X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=encoder%2Frdo.c;h=d4c6ba30bcbe8f24141f851d0601ad31fad50656;hb=93cba743c78959ad97812dbaf894903c608912d0;hp=035e4e3f312b2ce094048b36de6edde566643277;hpb=68cae61a9f484274594eeb264355f9c364f317c5;p=x264 diff --git a/encoder/rdo.c b/encoder/rdo.c index 035e4e3f..d4c6ba30 100644 --- a/encoder/rdo.c +++ b/encoder/rdo.c @@ -1,7 +1,7 @@ /***************************************************************************** - * rdo.c: h264 encoder library (rate-distortion optimization) + * rdo.c: rate-distortion optimization ***************************************************************************** - * Copyright (C) 2005-2008 x264 project + * Copyright (C) 2005-2015 x264 project * * Authors: Loren Merritt * Fiona Glaser @@ -19,6 +19,9 @@ * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111, USA. + * + * This program is also available under a commercial proprietary license. + * For more information, contact us at licensing@x264.com. *****************************************************************************/ /* duplicate all the writer functions, just calculating bit cost @@ -29,8 +32,8 @@ /* Transition and size tables for abs<9 MVD and residual coding */ /* Consist of i_prefix-2 1s, one zero, and a bypass sign bit */ -static uint8_t cabac_transition_unary[15][128]; -static uint16_t cabac_size_unary[15][128]; +uint8_t x264_cabac_transition_unary[15][128]; +uint16_t x264_cabac_size_unary[15][128]; /* Transition and size tables for abs>9 MVD */ /* Consist of 5 1s and a bypass sign bit */ static uint8_t cabac_transition_5ones[128]; @@ -50,6 +53,8 @@ static uint16_t cabac_size_5ones[128]; * fractional bits, but only finite precision. */ #undef x264_cabac_encode_decision #undef x264_cabac_encode_decision_noup +#undef x264_cabac_encode_bypass +#undef x264_cabac_encode_terminal #define x264_cabac_encode_decision(c,x,v) x264_cabac_size_decision(c,x,v) #define x264_cabac_encode_decision_noup(c,x,v) x264_cabac_size_decision_noup(c,x,v) #define x264_cabac_encode_terminal(c) ((c)->f8_bits_encoded += 7) @@ -59,45 +64,45 @@ static uint16_t cabac_size_5ones[128]; #include "cabac.c" #define COPY_CABAC h->mc.memcpy_aligned( &cabac_tmp.f8_bits_encoded, &h->cabac.f8_bits_encoded, \ - sizeof(x264_cabac_t) - offsetof(x264_cabac_t,f8_bits_encoded) ) + sizeof(x264_cabac_t) - offsetof(x264_cabac_t,f8_bits_encoded) - (CHROMA444 ? 0 : (1024+12)-460) ) #define COPY_CABAC_PART( pos, size )\ memcpy( &cb->state[pos], &h->cabac.state[pos], size ) -static ALWAYS_INLINE uint64_t cached_hadamard( x264_t *h, int pixel, int x, int y ) +static ALWAYS_INLINE uint64_t cached_hadamard( x264_t *h, int size, int x, int y ) { static const uint8_t hadamard_shift_x[4] = {4, 4, 3, 3}; static const uint8_t hadamard_shift_y[4] = {4-0, 3-0, 4-1, 3-1}; static const uint8_t hadamard_offset[4] = {0, 1, 3, 5}; - int cache_index = (x >> hadamard_shift_x[pixel]) + (y >> hadamard_shift_y[pixel]) - + hadamard_offset[pixel]; + int cache_index = (x >> hadamard_shift_x[size]) + (y >> hadamard_shift_y[size]) + + hadamard_offset[size]; uint64_t res = h->mb.pic.fenc_hadamard_cache[cache_index]; if( res ) return res - 1; else { - uint8_t *fenc = h->mb.pic.p_fenc[0] + x + y*FENC_STRIDE; - res = h->pixf.hadamard_ac[pixel]( fenc, FENC_STRIDE ); + pixel *fenc = h->mb.pic.p_fenc[0] + x + y*FENC_STRIDE; + res = h->pixf.hadamard_ac[size]( fenc, FENC_STRIDE ); h->mb.pic.fenc_hadamard_cache[cache_index] = res + 1; return res; } } -static ALWAYS_INLINE int cached_satd( x264_t *h, int pixel, int x, int y ) +static ALWAYS_INLINE int cached_satd( x264_t *h, int size, int x, int y ) { static const uint8_t satd_shift_x[3] = {3, 2, 2}; static const uint8_t satd_shift_y[3] = {2-1, 3-2, 2-2}; static const uint8_t satd_offset[3] = {0, 8, 16}; - ALIGNED_16( static uint8_t zero[16] ); - int cache_index = (x >> satd_shift_x[pixel - PIXEL_8x4]) + (y >> satd_shift_y[pixel - PIXEL_8x4]) - + satd_offset[pixel - PIXEL_8x4]; + ALIGNED_16( static pixel zero[16] ) = {0}; + int cache_index = (x >> satd_shift_x[size - PIXEL_8x4]) + (y >> satd_shift_y[size - PIXEL_8x4]) + + satd_offset[size - PIXEL_8x4]; int res = h->mb.pic.fenc_satd_cache[cache_index]; if( res ) return res - 1; else { - uint8_t *fenc = h->mb.pic.p_fenc[0] + x + y*FENC_STRIDE; - int dc = h->pixf.sad[pixel]( fenc, FENC_STRIDE, zero, 0 ) >> 1; - res = h->pixf.satd[pixel]( fenc, FENC_STRIDE, zero, 0 ) - dc; + pixel *fenc = h->mb.pic.p_fenc[0] + x + y*FENC_STRIDE; + int dc = h->pixf.sad[size]( fenc, FENC_STRIDE, zero, 0 ) >> 1; + res = h->pixf.satd[size]( fenc, FENC_STRIDE, zero, 0 ) - dc; h->mb.pic.fenc_satd_cache[cache_index] = res + 1; return res; } @@ -114,10 +119,10 @@ static ALWAYS_INLINE int cached_satd( x264_t *h, int pixel, int x, int y ) static inline int ssd_plane( x264_t *h, int size, int p, int x, int y ) { - ALIGNED_16(static uint8_t zero[16]); + ALIGNED_16( static pixel zero[16] ) = {0}; int satd = 0; - uint8_t *fdec = h->mb.pic.p_fdec[p] + x + y*FDEC_STRIDE; - uint8_t *fenc = h->mb.pic.p_fenc[p] + x + y*FENC_STRIDE; + pixel *fdec = h->mb.pic.p_fdec[p] + x + y*FDEC_STRIDE; + pixel *fenc = h->mb.pic.p_fenc[p] + x + y*FENC_STRIDE; if( p == 0 && h->mb.i_psy_rd ) { /* If the plane is smaller than 8x8, we can't do an SA8D; this probably isn't a big problem. */ @@ -141,9 +146,10 @@ static inline int ssd_plane( x264_t *h, int size, int p, int x, int y ) static inline int ssd_mb( x264_t *h ) { - int chromassd = ssd_plane(h, PIXEL_8x8, 1, 0, 0) + ssd_plane(h, PIXEL_8x8, 2, 0, 0); - chromassd = ((uint64_t)chromassd * h->mb.i_chroma_lambda2_offset + 128) >> 8; - return ssd_plane(h, PIXEL_16x16, 0, 0, 0) + chromassd; + int chroma_size = h->luma2chroma_pixel[PIXEL_16x16]; + int chroma_ssd = ssd_plane(h, chroma_size, 1, 0, 0) + ssd_plane(h, chroma_size, 2, 0, 0); + chroma_ssd = ((uint64_t)chroma_ssd * h->mb.i_chroma_lambda2_offset + 128) >> 8; + return ssd_plane(h, PIXEL_16x16, 0, 0, 0) + chroma_ssd; } static int x264_rd_cost_mb( x264_t *h, int i_lambda2 ) @@ -155,6 +161,9 @@ static int x264_rd_cost_mb( x264_t *h, int i_lambda2 ) x264_macroblock_encode( h ); + if( h->mb.b_deblock_rdo ) + x264_macroblock_deblock( h ); + i_ssd = ssd_mb( h ); if( IS_SKIP( h->mb.i_type ) ) @@ -171,36 +180,13 @@ static int x264_rd_cost_mb( x264_t *h, int i_lambda2 ) else { x264_macroblock_size_cavlc( h ); - i_bits = ( h->out.bs.i_bits_encoded * i_lambda2 + 128 ) >> 8; + i_bits = ( (uint64_t)h->out.bs.i_bits_encoded * i_lambda2 + 128 ) >> 8; } h->mb.b_transform_8x8 = b_transform_bak; h->mb.i_type = type_bak; - return i_ssd + i_bits; -} - -/* For small partitions (i.e. those using at most one DCT category's worth of CABAC states), - * it's faster to copy the individual parts than to perform a whole CABAC_COPY. */ -static ALWAYS_INLINE void x264_copy_cabac_part( x264_t *h, x264_cabac_t *cb, int cat, int intra ) -{ - if( intra ) - COPY_CABAC_PART( 68, 2 ); //intra pred mode - else - COPY_CABAC_PART( 40, 16 ); //mvd, rounded up to 16 bytes - - /* 8x8dct writes CBP, while non-8x8dct writes CBF */ - if( cat != DCT_LUMA_8x8 ) - COPY_CABAC_PART( 85 + cat * 4, 4 ); - else - COPY_CABAC_PART( 73, 4 ); - - /* Really should be 15 bytes, but rounding up a byte saves some - * instructions and is faster, and copying extra data doesn't hurt. */ - COPY_CABAC_PART( significant_coeff_flag_offset[h->mb.b_interlaced][cat], 16 ); - COPY_CABAC_PART( last_coeff_flag_offset[h->mb.b_interlaced][cat], 16 ); - COPY_CABAC_PART( coeff_abs_level_m1_offset[cat], 10 ); - cb->f8_bits_encoded = 0; + return X264_MIN( i_ssd + i_bits, COST_MAX ); } /* partition RD functions use 8 bits more precision to avoid large rounding errors at low QPs */ @@ -216,11 +202,18 @@ static uint64_t x264_rd_cost_subpart( x264_t *h, int i_lambda2, int i4, int i_pi x264_macroblock_encode_p4x4( h, i4+2 ); i_ssd = ssd_plane( h, i_pixel, 0, block_idx_x[i4]*4, block_idx_y[i4]*4 ); + if( CHROMA444 ) + { + int chromassd = ssd_plane( h, i_pixel, 1, block_idx_x[i4]*4, block_idx_y[i4]*4 ) + + ssd_plane( h, i_pixel, 2, block_idx_x[i4]*4, block_idx_y[i4]*4 ); + chromassd = ((uint64_t)chromassd * h->mb.i_chroma_lambda2_offset + 128) >> 8; + i_ssd += chromassd; + } if( h->param.b_cabac ) { x264_cabac_t cabac_tmp; - x264_copy_cabac_part( h, &cabac_tmp, DCT_LUMA_4x4, 0 ); + COPY_CABAC; x264_subpartition_size_cabac( h, &cabac_tmp, i4, i_pixel ); i_bits = ( (uint64_t)cabac_tmp.f8_bits_encoded * i_lambda2 + 128 ) >> 8; } @@ -234,7 +227,6 @@ uint64_t x264_rd_cost_part( x264_t *h, int i_lambda2, int i4, int i_pixel ) { uint64_t i_ssd, i_bits; int i8 = i4 >> 2; - int chromassd; if( i_pixel == PIXEL_16x16 ) { @@ -253,10 +245,13 @@ uint64_t x264_rd_cost_part( x264_t *h, int i_lambda2, int i4, int i_pixel ) if( i_pixel == PIXEL_8x16 ) x264_macroblock_encode_p8x8( h, i8+2 ); - chromassd = ssd_plane( h, i_pixel+3, 1, (i8&1)*4, (i8>>1)*4 ) - + ssd_plane( h, i_pixel+3, 2, (i8&1)*4, (i8>>1)*4 ); - chromassd = ((uint64_t)chromassd * h->mb.i_chroma_lambda2_offset + 128) >> 8; - i_ssd = ssd_plane( h, i_pixel, 0, (i8&1)*8, (i8>>1)*8 ) + chromassd; + int ssd_x = 8*(i8&1); + int ssd_y = 8*(i8>>1); + i_ssd = ssd_plane( h, i_pixel, 0, ssd_x, ssd_y ); + int chromapix = h->luma2chroma_pixel[i_pixel]; + int chromassd = ssd_plane( h, chromapix, 1, ssd_x>>CHROMA_H_SHIFT, ssd_y>>CHROMA_V_SHIFT ) + + ssd_plane( h, chromapix, 2, ssd_x>>CHROMA_H_SHIFT, ssd_y>>CHROMA_V_SHIFT ); + i_ssd += ((uint64_t)chromassd * h->mb.i_chroma_lambda2_offset + 128) >> 8; if( h->param.b_cabac ) { @@ -266,29 +261,43 @@ uint64_t x264_rd_cost_part( x264_t *h, int i_lambda2, int i4, int i_pixel ) i_bits = ( (uint64_t)cabac_tmp.f8_bits_encoded * i_lambda2 + 128 ) >> 8; } else - i_bits = x264_partition_size_cavlc( h, i8, i_pixel ) * i_lambda2; + i_bits = (uint64_t)x264_partition_size_cavlc( h, i8, i_pixel ) * i_lambda2; return (i_ssd<<8) + i_bits; } -static uint64_t x264_rd_cost_i8x8( x264_t *h, int i_lambda2, int i8, int i_mode ) +static uint64_t x264_rd_cost_i8x8( x264_t *h, int i_lambda2, int i8, int i_mode, pixel edge[4][32] ) { uint64_t i_ssd, i_bits; + int plane_count = CHROMA444 ? 3 : 1; + int i_qp = h->mb.i_qp; h->mb.i_cbp_luma &= ~(1<mb.b_transform_8x8 = 1; - x264_mb_encode_i8x8( h, i8, h->mb.i_qp ); + for( int p = 0; p < plane_count; p++ ) + { + x264_mb_encode_i8x8( h, p, i8, i_qp, i_mode, edge[p], 1 ); + i_qp = h->mb.i_chroma_qp; + } + i_ssd = ssd_plane( h, PIXEL_8x8, 0, (i8&1)*8, (i8>>1)*8 ); + if( CHROMA444 ) + { + int chromassd = ssd_plane( h, PIXEL_8x8, 1, (i8&1)*8, (i8>>1)*8 ) + + ssd_plane( h, PIXEL_8x8, 2, (i8&1)*8, (i8>>1)*8 ); + chromassd = ((uint64_t)chromassd * h->mb.i_chroma_lambda2_offset + 128) >> 8; + i_ssd += chromassd; + } if( h->param.b_cabac ) { x264_cabac_t cabac_tmp; - x264_copy_cabac_part( h, &cabac_tmp, DCT_LUMA_8x8, 1 ); + COPY_CABAC; x264_partition_i8x8_size_cabac( h, &cabac_tmp, i8, i_mode ); i_bits = ( (uint64_t)cabac_tmp.f8_bits_encoded * i_lambda2 + 128 ) >> 8; } else - i_bits = x264_partition_i8x8_size_cavlc( h, i8, i_mode ) * i_lambda2; + i_bits = (uint64_t)x264_partition_i8x8_size_cavlc( h, i8, i_mode ) * i_lambda2; return (i_ssd<<8) + i_bits; } @@ -296,31 +305,47 @@ static uint64_t x264_rd_cost_i8x8( x264_t *h, int i_lambda2, int i8, int i_mode static uint64_t x264_rd_cost_i4x4( x264_t *h, int i_lambda2, int i4, int i_mode ) { uint64_t i_ssd, i_bits; + int plane_count = CHROMA444 ? 3 : 1; + int i_qp = h->mb.i_qp; + + for( int p = 0; p < plane_count; p++ ) + { + x264_mb_encode_i4x4( h, p, i4, i_qp, i_mode, 1 ); + i_qp = h->mb.i_chroma_qp; + } - x264_mb_encode_i4x4( h, i4, h->mb.i_qp ); i_ssd = ssd_plane( h, PIXEL_4x4, 0, block_idx_x[i4]*4, block_idx_y[i4]*4 ); + if( CHROMA444 ) + { + int chromassd = ssd_plane( h, PIXEL_4x4, 1, block_idx_x[i4]*4, block_idx_y[i4]*4 ) + + ssd_plane( h, PIXEL_4x4, 2, block_idx_x[i4]*4, block_idx_y[i4]*4 ); + chromassd = ((uint64_t)chromassd * h->mb.i_chroma_lambda2_offset + 128) >> 8; + i_ssd += chromassd; + } if( h->param.b_cabac ) { x264_cabac_t cabac_tmp; - x264_copy_cabac_part( h, &cabac_tmp, DCT_LUMA_4x4, 1 ); + COPY_CABAC; x264_partition_i4x4_size_cabac( h, &cabac_tmp, i4, i_mode ); i_bits = ( (uint64_t)cabac_tmp.f8_bits_encoded * i_lambda2 + 128 ) >> 8; } else - i_bits = x264_partition_i4x4_size_cavlc( h, i4, i_mode ) * i_lambda2; + i_bits = (uint64_t)x264_partition_i4x4_size_cavlc( h, i4, i_mode ) * i_lambda2; return (i_ssd<<8) + i_bits; } -static uint64_t x264_rd_cost_i8x8_chroma( x264_t *h, int i_lambda2, int i_mode, int b_dct ) +static uint64_t x264_rd_cost_chroma( x264_t *h, int i_lambda2, int i_mode, int b_dct ) { uint64_t i_ssd, i_bits; if( b_dct ) - x264_mb_encode_8x8_chroma( h, 0, h->mb.i_chroma_qp ); - i_ssd = ssd_plane( h, PIXEL_8x8, 1, 0, 0 ) + - ssd_plane( h, PIXEL_8x8, 2, 0, 0 ); + x264_mb_encode_chroma( h, 0, h->mb.i_chroma_qp ); + + int chromapix = h->luma2chroma_pixel[PIXEL_16x16]; + i_ssd = ssd_plane( h, chromapix, 1, 0, 0 ) + + ssd_plane( h, chromapix, 2, 0, 0 ); h->mb.i_chroma_pred_mode = i_mode; @@ -328,11 +353,11 @@ static uint64_t x264_rd_cost_i8x8_chroma( x264_t *h, int i_lambda2, int i_mode, { x264_cabac_t cabac_tmp; COPY_CABAC; - x264_i8x8_chroma_size_cabac( h, &cabac_tmp ); + x264_chroma_size_cabac( h, &cabac_tmp ); i_bits = ( (uint64_t)cabac_tmp.f8_bits_encoded * i_lambda2 + 128 ) >> 8; } else - i_bits = x264_i8x8_chroma_size_cavlc( h ) * i_lambda2; + i_bits = (uint64_t)x264_chroma_size_cavlc( h ) * i_lambda2; return (i_ssd<<8) + i_bits; } @@ -340,9 +365,9 @@ static uint64_t x264_rd_cost_i8x8_chroma( x264_t *h, int i_lambda2, int i_mode, * Trellis RD quantization ****************************************************************************/ -#define TRELLIS_SCORE_MAX ((uint64_t)1<<50) +#define TRELLIS_SCORE_MAX -1LL // negative marks the node as invalid +#define TRELLIS_SCORE_BIAS 1LL<<60; // bias so that all valid scores are positive, even after negative contributions from psy #define CABAC_SIZE_BITS 8 -#define SSD_WEIGHT_BITS 5 #define LAMBDA_BITS 4 /* precalculate the cost of coding various combinations of bits in a single context */ @@ -361,8 +386,8 @@ void x264_rdo_init( void ) f8_bits += x264_cabac_size_decision2( &ctx, 0 ); f8_bits += 1 << CABAC_SIZE_BITS; //sign - cabac_size_unary[i_prefix][i_ctx] = f8_bits; - cabac_transition_unary[i_prefix][i_ctx] = ctx; + x264_cabac_size_unary[i_prefix][i_ctx] = f8_bits; + x264_cabac_transition_unary[i_prefix][i_ctx] = ctx; } } for( int i_ctx = 0; i_ctx < 128; i_ctx++ ) @@ -379,12 +404,19 @@ void x264_rdo_init( void ) } } -typedef struct { - int64_t score; +typedef struct +{ + uint64_t score; int level_idx; // index into level_tree[] - uint8_t cabac_state[10]; //just the contexts relevant to coding abs_level_m1 + uint8_t cabac_state[4]; // just contexts 0,4,8,9 of the 10 relevant to coding abs_level_m1 } trellis_node_t; +typedef struct +{ + uint16_t next; + uint16_t abs_level; +} trellis_level_t; + // TODO: // save cabac state between blocks? // use trellis' RD score instead of x264_mb_decimate_score? @@ -405,62 +437,307 @@ typedef struct { // comparable to the input. so unquant is the direct inverse of quant, // and uses the dct scaling factors, not the idct ones. -static ALWAYS_INLINE int quant_trellis_cabac( x264_t *h, int16_t *dct, - const uint16_t *quant_mf, const int *unquant_mf, - const int *coef_weight, const uint8_t *zigzag, - int i_ctxBlockCat, int i_lambda2, int b_ac, int dc, int i_coefs, int idx ) +#define SIGN(x,y) ((x^(y >> 31))-(y >> 31)) + +#define SET_LEVEL(ndst, nsrc, l) {\ + if( sizeof(trellis_level_t) == sizeof(uint32_t) )\ + M32( &level_tree[levels_used] ) = pack16to32( nsrc.level_idx, l );\ + else\ + level_tree[levels_used] = (trellis_level_t){ nsrc.level_idx, l };\ + ndst.level_idx = levels_used;\ + levels_used++;\ +} + +// encode all values of the dc coef in a block which is known to have no ac +static NOINLINE +int trellis_dc_shortcut( int sign_coef, int quant_coef, int unquant_mf, int coef_weight, int lambda2, uint8_t *cabac_state, int cost_sig ) { - int abs_coefs[64], signs[64]; - trellis_node_t nodes[2][8]; - trellis_node_t *nodes_cur = nodes[0]; - trellis_node_t *nodes_prev = nodes[1]; - trellis_node_t *bnode; - const int b_interlaced = h->mb.b_interlaced; - uint8_t *cabac_state_sig = &h->cabac.state[ significant_coeff_flag_offset[b_interlaced][i_ctxBlockCat] ]; - uint8_t *cabac_state_last = &h->cabac.state[ last_coeff_flag_offset[b_interlaced][i_ctxBlockCat] ]; - const int f = 1 << 15; // no deadzone - int i_last_nnz; - int i; + uint64_t bscore = TRELLIS_SCORE_MAX; + int ret = 0; + int q = abs( quant_coef ); + for( int abs_level = q-1; abs_level <= q; abs_level++ ) + { + int unquant_abs_level = (unquant_mf * abs_level + 128) >> 8; - // (# of coefs) * (# of ctx) * (# of levels tried) = 1024 - // we don't need to keep all of those: (# of coefs) * (# of ctx) would be enough, - // but it takes more time to remove dead states than you gain in reduced memory. - struct { - uint16_t abs_level; - uint16_t next; - } level_tree[64*8*2]; - int i_levels_used = 1; - - /* init coefs */ - for( i = i_coefs-1; i >= b_ac; i-- ) - if( (unsigned)(dct[zigzag[i]] * (dc?quant_mf[0]>>1:quant_mf[zigzag[i]]) + f-1) >= 2*f ) - break; + /* Optimize rounding for DC coefficients in DC-only luma 4x4/8x8 blocks. */ + int d = sign_coef - ((SIGN(unquant_abs_level, sign_coef) + 8)&~15); + uint64_t score = (uint64_t)d*d * coef_weight; + + /* code the proposed level, and count how much entropy it would take */ + if( abs_level ) + { + unsigned f8_bits = cost_sig; + int prefix = X264_MIN( abs_level - 1, 14 ); + f8_bits += x264_cabac_size_decision_noup2( cabac_state+1, prefix > 0 ); + f8_bits += x264_cabac_size_unary[prefix][cabac_state[5]]; + if( abs_level >= 15 ) + f8_bits += bs_size_ue_big( abs_level - 15 ) << CABAC_SIZE_BITS; + score += (uint64_t)f8_bits * lambda2 >> ( CABAC_SIZE_BITS - LAMBDA_BITS ); + } + + COPY2_IF_LT( bscore, score, ret, abs_level ); + } + return SIGN(ret, sign_coef); +} - if( i < b_ac ) +// encode one value of one coef in one context +static ALWAYS_INLINE +int trellis_coef( int j, int const_level, int abs_level, int prefix, int suffix_cost, + int node_ctx, int level1_ctx, int levelgt1_ctx, uint64_t ssd, int cost_siglast[3], + trellis_node_t *nodes_cur, trellis_node_t *nodes_prev, + trellis_level_t *level_tree, int levels_used, int lambda2, uint8_t *level_state ) +{ + uint64_t score = nodes_prev[j].score + ssd; + /* code the proposed level, and count how much entropy it would take */ + unsigned f8_bits = cost_siglast[ j ? 1 : 2 ]; + uint8_t level1_state = (j >= 3) ? nodes_prev[j].cabac_state[level1_ctx>>2] : level_state[level1_ctx]; + f8_bits += x264_cabac_entropy[level1_state ^ (const_level > 1)]; + uint8_t levelgt1_state; + if( const_level > 1 ) { - /* We only need to memset an empty 4x4 block. 