michael@0: /*
michael@0:  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
michael@0:  *
michael@0:  *  Use of this source code is governed by a BSD-style license
michael@0:  *  that can be found in the LICENSE file in the root of the source
michael@0:  *  tree. An additional intellectual property rights grant can be found
michael@0:  *  in the file PATENTS.  All contributing project authors may
michael@0:  *  be found in the AUTHORS file in the root of the source tree.
michael@0:  */
michael@0: 
michael@0: 
michael@0: #include "vp8/common/blockd.h"
michael@0: #include "onyxd_int.h"
michael@0: #include "vpx_mem/vpx_mem.h"
michael@0: #include "vpx_ports/mem.h"
michael@0: #include "detokenize.h"
michael@0: 
michael@0: void vp8_reset_mb_tokens_context(MACROBLOCKD *x)
michael@0: {
michael@0:     ENTROPY_CONTEXT *a_ctx = ((ENTROPY_CONTEXT *)x->above_context);
michael@0:     ENTROPY_CONTEXT *l_ctx = ((ENTROPY_CONTEXT *)x->left_context);
michael@0: 
michael@0:     vpx_memset(a_ctx, 0, sizeof(ENTROPY_CONTEXT_PLANES)-1);
michael@0:     vpx_memset(l_ctx, 0, sizeof(ENTROPY_CONTEXT_PLANES)-1);
michael@0: 
michael@0:     /* Clear entropy contexts for Y2 blocks */
michael@0:     if (!x->mode_info_context->mbmi.is_4x4)
michael@0:     {
michael@0:         a_ctx[8] = l_ctx[8] = 0;
michael@0:     }
michael@0: }
michael@0: 
michael@0: /*
michael@0:     ------------------------------------------------------------------------------
michael@0:     Residual decoding (Paragraph 13.2 / 13.3)
michael@0: */
michael@0: static const uint8_t kBands[16 + 1] = {
michael@0:   0, 1, 2, 3, 6, 4, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7,
michael@0:   0  /* extra entry as sentinel */
michael@0: };
michael@0: 
michael@0: static const uint8_t kCat3[] = { 173, 148, 140, 0 };
michael@0: static const uint8_t kCat4[] = { 176, 155, 140, 135, 0 };
michael@0: static const uint8_t kCat5[] = { 180, 157, 141, 134, 130, 0 };
michael@0: static const uint8_t kCat6[] =
michael@0:   { 254, 254, 243, 230, 196, 177, 153, 140, 133, 130, 129, 0 };
michael@0: static const uint8_t* const kCat3456[] = { kCat3, kCat4, kCat5, kCat6 };
michael@0: static const uint8_t kZigzag[16] = {
michael@0:   0, 1, 4, 8,  5, 2, 3, 6,  9, 12, 13, 10,  7, 11, 14, 15
michael@0: };
michael@0: 
michael@0: #define VP8GetBit vp8dx_decode_bool
michael@0: #define NUM_PROBAS  11
michael@0: #define NUM_CTX  3
michael@0: 
michael@0: /* for const-casting */
michael@0: typedef const uint8_t (*ProbaArray)[NUM_CTX][NUM_PROBAS];
michael@0: 
michael@0: static int GetSigned(BOOL_DECODER *br, int value_to_sign)
michael@0: {
michael@0:     int split = (br->range + 1) >> 1;
michael@0:     VP8_BD_VALUE bigsplit = (VP8_BD_VALUE)split << (VP8_BD_VALUE_SIZE - 8);
michael@0:     int v;
michael@0: 
michael@0:     if(br->count < 0)
michael@0:         vp8dx_bool_decoder_fill(br);
michael@0: 
michael@0:     if ( br->value < bigsplit )
michael@0:     {
michael@0:         br->range = split;
michael@0:         v= value_to_sign;
michael@0:     }
michael@0:     else
michael@0:     {
michael@0:         br->range = br->range-split;
michael@0:         br->value = br->value-bigsplit;
michael@0:         v = -value_to_sign;
michael@0:     }
michael@0:     br->range +=br->range;
michael@0:     br->value +=br->value;
michael@0:     br->count--;
michael@0: 
michael@0:     return v;
michael@0: }
michael@0: /*
michael@0:    Returns the position of the last non-zero coeff plus one
michael@0:    (and 0 if there's no coeff at all)
michael@0: */
michael@0: static int GetCoeffs(BOOL_DECODER *br, ProbaArray prob,
michael@0:                      int ctx, int n, int16_t* out)
michael@0: {
michael@0:     const uint8_t* p = prob[n][ctx];
michael@0:     if (!VP8GetBit(br, p[0]))
michael@0:     {   /* first EOB is more a 'CBP' bit. */
michael@0:         return 0;
michael@0:     }
michael@0:     while (1)
michael@0:     {
michael@0:         ++n;
michael@0:         if (!VP8GetBit(br, p[1]))
michael@0:         {
michael@0:             p = prob[kBands[n]][0];
michael@0:         }
michael@0:         else
michael@0:         {  /* non zero coeff */
michael@0:             int v, j;
michael@0:             if (!VP8GetBit(br, p[2]))
michael@0:             {
michael@0:                 p = prob[kBands[n]][1];
michael@0:                 v = 1;
michael@0:             }
michael@0:             else
michael@0:             {
michael@0:                 if (!VP8GetBit(br, p[3]))
michael@0:                 {
michael@0:                     if (!VP8GetBit(br, p[4]))
michael@0:                     {
michael@0:                         v = 2;
michael@0:                     }
