the relationship between rtp packet and frame

[cherishren]

The sequence is IPPP... I only want to lose the second frame, so I revise the rtp_loss.c in JM 18.4 as follows. I only read the second packet to the buffer, but not write it to the output file.

The problem is that I do not know the relationship between packet and frame. I can make the second packet lost, but not the second frame.

// rtp_loss.cpp : Defines the entry point for the console application.
//

#include <stdio.h>
#include <stdlib.h>
#include <memory.h>
#ifdef WIN32
#include <Winsock2.h>
#else
#include <netinet/in.h>
#endif

void print_usage(char *argv [])
{
  printf ("Usage: %s input_file output_file loss_percent <keep_leading_packets>\n", argv[0]);
  exit (-1);
}


int main(int argc, char* argv[])
{
  unsigned int bufsize, pacno=0;
  unsigned char buf[65000];
  int i, intime;
  FILE *fr;                                // file for reading
  FILE *fw;                                // file for writing

  
  if ((argc != 4) && (argc != 5))
  {
    print_usage (argv);
  }

  if (NULL == (fr = fopen (argv[1], "rb")))
  {
    printf ("%s: cannot open H.264 packet file %s for reading\n", argv[0], argv[1]);
    return -2;
  }

  if (NULL == (fw = fopen (argv[2], "wb")))
  {
    printf ("%s: cannot open H.264 packet file %s for reading\n", argv[0], argv[1]);
    fclose (fr);
    return -2;
  }


  if (argc==5)
  {
    for (i=0; i< atoi (argv[4]); i++)
    {
      if (4 != fread (&bufsize, 1, 4, fr))
        return 0;
      if (4 != fread (&intime, 1, 4, fr))
      {
        printf ("Panic, cannot read timestamp, old software version file?\n");
        return -1;
      }
      if (bufsize != fread (buf, 1, bufsize, fr))
      {
        printf ("Problems while reading buffer, exit\n");
        return -3;
      }

      if (4 != fwrite (&bufsize, 1, 4, fw))
      {
        printf ("Problems while writing buffer size, exit\n");
        return -1;
      }
      if (4 != fwrite (&intime, 1, 4, fw))
      {
        printf ("Problems while writing timestamp, exit\n");
        return -1;
      }
      if (bufsize != fwrite (buf, 1, bufsize, fw))
      {
        printf ("Problems while writing buffer, exit\n");
        return -3;
      }
      pacno++;
    }
  }
   
      if (4 != fread (&bufsize, 1, 4, fr))
        return 0;
      if (4 != fread (&intime, 1, 4, fr))
      {
        printf ("Panic, cannot read timestamp, old software version file?\n");
        return -1;
      }
      if (bufsize != fread (buf, 1, bufsize, fr))
      {
        printf ("Problems while reading buffer, exit\n");
        return -3;
      }
  printf ("lost packet #%d\n", pacno);
  pacno++;

	for (i=2; ; i++)
    {
      if (4 != fread (&bufsize, 1, 4, fr))
        return 0;
      if (4 != fread (&intime, 1, 4, fr))
      {
        printf ("Panic, cannot read timestamp, old software version file?\n");
        return -1;
      }
      if (bufsize != fread (buf, 1, bufsize, fr))
      {
        printf ("Problems while reading buffer, exit\n");
        return -3;
      }

      if (4 != fwrite (&bufsize, 1, 4, fw))
      {
        printf ("Problems while writing buffer size, exit\n");
        return -1;
      }
      if (4 != fwrite (&intime, 1, 4, fw))
      {
        printf ("Problems while writing timestamp, exit\n");
        return -1;
      }
      if (bufsize != fwrite (buf, 1, bufsize, fw))
      {
        printf ("Problems while writing buffer, exit\n");
        return -3;
      }
      pacno++;
    }
 }