libavcodec/h264.h

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/*
 * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef AVCODEC_H264_H
#define AVCODEC_H264_H

#include "libavutil/intreadwrite.h"
#include "dsputil.h"
#include "cabac.h"
#include "mpegvideo.h"
#include "h264dsp.h"
#include "h264pred.h"
#include "rectangle.h"

#define interlaced_dct interlaced_dct_is_a_bad_name
#define mb_intra mb_intra_is_not_initialized_see_mb_type

#define MAX_SPS_COUNT 32
#define MAX_PPS_COUNT 256

#define MAX_MMCO_COUNT 66

#define MAX_DELAYED_PIC_COUNT 16

#define MAX_MBPAIR_SIZE (256*1024) // a tighter bound could be calculated if someone cares about a few bytes

/* Compiling in interlaced support reduces the speed
 * of progressive decoding by about 2%. */
#define ALLOW_INTERLACE

#define FMO 0

#define MAX_SLICES 16

#ifdef ALLOW_INTERLACE
#define MB_MBAFF h->mb_mbaff
#define MB_FIELD h->mb_field_decoding_flag
#define FRAME_MBAFF h->mb_aff_frame
#define FIELD_PICTURE (s->picture_structure != PICT_FRAME)
#define LEFT_MBS 2
#define LTOP 0
#define LBOT 1
#define LEFT(i) (i)
#else
#define MB_MBAFF 0
#define MB_FIELD 0
#define FRAME_MBAFF 0
#define FIELD_PICTURE 0
#undef  IS_INTERLACED
#define IS_INTERLACED(mb_type) 0
#define LEFT_MBS 1
#define LTOP 0
#define LBOT 0
#define LEFT(i) 0
#endif
#define FIELD_OR_MBAFF_PICTURE (FRAME_MBAFF || FIELD_PICTURE)

#ifndef CABAC
#define CABAC h->pps.cabac
#endif

#define CHROMA422 (h->sps.chroma_format_idc == 2)
#define CHROMA444 (h->sps.chroma_format_idc == 3)

#define EXTENDED_SAR          255

#define MB_TYPE_REF0       MB_TYPE_ACPRED //dirty but it fits in 16 bit
#define MB_TYPE_8x8DCT     0x01000000
#define IS_REF0(a)         ((a) & MB_TYPE_REF0)
#define IS_8x8DCT(a)       ((a) & MB_TYPE_8x8DCT)

#define DELAYED_PIC_REF 4

#define QP_MAX_NUM (51 + 4*6)           // The maximum supported qp

/* NAL unit types */
enum {
    NAL_SLICE=1,
    NAL_DPA,
    NAL_DPB,
    NAL_DPC,
    NAL_IDR_SLICE,
    NAL_SEI,
    NAL_SPS,
    NAL_PPS,
    NAL_AUD,
    NAL_END_SEQUENCE,
    NAL_END_STREAM,
    NAL_FILLER_DATA,
    NAL_SPS_EXT,
    NAL_AUXILIARY_SLICE=19
};

typedef enum {
    SEI_BUFFERING_PERIOD             =  0, 
    SEI_TYPE_PIC_TIMING              =  1, 
    SEI_TYPE_USER_DATA_UNREGISTERED  =  5, 
    SEI_TYPE_RECOVERY_POINT          =  6  
} SEI_Type;

typedef enum {
    SEI_PIC_STRUCT_FRAME             = 0, 
    SEI_PIC_STRUCT_TOP_FIELD         = 1, 
    SEI_PIC_STRUCT_BOTTOM_FIELD      = 2, 
    SEI_PIC_STRUCT_TOP_BOTTOM        = 3, 
    SEI_PIC_STRUCT_BOTTOM_TOP        = 4, 
    SEI_PIC_STRUCT_TOP_BOTTOM_TOP    = 5, 
    SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM = 6, 
    SEI_PIC_STRUCT_FRAME_DOUBLING    = 7, 
    SEI_PIC_STRUCT_FRAME_TRIPLING    = 8  
} SEI_PicStructType;

