replace unpack_token() with a series of lookup tables

Originally committed as revision 4277 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/vp3.c

@@ -1667,10 +1667,11 @@ static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
 {
     int i;
     int token;
-    int zero_run;
-    DCTELEM coeff;
+    int zero_run = 0;
+    DCTELEM coeff = 0;
     Vp3Fragment *fragment;
     uint8_t *perm= s->scantable.permutated;
+    int bits_to_get;
 
     if ((first_fragment >= s->fragment_count) ||
         (last_fragment >= s->fragment_count)) {
@@ -1691,7 +1692,26 @@ static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
             token = get_vlc2(gb, table->table, 5, 3);
             debug_vlc(" token = %2d, ", token);
             /* use the token to get a zero run, a coefficient, and an eob run */
+#if 1
+            if (token <= 6) {
+                eob_run = eob_run_base[token];
+                if (eob_run_get_bits[token])
+                    eob_run += get_bits(gb, eob_run_get_bits[token]);
+                coeff = zero_run = 0;
+            } else {
+                bits_to_get = coeff_get_bits[token];
+                if (!bits_to_get)
+                    coeff = coeff_tables[token][0];
+                else
+                    coeff = coeff_tables[token][get_bits(gb, bits_to_get)];
+
+                zero_run = zero_run_base[token];
+                if (zero_run_get_bits[token])
+                    zero_run += get_bits(gb, zero_run_get_bits[token]);
+            }
+#else
             unpack_token(gb, token, &zero_run, &coeff, &eob_run);
+#endif
         }
 
         if (!eob_run) {

libavcodec/vp3data.h

@@ -163,6 +163,252 @@ static const int motion_vector_table[63] = {
     24, -24, 25, -25, 26, -26, 27, -27, 28, -28, 29, -29, 30, -30, 31, -31
 };
 