8x8 can be - implicitly emptied via zero nnz, as can dc. */ - if( i_coefs == 16 && !dc ) - memset( dct, 0, 16 * sizeof(int16_t) ); - return 0; + levelgt1_state = j >= 6 ? nodes_prev[j].cabac_state[levelgt1_ctx-6] : level_state[levelgt1_ctx]; + f8_bits += x264_cabac_size_unary[prefix][levelgt1_state] + suffix_cost; } + else + f8_bits += 1 << CABAC_SIZE_BITS; + score += (uint64_t)f8_bits * lambda2 >> ( CABAC_SIZE_BITS - LAMBDA_BITS ); - i_last_nnz = i; + /* save the node if it's better than any existing node with the same cabac ctx */ + if( score < nodes_cur[node_ctx].score ) + { + nodes_cur[node_ctx].score = score; + if( j == 2 || (j <= 3 && node_ctx == 4) ) // init from input state + M32(nodes_cur[node_ctx].cabac_state) = M32(level_state+12); + else if( j >= 3 ) + M32(nodes_cur[node_ctx].cabac_state) = M32(nodes_prev[j].cabac_state); + if( j >= 3 ) // skip the transition if we're not going to reuse the context + nodes_cur[node_ctx].cabac_state[level1_ctx>>2] = x264_cabac_transition[level1_state][const_level > 1]; + if( const_level > 1 && node_ctx == 7 ) + nodes_cur[node_ctx].cabac_state[levelgt1_ctx-6] = x264_cabac_transition_unary[prefix][levelgt1_state]; + nodes_cur[node_ctx].level_idx = nodes_prev[j].level_idx; + SET_LEVEL( nodes_cur[node_ctx], nodes_prev[j], abs_level ); + } + return levels_used; +} - for( ; i >= b_ac; i-- ) +// encode one value of one coef in all contexts, templated by which value that is. +// in ctx_lo, the set of live nodes is contiguous and starts at ctx0, so return as soon as we've seen one failure. +// in ctx_hi, they're contiguous within each block of 4 ctxs, but not necessarily starting at the beginning, +// so exploiting that would be more complicated. +static NOINLINE +int trellis_coef0_0( uint64_t ssd0, trellis_node_t *nodes_cur, trellis_node_t *nodes_prev, + trellis_level_t *level_tree, int levels_used ) +{ + nodes_cur[0].score = nodes_prev[0].score + ssd0; + nodes_cur[0].level_idx = nodes_prev[0].level_idx; + for( int j = 1; j < 4 && (int64_t)nodes_prev[j].score >= 0; j++ ) { - int coef = dct[zigzag[i]]; - abs_coefs[i] = abs(coef); - signs[i] = coef < 0 ? -1 : 1; + nodes_cur[j].score = nodes_prev[j].score; + if( j >= 3 ) + M32(nodes_cur[j].cabac_state) = M32(nodes_prev[j].cabac_state); + SET_LEVEL( nodes_cur[j], nodes_prev[j], 0 ); } + return levels_used; +} - /* init trellis */ +static NOINLINE +int trellis_coef0_1( uint64_t ssd0, trellis_node_t *nodes_cur, trellis_node_t *nodes_prev, + trellis_level_t *level_tree, int levels_used ) +{ for( int j = 1; j < 8; j++ ) + // this branch only affects speed, not function; there's nothing wrong with updating invalid nodes in coef0. + if( (int64_t)nodes_prev[j].score >= 0 ) + { + nodes_cur[j].score = nodes_prev[j].score; + if( j >= 3 ) + M32(nodes_cur[j].cabac_state) = M32(nodes_prev[j].cabac_state); + SET_LEVEL( nodes_cur[j], nodes_prev[j], 0 ); + } + return levels_used; +} + +#define COEF(const_level, ctx_hi, j, ...)\ + if( !j || (int64_t)nodes_prev[j].score >= 0 )\ + levels_used = trellis_coef( j, const_level, abs_level, prefix, suffix_cost, __VA_ARGS__,\ + j?ssd1:ssd0, cost_siglast, nodes_cur, nodes_prev,\ + level_tree, levels_used, lambda2, level_state );\ + else if( !ctx_hi )\ + return levels_used; + +static NOINLINE +int trellis_coef1_0( uint64_t ssd0, uint64_t ssd1, int cost_siglast[3], + trellis_node_t *nodes_cur, trellis_node_t *nodes_prev, + trellis_level_t *level_tree, int levels_used, int lambda2, + uint8_t *level_state ) +{ + int abs_level = 1, prefix = 1, suffix_cost = 0; + COEF( 1, 0, 0, 1, 1, 0 ); + COEF( 1, 0, 1, 2, 2, 0 ); + COEF( 1, 0, 2, 3, 3, 0 ); + COEF( 1, 0, 3, 3, 4, 0 ); + return levels_used; +} + +static NOINLINE +int trellis_coef1_1( uint64_t ssd0, uint64_t ssd1, int cost_siglast[3], + trellis_node_t *nodes_cur, trellis_node_t *nodes_prev, + trellis_level_t *level_tree, int levels_used, int lambda2, + uint8_t *level_state ) +{ + int abs_level = 1, prefix = 1, suffix_cost = 0; + COEF( 1, 1, 1, 2, 2, 0 ); + COEF( 1, 1, 2, 3, 3, 0 ); + COEF( 1, 1, 3, 3, 4, 0 ); + COEF( 1, 1, 4, 4, 0, 0 ); + COEF( 1, 1, 5, 5, 0, 0 ); + COEF( 1, 1, 6, 6, 0, 0 ); + COEF( 1, 1, 7, 7, 0, 0 ); + return levels_used; +} + +static NOINLINE +int trellis_coefn_0( int abs_level, uint64_t ssd0, uint64_t ssd1, int cost_siglast[3], + trellis_node_t *nodes_cur, trellis_node_t *nodes_prev, + trellis_level_t *level_tree, int levels_used, int lambda2, + uint8_t *level_state, int levelgt1_ctx ) +{ + int prefix = X264_MIN( abs_level-1, 14 ); + int suffix_cost = abs_level >= 15 ? bs_size_ue_big( abs_level - 15 ) << CABAC_SIZE_BITS : 0; + COEF( 2, 0, 0, 4, 1, 5 ); + COEF( 2, 0, 1, 4, 2, 5 ); + COEF( 2, 0, 2, 4, 3, 5 ); + COEF( 2, 0, 3, 4, 4, 5 ); + return levels_used; +} + +static NOINLINE +int trellis_coefn_1( int abs_level, uint64_t ssd0, uint64_t ssd1, int cost_siglast[3], + trellis_node_t *nodes_cur, trellis_node_t *nodes_prev, + trellis_level_t *level_tree, int levels_used, int lambda2, + uint8_t *level_state, int levelgt1_ctx ) +{ + int prefix = X264_MIN( abs_level-1, 14 ); + int suffix_cost = abs_level >= 15 ? bs_size_ue_big( abs_level - 15 ) << CABAC_SIZE_BITS : 0; + COEF( 2, 1, 1, 4, 2, 5 ); + COEF( 2, 1, 2, 4, 3, 5 ); + COEF( 2, 1, 3, 4, 4, 5 ); + COEF( 2, 1, 4, 5, 0, 6 ); + COEF( 2, 1, 5, 6, 0, 7 ); + COEF( 2, 1, 6, 7, 0, 8 ); + COEF( 2, 1, 7, 7, 0, levelgt1_ctx ); + return levels_used; +} + +static ALWAYS_INLINE +int quant_trellis_cabac( x264_t *h, dctcoef *dct, + udctcoef *quant_mf, udctcoef *quant_bias, const int *unquant_mf, + const uint8_t *zigzag, int ctx_block_cat, int lambda2, int b_ac, + int b_chroma, int dc, int num_coefs, int idx ) +{ + ALIGNED_ARRAY_N( dctcoef, orig_coefs, [64] ); + ALIGNED_ARRAY_N( dctcoef, quant_coefs, [64] ); + const uint32_t *coef_weight1 = num_coefs == 64 ? x264_dct8_weight_tab : x264_dct4_weight_tab; + const uint32_t *coef_weight2 = num_coefs == 64 ? x264_dct8_weight2_tab : x264_dct4_weight2_tab; + const int b_interlaced = MB_INTERLACED; + uint8_t *cabac_state_sig = &h->cabac.state[ x264_significant_coeff_flag_offset[b_interlaced][ctx_block_cat] ]; + uint8_t *cabac_state_last = &h->cabac.state[ x264_last_coeff_flag_offset[b_interlaced][ctx_block_cat] ]; + int levelgt1_ctx = b_chroma && dc ? 