/************************************************************************* COPYRIGHT AND WARRANTY INFORMATION** Copyright 2001, International Telecommunications Union, Geneva** DISCLAIMER OF WARRANTY** These software programs are available to the user without any* license fee or royalty on an "as is" basis. The ITU disclaims* any and all warranties, whether express, implied, or* statutory, including any implied warranties of merchantability* or of fitness for a particular purpose.  In no event shall the* contributor or the ITU be liable for any incidental, punitive, or* consequential damages of any kind whatsoever arising from the* use of these programs.** This disclaimer of warranty extends to the user of these programs* and user's customers, employees, agents, transferees, successors,* and assigns.** The ITU does not represent or warrant that the programs furnished* hereunder are free of infringement of any third-party patents.* Commercial implementations of ITU-T Recommendations, including* shareware, may be subject to royalty fees to patent holders.* Information regarding the ITU-T patent policy is available from* the ITU Web site at http://www.itu.int.** THIS IS NOT A GRANT OF PATENT RIGHTS - SEE THE ITU-T PATENT POLICY.*************************************************************************//*! ***************************************************************************** * * \file rtp.c * * \brief *    Functions to handle RTP headers and packets per RFC1889 and RTP NAL spec *    Functions support little endian systems only (Intel, not Motorola/Sparc) * * \date *    30 September 2001 * * \author *    Stephan Wenger   stewe@cs.tu-berlin.de *****************************************************************************/#include <stdio.h>#include <stdlib.h>#include <string.h>#include <assert.h>#include <memory.h>#include "rtp.h"#include "elements.h"#include "defines.h"#include "global.h"// A little trick to avoid those horrible #if TRACE all over the source code#if TRACE#define SYMTRACESTRING(s) strncpy(sym.tracestring,s,TRACESTRING_SIZE)#else#define SYMTRACESTRING(s) // to nothing#endifint CurrentRTPTimestamp = 0;      //! The RTP timestamp of the current packet,                                  //! incremented with all P and I framesint CurrentRTPSequenceNumber = 0; //! The RTP sequence number of the current packet                                  //! incremented by one for each sent packet/*! ***************************************************************************** * * \brief  *    ComposeRTPpacket composes the complete RTP packet using the various *    structure members of the RTPpacket_t structure * * \return *    0 in case of success *    negative error code in case of failure * * \para Parameters *    Caller is responsible to allocate enough memory for the generated packet *    in parameter->packet. Typically a malloc of 12+paylen bytes is sufficient * * \para Side effects *    none * * \para Other Notes *    Function contains assert() tests for debug purposes (consistency checks *    for RTP header fields * * \date *    30 Spetember 2001 * * \author *    Stephan Wenger   stewe@cs.tu-berlin.de *****************************************************************************/int ComposeRTPPacket (RTPpacket_t *p){  // Consistency checks through assert, only used for debug purposes  assert (p->v == 2);  assert (p->p == 0);  assert (p->x == 0);  assert (p->cc == 0);    // mixer designers need to change this one  assert (p->m == 0 || p->m == 1);  assert (p->pt < 128);  assert (p->seq < 65536);  assert (p->payload != NULL);  assert (p->paylen < 65536 - 40);  // 2**16 -40 for IP/UDP/RTP header  assert (p->packet != NULL);  // Compose RTP header, little endian  p->packet[0] = (   (p->v)                  |  (p->p << 2)                  |  (p->x << 3)                  |  (p->cc << 4) );  p->packet[1] = (   (p->m)                  |  (p->pt << 1) );  p->packet[2] = p->seq & 0xff;  p->packet[3] = (p->seq >> 8) & 0xff;  memcpy (&p->packet[4], &p->timestamp, 4);  // change to shifts for unified byte sex  memcpy (&p->packet[8], &p->ssrc, 4);// change to shifts for unified byte sex  // Copy payload   memcpy (&p->packet[12], p->payload, p->paylen);  p->packlen = p->paylen+12;  return 0;}/*! ***************************************************************************** * * \brief  *    WriteRTPPacket writes the supplied RTP packet to the output file * * \return *    0 in case of access *    <0 in case of write failure (typically fatal) * * \para Parameters *    p: the RTP packet to be written (after ComposeRTPPacket() ) *    f: output file * * \para Side effects *    none * * \date *    October 23, 2001 * * \author *    Stephan Wenger   stewe@cs.tu-berlin.de *****************************************************************************/int WriteRTPPacket (RTPpacket_t *p, FILE *f){  int intime = -1;  assert (f != NULL);  assert (p != NULL);  if (1 != fwrite (&p->packlen, 4, 1, f))    return -1;  if (1 != fwrite (&intime, 4, 1, f))    return -1;  if (1 != fwrite (p->packet, p->packlen, 1, f))    return -1;  return 0;}/*! ***************************************************************************** * * \brief  *    ComposeHeaderPacketPayload generates the payload for a header packet *    using the inp-> structure contents.  The header packet contains  *    definitions for a single parameter set 0, which is used for all  *    slices of the picture * * \return *    len of the genberated payload in bytes *    <0 in case of failure (typically fatal) * * \para Parameters *    p: the payload of the RTP packet to be written * * \para Side effects *    none * * \note *    This function should be revisited and checked in case of additional *    bit stream parameters that affect the picture header (or higher *    entitries).  Typical examples are more entropy coding schemes, other *    motion vector resolutiuon, and optional elements * * \date *    October 23, 2001 * * \author *    Stephan Wenger   stewe@cs.tu-berlin.de *****************************************************************************/int ComposeHeaderPacketPayload (byte *payload){  int slen=0;  int multpred;  assert (img->width%16 == 0);  assert (img->height%16 == 0);#ifdef _ADDITIONAL_REFERENCE_FRAME_  if (input->no_multpred <= 1 && input->add_ref_frame == 0)#else  if (input->no_multpred <= 1)#endif    multpred=FALSE;  else    multpred=TRUE;               // multiple reference frames in motion search    slen = snprintf (payload, MAXRTPPAYLOADLEN,              "a=H26L (0) MaxPicID %d\            \na=H26L (0) UseMultpred %d\            \na=H26L (0) BufCycle %d\            \na=H26L (0) PixAspectRatioX 1\            \na=H26L (0) PixAspectRatioY 1\            \na=H26L (0) DisplayWindowOffsetTop 0\            \na=H26L (0) DisplayWindowOffsetBottom 0\            \na=H26L (0) DisplayWindowOffsetRight 0\            \na=H26L (0) DisplayWindowOffsetLeft 0\            \na=H26L (0) XSizeMB %d\            \na=H26L (0) YSizeMB %d\            \na=H26L (0) EntropyCoding %s\            \na=H26L (0) MotionResolution %s\            \na=H26L (0) PartitioningType %s\            \na=H26L (0) IntraPredictionType %s\            \na=H26L (0) HRCParameters 0\            \            \na=H26L (-1) FramesToBeEncoded %d\            \na=H26L (-1) FrameSkip %d\            \na=H26L (-1) SequenceFileName %s\            %c%c",            256,            multpred==TRUE?1:0,            input->no_multpred,            input->img_width/16,            input->img_height/16,            input->symbol_mode==UVLC?"UVLC":"CABAC",            input->mv_res==0?"quater":"eigth",            input->partition_mode==0?"one":"three",            input->UseConstrainedIntraPred==0?"InterPredicted":"NotInterPredicted",            input->no_frames,            input->jumpd,            input->infile,            4,     // Unix Control D EOF symbol            26);  // MS-DOS/Windows Control Z EOF Symbol  return slen;}/*! ***************************************************************************** * * \brief  *    void RTPSequenceHeader (FILE *out) write the RTP Sequence header in the *       form of a header packet into the outfile.  It is assumed that the *       input-> structure is already filled (config file is parsed) * * \return *    length of sequence header * * \para Parameters *    out: fiel pointer of the output file * * \para Side effects *    header written, statistics are updated, RTP sequence number updated * * \para Note *    This function uses alloca() to reserve memry on the stack -- no freeing and *    no return value check necessary, error lead to stack overflows *