+/* only tokens 0..6 indicate eob runs */
+static const int eob_run_base[7] = {
+    1, 2, 3, 4, 8, 16, 0
+};
+static const int eob_run_get_bits[7] = {
+    0, 0, 0, 2, 3, 4, 12
+};
+
+static const int zero_run_base[32] = {
+    0, 0, 0, 0, 0, 0, 0,  /* 0..6 are never used */
+    0, 0,  /* 7..8 */
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* 9..22 */
+    1, 2, 3, 4, 5,  /* 23..27 */
+    6, 10, 1, 2  /* 28..31 */
+};
+static const int zero_run_get_bits[32] = {
+    0, 0, 0, 0, 0, 0, 0,  /* 0..6 are never used */
+    3, 6,  /* 7..8 */
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* 9..22 */
+    0, 0, 0, 0, 0,  /* 23..27 */
+    2, 3, 0, 1  /* 28..31 */
+};
+
+static const int coeff_get_bits[32] = {
+    0, 0, 0, 0, 0, 0, 0,  /* 0..6 are never used */
+    0, 0, 0, 0, 0, 0,  /* 7..12 use constant coeffs */
+    1, 1, 1, 1,  /* 13..16 are constants but still need sign bit */
+    2, 3, 4, 5, 6, 10,  /* 17..22, for reading large coeffs */
+    1, 1, 1, 1, 1, 1, 1,  /* 23..29 are constants but still need sign bit */
+    2, 2  /* 30..31 */    
+};
+
+static const int16_t coeff_table_token_7_8[1] = { 0 };
+static const int16_t coeff_table_token_9[1] = { 1 };
+static const int16_t coeff_table_token_10[1] = { -1 };
+static const int16_t coeff_table_token_11[1] = { 2 };
+static const int16_t coeff_table_token_12[1] = { -2 };
+
+static const int16_t coeff_table_token_13[2] = { 3, -3 };
+static const int16_t coeff_table_token_14[2] = { 4, -4 };
+static const int16_t coeff_table_token_15[2] = { 5, -5 };
+static const int16_t coeff_table_token_16[2] = { 6, -6 };
+
+static const int16_t coeff_table_token_23_24_25_26_27_28_29[2] = { 1, -1 };
+static const int16_t coeff_table_token_30[4] = { 2, 3, -2, -3 };
+static const int16_t coeff_table_token_31[4] = { 2, 3, -2, -3 };
+
+static const int16_t coeff_table_token_17[4] = {
+    7, 8, -7, -8
+};
+
+static const int16_t coeff_table_token_18[8] = {
+    9, 10, 11, 12, -9, -10, -11, -12
+};
+
+static const int16_t coeff_table_token_19[16] = {
+    13, 14, 15, 16, 17, 18, 19, 20, -13, -14, -15, -16, -17, -18, -19, -20
+};
+
+static const int16_t coeff_table_token_20[32] = {
+    21, 22, 23, 24, 25, 26, 27, 28, 
+    29, 30, 31, 32, 33, 34, 35, 36, 
+    -21, -22, -23, -24, -25, -26, -27, -28, 
+    -29, -30, -31, -32, -33, -34, -35, -36
+};
+
+static const int16_t coeff_table_token_21[64] = {
+    37, 38, 39, 40, 41, 42, 43, 44, 
+    45, 46, 47, 48, 49, 50, 51, 52, 
+    53, 54, 55, 56, 57, 58, 59, 60, 
+    61, 62, 63, 64, 65, 66, 67, 68, 
+    -37, -38, -39, -40, -41, -42, -43, -44, 
+    -45, -46, -47, -48, -49, -50, -51, -52, 
+    -53, -54, -55, -56, -57, -58, -59, -60, 
+    -61, -62, -63, -64, -65, -66, -67, -68
+};
+
+static const int16_t coeff_table_token_22[1024] = {
+    69, 70, 71, 72, 73, 74, 75, 76, 
+    77, 78, 79, 80, 81, 82, 83, 84, 
+    85, 86, 87, 88, 89, 90, 91, 92, 
+    93, 94, 95, 96, 97, 98, 99, 100, 
+    101, 102, 103, 104, 105, 106, 107, 108, 
+    109, 110, 111, 112, 113, 114, 115, 116, 
+    117, 118, 119, 120, 121, 122, 123, 124, 
+    125, 126, 127, 128, 129, 130, 131, 132, 
+    133, 134, 135, 136, 137, 138, 139, 140, 
+    141, 142, 143, 144, 145, 146, 147, 148, 
+    149, 150, 151, 152, 153, 154, 155, 156, 
+    157, 158, 159, 160, 161, 162, 163, 164, 
+    165, 166, 167, 168, 169, 170, 171, 172, 
+    173, 174, 175, 176, 177, 178, 179, 180, 
