liveMedia/QCELPAudioRTPSource.cpp

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/**********
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
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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.,
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**********/
// "liveMedia"
// Copyright (c) 1996-2008 Live Networks, Inc.  All rights reserved.
// Qualcomm "PureVoice" (aka. "QCELP") Audio RTP Sources
// Implementation

#include "QCELPAudioRTPSource.hh"
#include "MultiFramedRTPSource.hh"
#include "FramedFilter.hh"
#include <string.h>
#include <stdlib.h>

// This source is implemented internally by two separate sources:
// (i) a RTP source for the raw (interleaved) QCELP frames, and
// (ii) a deinterleaving filter that reads from this.
// Define these two new classes here:

class RawQCELPRTPSource: public MultiFramedRTPSource {
public:
  static RawQCELPRTPSource* createNew(UsageEnvironment& env,
                                      Groupsock* RTPgs,
                                      unsigned char rtpPayloadFormat,
                                      unsigned rtpTimestampFrequency);

  unsigned char interleaveL() const { return fInterleaveL; }
  unsigned char interleaveN() const { return fInterleaveN; }
  unsigned char& frameIndex() { return fFrameIndex; } // index within pkt

private:
  RawQCELPRTPSource(UsageEnvironment& env, Groupsock* RTPgs,
                    unsigned char rtpPayloadFormat,
                    unsigned rtpTimestampFrequency);
      // called only by createNew()

  virtual ~RawQCELPRTPSource();

private:
  // redefined virtual functions:
  virtual Boolean processSpecialHeader(BufferedPacket* packet,
                                       unsigned& resultSpecialHeaderSize);
  virtual char const* MIMEtype() const;

  virtual Boolean hasBeenSynchronizedUsingRTCP();

private:
  unsigned char fInterleaveL, fInterleaveN, fFrameIndex;
  unsigned fNumSuccessiveSyncedPackets;
};

class QCELPDeinterleaver: public FramedFilter {
public:
  static QCELPDeinterleaver* createNew(UsageEnvironment& env,
                                       RawQCELPRTPSource* inputSource);

private:
  QCELPDeinterleaver(UsageEnvironment& env,
                     RawQCELPRTPSource* inputSource);
      // called only by "createNew()"

  virtual ~QCELPDeinterleaver();

  static void afterGettingFrame(void* clientData, unsigned frameSize,
                                unsigned numTruncatedBytes,
                                struct timeval presentationTime,
                                unsigned durationInMicroseconds);
  void afterGettingFrame1(unsigned frameSize, struct timeval presentationTime);

private:
  // Redefined virtual functions:
  void doGetNextFrame();

private:
  class QCELPDeinterleavingBuffer* fDeinterleavingBuffer;
  Boolean fNeedAFrame;
};



FramedSource*
QCELPAudioRTPSource::createNew(UsageEnvironment& env,
                               Groupsock* RTPgs,
                               RTPSource*& resultRTPSource,
                               unsigned char rtpPayloadFormat,
                               unsigned rtpTimestampFrequency) {
  RawQCELPRTPSource* rawRTPSource;
  resultRTPSource = rawRTPSource
    = RawQCELPRTPSource::createNew(env, RTPgs, rtpPayloadFormat,
                                   rtpTimestampFrequency);
  if (resultRTPSource == NULL) return NULL;

  QCELPDeinterleaver* deinterleaver
    = QCELPDeinterleaver::createNew(env, rawRTPSource);
  if (deinterleaver == NULL) {
    Medium::close(resultRTPSource);
    resultRTPSource = NULL;
  }

  return deinterleaver;
}



// A subclass of BufferedPacket, used to separate out QCELP frames.

class QCELPBufferedPacket: public BufferedPacket {
public:
  QCELPBufferedPacket(RawQCELPRTPSource& ourSource);
  virtual ~QCELPBufferedPacket();

private: // redefined virtual functions
  virtual unsigned nextEnclosedFrameSize(unsigned char*& framePtr,
                                         unsigned dataSize);
private:
  RawQCELPRTPSource& fOurSource;
};

class QCELPBufferedPacketFactory: public BufferedPacketFactory {
private: // redefined virtual functions
  virtual BufferedPacket* createNewPacket(MultiFramedRTPSource* ourSource);
};



RawQCELPRTPSource*
RawQCELPRTPSource::createNew(UsageEnvironment& env, Groupsock* RTPgs,
                             unsigned char rtpPayloadFormat,
                             unsigned rtpTimestampFrequency) {
  return new RawQCELPRTPSource(env, RTPgs, rtpPayloadFormat,
                               rtpTimestampFrequency);
}

