?? cabac.c
字號:
if (img->MbaffFrameFlag && (currMB->mb_field == 0) && (img->mb_data[block_b.mb_addr].mb_field == 1))
b = (refframe_array[block_b.pos_x][block_b.pos_y] > 1 ? 1 : 0);
else
b = (refframe_array[block_b.pos_x][block_b.pos_y] > 0 ? 1 : 0);
}
if (!block_a.available)
a=0;
else if ((img->mb_data[block_a.mb_addr].mb_type==IPCM) || IS_DIRECT(&img->mb_data[block_a.mb_addr]) || (img->mb_data[block_a.mb_addr].b8mode[b8a]==0 && img->mb_data[block_a.mb_addr].b8pdir[b8a]==2))
a=0;
else
{
if (img->MbaffFrameFlag && (currMB->mb_field == 0) && (img->mb_data[block_a.mb_addr].mb_field == 1))
a = (refframe_array[block_a.pos_x][block_a.pos_y] > 1 ? 1 : 0);
else
a = (refframe_array[block_a.pos_x][block_a.pos_y] > 0 ? 1 : 0);
}
act_ctx = a + 2*b;
se->context = act_ctx; // store context
act_sym = biari_decode_symbol(dep_dp,ctx->ref_no_contexts[addctx] + act_ctx );
if (act_sym != 0)
{
act_ctx = 4;
act_sym = unary_bin_decode(dep_dp,ctx->ref_no_contexts[addctx]+act_ctx,1);
act_sym++;
}
se->value1 = act_sym;
#if TRACE
fprintf(p_trace, "@%d %s\t\t\t%d \n",symbolCount++, se->tracestring, se->value1);
// fprintf(p_trace," c: %d :%d \n",ctx->ref_no_contexts[addctx][act_ctx].cum_freq[0],ctx->ref_no_contexts[addctx][act_ctx].cum_freq[1]);
fflush(p_trace);
#endif
}
/*!
************************************************************************
* \brief
* This function is used to arithmetically decode the delta qp
* of a given MB.
************************************************************************
*/
void readDquant_CABAC( SyntaxElement *se,
struct inp_par *inp,
struct img_par *img,
DecodingEnvironmentPtr dep_dp)
{
MotionInfoContexts *ctx = img->currentSlice->mot_ctx;
int act_ctx;
int act_sym;
int dquant;
act_ctx = ( (last_dquant != 0) ? 1 : 0);
act_sym = biari_decode_symbol(dep_dp,ctx->delta_qp_contexts + act_ctx );
if (act_sym != 0)
{
act_ctx = 2;
act_sym = unary_bin_decode(dep_dp,ctx->delta_qp_contexts+act_ctx,1);
act_sym++;
}
dquant = (act_sym+1)/2;
if((act_sym & 0x01)==0) // lsb is signed bit
dquant = -dquant;
se->value1 = dquant;
last_dquant = dquant;
#if TRACE
fprintf(p_trace, "@%d %s\t\t\t%d\n",symbolCount++, se->tracestring, se->value1);
fflush(p_trace);
#endif
}
/*!
************************************************************************
* \brief
* This function is used to arithmetically decode the coded
* block pattern of a given MB.
