/*!
 *************************************************************************************
 * \file explicit_gop.c
 *
 * \brief
 *    Code for explicit gop support and pyramidal coding.
 *
 * \author
 *    Main contributors (see contributors.h for copyright, address and affiliation details)
 *     - Alexis Michael Tourapis                     <alexis@mobilygen.com, alexismt@ieee.org> 
 *************************************************************************************
 */

#include <stdlib.h>
#include <ctype.h>
#include <limits.h>
#include "global.h"
#include "contributors.h"
#include "explicit_gop.h"
#include "image.h"
#include "nalucommon.h"
#include "string.h"


/*!
************************************************************************
* \brief
*    Generation of Pyramid GOP
************************************************************************
*/
void create_pyramid()
{
  int i, j;
  int centerB=input->successive_Bframe/2;

  if (input->PyramidCoding == 1)
  {
    for (i=0;i<input->successive_Bframe;i++)
    {
      if (i < centerB)
      {
        gop_structure[i].slice_type = B_SLICE;
        gop_structure[i].display_no = i * 2 + 1;
        gop_structure[i].pyramid_layer = 0;
        gop_structure[i].reference_idc = NALU_PRIORITY_HIGH;
      }
      else
      {
        gop_structure[i].slice_type = B_SLICE;
        gop_structure[i].display_no = (i - centerB) * 2;
        gop_structure[i].pyramid_layer = 1;
        gop_structure[i].reference_idc = NALU_PRIORITY_DISPOSABLE;

      }      
    }
   
  }
  else
  {    
    int GOPlevels = 0;
    int Bframes = input->successive_Bframe;
    int *curGOPLevelfrm,*curGOPLeveldist ;
    int curlevel = GOPlevels ;
    int prvlevelrefs = input->successive_Bframe;
    int levelrefs = input->successive_Bframe;
    int i;

    while (Bframes > 2)
    {
      Bframes  /= 2;
      GOPlevels ++;
    }
     
    curlevel = GOPlevels ;
    curGOPLevelfrm = (int*)malloc(GOPlevels*sizeof(int));
    curGOPLeveldist= (int*)malloc(GOPlevels*sizeof(int));
    
    for (i=0; i <input->successive_Bframe; i++)
    {
      gop_structure[i].display_no = 0;
      gop_structure[i].slice_type = B_SLICE;
    }

    while (levelrefs > 2)
    {
      levelrefs /= 2;
      curGOPLevelfrm[ curlevel ] = prvlevelrefs - levelrefs;
      curGOPLeveldist[ GOPlevels - curlevel ] = levelrefs+ (levelrefs )% 2;
    
      prvlevelrefs =levelrefs ;
      curlevel --;
    }

    curGOPLevelfrm[ 0] = levelrefs;
    curGOPLeveldist[ GOPlevels] = levelrefs + (levelrefs )% 2;
  
        
    for (j=0; j<curGOPLevelfrm[0]; j++)
    {
      gop_pyramid(GOPlevels, (j+ 1) * curGOPLeveldist[ 0] - 1, curGOPLeveldist[ 0]-1, gop_structure);

    }

	
    for (j=input->successive_Bframe; j>0; j--)
    {
      for (i=1; i<j; i++)
      {
        int tempnum;      

        if (gop_structure[i].pyramid_layer>gop_structure[i-1].pyramid_layer)
        {
          tempnum=gop_structure[i -1].display_no;
          gop_structure[i-1].display_no = gop_structure[i].display_no;
          gop_structure[i].display_no = tempnum;
          
          tempnum=gop_structure[i-1].pyramid_layer;
          gop_structure[i-1].pyramid_layer = gop_structure[i].pyramid_layer;
          gop_structure[i].pyramid_layer = tempnum;

          tempnum=gop_structure[i -1].reference_idc;
          gop_structure[i-1].reference_idc = gop_structure[i].reference_idc;
          gop_structure[i].reference_idc = tempnum;

          tempnum=gop_structure[i -1].slice_type;
          gop_structure[i-1].slice_type = gop_structure[i].slice_type;
          gop_structure[i].slice_type = tempnum;

          tempnum=gop_structure[i -1].slice_qp;
          gop_structure[i-1].slice_qp = gop_structure[i].slice_qp;
          gop_structure[i].slice_qp = tempnum;
 
          tempnum=gop_structure[i -1].pyramidPocDelta;
          gop_structure[i-1].pyramidPocDelta = gop_structure[i].pyramidPocDelta;
          gop_structure[i].pyramidPocDelta = tempnum;

        }

      }     
   }

  }
}


/*!
************************************************************************
* \brief
*    True Pyramid GOP generation 
************************************************************************
*/
void gop_pyramid(int level, int frm_no, int frames, GOP_DATA *pyramid_structure)
{
  
  if (level == 0 )
  {
    if (frm_no>=0 && frm_no<input->successive_Bframe && pyramid_structure[frm_no].display_no == 0)
    {
        pyramid_structure[frm_no].slice_type = B_SLICE;
        pyramid_structure[frm_no].display_no = frm_no;
        pyramid_structure[frm_no].pyramid_layer = 0;
        pyramid_structure[frm_no].reference_idc = NALU_PRIORITY_DISPOSABLE;
    }
  }
  else
  {
    if (frm_no>=0 && frm_no<input->successive_Bframe)
    {
      pyramid_structure[frm_no].slice_type = B_SLICE;
      pyramid_structure[frm_no].display_no = frm_no;
      pyramid_structure[frm_no].pyramid_layer = level;
      pyramid_structure[frm_no].reference_idc = NALU_PRIORITY_HIGH;
    }

    
    gop_pyramid(level - 1, frm_no - (frames+1)/2,(frames+1)/2,pyramid_structure);
    gop_pyramid(level - 1, frm_no + (frames+1)/2,(frames+1)/2,pyramid_structure);
  }  
}


/*!
************************************************************************
* \brief
*    Initialization of GOP structure.
*
************************************************************************
*/
void init_gop_structure()
{
  int max_gopsize = input->PyramidCoding != 3 ? input->successive_Bframe  : input->jumpd;
  
  gop_structure = calloc(max(10,max_gopsize), sizeof (GOP_DATA)); // +1 for reordering
  if (NULL==gop_structure) 
    no_mem_exit("init_gop_structure: gop_structure");
}


/*!
************************************************************************
* \brief
*    Clear GOP structure
************************************************************************
*/
void clear_gop_structure()
{
  if (gop_structure)
    free(gop_structure);
}


/*!
************************************************************************
* \brief
*    Interpret GOP struct from input parameters
************************************************************************
*/
void interpret_gop_structure()
{

  int nLength = strlen(input->ExplicitPyramidFormat);
  int i =0, k, qp, display_no;
  int slice_read =0, order_read = 0, stored_read = 0, qp_read =0;
  int coded_frame = 0;
  
   
  if (nLength > 0)
  {
    
    for (i = 0; i < nLength ; i++)
    {    
      //! First lets read slice type
      if (slice_read == 0)
      {
        switch (input->ExplicitPyramidFormat[i])
        {
        case 'P':
        case 'p':
          gop_structure[coded_frame].slice_type=P_SLICE;
          break;
        case 'B':
        case 'b':
          gop_structure[coded_frame].slice_type=B_SLICE;
          break;
        case 'I':
        case 'i':
          gop_structure[coded_frame].slice_type=I_SLICE;
          break;
        default:
          snprintf(errortext, ET_SIZE, "Slice Type invalid in ExplicitPyramidFormat param. Please check configuration file.");
          error (errortext, 400);
          break;
        }
        slice_read = 1;
      }
      else