avcodec/wmaprodec: Use symbol table more efficiently

By using a symbol table one can already bake in applying
a LUT on the return value of get_vlc2(). So change the
symbol table for the vec2 and vec4 tables to avoid
using the symbol_to_vec2/4 LUTs.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

2 files changed, 72 insertions, 97 deletions

diff --git a/libavcodec/wmaprodata.h b/libavcodec/wmaprodata.h
index 3a30be40b5..057ce1d02d 100644
--- a/libavcodec/wmaprodata.h
+++ b/libavcodec/wmaprodata.h
@@ -325,67 +325,73 @@ static const float coef1_level[HUFF_COEF1_SIZE] = {
  */
 #define HUFF_VEC4_SIZE    127
 #define HUFF_VEC4_MAXBITS  14
-static const uint8_t vec4_table[HUFF_VEC4_SIZE][2] = {
-    { 126,  1 }, {  76,  6 }, {  28,  8 }, {  93, 10 }, {  69, 10 },
-    { 117, 10 }, {  98, 10 }, {  31,  8 }, {  84,  8 }, {  38, 10 },
-    {   9, 10 }, { 108,  9 }, {  96,  8 }, {  73,  8 }, {  67,  9 },
-    { 121, 12 }, {  90, 12 }, { 110, 11 }, {  35, 12 }, {  54, 12 },
-    {  17, 11 }, {  86,  9 }, {  44,  9 }, {  82,  8 }, {  41,  8 },
-    {  36,  9 }, { 103,  9 }, {  78,  8 }, {  66,  8 }, {  11,  9 },
-    {  97,  9 }, {   4, 12 }, {  19, 12 }, {  70, 12 }, {  55, 14 },
-    {  20, 14 }, {   5, 13 }, {  51, 11 }, {  94, 11 }, { 106,  9 },
-    { 101,  8 }, {  83,  9 }, {  42,  9 }, {  45, 11 }, {  46, 11 },
-    { 112, 10 }, {  99,  9 }, {   8,  8 }, {  56,  6 }, {   1,  6 },
-    {  75,  6 }, {  27,  6 }, {  72,  6 }, {  62,  6 }, { 113, 11 },
-    { 124, 11 }, { 114, 10 }, {  15, 11 }, { 116, 11 }, {  24, 10 },
-    {  59, 10 }, {  39, 11 }, {  10, 11 }, { 118,  9 }, { 105,  7 },
-    {  71,  6 }, {  77,  7 }, {  85,  7 }, {  21,  6 }, {   7,  6 },
-    {   6,  6 }, {   0,  5 }, {  79,  7 }, { 100, 11 }, {  48, 11 },
-    {  87, 10 }, { 107,  9 }, {  92,  8 }, {  57,  6 }, { 119,  9 },
-    {  29,  9 }, {  16, 10 }, {  49, 10 }, {  64,  9 }, {  95,  8 },
-    {  58,  8 }, {  26,  6 }, {  61,  6 }, {  22,  6 }, {  23,  8 },
-    {  81,  8 }, {  13,  9 }, {  53, 12 }, {  52, 12 }, { 123, 11 },
-    {  33, 10 }, {  12,  8 }, {  40,  8 }, {  30,  8 }, {  47, 10 },
-    { 111, 10 }, {   3, 10 }, {  68, 10 }, {  74,  9 }, { 115,  9 },
-    {  91,  8 }, { 120, 10 }, {  25, 11 }, { 122, 11 }, {  89,  9 },
-    {   2,  8 }, {  37,  8 }, {  65,  8 }, {  43,  9 }, {  34,  9 },
-    {  14, 10 }, {  60, 11 }, {  18, 12 }, { 125, 12 }, {  50,  9 },
-    {  80,  9 }, {  88,  9 }, { 109,  8 }, {  32,  8 }, { 102,  7 },
-    { 104,  7 }, {  63,  7 },
+static const uint8_t vec4_lens[HUFF_VEC4_SIZE] = {
+     1,  6,  8, 10, 10, 10, 10,  8,  8, 10, 10,  9,  8,  8,  9, 12, 12, 11,
+    12, 12, 11,  9,  9,  8,  8,  9,  9,  8,  8,  9,  9, 12, 12, 12, 14, 14,
+    13, 11, 11,  9,  8,  9,  9, 11, 11, 10,  9,  8,  6,  6,  6,  6,  6,  6,
+    11, 11, 10, 11, 11, 10, 10, 11, 11,  9,  7,  6,  7,  7,  6,  6,  6,  5,
+     7, 11, 11, 10,  9,  8,  6,  9,  9, 10, 10,  9,  8,  8,  6,  6,  6,  8,
+     8,  9, 12, 12, 11, 10,  8,  8,  8, 10, 10, 10, 10,  9,  9,  8, 10, 11,
+    11,  9,  8,  8,  8,  9,  9, 10, 11, 12, 12,  9,  9,  9,  8,  8,  7,  7,
+     7,
+};
+
+/* The entry in the following table with symbol zero indicates
+ * that four further entries are coded explicitly; all other
+ * entries encode four numbers in the 0..15 range via
+ * the four nibbles of (symbol - 1). */
+static const uint16_t vec4_syms[HUFF_VEC4_SIZE] = {
+        0,  4370,   275,  8195,  4146, 12545,  8225,   290,  4625,   515,
+       20,  8706,  8210,  4355,  4131, 16385,  5121,  8961,   321,  1041,
+       51,  4641,   546,  4610,   530,   513,  8451,  4385,  4130,    33,
+     8211,     5,    66,  4161,  1281,    81,     6,   801,  8196,  8481,
+     8449,  4611,   531,   561,   769, 12290,  8226,    19,  4097,     2,
+     4369,   274,  4354,  4114, 12291, 16641, 12305,    49, 12321,   260,
+     4100,   516,    21, 12546,  8466,  4353,  4371,  4626,   257,    18,
+       17,     1,  4386,  8241,   771,  4865,  8705,  8194,  4098, 12561,
+      276,    50,   785,  4116,  8209,  4099,   273,  4113,   258,   259,
+     4609,    35,  1026,  1025, 16401,   305,    34,   529,   289,   770,
+    12289,     4,  4145,  4356, 12306,  8193, 12801,   261, 16386,  4881,
+        3,   514,  4129,   545,   306,    36,  4101,    65, 20481,   786,
+     4401,  4866,  8721,   291,  8450,  8465,  4115,
 };
 