RawQCELPRTPSource::RawQCELPRTPSource(UsageEnvironment& env,
                                     Groupsock* RTPgs,
                                     unsigned char rtpPayloadFormat,
                                     unsigned rtpTimestampFrequency)
  : MultiFramedRTPSource(env, RTPgs, rtpPayloadFormat,
                         rtpTimestampFrequency,
                         new QCELPBufferedPacketFactory),
  fInterleaveL(0), fInterleaveN(0), fFrameIndex(0),
  fNumSuccessiveSyncedPackets(0) {
}

RawQCELPRTPSource::~RawQCELPRTPSource() {
}

Boolean RawQCELPRTPSource
::processSpecialHeader(BufferedPacket* packet,
                       unsigned& resultSpecialHeaderSize) {
  unsigned char* headerStart = packet->data();
  unsigned packetSize = packet->dataSize();

  // First, check whether this packet's RTP timestamp is synchronized:
  if (RTPSource::hasBeenSynchronizedUsingRTCP()) {
    ++fNumSuccessiveSyncedPackets;
  } else {
    fNumSuccessiveSyncedPackets = 0;
  }

  // There's a 1-byte header indicating the interleave parameters
  if (packetSize < 1) return False;

  // Get the interleaving parameters from the 1-byte header,
  // and check them for validity:
  unsigned char const firstByte = headerStart[0];
  unsigned char const interleaveL = (firstByte&0x38)>>3;
  unsigned char const interleaveN = firstByte&0x07;
#ifdef DEBUG
  fprintf(stderr, "packetSize: %d, interleaveL: %d, interleaveN: %d\n", packetSize, interleaveL, interleaveN);
#endif
  if (interleaveL > 5 || interleaveN > interleaveL) return False; //invalid

  fInterleaveL = interleaveL;
  fInterleaveN = interleaveN;
  fFrameIndex = 0; // initially

  resultSpecialHeaderSize = 1;
  return True;
}

char const* RawQCELPRTPSource::MIMEtype() const {
  return "audio/QCELP";
}

Boolean RawQCELPRTPSource::hasBeenSynchronizedUsingRTCP() {
  // Don't report ourselves as being synchronized until we've received
  // at least a complete interleave cycle of synchronized packets.
  // This ensures that the receiver is currently getting a frame from
  // a packet that was synchronized.
  if (fNumSuccessiveSyncedPackets > (unsigned)(fInterleaveL+1)) {
    fNumSuccessiveSyncedPackets = fInterleaveL+2; // prevents overflow
    return True;
  }
  return False;
}



QCELPBufferedPacket::QCELPBufferedPacket(RawQCELPRTPSource& ourSource)
  : fOurSource(ourSource) {
}

QCELPBufferedPacket::~QCELPBufferedPacket() {
}

unsigned QCELPBufferedPacket::
  nextEnclosedFrameSize(unsigned char*& framePtr, unsigned dataSize) {
  // The size of the QCELP frame is determined by the first byte:
  if (dataSize == 0) return 0; // sanity check
  unsigned char const firstByte = framePtr[0];

  unsigned frameSize;
  switch (firstByte) {
  case 0: { frameSize = 1; break; }
  case 1: { frameSize = 4; break; }
  case 2: { frameSize = 8; break; }
  case 3: { frameSize = 17; break; }
  case 4: { frameSize = 35; break; }
  default: { frameSize = 0; break; }
  }

#ifdef DEBUG
  fprintf(stderr, "QCELPBufferedPacket::nextEnclosedFrameSize(): frameSize: %d, dataSize: %d\n", frameSize, dataSize);
#endif
  if (dataSize < frameSize) return 0;

  ++fOurSource.frameIndex();
  return frameSize;
}

BufferedPacket* QCELPBufferedPacketFactory
::createNewPacket(MultiFramedRTPSource* ourSource) {
  return new QCELPBufferedPacket((RawQCELPRTPSource&)(*ourSource));
}

// (used to implement QCELPDeinterleaver)