8 : 9; + + if( dc ) + { + if( num_coefs == 16 ) + { + memcpy( orig_coefs, dct, sizeof(dctcoef)*16 ); + if( !h->quantf.quant_4x4_dc( dct, quant_mf[0] >> 1, quant_bias[0] << 1 ) ) + return 0; + h->zigzagf.scan_4x4( quant_coefs, dct ); + } + else + { + memcpy( orig_coefs, dct, sizeof(dctcoef)*num_coefs ); + int nz = h->quantf.quant_2x2_dc( &dct[0], quant_mf[0] >> 1, quant_bias[0] << 1 ); + if( num_coefs == 8 ) + nz |= h->quantf.quant_2x2_dc( &dct[4], quant_mf[0] >> 1, quant_bias[0] << 1 ); + if( !nz ) + return 0; + for( int i = 0; i < num_coefs; i++ ) + quant_coefs[i] = dct[zigzag[i]]; + } + } + else + { + if( num_coefs == 64 ) + { + h->mc.memcpy_aligned( orig_coefs, dct, sizeof(dctcoef)*64 ); + if( !h->quantf.quant_8x8( dct, quant_mf, quant_bias ) ) + return 0; + h->zigzagf.scan_8x8( quant_coefs, dct ); + } + else //if( num_coefs == 16 ) + { + memcpy( orig_coefs, dct, sizeof(dctcoef)*16 ); + if( !h->quantf.quant_4x4( dct, quant_mf, quant_bias ) ) + return 0; + h->zigzagf.scan_4x4( quant_coefs, dct ); + } + } + + int last_nnz = h->quantf.coeff_last[ctx_block_cat]( quant_coefs+b_ac )+b_ac; + uint8_t *cabac_state = &h->cabac.state[ x264_coeff_abs_level_m1_offset[ctx_block_cat] ]; + + /* shortcut for dc-only blocks. + * this doesn't affect the output, but saves some unnecessary computation. */ + if( last_nnz == 0 && !dc ) + { + int cost_sig = x264_cabac_size_decision_noup2( &cabac_state_sig[0], 1 ) + + x264_cabac_size_decision_noup2( &cabac_state_last[0], 1 ); + dct[0] = trellis_dc_shortcut( orig_coefs[0], quant_coefs[0], unquant_mf[0], coef_weight2[0], lambda2, cabac_state, cost_sig ); + return !!dct[0]; + } + +#if HAVE_MMX && ARCH_X86_64 +#define TRELLIS_ARGS unquant_mf, zigzag, lambda2, last_nnz, orig_coefs, quant_coefs, dct,\ + cabac_state_sig, cabac_state_last, M64(cabac_state), M16(cabac_state+8) + if( num_coefs == 16 && !dc ) + if( b_chroma || !h->mb.i_psy_trellis ) + return h->quantf.trellis_cabac_4x4( TRELLIS_ARGS, b_ac ); + else + return h->quantf.trellis_cabac_4x4_psy( TRELLIS_ARGS, b_ac, h->mb.pic.fenc_dct4[idx&15], h->mb.i_psy_trellis ); + else if( num_coefs == 64 && !dc ) + if( b_chroma || !h->mb.i_psy_trellis ) + return h->quantf.trellis_cabac_8x8( TRELLIS_ARGS, b_interlaced ); + else + return h->quantf.trellis_cabac_8x8_psy( TRELLIS_ARGS, b_interlaced, h->mb.pic.fenc_dct8[idx&3], h->mb.i_psy_trellis); + else if( num_coefs == 8 && dc ) + return h->quantf.trellis_cabac_chroma_422_dc( TRELLIS_ARGS ); + else if( dc ) + return h->quantf.trellis_cabac_dc( TRELLIS_ARGS, num_coefs-1 ); +#endif + + // (# of coefs) * (# of ctx) * (# of levels tried) = 1024 + // we don't need to keep all of those: (# of coefs) * (# of ctx) would be enough, + // but it takes more time to remove dead states than you gain in reduced memory. + trellis_level_t level_tree[64*8*2]; + int levels_used = 1; + /* init trellis */ + trellis_node_t nodes[2][8]; + trellis_node_t *nodes_cur = nodes[0]; + trellis_node_t *nodes_prev = nodes[1]; + trellis_node_t *bnode; + for( int j = 1; j < 4; j++ ) nodes_cur[j].score = TRELLIS_SCORE_MAX; - nodes_cur[0].score = 0; + nodes_cur[0].score = TRELLIS_SCORE_BIAS; nodes_cur[0].level_idx = 0; level_tree[0].abs_level = 0; level_tree[0].next = 0; + ALIGNED_4( uint8_t level_state[16] ); + memcpy( level_state, cabac_state, 10 ); + level_state[12] = cabac_state[0]; // packed subset for copying into trellis_node_t + level_state[13] = cabac_state[4]; + level_state[14] = cabac_state[8]; + level_state[15] = cabac_state[9]; + + idx &= num_coefs == 64 ? 3 : 15; // coefs are processed in reverse order, because that's how the abs value is coded. // last_coef and significant_coef flags are normally coded in forward order, but @@ -469,190 +746,421 @@ static ALWAYS_INLINE int quant_trellis_cabac( x264_t *h, int16_t *dct, // position, so the order doesn't matter, and we don't even have to update their contexts. // in 8x8 blocks, some positions share contexts, so we'll just have to hope that // cabac isn't too sensitive. + int i = last_nnz; +#define TRELLIS_LOOP(ctx_hi)\ + for( ; i >= b_ac; i-- )\ + {\ + /* skip 0s: this doesn't affect the output, but saves some unnecessary computation. */\ + if( !quant_coefs[i] )\ + {\ + /* no need to calculate ssd of 0s: it's the same in all nodes.\ + * no need to modify level_tree for ctx=0: it starts with an infinite loop of 0s. + * subtracting from one score is equivalent to adding to the rest. */\ + if( !ctx_hi )\ + {\ + int sigindex = !dc && num_coefs == 64 ? x264_significant_coeff_flag_offset_8x8[b_interlaced][i] :\ + b_chroma && dc && num_coefs == 8 ? x264_coeff_flag_offset_chroma_422_dc[i] : i;\ + uint64_t cost_sig0 = x264_cabac_size_decision_noup2( &cabac_state_sig[sigindex], 0 )\ + * (uint64_t)lambda2 >> ( CABAC_SIZE_BITS - LAMBDA_BITS );\ + nodes_cur[0].score -= cost_sig0;\ + }\ + for( int j = 1; j < (ctx_hi?8:4); j++ )\ + SET_LEVEL( nodes_cur[j], nodes_cur[j], 0 );\ + continue;\ + }\ +\ + int sign_coef = orig_coefs[zigzag[i]];\ + int abs_coef = abs( sign_coef );\ + int q = abs( quant_coefs[i] );\ + int cost_siglast[3]; /* { zero, nonzero, nonzero-and-last } */\ + XCHG( trellis_node_t*, nodes_cur, nodes_prev );\ + for( int j = ctx_hi; j < 8; j++ )\ + nodes_cur[j].score = TRELLIS_SCORE_MAX;\ +\ + if( i < num_coefs-1 || ctx_hi )\ + {\ + int sigindex = !dc && num_coefs == 64 ? x264_significant_coeff_flag_offset_8x8[b_interlaced][i] :\ + b_chroma && dc && num_coefs == 8 ? x264_coeff_flag_offset_chroma_422_dc[i] : i;\ + int lastindex = !dc && num_coefs == 64 ? x264_last_coeff_flag_offset_8x8[i] :\ + b_chroma && dc && num_coefs == 8 ? x264_coeff_flag_offset_chroma_422_dc[i] : i;\ + cost_siglast[0] = x264_cabac_size_decision_noup2( &cabac_state_sig[sigindex], 0 );\ + int cost_sig1 = x264_cabac_size_decision_noup2( &cabac_state_sig[sigindex], 1 );\ + cost_siglast[1] = x264_cabac_size_decision_noup2( &cabac_state_last[lastindex], 0 ) + cost_sig1;\ + if( !ctx_hi )\ + cost_siglast[2] = x264_cabac_size_decision_noup2( &cabac_state_last[lastindex], 1 ) + cost_sig1;\ + }\ + else\ + {\ + cost_siglast[0] = cost_siglast[1] = cost_siglast[2] = 0;\ + }\ +\ + /* there are a few cases where increasing the coeff magnitude helps,\ + * but it's only around .003 dB, and skipping them ~doubles the speed of trellis.\ + * could also try q-2: that sometimes helps, but also sometimes decimates blocks\ + * that are better left coded, especially at QP > 40. */\ + uint64_t ssd0[2], ssd1[2];\ + for( int k = 0; k < 2; k++ )\ + {\ + int abs_level = q-1+k;\ + int unquant_abs_level = (((dc?unquant_mf[0]<<1:unquant_mf[zigzag[i]]) * abs_level + 128) >> 8);\ + int d = abs_coef - unquant_abs_level;\ + /* Psy trellis: bias in favor of higher AC coefficients in the reconstructed frame. */\ + if( h->mb.i_psy_trellis && i && !dc && !b_chroma )\ + {\ + int orig_coef = (num_coefs == 64) ? h->mb.pic.fenc_dct8[idx][zigzag[i]] : h->mb.pic.fenc_dct4[idx][zigzag[i]];\ + int predicted_coef = orig_coef - sign_coef;\ + int psy_value = abs(unquant_abs_level + SIGN(predicted_coef, sign_coef));\ + int psy_weight = coef_weight1[zigzag[i]] * h->mb.i_psy_trellis;\ + ssd1[k] = (uint64_t)d*d * coef_weight2[zigzag[i]] - psy_weight * psy_value;\ + }\ + else\ + /* FIXME: for i16x16 dc is this weight