 
 #define HUFF_VEC2_SIZE    137
 #define HUFF_VEC2_MAXBITS  12
+/* The entry in the following table with symbol zero indicates
+ * that two further entries are coded explicitly; all other
+ * entries encode two numbers in the 0..15 range via
+ * (symbol - 1) & 0xF and (symbol - 1) >> 4. */
 static const uint8_t vec2_table[HUFF_VEC2_SIZE][2] = {
-    {  18,  5 }, { 119, 10 }, { 132, 11 }, {  44, 11 }, {  68, 10 },
-    { 121, 11 }, {  11, 11 }, {  75,  8 }, {  72,  7 }, {  36,  7 },
-    { 104,  9 }, { 122, 10 }, {  27, 10 }, {  88,  9 }, {  66,  9 },
-    {  33,  5 }, {  48,  6 }, {  91,  9 }, {   7,  9 }, {  85,  8 },
-    {  62,  7 }, { 136,  3 }, {  64,  8 }, {  97,  9 }, {  80, 10 },
-    { 123, 10 }, {  92,  8 }, { 120, 10 }, {   9, 10 }, {  42, 10 },
-    { 108, 10 }, {  59,  6 }, {  20,  6 }, {  23,  8 }, { 109,  9 },
-    {  25,  9 }, {  58,  7 }, {   4,  7 }, { 134, 11 }, { 133, 12 },
-    {  14, 12 }, { 124, 10 }, { 110,  9 }, {  93,  8 }, {  38,  8 },
-    {  78,  9 }, { 105,  9 }, {  73,  7 }, {  50,  7 }, {  40,  9 },
-    {  56, 10 }, {  30, 11 }, { 126, 11 }, { 125, 10 }, {  69, 10 },
-    { 111,  9 }, {  35,  6 }, {  60,  6 }, {  31,  6 }, {   2,  6 },
-    {  16,  6 }, {   1,  6 }, {  86,  8 }, {  76,  8 }, {  94,  8 },
-    {  52,  8 }, {  46,  5 }, {  19,  5 }, {  98,  9 }, {  54,  9 },
-    {  28, 10 }, { 127, 10 }, { 106,  9 }, {  81,  8 }, {   6,  8 },
-    {  89,  9 }, {  12, 11 }, { 135, 12 }, {  15, 12 }, {  43, 10 },
-    { 112,  9 }, {  67,  9 }, {  82,  7 }, {  22,  7 }, {  74,  7 },
-    {  63,  7 }, { 128, 10 }, { 115, 10 }, { 100,  9 }, {  65,  8 },
-    {  47,  5 }, {  34,  5 }, {  95,  8 }, {  57, 10 }, {  10, 10 },
-    { 116,  9 }, {   0,  7 }, {   3,  6 }, {  45,  6 }, {  61,  6 },
-    {   8,  9 }, {  26,  9 }, { 101,  8 }, {  37,  7 }, {  49,  6 },
-    {  83,  7 }, {  24,  8 }, { 113,  9 }, {  79,  9 }, {  87,  8 },
-    { 117,  9 }, { 129, 10 }, { 131, 10 }, { 107,  9 }, {  99,  9 },
-    {  39,  8 }, { 102,  8 }, {  41,  9 }, { 118,  9 }, {  96,  8 },
-    {  77,  8 }, {  70,  7 }, {   5,  7 }, {  51,  7 }, {  55,  9 },
-    {  29, 10 }, { 130, 11 }, {  13, 11 }, { 114,  9 }, {  90,  9 },
-    {  71,  6 }, {  21,  6 }, {  84,  7 }, { 103,  8 }, {  53,  8 },
-    {  17,  4 }, {  32,  4 },
+    {  19,  5 }, { 165, 10 }, { 211, 11 }, {  46, 11 }, {  75, 10 },
+    { 177, 11 }, {  12, 11 }, {  86,  8 }, {  83,  7 }, {  38,  7 },
+    { 133,  9 }, { 178, 10 }, {  28, 10 }, { 104,  9 }, {  73,  9 },
+    {  35,  5 }, {  52,  6 }, { 113,  9 }, {   8,  9 }, { 101,  8 },
+    {  69,  7 }, {   0,  3 }, {  71,  8 }, { 119,  9 }, {  91, 10 },
+    { 179, 10 }, { 114,  8 }, { 166, 10 }, {  10, 10 }, {  44, 10 },
+    { 145, 10 }, {  66,  6 }, {  21,  6 }, {  24,  8 }, { 146,  9 },
+    {  26,  9 }, {  65,  7 }, {   5,  7 }, { 226, 11 }, { 225, 12 },
+    {  15, 12 }, { 180, 10 }, { 147,  9 }, { 115,  8 }, {  40,  8 },
+    {  89,  9 }, { 134,  9 }, {  84,  7 }, {  54,  7 }, {  42,  9 },
+    {  60, 10 }, {  31, 11 }, { 193, 11 }, { 181, 10 }, {  76, 10 },
+    { 148,  9 }, {  37,  6 }, {  67,  6 }, {  33,  6 }, {   3,  6 },
+    {  17,  6 }, {   2,  6 }, { 102,  8 }, {  87,  8 }, { 116,  8 },
+    {  56,  8 }, {  50,  5 }, {  20,  5 }, { 120,  9 }, {  58,  9 },
+    {  29, 10 }, { 194, 10 }, { 135,  9 }, {  97,  8 }, {   7,  8 },
+    { 105,  9 }, {  13, 11 }, { 241, 12 }, {  16, 12 }, {  45, 10 },
+    { 149,  9 }, {  74,  9 }, {  98,  7 }, {  23,  7 }, {  85,  7 },
+    {  70,  7 }, { 195, 10 }, { 161, 10 }, { 129,  9 }, {  72,  8 },
+    {  51,  5 }, {  36,  5 }, { 117,  8 }, {  61, 10 }, {  11, 10 },
+    { 162,  9 }, {   1,  7 }, {   4,  6 }, {  49,  6 }, {  68,  6 },
+    {   9,  9 }, {  27,  9 }, { 130,  8 }, {  39,  7 }, {  53,  6 },
+    {  99,  7 }, {  25,  8 }, { 150,  9 }, {  90,  9 }, { 103,  8 },
+    { 163,  9 }, { 196, 10 }, { 210, 10 }, { 136,  9 }, { 121,  9 },
+    {  41,  8 }, { 131,  8 }, {  43,  9 }, { 164,  9 }, { 118,  8 },
+    {  88,  8 }, {  81,  7 }, {   6,  7 }, {  55,  7 }, {  59,  9 },
+    {  30, 10 }, { 209, 11 }, {  14, 11 }, { 151,  9 }, { 106,  9 },
+    {  82,  6 }, {  22,  6 }, { 100,  7 }, { 132,  8 }, {  57,  8 },
+    {  18,  4 }, {  34,  4 },
 };
 