************************************************************************
*/
void readCBP_CABAC(SyntaxElement *se,
struct inp_par *inp,
struct img_par *img,
DecodingEnvironmentPtr dep_dp)
{
TextureInfoContexts *ctx = img->currentSlice->tex_ctx;
Macroblock *currMB = &img->mb_data[img->current_mb_nr];
int mb_x, mb_y;
int a, b;
int curr_cbp_ctx, curr_cbp_idx;
int cbp = 0;
int cbp_bit;
int mask;
PixelPos block_a;
// coding of luma part (bit by bit)
for (mb_y=0; mb_y < 4; mb_y += 2)
{
for (mb_x=0; mb_x < 4; mb_x += 2)
{
if (currMB->b8mode[mb_y+(mb_x/2)]==IBLOCK)
curr_cbp_idx = 0;
else
curr_cbp_idx = 1;
if (mb_y == 0)
{
if (currMB->mb_available_up == NULL)
b = 0;
else
{
if((currMB->mb_available_up)->mb_type==IPCM)
b=0;
else
b = (( ((currMB->mb_available_up)->cbp & (1<<(2+mb_x/2))) == 0) ? 1 : 0);
}
}
else
b = ( ((cbp & (1<<(mb_x/2))) == 0) ? 1: 0);
if (mb_x == 0)
{
getLuma4x4Neighbour(img->current_mb_nr, mb_x, mb_y, -1, 0, &block_a);
if (block_a.available)
{
{
if(img->mb_data[block_a.mb_addr].mb_type==IPCM)
a=0;
else
a = (( (img->mb_data[block_a.mb_addr].cbp & (1<<(2*(block_a.y/2)+1))) == 0) ? 1 : 0);
}
}
else
a=0;
}
else
a = ( ((cbp & (1<<mb_y)) == 0) ? 1: 0);
curr_cbp_ctx = a+2*b;
mask = (1<<(mb_y+mb_x/2));
cbp_bit = biari_decode_symbol(dep_dp, ctx->cbp_contexts[0] + curr_cbp_ctx );
if (cbp_bit) cbp += mask;
}
}
if (img->yuv_format != YUV400)
{
// coding of chroma part
// CABAC decoding for BinIdx 0
b = 0;
if (currMB->mb_available_up != NULL)
{
if((currMB->mb_available_up)->mb_type==IPCM)
b=1;
else
b = ((currMB->mb_available_up)->cbp > 15) ? 1 : 0;
}
a = 0;
if (currMB->mb_available_left != NULL)
{
if((currMB->mb_available_left)->mb_type==IPCM)
a=1;
else
a = ((currMB->mb_available_left)->cbp > 15) ? 1 : 0;
}
curr_cbp_ctx = a+2*b;
cbp_bit = biari_decode_symbol(dep_dp, ctx->cbp_contexts[1] + curr_cbp_ctx );
// CABAC decoding for BinIdx 1
if (cbp_bit) // set the chroma bits
{
b = 0;
if (currMB->mb_available_up != NULL)
{
if((currMB->mb_available_up)->mb_type==IPCM)
b=1;
else
if ((currMB->mb_available_up)->cbp > 15)
b = (( ((currMB->mb_available_up)->cbp >> 4) == 2) ? 1 : 0);
}
a = 0;
if (currMB->mb_available_left != NULL)
{
if((currMB->mb_available_left)->mb_type==IPCM)
a=1;
else
if ((currMB->mb_available_left)->cbp > 15)
a = (( ((currMB->mb_available_left)->cbp >> 4) == 2) ? 1 : 0);
}
curr_cbp_ctx = a+2*b;
cbp_bit = biari_decode_symbol(dep_dp, ctx->cbp_contexts[2] + curr_cbp_ctx );
cbp += (cbp_bit == 1) ? 32 : 16;
}
}
se->value1 = cbp;
if (!cbp)
{
last_dquant=0;
}
#if TRACE
fprintf(p_trace, "@%d %s\t\t\t%d\n",symbolCount++, se->tracestring, se->value1);
fflush(p_trace);
#endif
}
/*!
************************************************************************
* \brief
* This function is used to arithmetically decode the chroma
* intra prediction mode of a given MB.
************************************************************************
*/ //GB
void readCIPredMode_CABAC(SyntaxElement *se,
struct inp_par *inp,
struct img_par *img,
DecodingEnvironmentPtr dep_dp)
{
TextureInfoContexts *ctx = img->currentSlice->tex_ctx;
Macroblock *currMB = &img->mb_data[img->current_mb_nr];
int act_ctx,a,b;
int act_sym = se->value1;
if (currMB->mb_available_up == NULL) b = 0;
else
{
if( (currMB->mb_available_up)->mb_type==IPCM)
b=0;
else
b = ( ((currMB->mb_available_up)->c_ipred_mode != 0) ? 1 : 0);
}
if (currMB->mb_available_left == NULL) a = 0;
else
{
if( (currMB->mb_available_left)->mb_type==IPCM)
a=0;
else
a = ( ((currMB->mb_available_left)->c_ipred_mode != 0) ? 1 : 0);
}
act_ctx = a+b;
act_sym = biari_decode_symbol(dep_dp, ctx->cipr_contexts + act_ctx );
if (act_sym!=0)
act_sym = unary_bin_max_decode(dep_dp,ctx->cipr_contexts+3,0,2)+1;
se->value1 = act_sym;
#if TRACE
fprintf(p_trace, "@%d %s\t\t\t%d\n",symbolCount++, se->tracestring, se->value1);
fflush(p_trace);
#endif
}
static const int maxpos [] = {16, 15, 64, 32, 32, 16, 4, 15, 8, 16};
static const int c1isdc [] = { 1, 0, 1, 1, 1, 1, 1, 0, 1, 1};
static const int type2ctx_bcbp[] = { 0, 1, 2, 2, 3, 4, 5, 6, 5, 5}; // 7
static const int type2ctx_map [] = { 0, 1, 2, 3, 4, 5, 6, 7, 6, 6}; // 8
static const int type2ctx_last[] = { 0, 1, 2, 3, 4, 5, 6, 7, 6, 6}; // 8
static const int type2ctx_one [] = { 0, 1, 2, 3, 3, 4, 5, 6, 5, 5}; // 7
static const int type2ctx_abs [] = { 0, 1, 2, 3, 3, 4, 5, 6, 5, 5}; // 7
static const int max_c2 [] = { 4, 4, 4, 4, 4, 4, 3, 4, 3, 3}; // 9
/*!
