1 /*

     2 * Copyright (c) 2010 Ixonos Plc.

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of the "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - Initial contribution

    11 *

    12 * Contributors:

    13 * Ixonos Plc

    14 *

    15 * Description:

    16 *

    17 */

    18 

    19 

    20 /**************************************************************************

    21   coupling.cpp - Coupling channel implementations (parsing only!).

    22  

    23   Author(s): Juha Ojanpera

    24   Copyright (c) 2000-2004 by Nokia Research Center, Speech and Audio Systems.

    25   *************************************************************************/

    26 

    27 /*-- System Headers. --*/

    28 #include <math.h>

    29 

    30 /*-- Project Headers. --*/

    31 #include "tool2.h"

    32 #include "defines.h"

    33 

    34 int16

    35 GetCCE(CAACAudDec *aac, TBitStream *bs, CMC_Info *mip, CCInfo **ccInfo)

    36 {

    37   TCh_Info cip;

    38   CToolInfo *tool;

    39   CWindowInfo *ccWin;

    40   int16 i, j, tag, cidx, ch, nele, nch;

    41   int16 shared[2 * ((LEN_NCC << 3) + 1)], global_gain;

    42 

    43   ZERO_MEMORY(&cip, sizeof(TCh_Info));

    44 

    45   /*-- Get (dummy) channel index for this coupling channel. --*/

    46   cidx = mip->dummyCCh;

    47 

    48   tool = ccInfo[cidx]->tool;

    49   ccWin = ccInfo[cidx]->winInfo;

    50 

    51   tag = (int16) BsGetBits(bs, LEN_TAG);

    52   mip->cc_ind[cidx] = (int16) BsGetBits(bs, LEN_IND_SW_CCE);

    53 

    54   /*-- Coupled (target) elements. --*/

    55   ZERO_MEMORY(shared, sizeof(shared));

    56   nele = (int16) BsGetBits(bs, LEN_NCC);

    57   for(i = 0, nch = 0; i < nele + 1; i++)

    58   {

    59     int16 cpe;

    60     

    61     cpe = (int16) BsGetBits(bs, LEN_IS_CPE);

    62     tag = (int16) BsGetBits(bs, LEN_TAG);

    63     ch = CCChIndex(mip, cpe, tag);

    64 

    65     if(!cpe)

    66       shared[nch++] = 0;

    67     else

    68     {

    69       int16 cc_l = (int16) BsGetBits(bs, LEN_CC_LR);

    70       int16 cc_r = (int16) BsGetBits(bs, LEN_CC_LR);

    71       j = (int16) ((cc_l << 1) | cc_r);

    72 

    73       switch(j)

    74       {

    75         /*-- Shared gain list. --*/

    76         case 0:

    77           shared[nch] = 1;

    78           shared[nch + 1] = 1;

    79           nch += 2;

    80           break;

    81  

    82         /*-- Left channel gain list. --*/

    83         case 1:

    84           shared[nch] = 0;

    85           nch += 1;

    86           break;

    87 

    88         /*-- Right channel gain list. --*/

    89         case 2:

    90           shared[nch] = 0;

    91           nch += 1;

    92           break;

    93 

    94         /*-- Two gain lists. --*/

    95         case 3:

    96           shared[nch] = 0;

    97           shared[nch + 1] = 0;

    98           nch += 2;

    99           break;

   100       

   101         default:

   102           shared[nch] = 0;

   103           shared[nch + 1] = 0;

   104           break;

   105       }

   106     }

   107   }

   108   

   109   int16 cc_dom = (int16) BsGetBits(bs, LEN_CC_DOM);

   110   int16 cc_gain_ele_sign = (int16) BsGetBits(bs, LEN_CC_SGN);

   111   int16 scl_idx = (int16) BsGetBits(bs, LEN_CCH_GES);

   112 

   113   /*-- Global gain. --*/

   114   global_gain = (int16) BsGetBits(bs, LEN_SCL_PCM);

   115 

   116   /*-- Side information. --*/

   117   if(!GetICSInfo(bs, ccWin, tool->ltp, NULL))

   118     return (-1);

   119   

   120   cip.info = mip->sfbInfo->winmap[ccWin->wnd];

   121   

   122   /*-- Channel parameters. --*/

   123   if (cip.sf_huf == 0) return (-1);

   124   if(!GetICS(bs, &cip, ccWin->group, ccWin->max_sfb, ccWin->cb_map, 

   125              tool->quant, global_gain, ccWin->sfac))

   126     return (-1);

   127   

   128   /*-- Coupling for first target channel(s) is already at correct scale. --*/

   129   ch = shared[0] ? (int16) 2 : (int16) 1;

   130 

   131   /*-- Bitstreams for target channel scale factors. --*/

   132   for( ; ch < nch; ch++)

   133   {

   134     /*-- If needed, get common gain elment present. --*/

   135     int16 cgep = (mip->cc_ind[cidx]) ? (int16) 1 : (int16) BsGetBits(bs, LEN_CCH_CGP);

   136 

   137     if(cgep) 

   138       int16 fac = (int16) (GetHcb(aac->sf_huf, bs) - MIDFAC);

   139     

   140     /*-- Must be dependently switched CCE. --*/

   141     else

   142       if(!huf_sfac(bs, &cip, ccWin->group, ccWin->cb_map, 0, ccWin->sfac, ccWin->max_sfb))

   143         return (-1);

   144   }

   145 

   146   return (TRUE);

   147 }