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T140TextRTPSink.hh
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16 // "liveMedia"
17 // Copyright (c) 1996-2021 Live Networks, Inc. All rights reserved.
18 // RTP sink for T.140 text (RFC 2793)
19 // C++ header
20 
21 #ifndef _T140_TEXT_RTP_SINK_HH
22 #define _T140_TEXT_RTP_SINK_HH
23 
24 #ifndef _TEXT_RTP_SINK_HH
25 #include "TextRTPSink.hh"
26 #endif
27 #ifndef _FRAMED_FILTER_HH
28 #include "FramedFilter.hh"
29 #endif
30 
31 class T140IdleFilter;
32 
34 public:
35  static T140TextRTPSink* createNew(UsageEnvironment& env, Groupsock* RTPgs, unsigned char rtpPayloadFormat);
36 
37 protected:
38  T140TextRTPSink(UsageEnvironment& env, Groupsock* RTPgs, unsigned char rtpPayloadFormat);
39  // called only by createNew()
40 
41  virtual ~T140TextRTPSink();
42 
43 protected: // redefined virtual functions:
45  virtual void doSpecialFrameHandling(unsigned fragmentationOffset,
46  unsigned char* frameStart,
47  unsigned numBytesInFrame,
48  struct timeval framePresentationTime,
49  unsigned numRemainingBytes);
50  virtual Boolean frameCanAppearAfterPacketStart(unsigned char const* frameStart,
51  unsigned numBytesInFrame) const;
52 
53 protected:
56 };
57 
58 
60 
61 // Because the T.140 text RTP payload format specification recommends that (empty) RTP packets be sent during 'idle periods'
62 // when no new text is available, we implement "T140TextRTPSink" using a separate "T140IdleFilter" class - sitting in front
63 // - that delivers, to the "T140TextRTPSink", a continuous sequence of (possibly) empty frames.
64 // (Note: This class should be used only by "T140TextRTPSink", or a subclass.)
65 
67 public:
69  virtual ~T140IdleFilter();
70 
71 private: // redefined virtual functions:
72  virtual void doGetNextFrame();
73  virtual void doStopGettingFrames();
74 
75 private:
76  static void afterGettingFrame(void* clientData, unsigned frameSize,
77  unsigned numTruncatedBytes,
78  struct timeval presentationTime,
79  unsigned durationInMicroseconds);
80  void afterGettingFrame(unsigned frameSize,
81  unsigned numTruncatedBytes,
82  struct timeval presentationTime,
83  unsigned durationInMicroseconds);
84 
85  static void handleIdleTimeout(void* clientData);
87 
90 
91  static void onSourceClosure(void* clientData);
93 
94 private:
97  char* fBuffer;
98  unsigned fBufferedNumTruncatedBytes; // a count of truncated bytes from the upstream
99  struct timeval fBufferedDataPresentationTime;
101 };
102 
103 #endif
unsigned char Boolean
Definition: Boolean.hh:25
void * TaskToken
FramedSource * inputSource() const
Definition: FramedFilter.hh:30
void afterGettingFrame(unsigned frameSize, unsigned numTruncatedBytes, struct timeval presentationTime, unsigned durationInMicroseconds)
void deliverEmptyFrame()
static void onSourceClosure(void *clientData)
virtual ~T140IdleFilter()
TaskToken fIdleTimerTask
static void handleIdleTimeout(void *clientData)
unsigned fBufferedDataDurationInMicroseconds
static void afterGettingFrame(void *clientData, unsigned frameSize, unsigned numTruncatedBytes, struct timeval presentationTime, unsigned durationInMicroseconds)
void handleIdleTimeout()
T140IdleFilter(UsageEnvironment &env, FramedSource *inputSource)
struct timeval fBufferedDataPresentationTime
void onSourceClosure()
unsigned fBufferedNumTruncatedBytes
void deliverFromBuffer()
unsigned fBufferSize
virtual void doStopGettingFrames()
virtual void doGetNextFrame()
unsigned fNumBufferedBytes
virtual Boolean continuePlaying()
static T140TextRTPSink * createNew(UsageEnvironment &env, Groupsock *RTPgs, unsigned char rtpPayloadFormat)
virtual Boolean frameCanAppearAfterPacketStart(unsigned char const *frameStart, unsigned numBytesInFrame) const
virtual void doSpecialFrameHandling(unsigned fragmentationOffset, unsigned char *frameStart, unsigned numBytesInFrame, struct timeval framePresentationTime, unsigned numRemainingBytes)
virtual ~T140TextRTPSink()
T140TextRTPSink(UsageEnvironment &env, Groupsock *RTPgs, unsigned char rtpPayloadFormat)
Boolean fAreInIdlePeriod
T140IdleFilter * fOurIdleFilter