typedef struct SPS{

    int profile_idc;
    int level_idc;
    int chroma_format_idc;
    int transform_bypass;              
    int log2_max_frame_num;            
    int poc_type;                      
    int log2_max_poc_lsb;              
    int delta_pic_order_always_zero_flag;
    int offset_for_non_ref_pic;
    int offset_for_top_to_bottom_field;
    int poc_cycle_length;              
    int ref_frame_count;               
    int gaps_in_frame_num_allowed_flag;
    int mb_width;                      
    int mb_height;                     
    int frame_mbs_only_flag;
    int mb_aff;                        
    int direct_8x8_inference_flag;
    int crop;                   
    unsigned int crop_left;            
    unsigned int crop_right;           
    unsigned int crop_top;             
    unsigned int crop_bottom;          
    int vui_parameters_present_flag;
    AVRational sar;
    int video_signal_type_present_flag;
    int full_range;
    int colour_description_present_flag;
    enum AVColorPrimaries color_primaries;
    enum AVColorTransferCharacteristic color_trc;
    enum AVColorSpace colorspace;
    int timing_info_present_flag;
    uint32_t num_units_in_tick;
    uint32_t time_scale;
    int fixed_frame_rate_flag;
    short offset_for_ref_frame[256]; //FIXME dyn aloc?
    int bitstream_restriction_flag;
    int num_reorder_frames;
    int scaling_matrix_present;
    uint8_t scaling_matrix4[6][16];
    uint8_t scaling_matrix8[6][64];
    int nal_hrd_parameters_present_flag;
    int vcl_hrd_parameters_present_flag;
    int pic_struct_present_flag;
    int time_offset_length;
    int cpb_cnt;                       
    int initial_cpb_removal_delay_length; 
    int cpb_removal_delay_length;      
    int dpb_output_delay_length;       
    int bit_depth_luma;                
    int bit_depth_chroma;              
    int residual_color_transform_flag; 
    int constraint_set_flags;          
}SPS;

typedef struct PPS{
    unsigned int sps_id;
    int cabac;                  
    int pic_order_present;      
    int slice_group_count;      
    int mb_slice_group_map_type;
    unsigned int ref_count[2];  
    int weighted_pred;          
    int weighted_bipred_idc;
    int init_qp;                
    int init_qs;                
    int chroma_qp_index_offset[2];
    int deblocking_filter_parameters_present; 
    int constrained_intra_pred; 
    int redundant_pic_cnt_present; 
    int transform_8x8_mode;     
    uint8_t scaling_matrix4[6][16];
    uint8_t scaling_matrix8[6][64];
    uint8_t chroma_qp_table[2][QP_MAX_NUM+1];  
    int chroma_qp_diff;
}PPS;

typedef enum MMCOOpcode{
    MMCO_END=0,
    MMCO_SHORT2UNUSED,
    MMCO_LONG2UNUSED,
    MMCO_SHORT2LONG,
    MMCO_SET_MAX_LONG,
    MMCO_RESET,
    MMCO_LONG,
} MMCOOpcode;

typedef struct MMCO{
    MMCOOpcode opcode;
    int short_pic_num;  
    int long_arg;       
} MMCO;

typedef struct H264Context{
    MpegEncContext s;
    H264DSPContext h264dsp;
    int pixel_shift;    
    int chroma_qp[2]; //QPc

    int qp_thresh;      

    int prev_mb_skipped;
    int next_mb_skipped;

    //prediction stuff
    int chroma_pred_mode;
    int intra16x16_pred_mode;

    int topleft_mb_xy;
    int top_mb_xy;
    int topright_mb_xy;
    int left_mb_xy[LEFT_MBS];

    int topleft_type;
    int top_type;
    int topright_type;
    int left_type[LEFT_MBS];

    const uint8_t * left_block;
    int topleft_partition;

    int8_t intra4x4_pred_mode_cache[5*8];
    int8_t (*intra4x4_pred_mode);
    H264PredContext hpc;
    unsigned int topleft_samples_available;
    unsigned int top_samples_available;
    unsigned int topright_samples_available;
    unsigned int left_samples_available;
    uint8_t (*top_borders[2])[(16*3)*2];

    DECLARE_ALIGNED(8, uint8_t, non_zero_count_cache)[15*8];

    uint8_t (*non_zero_count)[48];

    DECLARE_ALIGNED(16, int16_t, mv_cache)[2][5*8][2];
    DECLARE_ALIGNED(8, int8_t, ref_cache)[2][5*8];
#define LIST_NOT_USED -1 //FIXME rename?
#define PART_NOT_AVAILABLE -2

    int neighbor_transform_size;

    int block_offset[2*(16*3)];

    uint32_t *mb2b_xy; //FIXME are these 4 a good idea?
    uint32_t *mb2br_xy;
    int b_stride; //FIXME use s->b4_stride

    int mb_linesize;   
    int mb_uvlinesize;

    int emu_edge_width;
    int emu_edge_height;

