text: /*
   * Generic DCT based hybrid video encoder
   * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
   * Copyright (c) 2002-2004 Michael Niedermayer
   *
   * 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
   */
  
  /**
   * @file
   * mpegvideo header.
   */
  
  #ifndef AVCODEC_MPEGVIDEO_H
  #define AVCODEC_MPEGVIDEO_H
  
  #include "avcodec.h"
  #include "blockdsp.h"
  #include "error_resilience.h"
  #include "fdctdsp.h"
  #include "get_bits.h"
  #include "h264chroma.h"
  #include "h263dsp.h"
  #include "hpeldsp.h"
  #include "idctdsp.h"
  #include "me_cmp.h"
  #include "mpegvideodsp.h"
  #include "mpegvideoencdsp.h"
  #include "pixblockdsp.h"
  #include "put_bits.h"
  #include "ratecontrol.h"
  #include "parser.h"
  #include "mpeg12data.h"
  #include "qpeldsp.h"
  #include "rl.h"
  #include "thread.h"
  #include "videodsp.h"
  
  #include "libavutil/opt.h"
  #include "libavutil/timecode.h"
  
  #define FRAME_SKIPPED 100 ///< return value for header parsers if frame is not coded
  
  enum OutputFormat {
      FMT_MPEG1,
      FMT_H261,
      FMT_H263,
      FMT_MJPEG,
  };
  
  #define MAX_FCODE 7
  #define MAX_MV 4096
  
  #define MAX_THREADS 32
  #define MAX_PICTURE_COUNT 36
  
  #define MAX_B_FRAMES 16
  
  #define ME_MAP_SIZE 64
  
  #define MAX_MB_BYTES (30*16*16*3/8 + 120)
  
  #define INPLACE_OFFSET 16
  
  #define EDGE_WIDTH 16
  
  /* Start codes. */
  #define SEQ_END_CODE            0x000001b7
  #define SEQ_START_CODE          0x000001b3
  #define GOP_START_CODE          0x000001b8
  #define PICTURE_START_CODE      0x00000100
  #define SLICE_MIN_START_CODE    0x00000101
  #define SLICE_MAX_START_CODE    0x000001af
  #define EXT_START_CODE          0x000001b5
  #define USER_START_CODE         0x000001b2
  
  /* encoding scans */
  extern const uint8_t ff_alternate_horizontal_scan[64];
  extern const uint8_t ff_alternate_vertical_scan[64];
  
  struct MpegEncContext;
  
  /**
   * Picture.
   */
  typedef struct Picture{
      struct AVFrame *f;
      ThreadFrame tf;
  
      AVBufferRef *qscale_table_buf;
      int8_t *qscale_table;
  
      AVBufferRef *motion_val_buf[2];
      int16_t (*motion_val[2])[2];
  
      AVBufferRef *mb_type_buf;
      uint32_t *mb_type;          ///< types and macros are defined in mpegutils.h
  
      AVBufferRef *mbskip_table_buf;
      uint8_t *mbskip_table;
  
      AVBufferRef *ref_index_buf[2];
      int8_t *ref_index[2];
  
      AVBufferRef *mb_var_buf;
      uint16_t *mb_var;           ///< Table for MB variances
  
      AVBufferRef *mc_mb_var_buf;
      uint16_t *mc_mb_var;        ///< Table for motion compensated MB variances
  
      int alloc_mb_width;         ///< mb_width used to allocate tables
      int alloc_mb_height;        ///< mb_height used to allocate tables
  
      AVBufferRef *mb_mean_buf;
      uint8_t *mb_mean;           ///< Table for MB luminance
  
      AVBufferRef *hwaccel_priv_buf;
      /**
       * hardware accelerator private data
       */
      void *hwaccel_picture_private;
  
      int field_picture;          ///< whether or not the picture was encoded in separate fields
  
      int64_t mb_var_sum;         ///< sum of MB variance for current frame
      int64_t mc_mb_var_sum;      ///< motion compensated MB variance for current frame
  
      int b_frame_score;
      int needs_realloc;          ///< Picture needs to be reallocated (eg due to a frame size change)
  
      int reference;
      int shared;
  
      uint64_t error[AV_NUM_DATA_POINTERS];
  } Picture;
  
  /**
   * Motion estimation context.
   */
  typedef struct MotionEstContext{
      AVCodecContext *avctx;
      int skip;                          ///< set if ME is skipped for the current MB
      int co_located_mv[4][2];           ///< mv from last P-frame for direct mode ME
      int direct_basis_mv[4][2];
      uint8_t *scratchpad;               ///< data area for the ME algo, so that the ME does not need to malloc/free
      uint8_t *best_mb;
      uint8_t *temp_mb[2];
      uint8_t *temp;
      int best_bits;
      uint32_t *map;                     ///< map to avoid duplicate evaluations
      uint32_t *score_map;               ///< map to store the scores
      unsigned map_generation;
      int pre_penalty_factor;
      int penalty_factor;                /**< an estimate of the bits required to
                                          code a given mv value, e.g. (1,0) takes
                                          more bits than (0,0). We have to
                                          estimate whether any reduction in
                                          residual is worth the extra bits. */
      int sub_penalty_factor;
      int mb_penalty_factor;
      int flags;
      int sub_flags;
      int mb_flags;
      int pre_pass;                      ///< = 1 for the pre pass
      int dia_size;
      int xmin;
      int xmax;
      int ymin;
      int ymax;
      int pred_x;
      int pred_y;
      uint8_t *src[4][4];
      uint8_t *ref[4][4];
      int stride;
      int uvstride;
      /* temp variables for picture complexity calculation */
      int64_t mc_mb_var_sum_temp;
      int64_t mb_var_sum_temp;
      int scene_change_score;
  /*    cmp, chroma_cmp;*/
      op_pixels_func (*hpel_put)[4];
      op_pixels_func (*hpel_avg)[4];
      qpel_mc_func (*qpel_put)[16];
      qpel_mc_func (*qpel_avg)[16];
      uint8_t (*mv_penalty)[MAX_MV*2+1];  ///< amount of bits needed to encode a MV
      uint8_t *current_mv_penalty;
      int (*sub_motion_search)(struct MpegEncContext * s,
                                    int *mx_ptr, int *my_ptr, int dmin,
                                    int src_index, int ref_index,
                                    int size, int h);
  }MotionEstContext;
  