+    181, 182, 183, 184, 185, 186, 187, 188, 
+    189, 190, 191, 192, 193, 194, 195, 196, 
+    197, 198, 199, 200, 201, 202, 203, 204, 
+    205, 206, 207, 208, 209, 210, 211, 212, 
+    213, 214, 215, 216, 217, 218, 219, 220, 
+    221, 222, 223, 224, 225, 226, 227, 228, 
+    229, 230, 231, 232, 233, 234, 235, 236, 
+    237, 238, 239, 240, 241, 242, 243, 244, 
+    245, 246, 247, 248, 249, 250, 251, 252, 
+    253, 254, 255, 256, 257, 258, 259, 260, 
+    261, 262, 263, 264, 265, 266, 267, 268, 
+    269, 270, 271, 272, 273, 274, 275, 276, 
+    277, 278, 279, 280, 281, 282, 283, 284, 
+    285, 286, 287, 288, 289, 290, 291, 292, 
+    293, 294, 295, 296, 297, 298, 299, 300, 
+    301, 302, 303, 304, 305, 306, 307, 308, 
+    309, 310, 311, 312, 313, 314, 315, 316, 
+    317, 318, 319, 320, 321, 322, 323, 324, 
+    325, 326, 327, 328, 329, 330, 331, 332, 
+    333, 334, 335, 336, 337, 338, 339, 340, 
+    341, 342, 343, 344, 345, 346, 347, 348, 
+    349, 350, 351, 352, 353, 354, 355, 356, 
+    357, 358, 359, 360, 361, 362, 363, 364, 
+    365, 366, 367, 368, 369, 370, 371, 372, 
+    373, 374, 375, 376, 377, 378, 379, 380, 
+    381, 382, 383, 384, 385, 386, 387, 388, 
+    389, 390, 391, 392, 393, 394, 395, 396, 
+    397, 398, 399, 400, 401, 402, 403, 404, 
+    405, 406, 407, 408, 409, 410, 411, 412, 
+    413, 414, 415, 416, 417, 418, 419, 420, 
+    421, 422, 423, 424, 425, 426, 427, 428, 
+    429, 430, 431, 432, 433, 434, 435, 436, 
+    437, 438, 439, 440, 441, 442, 443, 444, 
+    445, 446, 447, 448, 449, 450, 451, 452, 
+    453, 454, 455, 456, 457, 458, 459, 460, 
+    461, 462, 463, 464, 465, 466, 467, 468, 
+    469, 470, 471, 472, 473, 474, 475, 476, 
+    477, 478, 479, 480, 481, 482, 483, 484, 
+    485, 486, 487, 488, 489, 490, 491, 492, 
+    493, 494, 495, 496, 497, 498, 499, 500, 
+    501, 502, 503, 504, 505, 506, 507, 508, 
+    509, 510, 511, 512, 513, 514, 515, 516, 
+    517, 518, 519, 520, 521, 522, 523, 524, 
+    525, 526, 527, 528, 529, 530, 531, 532, 
+    533, 534, 535, 536, 537, 538, 539, 540, 
+    541, 542, 543, 544, 545, 546, 547, 548, 
+    549, 550, 551, 552, 553, 554, 555, 556, 
+    557, 558, 559, 560, 561, 562, 563, 564, 
+    565, 566, 567, 568, 569, 570, 571, 572, 
+    573, 574, 575, 576, 577, 578, 579, 580,
+    -69, -70, -71, -72, -73, -74, -75, -76, 
+    -77, -78, -79, -80, -81, -82, -83, -84, 
+    -85, -86, -87, -88, -89, -90, -91, -92, 
+    -93, -94, -95, -96, -97, -98, -99, -100, 
+    -101, -102, -103, -104, -105, -106, -107, -108, 
+    -109, -110, -111, -112, -113, -114, -115, -116, 
+    -117, -118, -119, -120, -121, -122, -123, -124, 
+    -125, -126, -127, -128, -129, -130, -131, -132, 
+    -133, -134, -135, -136, -137, -138, -139, -140, 
+    -141, -142, -143, -144, -145, -146, -147, -148, 
+    -149, -150, -151, -152, -153, -154, -155, -156, 
+    -157, -158, -159, -160, -161, -162, -163, -164, 
+    -165, -166, -167, -168, -169, -170, -171, -172, 
+    -173, -174, -175, -176, -177, -178, -179, -180, 
+    -181, -182, -183, -184, -185, -186, -187, -188, 
+    -189, -190, -191, -192, -193, -194, -195, -196, 
+    -197, -198, -199, -200, -201, -202, -203, -204, 
+    -205, -206, -207, -208, -209, -210, -211, -212, 
+    -213, -214, -215, -216, -217, -218, -219, -220, 
+    -221, -222, -223, -224, -225, -226, -227, -228, 
