liveMedia/H264VideoRTPSink.cpp

/**********
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 H.264 video (RFC 3984)
// Implementation

#include "H264VideoRTPSink.hh"
#include "H264VideoStreamFramer.hh"
#include "Base64.hh"
#include "H264VideoRTPSource.hh" // for "parseSPropParameterSets()"

////////// H264VideoRTPSink implementation //////////

H264VideoRTPSink
::H264VideoRTPSink(UsageEnvironment& env, Groupsock* RTPgs, unsigned char rtpPayloadFormat,
		   u_int8_t const* sps, unsigned spsSize, u_int8_t const* pps, unsigned ppsSize)
  : H264or5VideoRTPSink(264, env, RTPgs, rtpPayloadFormat,
			NULL, 0, sps, spsSize, pps, ppsSize) {
}

H264VideoRTPSink::~H264VideoRTPSink() {
}

H264VideoRTPSink* H264VideoRTPSink
::createNew(UsageEnvironment& env, Groupsock* RTPgs, unsigned char rtpPayloadFormat) {
  return new H264VideoRTPSink(env, RTPgs, rtpPayloadFormat);
}

H264VideoRTPSink* H264VideoRTPSink
::createNew(UsageEnvironment& env, Groupsock* RTPgs, unsigned char rtpPayloadFormat,
	    u_int8_t const* sps, unsigned spsSize, u_int8_t const* pps, unsigned ppsSize) {
  return new H264VideoRTPSink(env, RTPgs, rtpPayloadFormat, sps, spsSize, pps, ppsSize);
}

H264VideoRTPSink* H264VideoRTPSink
::createNew(UsageEnvironment& env, Groupsock* RTPgs, unsigned char rtpPayloadFormat,
	    char const* sPropParameterSetsStr) {
  u_int8_t* sps = NULL; unsigned spsSize = 0;
  u_int8_t* pps = NULL; unsigned ppsSize = 0;

  unsigned numSPropRecords;
  SPropRecord* sPropRecords = parseSPropParameterSets(sPropParameterSetsStr, numSPropRecords);
  for (unsigned i = 0; i < numSPropRecords; ++i) {
    if (sPropRecords[i].sPropLength == 0) continue; // bad data
    u_int8_t nal_unit_type = (sPropRecords[i].sPropBytes[0])&0x1F;
    if (nal_unit_type == 7/*SPS*/) {
      sps = sPropRecords[i].sPropBytes;
      spsSize = sPropRecords[i].sPropLength;
    } else if (nal_unit_type == 8/*PPS*/) {
      pps = sPropRecords[i].sPropBytes;
      ppsSize = sPropRecords[i].sPropLength;
    }
  }

  H264VideoRTPSink* result
    = new H264VideoRTPSink(env, RTPgs, rtpPayloadFormat, sps, spsSize, pps, ppsSize);
  delete[] sPropRecords;

  return result;
}

Boolean H264VideoRTPSink::sourceIsCompatibleWithUs(MediaSource& source) {
  // Our source must be an appropriate framer:
  return source.isH264VideoStreamFramer();
}

char const* H264VideoRTPSink::auxSDPLine() {
  // Generate a new "a=fmtp:" line each time, using our SPS and PPS (if we have them),
  // otherwise parameters from our framer source (in case they've changed since the last time that
  // we were called):
  H264or5VideoStreamFramer* framerSource = NULL;
  u_int8_t* vpsDummy = NULL; unsigned vpsDummySize = 0;
  u_int8_t* sps = fSPS; unsigned spsSize = fSPSSize;
  u_int8_t* pps = fPPS; unsigned ppsSize = fPPSSize;
  if (sps == NULL || pps == NULL) {
    // We need to get SPS and PPS from our framer source:
    if (fOurFragmenter == NULL) return NULL; // we don't yet have a fragmenter (and therefore not a source)
    framerSource = (H264or5VideoStreamFramer*)(fOurFragmenter->inputSource());
    if (framerSource == NULL) return NULL; // we don't yet have a source

    framerSource->getVPSandSPSandPPS(vpsDummy, vpsDummySize, sps, spsSize, pps, ppsSize);
    if (sps == NULL || pps == NULL) return NULL; // our source isn't ready
  }

  // Set up the "a=fmtp:" SDP line for this stream:
  u_int8_t* spsWEB = new u_int8_t[spsSize]; // "WEB" means "Without Emulation Bytes"
  unsigned spsWEBSize = removeH264or5EmulationBytes(spsWEB, spsSize, sps, spsSize);
  if (spsWEBSize < 4) { // Bad SPS size => assume our source isn't ready
    delete[] spsWEB;
    return NULL;
  }
  u_int32_t profileLevelId = (spsWEB[1]<<16) | (spsWEB[2]<<8) | spsWEB[3];
  delete[] spsWEB;

  char* sps_base64 = base64Encode((char*)sps, spsSize);
  char* pps_base64 = base64Encode((char*)pps, ppsSize);

  char const* fmtpFmt =
    "a=fmtp:%d packetization-mode=1"
    ";profile-level-id=%06X"
    ";sprop-parameter-sets=%s,%s\r\n";
  unsigned fmtpFmtSize = strlen(fmtpFmt)
    + 3 /* max char len */
    + 6 /* 3 bytes in hex */
    + strlen(sps_base64) + strlen(pps_base64);
  char* fmtp = new char[fmtpFmtSize];
  sprintf(fmtp, fmtpFmt,
          rtpPayloadType(),
	  profileLevelId,
          sps_base64, pps_base64);

  delete[] sps_base64;
  delete[] pps_base64;

  delete[] fFmtpSDPLine; fFmtpSDPLine = fmtp;
  return fFmtpSDPLine;
}