 
@@ -414,37 +420,6 @@ static const uint8_t vec1_table[HUFF_VEC1_SIZE][2] = {
     {  80, 10 }, {  81, 10 }, {  43,  8 }, {  44,  8 }, {  24,  6 },
     {  12,  4 },
 };
-
-
-static const uint16_t symbol_to_vec4[HUFF_VEC4_SIZE] = {
-        0,    1,      2,     3,     4,     5,    16,    17,    18,    19,
-       20,   32,     33,    34,    35,    48,    49,    50,    64,    65,
-       80,   256,   257,   258,   259,   260,   272,   273,   274,   275,
-      288,   289,   290,   304,   305,   320,   512,   513,   514,   515,
-      528,   529,   530,   544,   545,   560,   768,   769,   770,   784,
-      785,   800,  1024,  1025,  1040,  1280,  4096,  4097,  4098,  4099,
-     4100,  4112,  4113,  4114,  4115,  4128,  4129,  4130,  4144,  4145,
-     4160,  4352,  4353,  4354,  4355,  4368,  4369,  4370,  4384,  4385,
-     4400,  4608,  4609,  4610,  4624,  4625,  4640,  4864,  4865,  4880,
-     5120,  8192,  8193,  8194,  8195,  8208,  8209,  8210,  8224,  8225,
-     8240,  8448,  8449,  8450,  8464,  8465,  8480,  8704,  8705,  8720,
-     8960, 12288, 12289, 12290, 12304, 12305, 12320, 12544, 12545, 12560,
-    12800, 16384, 16385, 16400, 16640, 20480,     0,
-};
-
-
-static const uint8_t symbol_to_vec2[HUFF_VEC2_SIZE] = {
-      0,   1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,
-     15,  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,  26,  27,  28,  29,
-     30,  32,  33,  34,  35,  36,  37,  38,  39,  40,  41,  42,  43,  44,  45,
-     48,  49,  50,  51,  52,  53,  54,  55,  56,  57,  58,  59,  60,  64,  65,
-     66,  67,  68,  69,  70,  71,  72,  73,  74,  75,  80,  81,  82,  83,  84,
-     85,  86,  87,  88,  89,  90,  96,  97,  98,  99, 100, 101, 102, 103, 104,
-    105, 112, 113, 114, 115, 116, 117, 118, 119, 120, 128, 129, 130, 131, 132,
-    133, 134, 135, 144, 145, 146, 147, 148, 149, 150, 160, 161, 162, 163, 164,
-    165, 176, 177, 178, 179, 180, 192, 193, 194, 195, 208, 209, 210, 224, 225,
-    240,   0,
-};
 /** @} */
 