#define QCELP_MAX_FRAME_SIZE 35
#define QCELP_MAX_INTERLEAVE_L 5
#define QCELP_MAX_FRAMES_PER_PACKET 10
#define QCELP_MAX_INTERLEAVE_GROUP_SIZE \
    ((QCELP_MAX_INTERLEAVE_L+1)*QCELP_MAX_FRAMES_PER_PACKET)

class QCELPDeinterleavingBuffer {
public:
  QCELPDeinterleavingBuffer();
  virtual ~QCELPDeinterleavingBuffer();

  void deliverIncomingFrame(unsigned frameSize,
                            unsigned char interleaveL,
                            unsigned char interleaveN,
                            unsigned char frameIndex,
                            unsigned short packetSeqNum,
                            struct timeval presentationTime);
  Boolean retrieveFrame(unsigned char* to, unsigned maxSize,
                        unsigned& resultFrameSize, unsigned& resultNumTruncatedBytes,
                        struct timeval& resultPresentationTime);

  unsigned char* inputBuffer() { return fInputBuffer; }
  unsigned inputBufferSize() const { return QCELP_MAX_FRAME_SIZE; }

private:
  class FrameDescriptor {
  public:
    FrameDescriptor();
    virtual ~FrameDescriptor();

    unsigned frameSize;
    unsigned char* frameData;
    struct timeval presentationTime;
  };

  // Use two banks of descriptors - one for incoming, one for outgoing
  FrameDescriptor fFrames[QCELP_MAX_INTERLEAVE_GROUP_SIZE][2];
  unsigned char fIncomingBankId; // toggles between 0 and 1
  unsigned char fIncomingBinMax; // in the incoming bank
  unsigned char fOutgoingBinMax; // in the outgoing bank
  unsigned char fNextOutgoingBin;
  Boolean fHaveSeenPackets;
  u_int16_t fLastPacketSeqNumForGroup;
  unsigned char* fInputBuffer;
  struct timeval fLastRetrievedPresentationTime;
};



QCELPDeinterleaver*
QCELPDeinterleaver::createNew(UsageEnvironment& env,
                              RawQCELPRTPSource* inputSource) {
  return new QCELPDeinterleaver(env, inputSource);
}

QCELPDeinterleaver::QCELPDeinterleaver(UsageEnvironment& env,
                                       RawQCELPRTPSource* inputSource)
  : FramedFilter(env, inputSource),
    fNeedAFrame(False) {
  fDeinterleavingBuffer = new QCELPDeinterleavingBuffer();
}

QCELPDeinterleaver::~QCELPDeinterleaver() {
  delete fDeinterleavingBuffer;
}

static unsigned const uSecsPerFrame = 20000; // 20 ms

void QCELPDeinterleaver::doGetNextFrame() {
  // First, try getting a frame from the deinterleaving buffer:
  if (fDeinterleavingBuffer->retrieveFrame(fTo, fMaxSize,
                                           fFrameSize, fNumTruncatedBytes,
                                           fPresentationTime)) {
    // Success!
    fNeedAFrame = False;

    fDurationInMicroseconds = uSecsPerFrame;

    // Call our own 'after getting' function.  Because we're not a 'leaf'
    // source, we can call this directly, without risking
    // infinite recursion
    afterGetting(this);
    return;
  }

  // No luck, so ask our source for help:
  fNeedAFrame = True;
  if (!fInputSource->isCurrentlyAwaitingData()) {
    fInputSource->getNextFrame(fDeinterleavingBuffer->inputBuffer(),
                               fDeinterleavingBuffer->inputBufferSize(),
                               afterGettingFrame, this,
                               FramedSource::handleClosure, this);
  }
}

void QCELPDeinterleaver
::afterGettingFrame(void* clientData, unsigned frameSize,
                    unsigned /*numTruncatedBytes*/,
                    struct timeval presentationTime,
                    unsigned /*durationInMicroseconds*/) {
  QCELPDeinterleaver* deinterleaver = (QCELPDeinterleaver*)clientData;
  deinterleaver->afterGettingFrame1(frameSize, presentationTime);
}

void QCELPDeinterleaver
::afterGettingFrame1(unsigned frameSize, struct timeval presentationTime) {
  RawQCELPRTPSource* source = (RawQCELPRTPSource*)fInputSource;

  // First, put the frame into our deinterleaving buffer:
  fDeinterleavingBuffer
    ->deliverIncomingFrame(frameSize, source->interleaveL(),
                           source->interleaveN(), source->frameIndex(),
                           source->curPacketRTPSeqNum(),
                           presentationTime);

  // Then, try delivering a frame to the client (if he wants one):
  if (fNeedAFrame) doGetNextFrame();
}



QCELPDeinterleavingBuffer::QCELPDeinterleavingBuffer()
  : fIncomingBankId(0), fIncomingBinMax(0),
    fOutgoingBinMax(0), fNextOutgoingBin(0),
    fHaveSeenPackets(False) {
  fInputBuffer = new unsigned char[QCELP_MAX_FRAME_SIZE];
}