    SPS sps; 

    PPS pps; //FIXME move to Picture perhaps? (->no) do we need that?

    uint32_t dequant4_buffer[6][QP_MAX_NUM+1][16]; //FIXME should these be moved down?
    uint32_t dequant8_buffer[6][QP_MAX_NUM+1][64];
    uint32_t (*dequant4_coeff[6])[16];
    uint32_t (*dequant8_coeff[6])[64];

    int slice_num;
    uint16_t *slice_table;     
    int slice_type;
    int slice_type_nos;        
    int slice_type_fixed;

    //interlacing specific flags
    int mb_aff_frame;
    int mb_field_decoding_flag;
    int mb_mbaff;              

    DECLARE_ALIGNED(8, uint16_t, sub_mb_type)[4];

    //Weighted pred stuff
    int use_weight;
    int use_weight_chroma;
    int luma_log2_weight_denom;
    int chroma_log2_weight_denom;
    //The following 2 can be changed to int8_t but that causes 10cpu cycles speedloss
    int luma_weight[48][2][2];
    int chroma_weight[48][2][2][2];
    int implicit_weight[48][48][2];

    int direct_spatial_mv_pred;
    int col_parity;
    int col_fieldoff;
    int dist_scale_factor[16];
    int dist_scale_factor_field[2][32];
    int map_col_to_list0[2][16+32];
    int map_col_to_list0_field[2][2][16+32];

    uint8_t *list_counts;            
    unsigned int ref_count[2];   
    unsigned int list_count;
    Picture ref_list[2][48];         
    int ref2frm[MAX_SLICES][2][64];  

    //data partitioning
    GetBitContext intra_gb;
    GetBitContext inter_gb;
    GetBitContext *intra_gb_ptr;
    GetBitContext *inter_gb_ptr;

    DECLARE_ALIGNED(16, DCTELEM, mb)[16*48*2]; 
    DECLARE_ALIGNED(16, DCTELEM, mb_luma_dc)[3][16*2];
    DCTELEM mb_padding[256*2];        

    CABACContext cabac;
    uint8_t      cabac_state[1024];

    /* 0x100 -> non null luma_dc, 0x80/0x40 -> non null chroma_dc (cb/cr), 0x?0 -> chroma_cbp(0,1,2), 0x0? luma_cbp */
    uint16_t     *cbp_table;
    int cbp;
    int top_cbp;
    int left_cbp;
    /* chroma_pred_mode for i4x4 or i16x16, else 0 */
    uint8_t     *chroma_pred_mode_table;
    int         last_qscale_diff;
    uint8_t     (*mvd_table[2])[2];
    DECLARE_ALIGNED(16, uint8_t, mvd_cache)[2][5*8][2];
    uint8_t     *direct_table;
    uint8_t     direct_cache[5*8];

    uint8_t zigzag_scan[16];
    uint8_t zigzag_scan8x8[64];
    uint8_t zigzag_scan8x8_cavlc[64];
    uint8_t field_scan[16];
    uint8_t field_scan8x8[64];
    uint8_t field_scan8x8_cavlc[64];
    const uint8_t *zigzag_scan_q0;
    const uint8_t *zigzag_scan8x8_q0;
    const uint8_t *zigzag_scan8x8_cavlc_q0;
    const uint8_t *field_scan_q0;
    const uint8_t *field_scan8x8_q0;
    const uint8_t *field_scan8x8_cavlc_q0;

    int x264_build;

    int mb_xy;

    int is_complex;

    //deblock
    int deblocking_filter;         
    int slice_alpha_c0_offset;
    int slice_beta_offset;

//=============================================================
    //Things below are not used in the MB or more inner code

    int nal_ref_idc;
    int nal_unit_type;
    uint8_t *rbsp_buffer[2];
    unsigned int rbsp_buffer_size[2];

    int is_avc; 
    int nal_length_size; 
    int got_first; 

    SPS *sps_buffers[MAX_SPS_COUNT];
    PPS *pps_buffers[MAX_PPS_COUNT];

    int dequant_coeff_pps;     

    uint16_t *slice_table_base;