 
diff --git a/libavcodec/wmaprodec.c b/libavcodec/wmaprodec.c
index 698841dcaf..701dfa955c 100644
--- a/libavcodec/wmaprodec.c
+++ b/libavcodec/wmaprodec.c
@@ -331,11 +331,11 @@ static av_cold void decode_init_static(void)
                                  &coef1_table[0][1], 2,
                                  &coef1_table[0][0], 2, 1, 0, 0, 3912);
     INIT_VLC_STATIC_FROM_LENGTHS(&vec4_vlc, VLCBITS, HUFF_VEC4_SIZE,
-                                 &vec4_table[0][1], 2,
-                                 &vec4_table[0][0], 2, 1, 0, 0, 604);
+                                 vec4_lens, 1,
+                                 vec4_syms, 2, 2, -1, 0, 604);
     INIT_VLC_STATIC_FROM_LENGTHS(&vec2_vlc, VLCBITS, HUFF_VEC2_SIZE,
                                  &vec2_table[0][1], 2,
-                                 &vec2_table[0][0], 2, 1, 0, 0, 562);
+                                 &vec2_table[0][0], 2, 1, -1, 0, 562);
     INIT_VLC_STATIC_FROM_LENGTHS(&vec1_vlc, VLCBITS, HUFF_VEC1_SIZE,
                                  &vec1_table[0][1], 2,
                                  &vec1_table[0][0], 2, 1, 0, 0, 562);
@@ -957,10 +957,10 @@ static int decode_coeffs(WMAProDecodeCtx *s, int c)
 
         idx = get_vlc2(&s->gb, vec4_vlc.table, VLCBITS, VEC4MAXDEPTH);
 
-        if (idx == HUFF_VEC4_SIZE - 1) {
+        if ((int)idx < 0) {
             for (i = 0; i < 4; i += 2) {
                 idx = get_vlc2(&s->gb, vec2_vlc.table, VLCBITS, VEC2MAXDEPTH);
-                if (idx == HUFF_VEC2_SIZE - 1) {
+                if ((int)idx < 0) {
                     uint32_t v0, v1;
                     v0 = get_vlc2(&s->gb, vec1_vlc.table, VLCBITS, VEC1MAXDEPTH);
                     if (v0 == HUFF_VEC1_SIZE - 1)
@@ -971,15 +971,15 @@ static int decode_coeffs(WMAProDecodeCtx *s, int c)
                     vals[i  ] = av_float2int(v0);
                     vals[i+1] = av_float2int(v1);
                 } else {
-                    vals[i]   = fval_tab[symbol_to_vec2[idx] >> 4 ];
-                    vals[i+1] = fval_tab[symbol_to_vec2[idx] & 0xF];
+                    vals[i]   = fval_tab[idx >> 4 ];
+                    vals[i+1] = fval_tab[idx & 0xF];
                 }
             }
         } else {
-            vals[0] = fval_tab[ symbol_to_vec4[idx] >> 12      ];
-            vals[1] = fval_tab[(symbol_to_vec4[idx] >> 8) & 0xF];
-            vals[2] = fval_tab[(symbol_to_vec4[idx] >> 4) & 0xF];
-            vals[3] = fval_tab[ symbol_to_vec4[idx]       & 0xF];
+            vals[0] = fval_tab[ idx >> 12      ];
+            vals[1] = fval_tab[(idx >> 8) & 0xF];
+            vals[2] = fval_tab[(idx >> 4) & 0xF];
+            vals[3] = fval_tab[ idx       & 0xF];
         }
 
         /** decode sign */