/**

  * @file

  * VP5 and VP6 compatible video decoder (common features)
  *
  * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
  *

  * 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_VP56_H
 #define AVCODEC_VP56_H

 
 #include "vp56data.h"
 #include "dsputil.h"

 #include "get_bits.h"

 #include "bytestream.h"

 #include "cabac.h"

 #include "vp56dsp.h"

 typedef struct vp56_context VP56Context;

 
 typedef struct {
     int16_t x;
     int16_t y;
 } DECLARE_ALIGNED(4, , VP56mv);

 typedef void (*VP56ParseVectorAdjustment)(VP56Context *s,

                                           VP56mv *vect);

 typedef void (*VP56Filter)(VP56Context *s, uint8_t *dst, uint8_t *src,

                            int offset1, int offset2, int stride,
                            VP56mv mv, int mask, int select, int luma);

 typedef void (*VP56ParseCoeff)(VP56Context *s);
 typedef void (*VP56DefaultModelsInit)(VP56Context *s);
 typedef void (*VP56ParseVectorModels)(VP56Context *s);

 typedef int  (*VP56ParseCoeffModels)(VP56Context *s);

 typedef int  (*VP56ParseHeader)(VP56Context *s, const uint8_t *buf,
                                 int buf_size, int *golden_frame);

 
 typedef struct {
     int high;

     int bits; /* stored negated (i.e. negative "bits" is a positive number of
                  bits left) in order to eliminate a negate in cache refilling */

     const uint8_t *buffer;

     const uint8_t *end;

     unsigned int code_word;

 } VP56RangeCoder;

 
 typedef struct {
     uint8_t not_null_dc;

     VP56Frame ref_frame;

     DCTELEM dc_coeff;

 } VP56RefDc;

 
 typedef struct {
     uint8_t type;

     VP56mv mv;
 } VP56Macroblock;

 typedef struct {
     uint8_t coeff_reorder[64];       /* used in vp6 only */
     uint8_t coeff_index_to_pos[64];  /* used in vp6 only */
     uint8_t vector_sig[2];           /* delta sign */
     uint8_t vector_dct[2];           /* delta coding types */
     uint8_t vector_pdi[2][2];        /* predefined delta init */
     uint8_t vector_pdv[2][7];        /* predefined delta values */
     uint8_t vector_fdv[2][8];        /* 8 bit delta value definition */
     uint8_t coeff_dccv[2][11];       /* DC coeff value */
     uint8_t coeff_ract[2][3][6][11]; /* Run/AC coding type and AC coeff value */
     uint8_t coeff_acct[2][3][3][6][5];/* vp5 only AC coding type for coding group < 3 */
     uint8_t coeff_dcct[2][36][5];    /* DC coeff coding type */
     uint8_t coeff_runv[2][14];       /* run value (vp6 only) */
     uint8_t mb_type[3][10][10];      /* model for decoding MB type */
     uint8_t mb_types_stats[3][10][2];/* contextual, next MB type stats */

 } VP56Model;

 struct vp56_context {
     AVCodecContext *avctx;
     DSPContext dsp;

     VP56DSPContext vp56dsp;

     ScanTable scantable;

     AVFrame frames[4];
     AVFrame *framep[6];

     uint8_t *edge_emu_buffer_alloc;
     uint8_t *edge_emu_buffer;

     VP56RangeCoder c;
     VP56RangeCoder cc;
     VP56RangeCoder *ccp;

     int sub_version;

 
     /* frame info */

     int plane_width[4];
     int plane_height[4];

     int mb_width;   /* number of horizontal MB */
     int mb_height;  /* number of vertical MB */
     int block_offset[6];
 
     int quantizer;
     uint16_t dequant_dc;
     uint16_t dequant_ac;

     int8_t *qscale_table;