    //POC stuff
    int poc_lsb;
    int poc_msb;
    int delta_poc_bottom;
    int delta_poc[2];
    int frame_num;
    int prev_poc_msb;             
    int prev_poc_lsb;             
    int frame_num_offset;         
    int prev_frame_num_offset;    
    int prev_frame_num;           

    int curr_pic_num;

    int max_pic_num;

    int redundant_pic_count;

    Picture *short_ref[32];
    Picture *long_ref[32];
    Picture default_ref_list[2][32]; 
    Picture *delayed_pic[MAX_DELAYED_PIC_COUNT+2]; //FIXME size?
    int last_pocs[MAX_DELAYED_PIC_COUNT];
    Picture *next_output_pic;
    int outputed_poc;
    int next_outputed_poc;

    MMCO mmco[MAX_MMCO_COUNT];
    int mmco_index;
    int mmco_reset;

    int long_ref_count;  
    int short_ref_count; 

    int          cabac_init_idc;

    struct H264Context *thread_context[MAX_THREADS];

    int current_slice;

    int max_contexts;

    int single_decode_warning;

    int last_slice_type;
    SEI_PicStructType sei_pic_struct;

    int prev_interlaced_frame;

    int sei_ct_type;

    int sei_dpb_output_delay;

    int sei_cpb_removal_delay;

    int sei_recovery_frame_cnt;
    int recovery_frame;

    int luma_weight_flag[2];   
    int chroma_weight_flag[2]; 

    // Timestamp stuff
    int sei_buffering_period_present;  
    int initial_cpb_removal_delay[32]; 

    int cur_chroma_format_idc;

    int16_t slice_row[MAX_SLICES]; 

    int sync;                      

    uint8_t parse_history[4];
    int parse_history_count;
    int parse_last_mb;
}H264Context;


extern const uint8_t ff_h264_chroma_qp[5][QP_MAX_NUM+1]; 

int ff_h264_decode_sei(H264Context *h);

int ff_h264_decode_seq_parameter_set(H264Context *h);

int ff_h264_get_profile(SPS *sps);

int ff_h264_decode_picture_parameter_set(H264Context *h, int bit_length);

const uint8_t *ff_h264_decode_nal(H264Context *h, const uint8_t *src, int *dst_length, int *consumed, int length);

av_cold void ff_h264_free_context(H264Context *h);

int ff_h264_get_slice_type(const H264Context *h);

int ff_h264_alloc_tables(H264Context *h);

int ff_h264_fill_default_ref_list(H264Context *h);

int ff_h264_decode_ref_pic_list_reordering(H264Context *h);
void ff_h264_fill_mbaff_ref_list(H264Context *h);
void ff_h264_remove_all_refs(H264Context *h);

int ff_h264_execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count);

int ff_h264_decode_ref_pic_marking(H264Context *h, GetBitContext *gb);

void ff_generate_sliding_window_mmcos(H264Context *h);


int ff_h264_check_intra4x4_pred_mode(H264Context *h);

int ff_h264_check_intra16x16_pred_mode(H264Context *h, int mode);

int ff_h264_check_intra_chroma_pred_mode(H264Context *h, int mode);

void ff_h264_hl_decode_mb(H264Context *h);
int ff_h264_frame_start(H264Context *h);
int ff_h264_decode_extradata(H264Context *h, const uint8_t *buf, int size);
av_cold int ff_h264_decode_init(AVCodecContext *avctx);
av_cold int ff_h264_decode_end(AVCodecContext *avctx);
av_cold void ff_h264_decode_init_vlc(void);

int ff_h264_decode_mb_cavlc(H264Context *h);

int ff_h264_decode_mb_cabac(H264Context *h);

void ff_h264_init_cabac_states(H264Context *h);

void ff_h264_direct_dist_scale_factor(H264Context * const h);
void ff_h264_direct_ref_list_init(H264Context * const h);
void ff_h264_pred_direct_motion(H264Context * const h, int *mb_type);

void ff_h264_filter_mb_fast( H264Context *h, int mb_x, int mb_y, uint8_t *img_y, uint8_t *img_cb, uint8_t *img_cr, unsigned int linesize, unsigned int uvlinesize);
void ff_h264_filter_mb( H264Context *h, int mb_x, int mb_y, uint8_t *img_y, uint8_t *img_cb, uint8_t *img_cr, unsigned int linesize, unsigned int uvlinesize);

void ff_h264_reset_sei(H264Context *h);