  /**
   * MpegEncContext.
   */
  typedef struct MpegEncContext {
      AVClass *class;
  
      int y_dc_scale, c_dc_scale;
      int ac_pred;
      int block_last_index[12];  ///< last non zero coefficient in block
      int h263_aic;              ///< Advanded INTRA Coding (AIC)
  
      /* scantables */
      ScanTable inter_scantable; ///< if inter == intra then intra should be used to reduce tha cache usage
      ScanTable intra_scantable;
      ScanTable intra_h_scantable;
      ScanTable intra_v_scantable;
  
      /* WARNING: changes above this line require updates to hardcoded
       *          offsets used in asm. */
  
      struct AVCodecContext *avctx;
      /* the following parameters must be initialized before encoding */
      int width, height;///< picture size. must be a multiple of 16
      int gop_size;
      int intra_only;   ///< if true, only intra pictures are generated
      int bit_rate;     ///< wanted bit rate
      enum OutputFormat out_format; ///< output format
      int h263_pred;    ///< use mpeg4/h263 ac/dc predictions
      int pb_frame;     ///< PB frame mode (0 = none, 1 = base, 2 = improved)
  
  /* the following codec id fields are deprecated in favor of codec_id */
      int h263_plus;    ///< h263 plus headers
      int h263_flv;     ///< use flv h263 header
  
      enum AVCodecID codec_id;     /* see AV_CODEC_ID_xxx */
      int fixed_qscale; ///< fixed qscale if non zero
      int encoding;     ///< true if we are encoding (vs decoding)
      int flags;        ///< AVCodecContext.flags (HQ, MV4, ...)
      int flags2;       ///< AVCodecContext.flags2
      int max_b_frames; ///< max number of b-frames for encoding
      int luma_elim_threshold;
      int chroma_elim_threshold;
      int strict_std_compliance; ///< strictly follow the std (MPEG4, ...)
      int workaround_bugs;       ///< workaround bugs in encoders which cannot be detected automatically
      int codec_tag;             ///< internal codec_tag upper case converted from avctx codec_tag
      int stream_codec_tag;      ///< internal stream_codec_tag upper case converted from avctx stream_codec_tag
      /* the following fields are managed internally by the encoder */
  
      /* sequence parameters */
      int context_initialized;
      int input_picture_number;  ///< used to set pic->display_picture_number, should not be used for/by anything else
      int coded_picture_number;  ///< used to set pic->coded_picture_number, should not be used for/by anything else
      int picture_number;       //FIXME remove, unclear definition
      int picture_in_gop_number; ///< 0-> first pic in gop, ...
      int mb_width, mb_height;   ///< number of MBs horizontally & vertically
      int mb_stride;             ///< mb_width+1 used for some arrays to allow simple addressing of left & top MBs without sig11
      int b8_stride;             ///< 2*mb_width+1 used for some 8x8 block arrays to allow simple addressing
      int h_edge_pos, v_edge_pos;///< horizontal / vertical position of the right/bottom edge (pixel replication)
      int mb_num;                ///< number of MBs of a picture
      ptrdiff_t linesize;        ///< line size, in bytes, may be different from width
      ptrdiff_t uvlinesize;      ///< line size, for chroma in bytes, may be different from width
      Picture *picture;          ///< main picture buffer
      Picture **input_picture;   ///< next pictures on display order for encoding
      Picture **reordered_input_picture; ///< pointer to the next pictures in codedorder for encoding
  
      int64_t user_specified_pts; ///< last non-zero pts from AVFrame which was passed into avcodec_encode_video2()
      /**
       * pts difference between the first and second input frame, used for
       * calculating dts of the first frame when there's a delay */
      int64_t dts_delta;
      /**
       * reordered pts to be used as dts for the next output frame when there's
       * a delay */
      int64_t reordered_pts;
  
      /** bit output */
      PutBitContext pb;
  
      int start_mb_y;            ///< start mb_y of this thread (so current thread should process start_mb_y <= row < end_mb_y)
      int end_mb_y;              ///< end   mb_y of this thread (so current thread should process start_mb_y <= row < end_mb_y)
      struct MpegEncContext *thread_context[MAX_THREADS];
      int slice_context_count;   ///< number of used thread_contexts
  