optimal? */\ + ssd1[k] = (uint64_t)d*d * (dc?256:coef_weight2[zigzag[i]]);\ + ssd0[k] = ssd1[k];\ + if( !i && !dc && !ctx_hi )\ + {\ + /* Optimize rounding for DC coefficients in DC-only luma 4x4/8x8 blocks. */\ + d = sign_coef - ((SIGN(unquant_abs_level, sign_coef) + 8)&~15);\ + ssd0[k] = (uint64_t)d*d * coef_weight2[zigzag[i]];\ + }\ + }\ +\ + /* argument passing imposes some significant overhead here. gcc's interprocedural register allocation isn't up to it. */\ + switch( q )\ + {\ + case 1:\ + ssd1[0] += (uint64_t)cost_siglast[0] * lambda2 >> ( CABAC_SIZE_BITS - LAMBDA_BITS );\ + levels_used = trellis_coef0_##ctx_hi( ssd0[0]-ssd1[0], nodes_cur, nodes_prev, level_tree, levels_used );\ + levels_used = trellis_coef1_##ctx_hi( ssd0[1]-ssd1[0], ssd1[1]-ssd1[0], cost_siglast, nodes_cur, nodes_prev, level_tree, levels_used, lambda2, level_state );\ + goto next##ctx_hi;\ + case 2:\ + levels_used = trellis_coef1_##ctx_hi( ssd0[0], ssd1[0], cost_siglast, nodes_cur, nodes_prev, level_tree, levels_used, lambda2, level_state );\ + levels_used = trellis_coefn_##ctx_hi( q, ssd0[1], ssd1[1], cost_siglast, nodes_cur, nodes_prev, level_tree, levels_used, lambda2, level_state, levelgt1_ctx );\ + goto next1;\ + default:\ + levels_used = trellis_coefn_##ctx_hi( q-1, ssd0[0], ssd1[0], cost_siglast, nodes_cur, nodes_prev, level_tree, levels_used, lambda2, level_state, levelgt1_ctx );\ + levels_used = trellis_coefn_##ctx_hi( q, ssd0[1], ssd1[1], cost_siglast, nodes_cur, nodes_prev, level_tree, levels_used, lambda2, level_state, levelgt1_ctx );\ + goto next1;\ + }\ + next##ctx_hi:;\ + }\ + /* output levels from the best path through the trellis */\ + bnode = &nodes_cur[ctx_hi];\ + for( int j = ctx_hi+1; j < (ctx_hi?8:4); j++ )\ + if( nodes_cur[j].score < bnode->score )\ + bnode = &nodes_cur[j]; - memcpy( nodes_cur[0].cabac_state, &h->cabac.state[ coeff_abs_level_m1_offset[i_ctxBlockCat] ], 10 ); + // keep 2 versions of the main quantization loop, depending on which subsets of the node_ctxs are live + // node_ctx 0..3, i.e. having not yet encountered any coefs that might be quantized to >1 + TRELLIS_LOOP(0); - for( i = i_last_nnz; i >= b_ac; i-- ) + if( bnode == &nodes_cur[0] ) { - int i_coef = abs_coefs[i]; - int q = ( f + i_coef * (dc?quant_mf[0]>>1:quant_mf[zigzag[i]]) ) >> 16; - int cost_sig[2], cost_last[2]; - trellis_node_t n; + /* We only need to zero an empty 4x4 block. 8x8 can be + implicitly emptied via zero nnz, as can dc. */ + if( num_coefs == 16 && !dc ) + memset( dct, 0, 16 * sizeof(dctcoef) ); + return 0; + } - // skip 0s: this doesn't affect the output, but saves some unnecessary computation. - if( q == 0 ) - { - // no need to calculate ssd of 0s: it's the same in all nodes. - // no need to modify level_tree for ctx=0: it starts with an infinite loop of 0s. - int sigindex = i_coefs == 64 ? significant_coeff_flag_offset_8x8[b_interlaced][i] : i; - const uint32_t cost_sig0 = x264_cabac_size_decision_noup2( &cabac_state_sig[sigindex], 0 ) - * (uint64_t)i_lambda2 >> ( CABAC_SIZE_BITS - LAMBDA_BITS ); - for( int j = 1; j < 8; j++ ) - { - if( nodes_cur[j].score != TRELLIS_SCORE_MAX ) - { -#define SET_LEVEL(n,l) \ - level_tree[i_levels_used].abs_level = l; \ - level_tree[i_levels_used].next = n.level_idx; \ - n.level_idx = i_levels_used; \ - i_levels_used++; - - SET_LEVEL( nodes_cur[j], 0 ); - nodes_cur[j].score += cost_sig0; - } - } - continue; - } + if(0) // accessible only by goto, not fallthrough + { + // node_ctx 1..7 (ctx0 ruled out because we never try both level0 and level2+ on the same coef) + TRELLIS_LOOP(1); + } - XCHG( trellis_node_t*, nodes_cur, nodes_prev ); + int level = bnode->level_idx; + for( i = b_ac; i <= last_nnz; i++ ) + { + dct[zigzag[i]] = SIGN(level_tree[level].abs_level, dct[zigzag[i]]); + level = level_tree[level].next; + } - for( int j = 0; j < 8; j++ ) - nodes_cur[j].score = TRELLIS_SCORE_MAX; + return 1; +} - if( i < i_coefs-1 ) - { - int sigindex = i_coefs == 64 ? significant_coeff_flag_offset_8x8[b_interlaced][i] : i; - int lastindex = i_coefs == 64 ? last_coeff_flag_offset_8x8[i] : i; - cost_sig[0] = x264_cabac_size_decision_noup2( &cabac_state_sig[sigindex], 0 ); - cost_sig[1] = x264_cabac_size_decision_noup2( &cabac_state_sig[sigindex], 1 ); - cost_last[0] = x264_cabac_size_decision_noup2( &cabac_state_last[lastindex], 0 ); - cost_last[1] = x264_cabac_size_decision_noup2( &cabac_state_last[lastindex], 1 ); - } - else - { - cost_sig[0] = cost_sig[1] = 0; - cost_last[0] = cost_last[1] = 0; - } +/* FIXME: This is a gigantic hack. See below. + * + * CAVLC is much more difficult to trellis than CABAC. + * + * CABAC has only three states to track: significance map, last, and the + * level state machine. + * CAVLC, by comparison, has five: coeff_token (trailing + total), + * total_zeroes, zero_run, and the level state machine. + * + * I know of no paper that has managed to design a close-to-optimal trellis + * that covers all five of these and isn't exponential-time. As a result, this + * "trellis" isn't: it's just a QNS search. Patches welcome for something better. + * It's actually surprisingly fast, albeit not quite optimal. It's pretty close + * though; since CAVLC only has 2^16 possible rounding modes (assuming only two + * roundings as options), a bruteforce search is feasible. Testing shows + * that this QNS is reasonably close to optimal in terms of compression. + * + * TODO: + * Don't bother changing large coefficients when it wouldn't affect bit cost + * (e.g. only affecting bypassed suffix bits). + * Don't re-run all parts of CAVLC bit cost calculation when not necessary. + * e.g. when changing a coefficient from one non-zero value to another in + * such a way that trailing ones and suffix length isn't affected. */ +static ALWAYS_INLINE +int quant_trellis_cavlc( x264_t *h, dctcoef *dct, + const udctcoef *quant_mf, const int *unquant_mf, + const uint8_t *zigzag, int ctx_block_cat, int lambda2, int b_ac, + int b_chroma, int dc, int num_coefs, int idx, int b_8x8 ) +{ + ALIGNED_16( dctcoef quant_coefs[2][16] ); + ALIGNED_16( dctcoef coefs[16] ) = {0}; + const uint32_t *coef_weight1 = b_8x8 ? x264_dct8_weight_tab : x264_dct4_weight_tab; + const uint32_t *coef_weight2 = b_8x8 ? x264_dct8_weight2_tab : x264_dct4_weight2_tab; + int delta_distortion[16]; + int64_t score = 1ULL<<62; + int i, j; + const int f = 1<<15; + int nC = b_chroma && dc ? 