text: /*
   * H.263 internal header
   *
   * 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_H263_H
  #define AVCODEC_H263_H
  
  #include <stdint.h>
  #include "libavutil/rational.h"
  #include "get_bits.h"
  #include "mpegvideo.h"
  #include "h263data.h"
  #include "rl.h"
  
  #if !FF_API_ASPECT_EXTENDED
  #define FF_ASPECT_EXTENDED 15
  #endif
  #define INT_BIT (CHAR_BIT * sizeof(int))
  
  // The defines below define the number of bits that are read at once for
  // reading vlc values. Changing these may improve speed and data cache needs
  // be aware though that decreasing them may need the number of stages that is
  // passed to get_vlc* to be increased.
  #define INTRA_MCBPC_VLC_BITS 6
  #define INTER_MCBPC_VLC_BITS 7
  #define CBPY_VLC_BITS 6
  #define TEX_VLC_BITS 9
  
  #define H263_GOB_HEIGHT(h) ((h) <= 400 ? 1 : (h) <= 800 ? 2 : 4)
  
  extern VLC ff_h263_intra_MCBPC_vlc;
  extern VLC ff_h263_inter_MCBPC_vlc;
  extern VLC ff_h263_cbpy_vlc;
  
  extern const enum AVPixelFormat ff_h263_hwaccel_pixfmt_list_420[];
  
  
  int ff_h263_decode_motion(MpegEncContext * s, int pred, int f_code);
  av_const int ff_h263_aspect_to_info(AVRational aspect);
  int ff_h263_decode_init(AVCodecContext *avctx);
  int ff_h263_decode_frame(AVCodecContext *avctx,
                               void *data, int *got_frame,
                               AVPacket *avpkt);
  int ff_h263_decode_end(AVCodecContext *avctx);
  void ff_h263_encode_mb(MpegEncContext *s,
                         int16_t block[6][64],
                         int motion_x, int motion_y);
  void ff_h263_encode_picture_header(MpegEncContext *s, int picture_number);
  void ff_h263_encode_gob_header(MpegEncContext * s, int mb_line);
  int16_t *ff_h263_pred_motion(MpegEncContext * s, int block, int dir,
                               int *px, int *py);
  void ff_h263_encode_init(MpegEncContext *s);
  void ff_h263_decode_init_vlc(void);
  int ff_h263_decode_picture_header(MpegEncContext *s);
  int ff_h263_decode_gob_header(MpegEncContext *s);
  void ff_h263_update_motion_val(MpegEncContext * s);
  void ff_h263_loop_filter(MpegEncContext * s);
  int ff_h263_decode_mba(MpegEncContext *s);
  void ff_h263_encode_mba(MpegEncContext *s);
  void ff_init_qscale_tab(MpegEncContext *s);
  int ff_h263_pred_dc(MpegEncContext * s, int n, int16_t **dc_val_ptr);
  void ff_h263_pred_acdc(MpegEncContext * s, int16_t *block, int n);
  
  
  /**
   * Print picture info if FF_DEBUG_PICT_INFO is set.
   */
  void ff_h263_show_pict_info(MpegEncContext *s);
  
  int ff_intel_h263_decode_picture_header(MpegEncContext *s);
  int ff_h263_decode_mb(MpegEncContext *s,
                        int16_t block[6][64]);
  
  /**
   * Return the value of the 3-bit "source format" syntax element.
   * This represents some standard picture dimensions or indicates that
   * width&height are explicitly stored later.
   */
  int av_const h263_get_picture_format(int width, int height);
  
  void ff_clean_h263_qscales(MpegEncContext *s);
  int ff_h263_resync(MpegEncContext *s);
  void ff_h263_encode_motion(PutBitContext *pb, int val, int f_code);
  
  
  static inline int h263_get_motion_length(int val, int f_code){
      int l, bit_size, code;
  
      if (val == 0) {
          return ff_mvtab[0][1];
      } else {
          bit_size = f_code - 1;
          /* modulo encoding */
          l= INT_BIT - 6 - bit_size;
          val = (val<<l)>>l;
          val--;
          code = (val >> bit_size) + 1;
  
          return ff_mvtab[code][1] + 1 + bit_size;
      }
  }
  
  static inline void ff_h263_encode_motion_vector(MpegEncContext * s, int x, int y, int f_code){
      if (s->avctx->flags2 & AV_CODEC_FLAG2_NO_OUTPUT) {
          skip_put_bits(&s->pb,
              h263_get_motion_length(x, f_code)
             +h263_get_motion_length(y, f_code));
      }else{
          ff_h263_encode_motion(&s->pb, x, f_code);
          ff_h263_encode_motion(&s->pb, y, f_code);
      }
  }
  
  static inline int get_p_cbp(MpegEncContext * s,
                        int16_t block[6][64],
                        int motion_x, int motion_y){
      int cbp, i;
  
      if (s->mpv_flags & FF_MPV_FLAG_CBP_RD) {
          int best_cbpy_score= INT_MAX;
          int best_cbpc_score= INT_MAX;
          int cbpc = (-1), cbpy= (-1);
          const int offset= (s->mv_type==MV_TYPE_16X16 ? 0 : 16) + (s->dquant ? 8 : 0);
          const int lambda= s->lambda2 >> (FF_LAMBDA_SHIFT - 6);
  
          for(i=0; i<4; i++){
              int score= ff_h263_inter_MCBPC_bits[i + offset] * lambda;
              if(i&1) score += s->coded_score[5];
              if(i&2) score += s->coded_score[4];
  
              if(score < best_cbpc_score){
                  best_cbpc_score= score;
                  cbpc= i;
              }
          }
  
          for(i=0; i<16; i++){
              int score= ff_h263_cbpy_tab[i ^ 0xF][1] * lambda;
              if(i&1) score += s->coded_score[3];
              if(i&2) score += s->coded_score[2];
              if(i&4) score += s->coded_score[1];
              if(i&8) score += s->coded_score[0];
  
              if(score < best_cbpy_score){
                  best_cbpy_score= score;
                  cbpy= i;
              }
          }
          cbp= cbpc + 4*cbpy;
          if ((motion_x | motion_y | s->dquant) == 0 && s->mv_type==MV_TYPE_16X16){
              if(best_cbpy_score + best_cbpc_score + 2*lambda >= 0)
                  cbp= 0;
          }
  
          for (i = 0; i < 6; i++) {
              if (s->block_last_index[i] >= 0 && ((cbp >> (5 - i))&1)==0 ){
                  s->block_last_index[i]= -1;
                  s->bdsp.clear_block(s->block[i]);
              }
          }
      }else{
          cbp= 0;
          for (i = 0; i < 6; i++) {
              if (s->block_last_index[i] >= 0)
                  cbp |= 1 << (5 - i);
          }
      }
      return cbp;
  }
  
  #endif /* AVCODEC_H263_H */
  