      /**
       * copy of the previous picture structure.
       * note, linesize & data, might not match the previous picture (for field pictures)
       */
      Picture last_picture;
  
      /**
       * copy of the next picture structure.
       * note, linesize & data, might not match the next picture (for field pictures)
       */
      Picture next_picture;
  
      /**
       * copy of the source picture structure for encoding.
       * note, linesize & data, might not match the source picture (for field pictures)
       */
      Picture new_picture;
  
      /**
       * copy of the current picture structure.
       * note, linesize & data, might not match the current picture (for field pictures)
       */
      Picture current_picture;    ///< buffer to store the decompressed current picture
  
      Picture *last_picture_ptr;     ///< pointer to the previous picture.
      Picture *next_picture_ptr;     ///< pointer to the next picture (for bidir pred)
      Picture *current_picture_ptr;  ///< pointer to the current picture
      int last_dc[3];                ///< last DC values for MPEG1
      int16_t *dc_val_base;
      int16_t *dc_val[3];            ///< used for mpeg4 DC prediction, all 3 arrays must be continuous
      const uint8_t *y_dc_scale_table;     ///< qscale -> y_dc_scale table
      const uint8_t *c_dc_scale_table;     ///< qscale -> c_dc_scale table
      const uint8_t *chroma_qscale_table;  ///< qscale -> chroma_qscale (h263)
      uint8_t *coded_block_base;
      uint8_t *coded_block;          ///< used for coded block pattern prediction (msmpeg4v3, wmv1)
      int16_t (*ac_val_base)[16];
      int16_t (*ac_val[3])[16];      ///< used for mpeg4 AC prediction, all 3 arrays must be continuous
      int mb_skipped;                ///< MUST BE SET only during DECODING
      uint8_t *mbskip_table;        /**< used to avoid copy if macroblock skipped (for black regions for example)
                                     and used for b-frame encoding & decoding (contains skip table of next P Frame) */
      uint8_t *mbintra_table;       ///< used to avoid setting {ac, dc, cbp}-pred stuff to zero on inter MB decoding
      uint8_t *cbp_table;           ///< used to store cbp, ac_pred for partitioned decoding
      uint8_t *pred_dir_table;      ///< used to store pred_dir for partitioned decoding
      uint8_t *edge_emu_buffer;     ///< temporary buffer for if MVs point to out-of-frame data
      uint8_t *rd_scratchpad;       ///< scratchpad for rate distortion mb decision
      uint8_t *obmc_scratchpad;
      uint8_t *b_scratchpad;        ///< scratchpad used for writing into write only buffers
  
      int qscale;                 ///< QP
      int chroma_qscale;          ///< chroma QP
      unsigned int lambda;        ///< lagrange multipler used in rate distortion
      unsigned int lambda2;       ///< (lambda*lambda) >> FF_LAMBDA_SHIFT
      int *lambda_table;
      int adaptive_quant;         ///< use adaptive quantization
      int dquant;                 ///< qscale difference to prev qscale
      int closed_gop;             ///< MPEG1/2 GOP is closed
      int pict_type;              ///< AV_PICTURE_TYPE_I, AV_PICTURE_TYPE_P, AV_PICTURE_TYPE_B, ...
      int vbv_delay;
      int last_pict_type; //FIXME removes
      int last_non_b_pict_type;   ///< used for mpeg4 gmc b-frames & ratecontrol
      int droppable;
      int frame_rate_index;
      AVRational mpeg2_frame_rate_ext;
      int last_lambda_for[5];     ///< last lambda for a specific pict type
      int skipdct;                ///< skip dct and code zero residual
  
      /* motion compensation */
      int unrestricted_mv;        ///< mv can point outside of the coded picture
      int h263_long_vectors;      ///< use horrible h263v1 long vector mode
  