************************************************************************
* \brief
* Read CBP4-BIT
************************************************************************
*/
int read_and_store_CBP_block_bit (Macroblock *currMB,
DecodingEnvironmentPtr dep_dp,
struct img_par *img,
int type)
{
#define BIT_SET(x,n) ((int)(((x)&(1<<(n)))>>(n)))
int y_ac = (type==LUMA_16AC || type==LUMA_8x8 || type==LUMA_8x4 || type==LUMA_4x8 || type==LUMA_4x4);
int y_dc = (type==LUMA_16DC);
int u_ac = (type==CHROMA_AC && !img->is_v_block);
int v_ac = (type==CHROMA_AC && img->is_v_block);
int chroma_dc = (type==CHROMA_DC || type==CHROMA_DC_2x4 || type==CHROMA_DC_4x4);
int u_dc = (chroma_dc && !img->is_v_block);
int v_dc = (chroma_dc && img->is_v_block);
int j = (y_ac || u_ac || v_ac ? img->subblock_y : 0);
int i = (y_ac || u_ac || v_ac ? img->subblock_x : 0);
int bit = (y_dc ? 0 : y_ac ? 1 : u_dc ? 17 : v_dc ? 18 : u_ac ? 19 : 23);
int default_bit = (img->is_intra_block ? 1 : 0);
int upper_bit = default_bit;
int left_bit = default_bit;
int cbp_bit = 1; // always one for 8x8 mode
int ctx;
int bit_pos_a = 0;
int bit_pos_b = 0;
PixelPos block_a, block_b;
if (y_ac || y_dc)
{
getLuma4x4Neighbour(img->current_mb_nr, i, j, -1, 0, &block_a);
getLuma4x4Neighbour(img->current_mb_nr, i, j, 0, -1, &block_b);
if (y_ac)
{
if (block_a.available)
bit_pos_a = 4*block_a.y + block_a.x;
if (block_b.available)
bit_pos_b = 4*block_b.y + block_b.x;
}
}
else
{
getChroma4x4Neighbour(img->current_mb_nr, i, j, -1, 0, &block_a);
getChroma4x4Neighbour(img->current_mb_nr, i, j, 0, -1, &block_b);
if (u_ac||v_ac)
{
if (block_a.available)
bit_pos_a = 2*block_a.y + block_a.x;
if (block_b.available)
bit_pos_b = 2*block_b.y + block_b.x;
}
}
if (type!=LUMA_8x8)
{
//--- get bits from neighbouring blocks ---
if (block_b.available)
{
if(img->mb_data[block_b.mb_addr].mb_type==IPCM)
upper_bit=1;
else
upper_bit = BIT_SET(img->mb_data[block_b.mb_addr].cbp_bits,bit+bit_pos_b);
}
if (block_a.available)
{
if(img->mb_data[block_a.mb_addr].mb_type==IPCM)
left_bit=1;
else
left_bit = BIT_SET(img->mb_data[block_a.mb_addr].cbp_bits,bit+bit_pos_a);
}
ctx = 2*upper_bit+left_bit;
//===== encode symbol =====
cbp_bit = biari_decode_symbol (dep_dp, img->currentSlice->tex_ctx->bcbp_contexts[type2ctx_bcbp[type]] + ctx);
}
//--- set bits for current block ---
bit = (y_dc ? 0 : y_ac ? 1+4*j+i : u_dc ? 17 : v_dc ? 18 : u_ac ? 19+2*j+i : 23+2*j+i);
if (cbp_bit)
{
if (type==LUMA_8x8)
{
currMB->cbp_bits |= (1<< bit );
currMB->cbp_bits |= (1<<(bit+1));
currMB->cbp_bits |= (1<<(bit+4));
currMB->cbp_bits |= (1<<(bit+5));
}
else if (type==LUMA_8x4)
{
