git.sesse.net Git - vlc/blob - src/ac3_decoder/ac3_rematrix.c

   1 #include <unistd.h>                                              /* getpid() */
   2
   3 #include <stdio.h>                                           /* "intf_msg.h" */
   4 #include <stdlib.h>                                      /* malloc(), free() */
   5 #include <sys/soundcard.h>                               /* "audio_output.h" */
   6 #include <sys/types.h>
   7 #include <sys/uio.h>                                            /* "input.h" */
   8
   9 #include "common.h"
  10 #include "config.h"
  11 #include "mtime.h"
  12 #include "vlc_thread.h"
  13 #include "debug.h"                                      /* "input_netlist.h" */
  14
  15 #include "intf_msg.h"                        /* intf_DbgMsg(), intf_ErrMsg() */
  16
  17 #include "input.h"                                           /* pes_packet_t */
  18 #include "input_netlist.h"                         /* input_NetlistFreePES() */
  19 #include "decoder_fifo.h"         /* DECODER_FIFO_(ISEMPTY|START|INCSTART)() */
  20
  21 #include "audio_output.h"
  22
  23 #include "ac3_decoder.h"
  24 #include "ac3_parse.h"
  25 #include "ac3_exponent.h"
  26 #include "ac3_bit_allocate.h"
  27 #include "ac3_mantissa.h"
  28 #include "ac3_rematrix.h"
  29
  30 struct rematrix_band_s
  31 {
  32         u32 start;
  33         u32 end;
  34 };
  35
  36 static struct rematrix_band_s rematrix_band[] = { {13,24}, {25,36}, {37 ,60}, {61,252}};
  37
  38 static __inline__ u32 min( u32 a, u32 b )
  39 {
  40         return( a < b ? a : b );
  41 }
  42
  43 /* This routine simply does stereo rematixing for the 2 channel
  44  * stereo mode */
  45 void rematrix( ac3dec_t * p_ac3dec )
  46 {
  47         u32 num_bands;
  48         u32 start;
  49         u32 end;
  50         u32 i,j;
  51         float left,right;
  52
  53         if(p_ac3dec->audblk.cplinu || p_ac3dec->audblk.cplbegf > 2)
  54                 num_bands = 4;
  55         else if (p_ac3dec->audblk.cplbegf > 0)
  56                 num_bands = 3;
  57         else
  58                 num_bands = 2;
  59
  60         for(i=0;i < num_bands; i++)
  61         {
  62                 if(!p_ac3dec->audblk.rematflg[i])
  63                         continue;
  64
  65                 start = rematrix_band[i].start;
  66                 end = min(rematrix_band[i].end ,12 * p_ac3dec->audblk.cplbegf + 36);
  67
  68                 for(j=start;j < end; j++)
  69                 {
  70                         left  = 0.5f * (p_ac3dec->coeffs.fbw[0][j] + p_ac3dec->coeffs.fbw[1][j]);
  71                         right = 0.5f * (p_ac3dec->coeffs.fbw[0][j] - p_ac3dec->coeffs.fbw[1][j]);
  72                         p_ac3dec->coeffs.fbw[0][j] = left;
  73                         p_ac3dec->coeffs.fbw[1][j] = right;
  74                 }
  75         }
  76 }