      BlockDSPContext bdsp;
      FDCTDSPContext fdsp;
      H264ChromaContext h264chroma;
      HpelDSPContext hdsp;
      IDCTDSPContext idsp;
      MECmpContext mecc;
      MpegVideoDSPContext mdsp;
      MpegvideoEncDSPContext mpvencdsp;
      PixblockDSPContext pdsp;
      QpelDSPContext qdsp;
      VideoDSPContext vdsp;
      H263DSPContext h263dsp;
      int f_code;                 ///< forward MV resolution
      int b_code;                 ///< backward MV resolution for B Frames (mpeg4)
      int16_t (*p_mv_table_base)[2];
      int16_t (*b_forw_mv_table_base)[2];
      int16_t (*b_back_mv_table_base)[2];
      int16_t (*b_bidir_forw_mv_table_base)[2];
      int16_t (*b_bidir_back_mv_table_base)[2];
      int16_t (*b_direct_mv_table_base)[2];
      int16_t (*p_field_mv_table_base[2][2])[2];
      int16_t (*b_field_mv_table_base[2][2][2])[2];
      int16_t (*p_mv_table)[2];            ///< MV table (1MV per MB) p-frame encoding
      int16_t (*b_forw_mv_table)[2];       ///< MV table (1MV per MB) forward mode b-frame encoding
      int16_t (*b_back_mv_table)[2];       ///< MV table (1MV per MB) backward mode b-frame encoding
      int16_t (*b_bidir_forw_mv_table)[2]; ///< MV table (1MV per MB) bidir mode b-frame encoding
      int16_t (*b_bidir_back_mv_table)[2]; ///< MV table (1MV per MB) bidir mode b-frame encoding
      int16_t (*b_direct_mv_table)[2];     ///< MV table (1MV per MB) direct mode b-frame encoding
      int16_t (*p_field_mv_table[2][2])[2];   ///< MV table (2MV per MB) interlaced p-frame encoding
      int16_t (*b_field_mv_table[2][2][2])[2];///< MV table (4MV per MB) interlaced b-frame encoding
      uint8_t (*p_field_select_table[2]);
      uint8_t (*b_field_select_table[2][2]);
      int me_method;                       ///< ME algorithm
      int mv_dir;
  #define MV_DIR_FORWARD   1
  #define MV_DIR_BACKWARD  2
  #define MV_DIRECT        4 ///< bidirectional mode where the difference equals the MV of the last P/S/I-Frame (mpeg4)
      int mv_type;
  #define MV_TYPE_16X16       0   ///< 1 vector for the whole mb
  #define MV_TYPE_8X8         1   ///< 4 vectors (h263, mpeg4 4MV)
  #define MV_TYPE_16X8        2   ///< 2 vectors, one per 16x8 block
  #define MV_TYPE_FIELD       3   ///< 2 vectors, one per field
  #define MV_TYPE_DMV         4   ///< 2 vectors, special mpeg2 Dual Prime Vectors
      /**motion vectors for a macroblock
         first coordinate : 0 = forward 1 = backward
         second "         : depend on type
         third  "         : 0 = x, 1 = y
      */
      int mv[2][4][2];
      int field_select[2][2];
      int last_mv[2][2][2];             ///< last MV, used for MV prediction in MPEG1 & B-frame MPEG4
      uint8_t *fcode_tab;               ///< smallest fcode needed for each MV
      int16_t direct_scale_mv[2][64];   ///< precomputed to avoid divisions in ff_mpeg4_set_direct_mv
  
      MotionEstContext me;
  
      int no_rounding;  /**< apply no rounding to motion compensation (MPEG4, msmpeg4, ...)
                          for b-frames rounding mode is always 0 */
  
      /* macroblock layer */
      int mb_x, mb_y;
      int mb_skip_run;
      int mb_intra;
      uint16_t *mb_type;  ///< Table for candidate MB types for encoding (defines in mpegutils.h)
  
      int block_index[6]; ///< index to current MB in block based arrays with edges
      int block_wrap[6];
      uint8_t *dest[3];
  
      int *mb_index2xy;        ///< mb_index -> mb_x + mb_y*mb_stride
  
      /** matrix transmitted in the bitstream */
      uint16_t intra_matrix[64];
      uint16_t chroma_intra_matrix[64];
      uint16_t inter_matrix[64];
      uint16_t chroma_inter_matrix[64];
  
      int intra_quant_bias;    ///< bias for the quantizer
      int inter_quant_bias;    ///< bias for the quantizer
      int min_qcoeff;          ///< minimum encodable coefficient
      int max_qcoeff;          ///< maximum encodable coefficient
      int ac_esc_length;       ///< num of bits needed to encode the longest esc
      uint8_t *intra_ac_vlc_length;
      uint8_t *intra_ac_vlc_last_length;
      uint8_t *inter_ac_vlc_length;
      uint8_t *inter_ac_vlc_last_length;
      uint8_t *luma_dc_vlc_length;
  #define UNI_AC_ENC_INDEX(run,level) ((run)*128 + (level))
  
      int coded_score[12];
  
      /** precomputed matrix (combine qscale and DCT renorm) */
      int (*q_intra_matrix)[64];
      int (*q_chroma_intra_matrix)[64];
      int (*q_inter_matrix)[64];
      /** identical to the above but for MMX & these are not permutated, second 64 entries are bias*/
      uint16_t (*q_intra_matrix16)[2][64];
      uint16_t (*q_chroma_intra_matrix16)[2][64];
      uint16_t (*q_inter_matrix16)[2][64];
  
      /* noise reduction */
      int (*dct_error_sum)[64];
      int dct_count[2];
      uint16_t (*dct_offset)[64];
  
      /* bit rate control */
      int64_t total_bits;
      int frame_bits;                ///< bits used for the current frame
      int stuffing_bits;             ///< bits used for stuffing
      int next_lambda;               ///< next lambda used for retrying to encode a frame
      RateControlContext rc_context; ///< contains stuff only accessed in ratecontrol.c
  
      /* statistics, used for 2-pass encoding */
      int mv_bits;
      int header_bits;
      int i_tex_bits;
      int p_tex_bits;
      int i_count;
      int f_count;
      int b_count;
      int skip_count;
      int misc_bits; ///< cbp, mb_type
      int last_bits; ///< temp var used for calculating the above vars
  
      /* error concealment / resync */
      int resync_mb_x;                 ///< x position of last resync marker
      int resync_mb_y;                 ///< y position of last resync marker
      GetBitContext last_resync_gb;    ///< used to search for the next resync marker
      int mb_num_left;                 ///< number of MBs left in this video packet (for partitioned Slices only)
      int next_p_frame_damaged;        ///< set if the next p frame is damaged, to avoid showing trashed b frames
      int err_recognition;
  
      ParseContext parse_context;
  