/*
o-o o-o
 / / /
o-o o-o
 ,---'
o-o o-o
 / / /
o-o o-o
*/

/* Scan8 organization:
 *    0 1 2 3 4 5 6 7
 * 0  DY    y y y y y
 * 1        y Y Y Y Y
 * 2        y Y Y Y Y
 * 3        y Y Y Y Y
 * 4        y Y Y Y Y
 * 5  DU    u u u u u
 * 6        u U U U U
 * 7        u U U U U
 * 8        u U U U U
 * 9        u U U U U
 * 10 DV    v v v v v
 * 11       v V V V V
 * 12       v V V V V
 * 13       v V V V V
 * 14       v V V V V
 * DY/DU/DV are for luma/chroma DC.
 */

#define LUMA_DC_BLOCK_INDEX   48
#define CHROMA_DC_BLOCK_INDEX 49

//This table must be here because scan8[constant] must be known at compiletime
static const uint8_t scan8[16*3 + 3]={
 4+ 1*8, 5+ 1*8, 4+ 2*8, 5+ 2*8,
 6+ 1*8, 7+ 1*8, 6+ 2*8, 7+ 2*8,
 4+ 3*8, 5+ 3*8, 4+ 4*8, 5+ 4*8,
 6+ 3*8, 7+ 3*8, 6+ 4*8, 7+ 4*8,
 4+ 6*8, 5+ 6*8, 4+ 7*8, 5+ 7*8,
 6+ 6*8, 7+ 6*8, 6+ 7*8, 7+ 7*8,
 4+ 8*8, 5+ 8*8, 4+ 9*8, 5+ 9*8,
 6+ 8*8, 7+ 8*8, 6+ 9*8, 7+ 9*8,
 4+11*8, 5+11*8, 4+12*8, 5+12*8,
 6+11*8, 7+11*8, 6+12*8, 7+12*8,
 4+13*8, 5+13*8, 4+14*8, 5+14*8,
 6+13*8, 7+13*8, 6+14*8, 7+14*8,
 0+ 0*8, 0+ 5*8, 0+10*8
};

static av_always_inline uint32_t pack16to32(int a, int b){
#if HAVE_BIGENDIAN
   return (b&0xFFFF) + (a<<16);
#else
   return (a&0xFFFF) + (b<<16);
#endif
}

static av_always_inline uint16_t pack8to16(int a, int b){
#if HAVE_BIGENDIAN
   return (b&0xFF) + (a<<8);
#else
   return (a&0xFF) + (b<<8);
#endif
}

static av_always_inline int get_chroma_qp(H264Context *h, int t, int qscale){
    return h->pps.chroma_qp_table[t][qscale];
}

static av_always_inline int pred_intra_mode(H264Context *h, int n){
    const int index8= scan8[n];
    const int left= h->intra4x4_pred_mode_cache[index8 - 1];
    const int top = h->intra4x4_pred_mode_cache[index8 - 8];
    const int min= FFMIN(left, top);

    tprintf(h->s.avctx, "mode:%d %d min:%d\n", left ,top, min);

    if(min<0) return DC_PRED;
    else      return min;
}

static av_always_inline void write_back_intra_pred_mode(H264Context *h){
    int8_t *i4x4= h->intra4x4_pred_mode + h->mb2br_xy[h->mb_xy];
    int8_t *i4x4_cache= h->intra4x4_pred_mode_cache;

    AV_COPY32(i4x4, i4x4_cache + 4 + 8*4);
    i4x4[4]= i4x4_cache[7+8*3];
    i4x4[5]= i4x4_cache[7+8*2];
    i4x4[6]= i4x4_cache[7+8*1];
}

static av_always_inline void write_back_non_zero_count(H264Context *h){
    const int mb_xy= h->mb_xy;
    uint8_t *nnz = h->non_zero_count[mb_xy];
    uint8_t *nnz_cache = h->non_zero_count_cache;