michael@0:                     else
michael@0:                     {
michael@0:                         v = 3 + VP8GetBit(br, p[5]);
michael@0:                     }
michael@0:                 }
michael@0:                 else
michael@0:                 {
michael@0:                     if (!VP8GetBit(br, p[6]))
michael@0:                     {
michael@0:                         if (!VP8GetBit(br, p[7]))
michael@0:                         {
michael@0:                             v = 5 + VP8GetBit(br, 159);
michael@0:                         } else
michael@0:                         {
michael@0:                             v = 7 + 2 * VP8GetBit(br, 165);
michael@0:                             v += VP8GetBit(br, 145);
michael@0:                         }
michael@0:                     }
michael@0:                     else
michael@0:                     {
michael@0:                         const uint8_t* tab;
michael@0:                         const int bit1 = VP8GetBit(br, p[8]);
michael@0:                         const int bit0 = VP8GetBit(br, p[9 + bit1]);
michael@0:                         const int cat = 2 * bit1 + bit0;
michael@0:                         v = 0;
michael@0:                         for (tab = kCat3456[cat]; *tab; ++tab)
michael@0:                         {
michael@0:                             v += v + VP8GetBit(br, *tab);
michael@0:                         }
michael@0:                         v += 3 + (8 << cat);
michael@0:                     }
michael@0:                 }
michael@0:                 p = prob[kBands[n]][2];
michael@0:             }
michael@0:             j = kZigzag[n - 1];
michael@0: 
michael@0:             out[j] = GetSigned(br, v);
michael@0: 
michael@0:             if (n == 16 || !VP8GetBit(br, p[0]))
michael@0:             {   /* EOB */
michael@0:                 return n;
michael@0:             }
michael@0:         }
michael@0:         if (n == 16)
michael@0:         {
michael@0:             return 16;
michael@0:         }
michael@0:     }
michael@0: }
michael@0: 
michael@0: int vp8_decode_mb_tokens(VP8D_COMP *dx, MACROBLOCKD *x)
michael@0: {
michael@0:     BOOL_DECODER *bc = x->current_bc;
michael@0:     const FRAME_CONTEXT * const fc = &dx->common.fc;
michael@0:     char *eobs = x->eobs;
michael@0: 
michael@0:     int i;
michael@0:     int nonzeros;
michael@0:     int eobtotal = 0;
michael@0: 
michael@0:     short *qcoeff_ptr;
michael@0:     ProbaArray coef_probs;
michael@0:     ENTROPY_CONTEXT *a_ctx = ((ENTROPY_CONTEXT *)x->above_context);
michael@0:     ENTROPY_CONTEXT *l_ctx = ((ENTROPY_CONTEXT *)x->left_context);
michael@0:     ENTROPY_CONTEXT *a;
michael@0:     ENTROPY_CONTEXT *l;
michael@0:     int skip_dc = 0;
michael@0: 
michael@0:     qcoeff_ptr = &x->qcoeff[0];
michael@0: 
michael@0:     if (!x->mode_info_context->mbmi.is_4x4)
michael@0:     {
michael@0:         a = a_ctx + 8;
michael@0:         l = l_ctx + 8;
michael@0: 
michael@0:         coef_probs = fc->coef_probs [1];
michael@0: 
michael@0:         nonzeros = GetCoeffs(bc, coef_probs, (*a + *l), 0, qcoeff_ptr + 24 * 16);
michael@0:         *a = *l = (nonzeros > 0);
michael@0: 
michael@0:         eobs[24] = nonzeros;
michael@0:         eobtotal += nonzeros - 16;
michael@0: 
michael@0:         coef_probs = fc->coef_probs [0];
michael@0:         skip_dc = 1;
michael@0:     }
michael@0:     else
michael@0:     {
michael@0:         coef_probs = fc->coef_probs [3];
michael@0:         skip_dc = 0;
michael@0:     }
michael@0: 
michael@0:     for (i = 0; i < 16; ++i)
michael@0:     {
michael@0:         a = a_ctx + (i&3);
michael@0:         l = l_ctx + ((i&0xc)>>2);
michael@0: 
michael@0:         nonzeros = GetCoeffs(bc, coef_probs, (*a + *l), skip_dc, qcoeff_ptr);
michael@0:         *a = *l = (nonzeros > 0);
michael@0: 
michael@0:         nonzeros += skip_dc;
michael@0:         eobs[i] = nonzeros;
michael@0:         eobtotal += nonzeros;
michael@0:         qcoeff_ptr += 16;
michael@0:     }
michael@0: 
michael@0:     coef_probs = fc->coef_probs [2];
michael@0: 
michael@0:     a_ctx += 4;
michael@0:     l_ctx += 4;
michael@0:     for (i = 16; i < 24; ++i)
michael@0:     {
michael@0:         a = a_ctx + ((i > 19)<<1) + (i&1);
michael@0:         l = l_ctx + ((i > 19)<<1) + ((i&3)>1);
michael@0: 
michael@0:         nonzeros = GetCoeffs(bc, coef_probs, (*a + *l), 0, qcoeff_ptr);
michael@0:         *a = *l = (nonzeros > 0);
michael@0: 
michael@0:         eobs[i] = nonzeros;
michael@0:         eobtotal += nonzeros;
michael@0:         qcoeff_ptr += 16;
michael@0:     }
michael@0: 
michael@0:     return eobtotal;
michael@0: }
michael@0: