mpeg2dec.c

一份实用不错的MPEG2的编解码,可以支持在语间,网络,电视的语间压缩,本人已在多个项目中已有应用.

      case 'F':
        Frame_Store_Flag = 1;
        break;

      case 'G':
        Big_Picture_Flag = 1;
        break;


      case 'I':
#ifdef VERIFY
        Stats_Flag = atoi(&argv[i][2]); 
#else /* VERIFY */
        printf("WARNING: This program not compiled for -i option\n");
#endif /* VERIFY */     
        break;
    
      case 'L':  /* spatial scalability flag */
        Spatial_Flag = 1;

       if(NextArg || LastArg)
       {
         printf("ERROR: -l must be followed by filename\n");
         exit(ERROR);
       }
       else
         Lower_Layer_Picture_Filename = argv[++i]; 

        break;

      case 'O':
  
        Output_Type = atoi(&argv[i][2]); 
  
        if((Output_Type==4) || (Output_Type==5))
          Output_Picture_Filename = "";  /* no need of filename */
        else if(NextArg || LastArg)  
        {
          printf("ERROR: -o must be followed by filename\n");
          exit(ERROR);
        }
        else
        /* filename is separated by space, so it becomes the next argument */
          Output_Picture_Filename = argv[++i]; 

#ifdef DISPLAY
        if (Output_Type==T_X11HIQ)
        {
          hiQdither = 1;
          Output_Type=T_X11;
        }
#endif /* DISPLAY */
        break;

      case 'Q':
        Quiet_Flag = 1;
        break;

      case 'R':
        Reference_IDCT_Flag = 1;
        break;
    
      case 'T':
#ifdef TRACE
        Trace_Flag = 1;
#else /* TRACE */
        printf("WARNING: This program not compiled for -t option\n");
#endif /* TRACE */
        break;

      case 'U':
        User_Data_Flag = 1;

      case 'V':
#ifdef VERBOSE
        Verbose_Flag = atoi(&argv[i][2]); 
#else /* VERBOSE */
        printf("This program not compiled for -v option\n");
#endif /* VERBOSE */
        break;


      case 'X':
        Ersatz_Flag = 1;

       if(NextArg || LastArg)
       {
         printf("ERROR: -x must be followed by filename\n"); 
         exit(ERROR);
       }
       else
        Substitute_Picture_Filename = argv[++i]; 

        break;



      default:
        fprintf(stderr,"undefined option -%c ignored. Exiting program\n", 
          argv[i][1]);

        exit(ERROR);
    
      } /* switch() */
    } /* if argv[i][0] == '-' */
    
    i++;

  	/* check for bitstream filename argument (there must always be one, at the very end
	   of the command line arguments */

  } /* while() */


  /* options sense checking */

  if(Main_Bitstream_Flag!=1)
  {
    printf("There must be a main bitstream specified (-b filename)\n");
  }

  /* force display process to show frame pictures */
  if((Output_Type==4 || Output_Type==5) && Frame_Store_Flag)
    Display_Progressive_Flag = 1;
  else
    Display_Progressive_Flag = 0;

#ifdef VERIFY
  /* parse the bitstream, do not actually decode it completely */
  

#if 0
  if(Output_Type==-1)
  {
    Decode_Layer = Verify_Flag;
    printf("FYI: Decoding bitstream elements up to: %s\n", 
      Layer_Table[Decode_Layer]);
  }
  else
#endif
    Decode_Layer = ALL_LAYERS;

#endif /* VERIFY */

  /* no output type specified */
  if(Output_Type==-1)
  {
    Output_Type = 9; 
    Output_Picture_Filename = "";
  }


#ifdef DISPLAY
  if (Output_Type==T_X11)
  {
    if(Frame_Store_Flag)
      Display_Progressive_Flag = 1;
    else
      Display_Progressive_Flag = 0;

    Frame_Store_Flag = 1; /* to avoid calling dither() twice */
  }
#endif


}


#ifdef OLD
/* 
   this is an old routine used to convert command line arguments
   into integers 
*/
static int Get_Val(argv)
char *argv[];
{
  int val;

  if (sscanf(argv[1]+2,"%d",&val)!=1)
    return 0;

  while (isdigit(argv[1][2]))
    argv[1]++;

  return val;
}
#endif



static int Headers()
{
  int ret;

  ld = &base;
  

  /* return when end of sequence (0) or picture
     header has been parsed (1) */

  ret = Get_Hdr();


  if (Two_Streams)
  {
    ld = &enhan;
    if (Get_Hdr()!=ret && !Quiet_Flag)
      fprintf(stderr,"streams out of sync\n");
    ld = &base;
  }

  return ret;
}



static int Decode_Bitstream()
{
  int ret;
  int Bitstream_Framenum;