3 + (num_coefs>>2) + : ct_index[x264_mb_predict_non_zero_code( h, !b_chroma && dc ? (idx - LUMA_DC)*16 : idx )]; + + /* Code for handling 8x8dct -> 4x4dct CAVLC munging. Input/output use a different + * step/start/end than internal processing. */ + int step = 1; + int start = b_ac; + int end = num_coefs - 1; + if( b_8x8 ) + { + start = idx&3; + end = 60 + start; + step = 4; + } + idx &= 15; + + lambda2 <<= LAMBDA_BITS; - // there are a few cases where increasing the coeff magnitude helps, - // but it's only around .003 dB, and skipping them ~doubles the speed of trellis. - // could also try q-2: that sometimes helps, but also sometimes decimates blocks - // that are better left coded, especially at QP > 40. - for( int abs_level = q; abs_level >= q-1; abs_level-- ) + /* Find last non-zero coefficient. */ + for( i = end; i >= start; i -= step ) + if( (unsigned)(dct[zigzag[i]] * (dc?quant_mf[0]>>1:quant_mf[zigzag[i]]) + f-1) >= 2*f ) + break; + + if( i < start ) + goto zeroblock; + + /* Prepare for QNS search: calculate distortion caused by each DCT coefficient + * rounding to be searched. + * + * We only search two roundings (nearest and nearest-1) like in CABAC trellis, + * so we just store the difference in distortion between them. */ + int last_nnz = b_8x8 ? i >> 2 : i; + int coef_mask = 0; + int round_mask = 0; + for( i = b_ac, j = start; i <= last_nnz; i++, j += step ) + { + int coef = dct[zigzag[j]]; + int abs_coef = abs(coef); + int sign = coef < 0 ? -1 : 1; + int nearest_quant = ( f + abs_coef * (dc?quant_mf[0]>>1:quant_mf[zigzag[j]]) ) >> 16; + quant_coefs[1][i] = quant_coefs[0][i] = sign * nearest_quant; + coefs[i] = quant_coefs[1][i]; + if( nearest_quant ) { - int unquant_abs_level = (((dc?unquant_mf[0]<<1:unquant_mf[zigzag[i]]) * abs_level + 128) >> 8); - int d = i_coef - unquant_abs_level; - int64_t ssd; + /* We initialize the trellis with a deadzone halfway between nearest rounding + * and always-round-down. This gives much better results than initializing to either + * extreme. + * FIXME: should we initialize to the deadzones used by deadzone quant? */ + int deadzone_quant = ( f/2 + abs_coef * (dc?quant_mf[0]>>1:quant_mf[zigzag[j]]) ) >> 16; + int unquant1 = (((dc?unquant_mf[0]<<1:unquant_mf[zigzag[j]]) * (nearest_quant-0) + 128) >> 8); + int unquant0 = (((dc?unquant_mf[0]<<1:unquant_mf[zigzag[j]]) * (nearest_quant-1) + 128) >> 8); + int d1 = abs_coef - unquant1; + int d0 = abs_coef - unquant0; + delta_distortion[i] = (d0*d0 - d1*d1) * (dc?256:coef_weight2[zigzag[j]]); + /* Psy trellis: bias in favor of higher AC coefficients in the reconstructed frame. */ - if( h->mb.i_psy_trellis && i && !dc && i_ctxBlockCat != DCT_CHROMA_AC ) + if( h->mb.i_psy_trellis && j && !dc && !b_chroma ) { - int orig_coef = (i_coefs == 64) ? h->mb.pic.fenc_dct8[idx][zigzag[i]] : h->mb.pic.fenc_dct4[idx][zigzag[i]]; - int predicted_coef = orig_coef - i_coef * signs[i]; - int psy_value = h->mb.i_psy_trellis * abs(predicted_coef + unquant_abs_level * signs[i]); - int psy_weight = (i_coefs == 64) ? x264_dct8_weight_tab[zigzag[i]] : x264_dct4_weight_tab[zigzag[i]]; - ssd = (int64_t)d*d * coef_weight[i] - psy_weight * psy_value; + int orig_coef = b_8x8 ? h->mb.pic.fenc_dct8[idx>>2][zigzag[j]] : h->mb.pic.fenc_dct4[idx][zigzag[j]]; + int predicted_coef = orig_coef - coef; + int psy_weight = coef_weight1[zigzag[j]]; + int psy_value0 = h->mb.i_psy_trellis * abs(predicted_coef + unquant0 * sign); + int psy_value1 = h->mb.i_psy_trellis * abs(predicted_coef + unquant1 * sign); + delta_distortion[i] += (psy_value0 - psy_value1) * psy_weight; } + + quant_coefs[0][i] = sign * (nearest_quant-1); + if( deadzone_quant != nearest_quant ) + coefs[i] = quant_coefs[0][i]; else - /* FIXME: for i16x16 dc is this weight optimal? */ - ssd = (int64_t)d*d * (dc?256:coef_weight[i]); + round_mask |= 1 << i; + } + else + delta_distortion[i] = 0; + coef_mask |= (!!coefs[i]) << i; + } + + /* Calculate the cost of the starting state. */ + h->out.bs.i_bits_encoded = 0; + if( !coef_mask ) + bs_write_vlc( &h->out.bs, x264_coeff0_token[nC] ); + else + x264_cavlc_block_residual_internal( h, ctx_block_cat, coefs + b_ac, nC ); + score = (int64_t)h->out.bs.i_bits_encoded * lambda2; - for( int j = 0; j < 8; j++ ) + /* QNS loop: pick the change that improves RD the most, apply it, repeat. + * coef_mask and round_mask are used to simplify tracking of nonzeroness + * and rounding modes chosen. */ + while( 1 ) + { + int64_t iter_score = score; + int iter_distortion_delta = 0; + int iter_coef = -1; + int iter_mask = coef_mask; + int iter_round = round_mask; + for( i = b_ac; i <= last_nnz; i++ ) + { + if( !delta_distortion[i] ) + continue; + + /* Set up all the variables for this iteration. */ + int cur_round = round_mask ^ (1 << i); + int round_change = (cur_round >> i)&1; + int old_coef = coefs[i]; + int new_coef = quant_coefs[round_change][i]; + int cur_mask = (coef_mask&~(1 << i))|(!!new_coef << i); + int cur_distortion_delta = delta_distortion[i] * (round_change ? -1 : 1); + int64_t cur_score = cur_distortion_delta; + coefs[i] = new_coef; + + /* Count up bits. */ + h->out.bs.i_bits_encoded = 0; + if( !cur_mask ) + bs_write_vlc( &h->out.bs, x264_coeff0_token[nC] ); + else + x264_cavlc_block_residual_internal( h, ctx_block_cat, coefs + b_ac, nC ); + cur_score += (int64_t)h->out.bs.i_bits_encoded * lambda2; + + coefs[i] = old_coef; + if( cur_score < iter_score ) { - int node_ctx = j; - if( nodes_prev[j].score == TRELLIS_SCORE_MAX ) - continue; - n = nodes_prev[j]; - - /* code the proposed level, and count how much entropy it would take */ - if( abs_level || node_ctx ) - { - unsigned f8_bits = cost_sig[ abs_level != 0 ]; - if( abs_level ) - { - const int i_prefix = X264_MIN( abs_level - 1, 14 ); - f8_bits += cost_last[ node_ctx == 0 ]; - f8_bits += x264_cabac_size_decision2( &n.cabac_state[coeff_abs_level1_ctx[node_ctx]], i_prefix > 0 ); - if( i_prefix > 0 ) - { - uint8_t *ctx = &n.cabac_state[coeff_abs_levelgt1_ctx[node_ctx]]; - f8_bits += cabac_size_unary[i_prefix][*ctx]; - *ctx = cabac_transition_unary[i_prefix][*ctx]; - if( abs_level >= 15 ) - f8_bits += bs_size_ue_big( abs_level - 15 ) << CABAC_SIZE_BITS; - node_ctx = coeff_abs_level_transition[1][node_ctx]; - } - else - { - f8_bits += 1 << CABAC_SIZE_BITS; - node_ctx = coeff_abs_level_transition[0][node_ctx]; - } - } - n.score += (uint64_t)f8_bits * i_lambda2 >> ( CABAC_SIZE_BITS - LAMBDA_BITS ); - } - - if( j || i || dc ) - n.score += ssd; - /* Optimize rounding for DC coefficients in DC-only luma 4x4/8x8 blocks. */ - else - { - d = i_coef * signs[0] - ((unquant_abs_level * signs[0] + 8)&~15); - n.score += (int64_t)d*d * coef_weight[i]; - } - - /* save the node if it's better than any existing node with the same cabac ctx */ - if( n.score < nodes_cur[node_ctx].score ) - { - SET_LEVEL( n, abs_level ); - nodes_cur[node_ctx] = n; - } + iter_score = cur_score; + iter_coef = i; + iter_mask = cur_mask; + iter_round = cur_round; + iter_distortion_delta = cur_distortion_delta; } } + if( iter_coef >= 0 ) + { + score = iter_score - iter_distortion_delta; + coef_mask = iter_mask; + round_mask = iter_round; + coefs[iter_coef] = quant_coefs[((round_mask >> iter_coef)&1)][iter_coef]; + /* Don't try adjusting coefficients we've already adjusted. + * Testing suggests this doesn't hurt results -- and sometimes actually helps. */ + delta_distortion[iter_coef] = 0; + } + else + break; } - /* output levels from the best path through the trellis */ - bnode = &nodes_cur[0]; - for( int j = 1; j < 8; j++ ) - if( nodes_cur[j].score < bnode->score ) - bnode = &nodes_cur[j]; - - if( bnode == &nodes_cur[0] ) + if( coef_mask ) { - if( i_coefs == 16 && !dc ) - memset( dct, 0, 16 * sizeof(int16_t) ); - return 0; + for( i = b_ac, j = start; i < num_coefs; i++, j += step ) + dct[zigzag[j]] = coefs[i]; + return 1; } - int level = bnode->level_idx; - for( i = b_ac; level; i++ ) +zeroblock: + if( !dc ) { - dct[zigzag[i]] = level_tree[level].abs_level * signs[i]; - level = level_tree[level].next; + if( b_8x8 ) + for( i = start; i <= end; i+=step ) + dct[zigzag[i]] = 0; + else + memset( dct, 0, 16*sizeof(dctcoef) ); } - for( ; i < i_coefs; i++ ) - dct[zigzag[i]] = 0; + return 0; +} - return 1; +int x264_quant_luma_dc_trellis( x264_t *h, dctcoef *dct, int i_quant_cat, int i_qp, int ctx_block_cat, int b_intra, int idx ) +{ + if( h->param.b_cabac ) + return quant_trellis_cabac( h, dct, + h->quant4_mf[i_quant_cat][i_qp], h->quant4_bias0[i_quant_cat][i_qp], + h->unquant4_mf[i_quant_cat][i_qp], x264_zigzag_scan4[MB_INTERLACED], + ctx_block_cat, h->mb.i_trellis_lambda2[0][b_intra], 0, 0, 1, 16, idx ); + + return quant_trellis_cavlc( h, dct, + h->quant4_mf[i_quant_cat][i_qp], h->unquant4_mf[i_quant_cat][i_qp], x264_zigzag_scan4[MB_INTERLACED], + DCT_LUMA_DC, h->mb.i_trellis_lambda2[0][b_intra], 0, 0, 1, 16, idx, 0 ); } -const static uint8_t x264_zigzag_scan2[4] = {0,1,2,3}; +static const uint8_t x264_zigzag_scan2x2[4] = { 0, 1, 2, 3 }; +static const uint8_t x264_zigzag_scan2x4[8] = { 0, 2, 1, 4, 6, 3, 5, 7 }; -int x264_quant_dc_trellis( x264_t *h, int16_t *dct, int i_quant_cat, - int i_qp, int i_ctxBlockCat, int b_intra, int b_chroma ) +int x264_quant_chroma_dc_trellis( x264_t *h, dctcoef *dct, int i_qp, int b_intra, int idx ) { - return quant_trellis_cabac( h, dct, - h->quant4_mf[i_quant_cat][i_qp], h->unquant4_mf[i_quant_cat][i_qp], - NULL, i_ctxBlockCat==DCT_CHROMA_DC ? x264_zigzag_scan2 : x264_zigzag_scan4[h->mb.b_interlaced], - i_ctxBlockCat, h->mb.i_trellis_lambda2[b_chroma][b_intra], 0, 1, i_ctxBlockCat==DCT_CHROMA_DC ? 4 : 16, 0 ); + const uint8_t *zigzag; + int num_coefs; + int quant_cat = CQM_4IC+1 - b_intra; + + if( CHROMA_FORMAT == CHROMA_422 ) + { + zigzag = x264_zigzag_scan2x4; + num_coefs = 8; + } + else + { + zigzag = x264_zigzag_scan2x2; + num_coefs = 4; + } + + if( h->param.b_cabac ) + return quant_trellis_cabac( h, dct, + h->quant4_mf[quant_cat][i_qp], h->quant4_bias0[quant_cat][i_qp], + h->unquant4_mf[quant_cat][i_qp], zigzag, + DCT_CHROMA_DC, h->mb.i_trellis_lambda2[1][b_intra], 0, 1, 1, num_coefs, idx ); + + return quant_trellis_cavlc( h, dct, + h->quant4_mf[quant_cat][i_qp], h->unquant4_mf[quant_cat][i_qp], zigzag, + DCT_CHROMA_DC, h->mb.i_trellis_lambda2[1][b_intra], 0, 1, 1, num_coefs, idx, 0 ); } -int x264_quant_4x4_trellis( x264_t *h, int16_t *dct, int i_quant_cat, - int i_qp, int i_ctxBlockCat, int b_intra, int b_chroma, int idx ) +int x264_quant_4x4_trellis( x264_t *h, dctcoef *dct, int i_quant_cat, + int i_qp, int ctx_block_cat, int b_intra, int b_chroma, int idx ) { - int b_ac = (i_ctxBlockCat == DCT_LUMA_AC || i_ctxBlockCat == DCT_CHROMA_AC); - return quant_trellis_cabac( h, dct, - h->quant4_mf[i_quant_cat][i_qp], h->unquant4_mf[i_quant_cat][i_qp], - x264_dct4_weight2_zigzag[h->mb.b_interlaced], - x264_zigzag_scan4[h->mb.b_interlaced], - i_ctxBlockCat, h->mb.i_trellis_lambda2[b_chroma][b_intra], b_ac, 0, 16, idx ); + static const uint8_t ctx_ac[14] = {0,1,0,0,1,0,0,1,0,0,0,1,0,0}; + int b_ac = ctx_ac[ctx_block_cat]; + if( h->param.b_cabac ) + return quant_trellis_cabac( h, dct, + h->quant4_mf[i_quant_cat][i_qp], h->quant4_bias0[i_quant_cat][i_qp], + h->unquant4_mf[i_quant_cat][i_qp], x264_zigzag_scan4[MB_INTERLACED], + ctx_block_cat, h->mb.i_trellis_lambda2[b_chroma][b_intra], b_ac, b_chroma, 0, 16, idx ); + + return quant_trellis_cavlc( h, dct, + h->quant4_mf[i_quant_cat][i_qp], h->unquant4_mf[i_quant_cat][i_qp], + x264_zigzag_scan4[MB_INTERLACED], + ctx_block_cat, h->mb.i_trellis_lambda2[b_chroma][b_intra], b_ac, b_chroma, 0, 16, idx, 0 ); } -int x264_quant_8x8_trellis( x264_t *h, int16_t *dct, int i_quant_cat, - int i_qp, int b_intra, int idx ) +int x264_quant_8x8_trellis( x264_t *h, dctcoef *dct, int i_quant_cat, + int i_qp, int ctx_block_cat, int b_intra, int b_chroma, int idx ) { - return quant_trellis_cabac( h, dct, - h->quant8_mf[i_quant_cat][i_qp], h->unquant8_mf[i_quant_cat][i_qp], - x264_dct8_weight2_zigzag[h->mb.b_interlaced], - x264_zigzag_scan8[h->mb.b_interlaced], - DCT_LUMA_8x8, h->mb.i_trellis_lambda2[0][b_intra], 0, 0, 64, idx ); -} + if( h->param.b_cabac ) + { + return quant_trellis_cabac( h, dct, + h->quant8_mf[i_quant_cat][i_qp], h->quant8_bias0[i_quant_cat][i_qp], + h->unquant8_mf[i_quant_cat][i_qp], x264_zigzag_scan8[MB_INTERLACED], + ctx_block_cat, h->mb.i_trellis_lambda2[b_chroma][b_intra], 0, b_chroma, 0, 64, idx ); + } + /* 8x8 CAVLC is split into 4 4x4 blocks */ + int nzaccum = 0; + for( int i = 0; i < 4; i++ ) + { + int nz = quant_trellis_cavlc( h, dct, + h->quant8_mf[i_quant_cat][i_qp], h->unquant8_mf[i_quant_cat][i_qp], + x264_zigzag_scan8[MB_INTERLACED], + DCT_LUMA_4x4, h->mb.i_trellis_lambda2[b_chroma][b_intra], 0, b_chroma, 0, 16, idx*4+i, 1 ); + /* Set up nonzero count for future calls */ + h->mb.cache.non_zero_count[x264_scan8[idx*4+i]] = nz; + nzaccum |= nz; + } + STORE_8x8_NNZ( 0, idx, 0 ); + return nzaccum; +}