      /* H.263 specific */
      int gob_index;
      int obmc;                       ///< overlapped block motion compensation
      int mb_info;                    ///< interval for outputting info about mb offsets as side data
      int prev_mb_info, last_mb_info;
      uint8_t *mb_info_ptr;
      int mb_info_size;
      int ehc_mode;
  
      /* H.263+ specific */
      int umvplus;                    ///< == H263+ && unrestricted_mv
      int h263_aic_dir;               ///< AIC direction: 0 = left, 1 = top
      int h263_slice_structured;
      int alt_inter_vlc;              ///< alternative inter vlc
      int modified_quant;
      int loop_filter;
      int custom_pcf;
  
      /* mpeg4 specific */
      ///< number of bits to represent the fractional part of time (encoder only)
      int time_increment_bits;
      int last_time_base;
      int time_base;                  ///< time in seconds of last I,P,S Frame
      int64_t time;                   ///< time of current frame
      int64_t last_non_b_time;
      uint16_t pp_time;               ///< time distance between the last 2 p,s,i frames
      uint16_t pb_time;               ///< time distance between the last b and p,s,i frame
      uint16_t pp_field_time;
      uint16_t pb_field_time;         ///< like above, just for interlaced
      int real_sprite_warping_points;
      int sprite_offset[2][2];         ///< sprite offset[isChroma][isMVY]
      int sprite_delta[2][2];          ///< sprite_delta [isY][isMVY]
      int mcsel;
      int quant_precision;
      int quarter_sample;              ///< 1->qpel, 0->half pel ME/MC
      int aspect_ratio_info; //FIXME remove
      int sprite_warping_accuracy;
      int data_partitioning;           ///< data partitioning flag from header
      int partitioned_frame;           ///< is current frame partitioned
      int low_delay;                   ///< no reordering needed / has no b-frames
      int vo_type;
      PutBitContext tex_pb;            ///< used for data partitioned VOPs
      PutBitContext pb2;               ///< used for data partitioned VOPs
      int mpeg_quant;
      int padding_bug_score;             ///< used to detect the VERY common padding bug in MPEG4
  
      /* divx specific, used to workaround (many) bugs in divx5 */
      int divx_packed;
      uint8_t *bitstream_buffer; //Divx 5.01 puts several frames in a single one, this is used to reorder them
      int bitstream_buffer_size;
      unsigned int allocated_bitstream_buffer_size;
  
      /* RV10 specific */
      int rv10_version; ///< RV10 version: 0 or 3
      int rv10_first_dc_coded[3];
  
      /* MJPEG specific */
      struct MJpegContext *mjpeg_ctx;
      int esc_pos;
  
      /* MSMPEG4 specific */
      int mv_table_index;
      int rl_table_index;
      int rl_chroma_table_index;
      int dc_table_index;
      int use_skip_mb_code;
      int slice_height;      ///< in macroblocks
      int first_slice_line;  ///< used in mpeg4 too to handle resync markers
      int flipflop_rounding;
      int msmpeg4_version;   ///< 0=not msmpeg4, 1=mp41, 2=mp42, 3=mp43/divx3 4=wmv1/7 5=wmv2/8
      int per_mb_rl_table;
      int esc3_level_length;
      int esc3_run_length;
      /** [mb_intra][isChroma][level][run][last] */
      int (*ac_stats)[2][MAX_LEVEL+1][MAX_RUN+1][2];
      int inter_intra_pred;
      int mspel;
  
      /* decompression specific */
      GetBitContext gb;
  
      /* Mpeg1 specific */
      int gop_picture_number;  ///< index of the first picture of a GOP based on fake_pic_num & mpeg1 specific
      int last_mv_dir;         ///< last mv_dir, used for b frame encoding
      uint8_t *vbv_delay_ptr;  ///< pointer to vbv_delay in the bitstream
  
      /* MPEG-2-specific - I wished not to have to support this mess. */
      int progressive_sequence;
      int mpeg_f_code[2][2];
  
      // picture structure defines are loaded from mpegutils.h
      int picture_structure;
  
      int intra_dc_precision;
      int frame_pred_frame_dct;
      int top_field_first;
      int concealment_motion_vectors;
      int q_scale_type;
      int intra_vlc_format;
      int alternate_scan;
      int seq_disp_ext;
      int repeat_first_field;
      int chroma_420_type;
      int chroma_format;
  #define CHROMA_420 1
  #define CHROMA_422 2
  #define CHROMA_444 3
      int chroma_x_shift;//depend on pix_format, that depend on chroma_format
      int chroma_y_shift;
  
      int progressive_frame;
      int full_pel[2];
      int interlaced_dct;
      int first_field;         ///< is 1 for the first field of a field picture 0 otherwise
      int drop_frame_timecode; ///< timecode is in drop frame format.
      int scan_offset;         ///< reserve space for SVCD scan offset user data.
  
