contrib/patch-a52dec.patch

   1 diff -Naur a52dec_original/include/a52.h a52dec_patched/include/a52.h
   2 --- a52dec_original/include/a52.h       2002-01-28 05:37:54.000000000 +0000
   3 +++ a52dec_patched/include/a52.h        2007-04-04 19:12:57.000000000 +0100
   4 @@ -48,6 +48,10 @@
   5  #define A52_LFE 16
   6  #define A52_ADJUST_LEVEL 32
   7
   8 +// this next constant can be ORed with A52_DOLBY to tell liba52 to use 5.0 DPLII matrix encoding,
   9 +// rather than just 4.0 Dolby Surround matrix encoding
  10 +#define A52_USE_DPLII 64
  11 +
  12  a52_state_t * a52_init (uint32_t mm_accel);
  13  sample_t * a52_samples (a52_state_t * state);
  14  int a52_syncinfo (uint8_t * buf, int * flags,
  15 diff -Naur a52dec_original/liba52/a52_internal.h a52dec_patched/liba52/a52_internal.h
  16 --- a52dec_original/liba52/a52_internal.h       2002-07-28 02:52:06.000000000 +0100
  17 +++ a52dec_patched/liba52/a52_internal.h        2007-04-04 19:11:43.000000000 +0100
  18 @@ -93,6 +93,10 @@
  19  #define LEVEL_45DB 0.5946035575013605
  20  #define LEVEL_6DB 0.5
  21
  22 +// these next two constants are used for DPL matrix encoding in downmix.c
  23 +#define LEVEL_SQRT_1_2 0.5
  24 +#define LEVEL_SQRT_3_4 0.8660254037844386
  25 +
  26  #define EXP_REUSE (0)
  27  #define EXP_D15   (1)
  28  #define EXP_D25   (2)
  29 diff -Naur a52dec_original/liba52/downmix.c a52dec_patched/liba52/downmix.c
  30 --- a52dec_original/liba52/downmix.c    2002-01-28 05:37:54.000000000 +0000
  31 +++ a52dec_patched/liba52/downmix.c     2007-04-06 13:47:49.000000000 +0100
  32 @@ -34,6 +34,7 @@
  33  int a52_downmix_init (int input, int flags, sample_t * level,
  34                       sample_t clev, sample_t slev)
  35  {
  36 +
  37      static uint8_t table[11][8] = {
  38         {A52_CHANNEL,   A52_DOLBY,      A52_STEREO,     A52_STEREO,
  39          A52_STEREO,    A52_STEREO,     A52_STEREO,     A52_STEREO},
  40 @@ -148,6 +149,9 @@
  41             break;
  42         }
  43
  44 +       // add the DPLII flag back into the output if it was passed in
  45 +       output = output | (flags & A52_USE_DPLII);
  46 +
  47      return output;
  48  }
  49
  50 @@ -418,17 +422,46 @@
  51      }
  52  }
  53
  54 -static void mix32toS (sample_t * samples, sample_t bias)
  55 +static void mix32toS (sample_t * samples, sample_t bias, int use_dpl2)
  56  {
  57 -    int i;
  58 -    sample_t common, surround;
  59
  60 -    for (i = 0; i < 256; i++) {
  61 -       common = samples[i + 256] + bias;
  62 -       surround = samples[i + 768] + samples[i + 1024];
  63 -       samples[i] += common - surround;
  64 -       samples[i + 256] = samples[i + 512] + common + surround;
  65 -    }
  66 +       if (use_dpl2 == 1) {
  67 +
  68 +               int i;
  69 +               sample_t cc, Lt, Rt, Ls, Rs, Lss, Rss;
  70 +
  71 +               for (i = 0; i < 256; i++) {
  72 +
  73 +                       cc = samples[i + 256] * LEVEL_3DB;
  74 +
  75 +                       Lt = samples[i] + cc;
  76 +                       Rt = samples[i + 512] + cc;
  77 +
  78 +                       Ls = samples[i + 768];
  79 +                       Rs = samples[i + 1024];
  80 +
  81 +                       Lss = (LEVEL_SQRT_3_4 * Ls) - (LEVEL_SQRT_1_2 * Rs);
  82 +                       Rss = -(LEVEL_SQRT_1_2 * Ls) + (LEVEL_SQRT_3_4 * Rs);
  83 +
  84 +                       samples[i] = bias + Lt + Lss;
  85 +                       samples[i + 256] = bias + Rt + Rss;
  86 +
  87 +               }
  88 +
  89 +       } else {
  90 +
  91 +               int i;
  92 +               sample_t common, surround;
  93 +
  94 +               for (i = 0; i < 256; i++) {
  95 +               common = samples[i + 256] + bias;
  96 +               surround = samples[i + 768] + samples[i + 1024];
  97 +               samples[i] += common - surround;
  98 +               samples[i + 256] = samples[i + 512] + common + surround;
  99 +               }
 100 +
 101 +       }
 102 +
 103  }
 104
 105  static void move2to1 (sample_t * src, sample_t * dest, sample_t bias)
 106 @@ -533,7 +566,7 @@
 107         break;
 108
 109      case CONVERT (A52_3F2R, A52_DOLBY):
 110 -       mix32toS (samples, bias);
 111 +       mix32toS (samples, bias, ((output & A52_USE_DPLII) == A52_USE_DPLII));
 112         break;
 113
 114      case CONVERT (A52_3F1R, A52_3F):