Restore WIP g729 code that has been remvoed by diego biurrun.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 85 insertions, 0 deletions

diff --git a/libavcodec/celp_math.c b/libavcodec/celp_math.c
index de33109b44..09111da819 100644
--- a/libavcodec/celp_math.c
+++ b/libavcodec/celp_math.c
@@ -27,6 +27,82 @@
 #include "avcodec.h"
 #include "celp_math.h"
 
+#ifdef G729_BITEXACT
+/**
+ * Cosine table: base_cos[i] = (1<<15) * cos(i*PI/64)
+ */
+static const int16_t base_cos[64] =
+{
+  32767,  32729,  32610,  32413,  32138,  31786,  31357,  30853,
+  30274,  29622,  28899,  28106,  27246,  26320,  25330,  24279,
+  23170,  22006,  20788,  19520,  18205,  16846,  15447,  14010,
+  12540,  11039,   9512,   7962,   6393,   4808,   3212,   1608,
+      0,  -1608,  -3212,  -4808,  -6393,  -7962,  -9512, -11039,
+ -12540, -14010, -15447, -16846, -18205, -19520, -20788, -22006,
+ -23170, -24279, -25330, -26320, -27246, -28106, -28899, -29622,
+ -30274, -30853, -31357, -31786, -32138, -32413, -32610, -32729
+};
+
+/**
+ * Slope used to compute cos(x)
+ *
+ * cos(ind*64+offset) = base_cos[ind]+offset*slope_cos[ind]
+ * values multiplied by 1<<19
+ */
+static const int16_t slope_cos[64] =
+{
+   -632,  -1893,  -3150,  -4399,  -5638,  -6863,  -8072,  -9261,
+ -10428, -11570, -12684, -13767, -14817, -15832, -16808, -17744,
+ -18637, -19486, -20287, -21039, -21741, -22390, -22986, -23526,
+ -24009, -24435, -24801, -25108, -25354, -25540, -25664, -25726,
+ -25726, -25664, -25540, -25354, -25108, -24801, -24435, -24009,
+ -23526, -22986, -22390, -21741, -21039, -20287, -19486, -18637,
+ -17744, -16808, -15832, -14817, -13767, -12684, -11570, -10428,
+  -9261,  -8072,  -6863,  -5638,  -4399,  -3150,  -1893,   -632
+};
+
+/**
+ * Table used to compute exp2(x)
+ *
+ * tab_exp2[i] = (1<<14) * exp2(i/32) = 2^(i/32) i=0..32
+ */
+static const uint16_t tab_exp2[33] =
+{
+  16384, 16743, 17109, 17484, 17867, 18258, 18658, 19066, 19484, 19911,
+  20347, 20792, 21247, 21713, 22188, 22674, 23170, 23678, 24196, 24726,
+  25268, 25821, 26386, 26964, 27554, 28158, 28774, 29405, 30048, 30706,
+  31379, 32066, 32767
+};
+
+int16_t ff_cos(uint16_t arg)
+{
+    uint8_t offset= arg;
+    uint8_t ind = arg >> 8;
+
+    assert(arg < 0x4000);
+
+    return FFMAX(base_cos[ind] + ((slope_cos[ind] * offset) >> 12), -0x8000);
+}
+
+int ff_exp2(uint16_t power)
+{
+    uint16_t frac_x0;
+    uint16_t frac_dx;
+    int result;
+
+    assert(power <= 0x7fff);
+
+    frac_x0 = power >> 10;
+    frac_dx = (power & 0x03ff) << 5;
+
+    result = tab_exp2[frac_x0] << 15;
+    result += frac_dx * (tab_exp2[frac_x0+1] - tab_exp2[frac_x0]);
+
+    return result >> 10;
+}
+
+#else // G729_BITEXACT
+
 /**
  * Cosine table: base_cos[i] = (1<<15) * cos(i*PI/64)
  */
@@ -78,6 +154,8 @@ int ff_exp2(uint16_t power)
     return result + ((result*(power&31)*89)>>22);
 }
 
+#endif // else G729_BITEXACT
+
 /**
  * Table used to compute log2(x)
  *
@@ -85,10 +163,17 @@ int ff_exp2(uint16_t power)
  */
 static const uint16_t tab_log2[33] =
 {
+#ifdef G729_BITEXACT
+      0,   1455,   2866,   4236,   5568,   6863,   8124,   9352,
+  10549,  11716,  12855,  13967,  15054,  16117,  17156,  18172,
+  19167,  20142,  21097,  22033,  22951,  23852,  24735,  25603,
+  26455,  27291,  28113,  28922,  29716,  30497,  31266,  32023,  32767,
+#else
       4,   1459,   2870,   4240,   5572,   6867,   8127,   9355,
   10552,  11719,  12858,  13971,  15057,  16120,  17158,  18175,
   19170,  20145,  21100,  22036,  22954,  23854,  24738,  25605,
   26457,  27294,  28116,  28924,  29719,  30500,  31269,  32025,  32769,
+#endif
 };
 
 int ff_log2(uint32_t value)