      /* RTP specific */
      int rtp_mode;
  
      char *tc_opt_str;        ///< timecode option string
      AVTimecode tc;           ///< timecode context
  
      uint8_t *ptr_lastgob;
      int swap_uv;             //vcr2 codec is an MPEG-2 variant with U and V swapped
      int pack_pblocks;        //xvmc needs to keep blocks without gaps.
      int16_t (*pblocks[12])[64];
  
      int16_t (*block)[64]; ///< points to one of the following blocks
      int16_t (*blocks)[12][64]; // for HQ mode we need to keep the best block
      int (*decode_mb)(struct MpegEncContext *s, int16_t block[6][64]); // used by some codecs to avoid a switch()
  #define SLICE_OK         0
  #define SLICE_ERROR     -1
  #define SLICE_END       -2 ///<end marker found
  #define SLICE_NOEND     -3 ///<no end marker or error found but mb count exceeded
  
      void (*dct_unquantize_mpeg1_intra)(struct MpegEncContext *s,
                             int16_t *block/*align 16*/, int n, int qscale);
      void (*dct_unquantize_mpeg1_inter)(struct MpegEncContext *s,
                             int16_t *block/*align 16*/, int n, int qscale);
      void (*dct_unquantize_mpeg2_intra)(struct MpegEncContext *s,
                             int16_t *block/*align 16*/, int n, int qscale);
      void (*dct_unquantize_mpeg2_inter)(struct MpegEncContext *s,
                             int16_t *block/*align 16*/, int n, int qscale);
      void (*dct_unquantize_h263_intra)(struct MpegEncContext *s,
                             int16_t *block/*align 16*/, int n, int qscale);
      void (*dct_unquantize_h263_inter)(struct MpegEncContext *s,
                             int16_t *block/*align 16*/, int n, int qscale);
      void (*dct_unquantize_intra)(struct MpegEncContext *s, // unquantizer to use (mpeg4 can use both)
                             int16_t *block/*align 16*/, int n, int qscale);
      void (*dct_unquantize_inter)(struct MpegEncContext *s, // unquantizer to use (mpeg4 can use both)
                             int16_t *block/*align 16*/, int n, int qscale);
      int (*dct_quantize)(struct MpegEncContext *s, int16_t *block/*align 16*/, int n, int qscale, int *overflow);
      int (*fast_dct_quantize)(struct MpegEncContext *s, int16_t *block/*align 16*/, int n, int qscale, int *overflow);
      void (*denoise_dct)(struct MpegEncContext *s, int16_t *block);
  
      int mpv_flags;      ///< flags set by private options
      int quantizer_noise_shaping;
  
      /* temp buffers for rate control */
      float *cplx_tab, *bits_tab;
  
      /* flag to indicate a reinitialization is required, e.g. after
       * a frame size change */
      int context_reinit;
  
      ERContext er;
  
      int error_rate;
  
      /* temporary frames used by b_frame_strategy = 2 */
      AVFrame *tmp_frames[MAX_B_FRAMES + 2];
  } MpegEncContext;
  
  #define REBASE_PICTURE(pic, new_ctx, old_ctx)             \
      ((pic && pic >= old_ctx->picture &&                   \
        pic < old_ctx->picture + MAX_PICTURE_COUNT) ?  \
          &new_ctx->picture[pic - old_ctx->picture] : NULL)
  
  /* mpegvideo_enc common options */
  #define FF_MPV_FLAG_SKIP_RD      0x0001
  #define FF_MPV_FLAG_STRICT_GOP   0x0002
  #define FF_MPV_FLAG_QP_RD        0x0004
  #define FF_MPV_FLAG_CBP_RD       0x0008
  #define FF_MPV_FLAG_NAQ          0x0010
  #define FF_MPV_FLAG_MV0          0x0020
  
  #define FF_MPV_OFFSET(x) offsetof(MpegEncContext, x)
  #define FF_MPV_OPT_FLAGS (AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM)
  
  #define FF_MPV_COMMON_OPTS \
  { "mpv_flags",      "Flags common for all mpegvideo-based encoders.", FF_MPV_OFFSET(mpv_flags), AV_OPT_TYPE_FLAGS, { .i64 = 0 }, INT_MIN, INT_MAX, FF_MPV_OPT_FLAGS, "mpv_flags" },\
  { "skip_rd",        "RD optimal MB level residual skipping", 0, AV_OPT_TYPE_CONST, { .i64 = FF_MPV_FLAG_SKIP_RD },    0, 0, FF_MPV_OPT_FLAGS, "mpv_flags" },\
  { "strict_gop",     "Strictly enforce gop size",             0, AV_OPT_TYPE_CONST, { .i64 = FF_MPV_FLAG_STRICT_GOP }, 0, 0, FF_MPV_OPT_FLAGS, "mpv_flags" },\
  { "qp_rd",          "Use rate distortion optimization for qp selection", 0, AV_OPT_TYPE_CONST, { .i64 = FF_MPV_FLAG_QP_RD },  0, 0, FF_MPV_OPT_FLAGS, "mpv_flags" },\
  { "cbp_rd",         "use rate distortion optimization for CBP",          0, AV_OPT_TYPE_CONST, { .i64 = FF_MPV_FLAG_CBP_RD }, 0, 0, FF_MPV_OPT_FLAGS, "mpv_flags" },\
  { "naq",            "normalize adaptive quantization",                   0, AV_OPT_TYPE_CONST, { .i64 = FF_MPV_FLAG_NAQ },    0, 0, FF_MPV_OPT_FLAGS, "mpv_flags" },\
  { "mv0",            "always try a mb with mv=<0,0>",                     0, AV_OPT_TYPE_CONST, { .i64 = FF_MPV_FLAG_MV0 },    0, 0, FF_MPV_OPT_FLAGS, "mpv_flags" },\
  { "luma_elim_threshold",   "single coefficient elimination threshold for luminance (negative values also consider dc coefficient)",\
                                                                        FF_MPV_OFFSET(luma_elim_threshold), AV_OPT_TYPE_INT, { .i64 = 0 }, INT_MIN, INT_MAX, FF_MPV_OPT_FLAGS },\
  { "chroma_elim_threshold", "single coefficient elimination threshold for chrominance (negative values also consider dc coefficient)",\
                                                                        FF_MPV_OFFSET(chroma_elim_threshold), AV_OPT_TYPE_INT, { .i64 = 0 }, INT_MIN, INT_MAX, FF_MPV_OPT_FLAGS },\
  { "quantizer_noise_shaping", NULL,                                  FF_MPV_OFFSET(quantizer_noise_shaping), AV_OPT_TYPE_INT, { .i64 = 0 },       0, INT_MAX, FF_MPV_OPT_FLAGS },\
  { "error_rate", "Simulate errors in the bitstream to test error concealment.",                                                                                                  \
                                                                      FF_MPV_OFFSET(error_rate),              AV_OPT_TYPE_INT, { .i64 = 0 },       0, INT_MAX, FF_MPV_OPT_FLAGS },
  
