Generate channel layout, reordering for DTS-XXCH extension and, undo embedded downmixes

Reviewed-by: Benjamin Larsson <benjamin@southpole.se>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/dcadata.h

@@ -7528,6 +7528,40 @@ static const float dca_downmix_coeffs[65] = {
   0.001412537544623, 0.001000000000000, 0.000501187233627, 0.000251188643151, 0.000000000000000,
 };
 
+static const float dca_downmix_scale_factors[241] = {
+    0.001000, 0.001059, 0.001122, 0.001189, 0.001259, 0.001334, 0.001413, 0.001496,
+    0.001585, 0.001679, 0.001778, 0.001884, 0.001995, 0.002113, 0.002239, 0.002371,
+    0.002512, 0.002661, 0.002818, 0.002985, 0.003162, 0.003350, 0.003548, 0.003758,
+    0.003981, 0.004217, 0.004467, 0.004732, 0.005012, 0.005309, 0.005623, 0.005957,
+    0.006310, 0.006683, 0.007079, 0.007499, 0.007943, 0.008414, 0.008913, 0.009441,
+    0.010000, 0.010593, 0.011220, 0.011885, 0.012589, 0.013335, 0.014125, 0.014962,
+    0.015849, 0.016788, 0.017783, 0.018836, 0.019953, 0.021135, 0.022387, 0.023714,
+    0.025119, 0.026607, 0.028184, 0.029854, 0.031623, 0.032546, 0.033497, 0.034475,
+    0.035481, 0.036517, 0.037584, 0.038681, 0.039811, 0.040973, 0.042170, 0.043401,
+    0.044668, 0.045973, 0.047315, 0.048697, 0.050119, 0.051582, 0.053088, 0.054639,
+    0.056234, 0.057876, 0.059566, 0.061306, 0.063096, 0.064938, 0.066834, 0.068786,
+    0.070795, 0.072862, 0.074989, 0.077179, 0.079433, 0.081752, 0.084140, 0.086596,
+    0.089125, 0.091728, 0.094406, 0.097163, 0.100000, 0.102920, 0.105925, 0.109018,
+    0.112202, 0.115478, 0.118850, 0.122321, 0.125893, 0.129569, 0.133352, 0.137246,
+    0.141254, 0.145378, 0.149624, 0.153993, 0.158489, 0.163117, 0.167880, 0.172783,
+    0.177828, 0.180406, 0.183021, 0.185674, 0.188365, 0.191095, 0.193865, 0.196675,
+    0.199526, 0.202418, 0.205353, 0.208329, 0.211349, 0.214412, 0.217520, 0.220673,
+    0.223872, 0.227117, 0.230409, 0.233749, 0.237137, 0.240575, 0.244062, 0.247600,
+    0.251189, 0.254830, 0.258523, 0.262271, 0.266073, 0.269929, 0.273842, 0.277811,
+    0.281838, 0.285924, 0.290068, 0.294273, 0.298538, 0.302866, 0.307256, 0.311709,
+    0.316228, 0.320812, 0.325462, 0.330179, 0.334965, 0.339821, 0.344747, 0.349744,
+    0.354813, 0.359956, 0.365174, 0.370467, 0.375837, 0.381285, 0.386812, 0.392419,
+    0.398107, 0.403878, 0.409732, 0.415671, 0.421697, 0.427809, 0.434010, 0.440301,
+    0.446684, 0.453158, 0.459727, 0.466391, 0.473151, 0.480010, 0.486968, 0.494026,
+    0.501187, 0.508452, 0.515822, 0.523299, 0.530884, 0.538580, 0.546387, 0.554307,
+    0.562341, 0.570493, 0.578762, 0.587151, 0.595662, 0.604296, 0.613056, 0.621942,
+    0.630957, 0.640103, 0.649382, 0.658795, 0.668344, 0.678032, 0.687860, 0.697831,
+    0.707107, 0.718208, 0.728618, 0.739180, 0.749894, 0.760764, 0.771792, 0.782979,
+    0.794328, 0.805842, 0.817523, 0.829373, 0.841395, 0.853591, 0.865964, 0.878517,
+    0.891251, 0.904170, 0.917276, 0.930572, 0.944061, 0.957745, 0.971628, 0.985712,
+    1.000000
+};
+
 static const uint8_t dca_default_coeffs[10][5][2] = {
     { { 13, 13 },                                                 },
     { {  0, 64 }, { 64,  0 },                                     },