    AV_COPY32(&nnz[ 0], &nnz_cache[4+8* 1]);
    AV_COPY32(&nnz[ 4], &nnz_cache[4+8* 2]);
    AV_COPY32(&nnz[ 8], &nnz_cache[4+8* 3]);
    AV_COPY32(&nnz[12], &nnz_cache[4+8* 4]);
    AV_COPY32(&nnz[16], &nnz_cache[4+8* 6]);
    AV_COPY32(&nnz[20], &nnz_cache[4+8* 7]);
    AV_COPY32(&nnz[32], &nnz_cache[4+8*11]);
    AV_COPY32(&nnz[36], &nnz_cache[4+8*12]);

    if(!h->s.chroma_y_shift){
        AV_COPY32(&nnz[24], &nnz_cache[4+8* 8]);
        AV_COPY32(&nnz[28], &nnz_cache[4+8* 9]);
        AV_COPY32(&nnz[40], &nnz_cache[4+8*13]);
        AV_COPY32(&nnz[44], &nnz_cache[4+8*14]);
    }
}

static av_always_inline void write_back_motion_list(H264Context *h, MpegEncContext * const s, int b_stride,
                                                    int b_xy, int b8_xy, int mb_type, int list )
{
    int16_t (*mv_dst)[2] = &s->current_picture.f.motion_val[list][b_xy];
    int16_t (*mv_src)[2] = &h->mv_cache[list][scan8[0]];
    AV_COPY128(mv_dst + 0*b_stride, mv_src + 8*0);
    AV_COPY128(mv_dst + 1*b_stride, mv_src + 8*1);
    AV_COPY128(mv_dst + 2*b_stride, mv_src + 8*2);
    AV_COPY128(mv_dst + 3*b_stride, mv_src + 8*3);
    if( CABAC ) {
        uint8_t (*mvd_dst)[2] = &h->mvd_table[list][FMO ? 8*h->mb_xy : h->mb2br_xy[h->mb_xy]];
        uint8_t (*mvd_src)[2] = &h->mvd_cache[list][scan8[0]];
        if(IS_SKIP(mb_type))
            AV_ZERO128(mvd_dst);
        else{
            AV_COPY64(mvd_dst, mvd_src + 8*3);
            AV_COPY16(mvd_dst + 3 + 3, mvd_src + 3 + 8*0);
            AV_COPY16(mvd_dst + 3 + 2, mvd_src + 3 + 8*1);
            AV_COPY16(mvd_dst + 3 + 1, mvd_src + 3 + 8*2);
        }
    }

    {
        int8_t *ref_index = &s->current_picture.f.ref_index[list][b8_xy];
        int8_t *ref_cache = h->ref_cache[list];
        ref_index[0+0*2]= ref_cache[scan8[0]];
        ref_index[1+0*2]= ref_cache[scan8[4]];
        ref_index[0+1*2]= ref_cache[scan8[8]];
        ref_index[1+1*2]= ref_cache[scan8[12]];
    }
}

static av_always_inline void write_back_motion(H264Context *h, int mb_type){
    MpegEncContext * const s = &h->s;
    const int b_stride = h->b_stride;
    const int b_xy = 4*s->mb_x + 4*s->mb_y*h->b_stride; //try mb2b(8)_xy
    const int b8_xy= 4*h->mb_xy;

    if(USES_LIST(mb_type, 0)){
        write_back_motion_list(h, s, b_stride, b_xy, b8_xy, mb_type, 0);
    }else{
        fill_rectangle(&s->current_picture.f.ref_index[0][b8_xy],
                       2, 2, 2, (uint8_t)LIST_NOT_USED, 1);
    }
    if(USES_LIST(mb_type, 1)){
        write_back_motion_list(h, s, b_stride, b_xy, b8_xy, mb_type, 1);
    }

    if(h->slice_type_nos == AV_PICTURE_TYPE_B && CABAC){
        if(IS_8X8(mb_type)){
            uint8_t *direct_table = &h->direct_table[4*h->mb_xy];
            direct_table[1] = h->sub_mb_type[1]>>1;
            direct_table[2] = h->sub_mb_type[2]>>1;
            direct_table[3] = h->sub_mb_type[3]>>1;
        }
    }
}

static av_always_inline int get_dct8x8_allowed(H264Context *h){
    if(h->sps.direct_8x8_inference_flag)
        return !(AV_RN64A(h->sub_mb_type) & ((MB_TYPE_16x8|MB_TYPE_8x16|MB_TYPE_8x8                )*0x0001000100010001ULL));
    else
        return !(AV_RN64A(h->sub_mb_type) & ((MB_TYPE_16x8|MB_TYPE_8x16|MB_TYPE_8x8|MB_TYPE_DIRECT2)*0x0001000100010001ULL));
}

#endif /* AVCODEC_H264_H */

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