  extern const AVOption ff_mpv_generic_options[];
  
  #define FF_MPV_GENERIC_CLASS(name) \
  static const AVClass name ## _class = {\
      .class_name = #name " encoder",\
      .item_name  = av_default_item_name,\
      .option     = ff_mpv_generic_options,\
      .version    = LIBAVUTIL_VERSION_INT,\
  };
  
  /**
   * Set the given MpegEncContext to common defaults (same for encoding
   * and decoding).  The changed fields will not depend upon the prior
   * state of the MpegEncContext.
   */
  void ff_mpv_common_defaults(MpegEncContext *s);
  
  void ff_dct_encode_init_x86(MpegEncContext *s);
  
  int ff_mpv_common_init(MpegEncContext *s);
  void ff_mpv_common_init_arm(MpegEncContext *s);
  void ff_mpv_common_init_axp(MpegEncContext *s);
  void ff_mpv_common_init_neon(MpegEncContext *s);
  void ff_mpv_common_init_ppc(MpegEncContext *s);
  void ff_mpv_common_init_x86(MpegEncContext *s);
  
  int ff_mpv_common_frame_size_change(MpegEncContext *s);
  void ff_mpv_common_end(MpegEncContext *s);
  
  void ff_mpv_decode_defaults(MpegEncContext *s);
  void ff_mpv_decode_init(MpegEncContext *s, AVCodecContext *avctx);
  void ff_mpv_decode_mb(MpegEncContext *s, int16_t block[12][64]);
  void ff_mpv_report_decode_progress(MpegEncContext *s);
  
  int ff_mpv_frame_start(MpegEncContext *s, AVCodecContext *avctx);
  void ff_mpv_frame_end(MpegEncContext *s);
  
  int ff_mpv_lowest_referenced_row(MpegEncContext *s, int dir);
  
  int ff_mpv_encode_init(AVCodecContext *avctx);
  void ff_mpv_encode_init_x86(MpegEncContext *s);
  
  int ff_mpv_encode_end(AVCodecContext *avctx);
  int ff_mpv_encode_picture(AVCodecContext *avctx, AVPacket *pkt,
                            const AVFrame *frame, int *got_packet);
  
  void ff_clean_intra_table_entries(MpegEncContext *s);
  void ff_mpeg_draw_horiz_band(MpegEncContext *s, int y, int h);
  void ff_mpeg_flush(AVCodecContext *avctx);
  
  void ff_print_debug_info(MpegEncContext *s, Picture *p, AVFrame *pict);
  void ff_print_debug_info2(AVCodecContext *avctx, AVFrame *pict, uint8_t *mbskip_table,
                           uint32_t *mbtype_table, int8_t *qscale_table, int16_t (*motion_val[2])[2],
                           int *low_delay,
                           int mb_width, int mb_height, int mb_stride, int quarter_sample);
  
  int ff_mpv_export_qp_table(MpegEncContext *s, AVFrame *f, Picture *p, int qp_type);
  
  void ff_write_quant_matrix(PutBitContext *pb, uint16_t *matrix);
  int ff_find_unused_picture(MpegEncContext *s, int shared);
  void ff_denoise_dct(MpegEncContext *s, int16_t *block);
  int ff_update_duplicate_context(MpegEncContext *dst, MpegEncContext *src);
  int ff_mpeg_update_thread_context(AVCodecContext *dst, const AVCodecContext *src);
  void ff_set_qscale(MpegEncContext * s, int qscale);
  
  void ff_mpv_idct_init(MpegEncContext *s);
  int ff_dct_encode_init(MpegEncContext *s);
  void ff_convert_matrix(MpegEncContext *s, int (*qmat)[64], uint16_t (*qmat16)[2][64],
                         const uint16_t *quant_matrix, int bias, int qmin, int qmax, int intra);
  int ff_dct_quantize_c(MpegEncContext *s, int16_t *block, int n, int qscale, int *overflow);
  
  void ff_init_block_index(MpegEncContext *s);
  
  void ff_mpv_motion(MpegEncContext *s,
                     uint8_t *dest_y, uint8_t *dest_cb,
                     uint8_t *dest_cr, int dir,
                     uint8_t **ref_picture,
                     op_pixels_func (*pix_op)[4],
                     qpel_mc_func (*qpix_op)[16]);
  
