| /********** |
| This library is free software; you can redistribute it and/or modify it under |
| the terms of the GNU Lesser General Public License as published by the |
| Free Software Foundation; either version 3 of the License, or (at your |
| option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.) |
| |
| This library 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 Lesser General Public License for |
| more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with this library; if not, write to the Free Software Foundation, Inc., |
| 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| **********/ |
| // "liveMedia" |
| // Copyright (c) 1996-2020 Live Networks, Inc. All rights reserved. |
| // RTP sink for T.140 text (RFC 2793) |
| // C++ header |
| |
| #ifndef _T140_TEXT_RTP_SINK_HH |
| #define _T140_TEXT_RTP_SINK_HH |
| |
| #ifndef _TEXT_RTP_SINK_HH |
| #include "TextRTPSink.hh" |
| #endif |
| #ifndef _FRAMED_FILTER_HH |
| #include "FramedFilter.hh" |
| #endif |
| |
| class T140IdleFilter; |
| |
| class T140TextRTPSink: public TextRTPSink { |
| public: |
| static T140TextRTPSink* createNew(UsageEnvironment& env, Groupsock* RTPgs, unsigned char rtpPayloadFormat); |
| |
| protected: |
| T140TextRTPSink(UsageEnvironment& env, Groupsock* RTPgs, unsigned char rtpPayloadFormat); |
| // called only by createNew() |
| |
| virtual ~T140TextRTPSink(); |
| |
| protected: // redefined virtual functions: |
| virtual Boolean continuePlaying(); |
| virtual void doSpecialFrameHandling(unsigned fragmentationOffset, |
| unsigned char* frameStart, |
| unsigned numBytesInFrame, |
| struct timeval framePresentationTime, |
| unsigned numRemainingBytes); |
| virtual Boolean frameCanAppearAfterPacketStart(unsigned char const* frameStart, |
| unsigned numBytesInFrame) const; |
| |
| protected: |
| T140IdleFilter* fOurIdleFilter; |
| Boolean fAreInIdlePeriod; |
| }; |
| |
| |
| ////////// T140IdleFilter definition ////////// |
| |
| // Because the T.140 text RTP payload format specification recommends that (empty) RTP packets be sent during 'idle periods' |
| // when no new text is available, we implement "T140TextRTPSink" using a separate "T140IdleFilter" class - sitting in front |
| // - that delivers, to the "T140TextRTPSink", a continuous sequence of (possibly) empty frames. |
| // (Note: This class should be used only by "T140TextRTPSink", or a subclass.) |
| |
| class T140IdleFilter: public FramedFilter { |
| public: |
| T140IdleFilter(UsageEnvironment& env, FramedSource* inputSource); |
| virtual ~T140IdleFilter(); |
| |
| private: // redefined virtual functions: |
| virtual void doGetNextFrame(); |
| virtual void doStopGettingFrames(); |
| |
| private: |
| static void afterGettingFrame(void* clientData, unsigned frameSize, |
| unsigned numTruncatedBytes, |
| struct timeval presentationTime, |
| unsigned durationInMicroseconds); |
| void afterGettingFrame(unsigned frameSize, |
| unsigned numTruncatedBytes, |
| struct timeval presentationTime, |
| unsigned durationInMicroseconds); |
| |
| static void handleIdleTimeout(void* clientData); |
| void handleIdleTimeout(); |
| |
| void deliverFromBuffer(); |
| void deliverEmptyFrame(); |
| |
| static void onSourceClosure(void* clientData); |
| void onSourceClosure(); |
| |
| private: |
| TaskToken fIdleTimerTask; |
| unsigned fBufferSize, fNumBufferedBytes; |
| char* fBuffer; |
| unsigned fBufferedNumTruncatedBytes; // a count of truncated bytes from the upstream |
| struct timeval fBufferedDataPresentationTime; |
| unsigned fBufferedDataDurationInMicroseconds; |
| }; |
| |
| #endif |