  Bitstream_Framenum = 0;

  for(;;)
  {

#ifdef VERIFY
    Clear_Verify_Headers();
#endif /* VERIFY */

    ret = Headers();
    
    if(ret==1)
    {
      ret = video_sequence(&Bitstream_Framenum);
    }
    else
      return(ret);
  }

}


static void Deinitialize_Sequence()
{
  int i;

  /* clear flags */
  base.MPEG2_Flag=0;

  for(i=0;i<3;i++)
  {
    free(backward_reference_frame[i]);
    free(forward_reference_frame[i]);
    free(auxframe[i]);

    if (base.scalable_mode==SC_SPAT)
    {
     free(llframe0[i]);
     free(llframe1[i]);
    }
  }

  if (base.scalable_mode==SC_SPAT)
    free(lltmp);

#ifdef DISPLAY
  if (Output_Type==T_X11) 
    Terminate_Display_Process();
#endif
}


static int video_sequence(Bitstream_Framenumber)
int *Bitstream_Framenumber;
{
  int Bitstream_Framenum;
  int Sequence_Framenum;
  int Return_Value;

  Bitstream_Framenum = *Bitstream_Framenumber;
  Sequence_Framenum=0;

  Initialize_Sequence();

  /* decode picture whose header has already been parsed in 
     Decode_Bitstream() */


  Decode_Picture(Bitstream_Framenum, Sequence_Framenum);

  /* update picture numbers */
  if (!Second_Field)
  {
    Bitstream_Framenum++;
    Sequence_Framenum++;
  }

  /* loop through the rest of the pictures in the sequence */
  while ((Return_Value=Headers()))
  {
    Decode_Picture(Bitstream_Framenum, Sequence_Framenum);

    if (!Second_Field)
    {
      Bitstream_Framenum++;
      Sequence_Framenum++;
    }
  }

  /* put last frame */
  if (Sequence_Framenum!=0)
  {
    Output_Last_Frame_of_Sequence(Bitstream_Framenum);
  }

  Deinitialize_Sequence();

#ifdef VERIFY
    Clear_Verify_Headers();
#endif /* VERIFY */

  *Bitstream_Framenumber = Bitstream_Framenum;
  return(Return_Value);
}



static void Clear_Options()
{
  Verbose_Flag = 0;
  Output_Type = 0;
  Output_Picture_Filename = " ";
  hiQdither  = 0;
  Output_Type = 0;
  Frame_Store_Flag = 0;
  Spatial_Flag = 0;
  Lower_Layer_Picture_Filename = " ";
  Reference_IDCT_Flag = 0;
  Trace_Flag = 0;
  Quiet_Flag = 0;
  Ersatz_Flag = 0;
  Substitute_Picture_Filename  = " ";
  Two_Streams = 0;
  Enhancement_Layer_Bitstream_Filename = " ";
  Big_Picture_Flag = 0;
  Main_Bitstream_Flag = 0;
  Main_Bitstream_Filename = " ";
  Verify_Flag = 0;
  Stats_Flag  = 0;
  User_Data_Flag = 0; 
}


#ifdef DEBUG
static void Print_Options()
{
  
  printf("Verbose_Flag                         = %d\n", Verbose_Flag);
  printf("Output_Type                          = %d\n", Output_Type);
  printf("Output_Picture_Filename              = %s\n", Output_Picture_Filename);
  printf("hiQdither                            = %d\n", hiQdither);
  printf("Output_Type                          = %d\n", Output_Type);
  printf("Frame_Store_Flag                     = %d\n", Frame_Store_Flag);
  printf("Spatial_Flag                         = %d\n", Spatial_Flag);
  printf("Lower_Layer_Picture_Filename         = %s\n", Lower_Layer_Picture_Filename);
  printf("Reference_IDCT_Flag                  = %d\n", Reference_IDCT_Flag);
  printf("Trace_Flag                           = %d\n", Trace_Flag);
  printf("Quiet_Flag                           = %d\n", Quiet_Flag);
  printf("Ersatz_Flag                          = %d\n", Ersatz_Flag);
  printf("Substitute_Picture_Filename          = %s\n", Substitute_Picture_Filename);
  printf("Two_Streams                          = %d\n", Two_Streams);
  printf("Enhancement_Layer_Bitstream_Filename = %s\n", Enhancement_Layer_Bitstream_Filename);
  printf("Big_Picture_Flag                     = %d\n", Big_Picture_Flag);
  printf("Main_Bitstream_Flag                  = %d\n", Main_Bitstream_Flag);
  printf("Main_Bitstream_Filename              = %s\n", Main_Bitstream_Filename);
  printf("Verify_Flag                          = %d\n", Verify_Flag);
  printf("Stats_Flag                           = %d\n", Stats_Flag);
  printf("User_Data_Flag                       = %d\n", User_Data_Flag);

}
#endif