  /**
   * Allocate a Picture.
   * The pixels are allocated/set by calling get_buffer() if shared = 0.
   */
  int ff_alloc_picture(MpegEncContext *s, Picture *pic, int shared);
  
  /**
   * permute block according to permuatation.
   * @param last last non zero element in scantable order
   */
  void ff_block_permute(int16_t *block, uint8_t *permutation, const uint8_t *scantable, int last);
  
  static inline void ff_update_block_index(MpegEncContext *s){
      const int block_size= 8 >> s->avctx->lowres;
  
      s->block_index[0]+=2;
      s->block_index[1]+=2;
      s->block_index[2]+=2;
      s->block_index[3]+=2;
      s->block_index[4]++;
      s->block_index[5]++;
      s->dest[0]+= 2*block_size;
      s->dest[1]+= block_size;
      s->dest[2]+= block_size;
  }
  
  static inline int get_bits_diff(MpegEncContext *s){
      const int bits= put_bits_count(&s->pb);
      const int last= s->last_bits;
  
      s->last_bits = bits;
  
      return bits - last;
  }
  
  static inline int ff_h263_round_chroma(int x){
      static const uint8_t h263_chroma_roundtab[16] = {
      //  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15
          0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1,
      };
      return h263_chroma_roundtab[x & 0xf] + (x >> 3);
  }
  
  /* motion_est.c */
  void ff_estimate_p_frame_motion(MpegEncContext * s,
                               int mb_x, int mb_y);
  void ff_estimate_b_frame_motion(MpegEncContext * s,
                               int mb_x, int mb_y);
  int ff_get_best_fcode(MpegEncContext * s, int16_t (*mv_table)[2], int type);
  void ff_fix_long_p_mvs(MpegEncContext * s);
  void ff_fix_long_mvs(MpegEncContext * s, uint8_t *field_select_table, int field_select,
                       int16_t (*mv_table)[2], int f_code, int type, int truncate);
  int ff_init_me(MpegEncContext *s);
  int ff_pre_estimate_p_frame_motion(MpegEncContext * s, int mb_x, int mb_y);
  int ff_epzs_motion_search(MpegEncContext * s, int *mx_ptr, int *my_ptr,
                               int P[10][2], int src_index, int ref_index, int16_t (*last_mv)[2],
                               int ref_mv_scale, int size, int h);
  int ff_get_mb_score(MpegEncContext * s, int mx, int my, int src_index,
                                 int ref_index, int size, int h, int add_rate);
  
  /* mpeg12.c */
  extern const uint8_t ff_mpeg1_dc_scale_table[128];
  extern const uint8_t * const ff_mpeg2_dc_scale_table[4];
  
  void ff_mpeg1_encode_picture_header(MpegEncContext *s, int picture_number);
  void ff_mpeg1_encode_mb(MpegEncContext *s,
                          int16_t block[6][64],
                          int motion_x, int motion_y);
  void ff_mpeg1_encode_init(MpegEncContext *s);
  void ff_mpeg1_encode_slice_header(MpegEncContext *s);
  
  extern const uint8_t ff_aic_dc_scale_table[32];
  extern const uint8_t ff_h263_chroma_qscale_table[32];
  
  /* rv10.c */
  void ff_rv10_encode_picture_header(MpegEncContext *s, int picture_number);
  int ff_rv_decode_dc(MpegEncContext *s, int n);
  void ff_rv20_encode_picture_header(MpegEncContext *s, int picture_number);
  
  
  /* msmpeg4.c */
  void ff_msmpeg4_encode_picture_header(MpegEncContext * s, int picture_number);
  void ff_msmpeg4_encode_ext_header(MpegEncContext * s);
  void ff_msmpeg4_encode_mb(MpegEncContext * s,
                            int16_t block[6][64],
                            int motion_x, int motion_y);
  int ff_msmpeg4_decode_picture_header(MpegEncContext * s);
  int ff_msmpeg4_decode_ext_header(MpegEncContext * s, int buf_size);
  int ff_msmpeg4_decode_init(AVCodecContext *avctx);
  void ff_msmpeg4_encode_init(MpegEncContext *s);
  int ff_wmv2_decode_picture_header(MpegEncContext * s);
  int ff_wmv2_decode_secondary_picture_header(MpegEncContext * s);
  void ff_wmv2_add_mb(MpegEncContext *s, int16_t block[6][64], uint8_t *dest_y, uint8_t *dest_cb, uint8_t *dest_cr);
  void ff_mspel_motion(MpegEncContext *s,
                                 uint8_t *dest_y, uint8_t *dest_cb, uint8_t *dest_cr,
                                 uint8_t **ref_picture, op_pixels_func (*pix_op)[4],
                                 int motion_x, int motion_y, int h);
  int ff_wmv2_encode_picture_header(MpegEncContext * s, int picture_number);
  void ff_wmv2_encode_mb(MpegEncContext * s,
                         int16_t block[6][64],
                         int motion_x, int motion_y);
  
  int ff_mpeg_ref_picture(MpegEncContext *s, Picture *dst, Picture *src);
  void ff_mpeg_unref_picture(MpegEncContext *s, Picture *picture);
  void ff_free_picture_tables(Picture *pic);
  
  
  #endif /* AVCODEC_MPEGVIDEO_H */
  