QCELPDeinterleavingBuffer::~QCELPDeinterleavingBuffer() {
  delete[] fInputBuffer;
}

void QCELPDeinterleavingBuffer
::deliverIncomingFrame(unsigned frameSize,
                       unsigned char interleaveL,
                       unsigned char interleaveN,
                       unsigned char frameIndex,
                       unsigned short packetSeqNum,
                       struct timeval presentationTime) {
  // First perform a sanity check on the parameters:
  // (This is overkill, as the source should have already done this.)
  if (frameSize > QCELP_MAX_FRAME_SIZE
      || interleaveL > QCELP_MAX_INTERLEAVE_L || interleaveN > interleaveL
      || frameIndex == 0 || frameIndex > QCELP_MAX_FRAMES_PER_PACKET) {
#ifdef DEBUG
    fprintf(stderr, "QCELPDeinterleavingBuffer::deliverIncomingFrame() param sanity check failed (%d,%d,%d,%d)\n", frameSize, interleaveL, interleaveN, frameIndex);
#endif
    exit(1);
  }

  // The input "presentationTime" was that of the first frame in this
  // packet.  Update it for the current frame:
  unsigned uSecIncrement = (frameIndex-1)*(interleaveL+1)*uSecsPerFrame;
  presentationTime.tv_usec += uSecIncrement;
  presentationTime.tv_sec += presentationTime.tv_usec/1000000;
  presentationTime.tv_usec = presentationTime.tv_usec%1000000;

  // Next, check whether this packet is part of a new interleave group
  if (!fHaveSeenPackets
      || seqNumLT(fLastPacketSeqNumForGroup, packetSeqNum)) {
    // We've moved to a new interleave group
    fHaveSeenPackets = True;
    fLastPacketSeqNumForGroup = packetSeqNum + interleaveL - interleaveN;

    // Switch the incoming and outgoing banks:
    fIncomingBankId ^= 1;
    unsigned char tmp = fIncomingBinMax;
    fIncomingBinMax = fOutgoingBinMax;
    fOutgoingBinMax = tmp;
    fNextOutgoingBin = 0;
  }

  // Now move the incoming frame into the appropriate bin:
  unsigned const binNumber
    = interleaveN + (frameIndex-1)*(interleaveL+1);
  FrameDescriptor& inBin = fFrames[binNumber][fIncomingBankId];
  unsigned char* curBuffer = inBin.frameData;
  inBin.frameData = fInputBuffer;
  inBin.frameSize = frameSize;
  inBin.presentationTime = presentationTime;

  if (curBuffer == NULL) curBuffer = new unsigned char[QCELP_MAX_FRAME_SIZE];
  fInputBuffer = curBuffer;

  if (binNumber >= fIncomingBinMax) {
    fIncomingBinMax = binNumber + 1;
  }
}

Boolean QCELPDeinterleavingBuffer
::retrieveFrame(unsigned char* to, unsigned maxSize,
                unsigned& resultFrameSize, unsigned& resultNumTruncatedBytes,
                struct timeval& resultPresentationTime) {
  if (fNextOutgoingBin >= fOutgoingBinMax) return False; // none left

  FrameDescriptor& outBin = fFrames[fNextOutgoingBin][fIncomingBankId^1];
  unsigned char* fromPtr;
  unsigned char fromSize = outBin.frameSize;
  outBin.frameSize = 0; // for the next time this bin is used

  // Check whether this frame is missing; if so, return an 'erasure' frame:
  unsigned char erasure = 14;
  if (fromSize == 0) {
    fromPtr = &erasure;
    fromSize = 1;

    // Compute this erasure frame's presentation time via extrapolation:
    resultPresentationTime = fLastRetrievedPresentationTime;
    resultPresentationTime.tv_usec += uSecsPerFrame;
    if (resultPresentationTime.tv_usec >= 1000000) {
      ++resultPresentationTime.tv_sec;
      resultPresentationTime.tv_usec -= 1000000;
    }
  } else {
    // Normal case - a frame exists:
    fromPtr = outBin.frameData;
    resultPresentationTime = outBin.presentationTime;
  }

  fLastRetrievedPresentationTime = resultPresentationTime;

  if (fromSize > maxSize) {
    resultNumTruncatedBytes = fromSize - maxSize;
    resultFrameSize = maxSize;
  } else {
    resultNumTruncatedBytes = 0;
    resultFrameSize = fromSize;
  }
  memmove(to, fromPtr, resultFrameSize);

  ++fNextOutgoingBin;
  return True;
}

QCELPDeinterleavingBuffer::FrameDescriptor::FrameDescriptor()
  : frameSize(0), frameData(NULL) {
}

QCELPDeinterleavingBuffer::FrameDescriptor::~FrameDescriptor() {
  delete[] frameData;
}

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