virtual Boolean frameCanAppearAfterPacketStart(unsigned char const* frameStart,
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unsigned numBytesInFrame) const;
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protected:
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T140IdleFilter* fOurIdleFilter;
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Boolean fAreInIdlePeriod;
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};
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////////// T140IdleFilter definition //////////
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// Because the T.140 text RTP payload format specification recommends that (empty) RTP packets be sent during 'idle periods'
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// when no new text is available, we implement "T140TextRTPSink" using a separate "T140IdleFilter" class - sitting in front
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// - that delivers, to the "T140TextRTPSink", a continuous sequence of (possibly) empty frames.
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// (Note: This class should be used only by "T140TextRTPSink", or a subclass.)
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class T140IdleFilter: public FramedFilter {
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public:
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T140IdleFilter(UsageEnvironment& env, FramedSource* inputSource);
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virtual ~T140IdleFilter();
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private: // redefined virtual functions:
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virtual void doGetNextFrame();
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virtual void doStopGettingFrames();
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private:
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static void afterGettingFrame(void* clientData, unsigned frameSize,
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unsigned numTruncatedBytes,
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struct timeval presentationTime,
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unsigned durationInMicroseconds);
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void afterGettingFrame(unsigned frameSize,
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unsigned numTruncatedBytes,
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struct timeval presentationTime,
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unsigned durationInMicroseconds);
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static void handleIdleTimeout(void* clientData);
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void handleIdleTimeout();
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void deliverFromBuffer();
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void deliverEmptyFrame();
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static void onSourceClosure(void* clientData);
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void onSourceClosure();
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private:
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TaskToken fIdleTimerTask;
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unsigned fBufferSize, fNumBufferedBytes;
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char* fBuffer;
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unsigned fBufferedNumTruncatedBytes; // a count of truncated bytes from the upstream
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struct timeval fBufferedDataPresentationTime;
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unsigned fBufferedDataDurationInMicroseconds;
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};
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#endif
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