currMB->cbp_bits |= (1<< bit );
currMB->cbp_bits |= (1<<(bit+1));
}
else if (type==LUMA_4x8)
{
currMB->cbp_bits |= (1<< bit );
currMB->cbp_bits |= (1<<(bit+4));
}
else
{
currMB->cbp_bits |= (1<<bit);
}
}
return cbp_bit;
}
//===== position -> ctx for MAP =====
//--- zig-zag scan ----
static const int pos2ctx_map8x8 [] = { 0, 1, 2, 3, 4, 5, 5, 4, 4, 3, 3, 4, 4, 4, 5, 5,
4, 4, 4, 4, 3, 3, 6, 7, 7, 7, 8, 9, 10, 9, 8, 7,
7, 6, 11, 12, 13, 11, 6, 7, 8, 9, 14, 10, 9, 8, 6, 11,
12, 13, 11, 6, 9, 14, 10, 9, 11, 12, 13, 11 ,14, 10, 12, 14}; // 15 CTX
static const int pos2ctx_map8x4 [] = { 0, 1, 2, 3, 4, 5, 7, 8, 9, 10, 11, 9, 8, 6, 7, 8,
9, 10, 11, 9, 8, 6, 12, 8, 9, 10, 11, 9, 13, 13, 14, 14}; // 15 CTX
static const int pos2ctx_map4x4 [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 14}; // 15 CTX
static const int pos2ctx_map2x4c[] = { 0, 0, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2}; // 15 CTX
static const int pos2ctx_map4x4c[] = { 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2}; // 15 CTX
static const int* pos2ctx_map [] = {pos2ctx_map4x4, pos2ctx_map4x4, pos2ctx_map8x8, pos2ctx_map8x4,
pos2ctx_map8x4, pos2ctx_map4x4, pos2ctx_map4x4, pos2ctx_map4x4,
pos2ctx_map2x4c, pos2ctx_map4x4c};
//--- interlace scan ----
//taken from ABT
static const int pos2ctx_map8x8i[] = { 0, 1, 1, 2, 2, 3, 3, 4, 5, 6, 7, 7, 7, 8, 4, 5,
6, 9, 10, 10, 8, 11, 12, 11, 9, 9, 10, 10, 8, 11, 12, 11,
9, 9, 10, 10, 8, 11, 12, 11, 9, 9, 10, 10, 8, 13, 13, 9,
9, 10, 10, 8, 13, 13, 9, 9, 10, 10, 14, 14, 14, 14, 14, 14}; // 15 CTX
static const int pos2ctx_map8x4i[] = { 0, 1, 2, 3, 4, 5, 6, 3, 4, 5, 6, 3, 4, 7, 6, 8,
9, 7, 6, 8, 9, 10, 11, 12, 12, 10, 11, 13, 13, 14, 14, 14}; // 15 CTX
static const int pos2ctx_map4x8i[] = { 0, 1, 1, 1, 2, 3, 3, 4, 4, 4, 5, 6, 2, 7, 7, 8,
8, 8, 5, 6, 9, 10, 10, 11, 11, 11, 12, 13, 13, 14, 14, 14}; // 15 CTX
static const int* pos2ctx_map_int[] = {pos2ctx_map4x4, pos2ctx_map4x4, pos2ctx_map8x8i,pos2ctx_map8x4i,
pos2ctx_map4x8i,pos2ctx_map4x4, pos2ctx_map4x4, pos2ctx_map4x4,
pos2ctx_map2x4c, pos2ctx_map4x4c};
//===== position -> ctx for LAST =====
static const int pos2ctx_last8x8 [] = { 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8}; // 9 CTX
static const int pos2ctx_last8x4 [] = { 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2,
3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8}; // 9 CTX
static const int pos2ctx_last4x4 [] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}; // 15 CTX
static const int pos2ctx_last2x4c[] = { 0, 0, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2}; // 15 CTX
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