+    -229, -230, -231, -232, -233, -234, -235, -236, 
+    -237, -238, -239, -240, -241, -242, -243, -244, 
+    -245, -246, -247, -248, -249, -250, -251, -252, 
+    -253, -254, -255, -256, -257, -258, -259, -260, 
+    -261, -262, -263, -264, -265, -266, -267, -268, 
+    -269, -270, -271, -272, -273, -274, -275, -276, 
+    -277, -278, -279, -280, -281, -282, -283, -284, 
+    -285, -286, -287, -288, -289, -290, -291, -292, 
+    -293, -294, -295, -296, -297, -298, -299, -300, 
+    -301, -302, -303, -304, -305, -306, -307, -308, 
+    -309, -310, -311, -312, -313, -314, -315, -316, 
+    -317, -318, -319, -320, -321, -322, -323, -324, 
+    -325, -326, -327, -328, -329, -330, -331, -332, 
+    -333, -334, -335, -336, -337, -338, -339, -340, 
+    -341, -342, -343, -344, -345, -346, -347, -348, 
+    -349, -350, -351, -352, -353, -354, -355, -356, 
+    -357, -358, -359, -360, -361, -362, -363, -364, 
+    -365, -366, -367, -368, -369, -370, -371, -372, 
+    -373, -374, -375, -376, -377, -378, -379, -380, 
+    -381, -382, -383, -384, -385, -386, -387, -388, 
+    -389, -390, -391, -392, -393, -394, -395, -396, 
+    -397, -398, -399, -400, -401, -402, -403, -404, 
+    -405, -406, -407, -408, -409, -410, -411, -412, 
+    -413, -414, -415, -416, -417, -418, -419, -420, 
+    -421, -422, -423, -424, -425, -426, -427, -428, 
+    -429, -430, -431, -432, -433, -434, -435, -436, 
+    -437, -438, -439, -440, -441, -442, -443, -444, 
+    -445, -446, -447, -448, -449, -450, -451, -452, 
+    -453, -454, -455, -456, -457, -458, -459, -460, 
+    -461, -462, -463, -464, -465, -466, -467, -468, 
+    -469, -470, -471, -472, -473, -474, -475, -476, 
+    -477, -478, -479, -480, -481, -482, -483, -484, 
+    -485, -486, -487, -488, -489, -490, -491, -492, 
+    -493, -494, -495, -496, -497, -498, -499, -500, 
+    -501, -502, -503, -504, -505, -506, -507, -508, 
+    -509, -510, -511, -512, -513, -514, -515, -516, 
+    -517, -518, -519, -520, -521, -522, -523, -524, 
+    -525, -526, -527, -528, -529, -530, -531, -532, 
+    -533, -534, -535, -536, -537, -538, -539, -540, 
+    -541, -542, -543, -544, -545, -546, -547, -548, 
+    -549, -550, -551, -552, -553, -554, -555, -556, 
+    -557, -558, -559, -560, -561, -562, -563, -564, 
+    -565, -566, -567, -568, -569, -570, -571, -572, 
+    -573, -574, -575, -576, -577, -578, -579, -580
+};
+
+static const int16_t *coeff_tables[32] = {
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    coeff_table_token_7_8,
+
+    coeff_table_token_7_8,
+    coeff_table_token_9,
+    coeff_table_token_10,
+    coeff_table_token_11,
+    coeff_table_token_12,
+    coeff_table_token_13,
+    coeff_table_token_14,
+    coeff_table_token_15,
+
+    coeff_table_token_16,
+    coeff_table_token_17,
+    coeff_table_token_18,
+    coeff_table_token_19,
+    coeff_table_token_20,
+    coeff_table_token_21,
+    coeff_table_token_22,
+    coeff_table_token_23_24_25_26_27_28_29,
+
+    coeff_table_token_23_24_25_26_27_28_29,
+    coeff_table_token_23_24_25_26_27_28_29,
+    coeff_table_token_23_24_25_26_27_28_29,
+    coeff_table_token_23_24_25_26_27_28_29,
+    coeff_table_token_23_24_25_26_27_28_29,
+    coeff_table_token_23_24_25_26_27_28_29,
+    coeff_table_token_30,
+    coeff_table_token_31
+};
+
 static const uint16_t dc_bias[16][32][2] = {
   {  /* DC bias table 0 */
     { 0x2D, 6 },