 
     /* DC predictors management */

     VP56RefDc *above_blocks;
     VP56RefDc left_block[4];

     int above_block_idx[6];
     DCTELEM prev_dc[3][3];    /* [plan][ref_frame] */
 
     /* blocks / macroblock */

     VP56mb mb_type;
     VP56Macroblock *macroblocks;

     DECLARE_ALIGNED(16, DCTELEM, block_coeff)[6][64];

 
     /* motion vectors */

     VP56mv mv[6];  /* vectors for each block in MB */
     VP56mv vector_candidate[2];

     int vector_candidate_pos;
 
     /* filtering hints */

     int filter_header;               /* used in vp6 only */

     int deblock_filtering;
     int filter_selection;
     int filter_mode;
     int max_vector_length;
     int sample_variance_threshold;
 
     uint8_t coeff_ctx[4][64];              /* used in vp5 only */
     uint8_t coeff_ctx_last[4];             /* used in vp5 only */
 

     int has_alpha;
 

     /* upside-down flipping hints */
     int flip;  /* are we flipping ? */
     int frbi;  /* first row block index in MB */
     int srbi;  /* second row block index in MB */

     int stride[4];  /* stride for each plan */

 
     const uint8_t *vp56_coord_div;

     VP56ParseVectorAdjustment parse_vector_adjustment;
     VP56Filter filter;
     VP56ParseCoeff parse_coeff;
     VP56DefaultModelsInit default_models_init;
     VP56ParseVectorModels parse_vector_models;
     VP56ParseCoeffModels parse_coeff_models;
     VP56ParseHeader parse_header;
 

     VP56Model *modelp;
     VP56Model models[2];

 
     /* huffman decoding */
     int use_huffman;
     GetBitContext gb;
     VLC dccv_vlc[2];
     VLC runv_vlc[2];
     VLC ract_vlc[2][3][6];
     unsigned int nb_null[2][2];       /* number of consecutive NULL DC/AC */

 };
 
 

 void ff_vp56_init(AVCodecContext *avctx, int flip, int has_alpha);
 int ff_vp56_free(AVCodecContext *avctx);
 void ff_vp56_init_dequant(VP56Context *s, int quantizer);
 int ff_vp56_decode_frame(AVCodecContext *avctx, void *data, int *data_size,

                          AVPacket *avpkt);

 
 
 /**
  * vp56 specific range coder implementation
  */
 

 extern const uint8_t ff_vp56_norm_shift[256];
 void ff_vp56_init_range_decoder(VP56RangeCoder *c, const uint8_t *buf, int buf_size);

 static av_always_inline unsigned int vp56_rac_renorm(VP56RangeCoder *c)

 {

     int shift = ff_vp56_norm_shift[c->high];

     int bits = c->bits;

     unsigned int code_word = c->code_word;

 
     c->high   <<= shift;
     code_word <<= shift;
     bits       += shift;
     if(bits >= 0 && c->buffer < c->end) {

         code_word |= bytestream_get_be16(&c->buffer) << bits;
         bits -= 16;

     }
     c->bits = bits;

     return code_word;

 }
 

 #if   ARCH_ARM
 #include "arm/vp56_arith.h"
 #elif ARCH_X86

 #include "x86/vp56_arith.h"
 #endif
 
 #ifndef vp56_rac_get_prob
 #define vp56_rac_get_prob vp56_rac_get_prob

 static av_always_inline int vp56_rac_get_prob(VP56RangeCoder *c, uint8_t prob)

 {

     unsigned int code_word = vp56_rac_renorm(c);

     unsigned int low = 1 + (((c->high - 1) * prob) >> 8);

     unsigned int low_shift = low << 16;

     int bit = code_word >= low_shift;

     c->high = bit ? c->high - low : low;

     c->code_word = bit ? code_word - low_shift : code_word;

 
     return bit;
 }

 #endif

 #ifndef vp56_rac_get_prob_branchy

 // branchy variant, to be used where there's a branch based on the bit decoded
 static av_always_inline int vp56_rac_get_prob_branchy(VP56RangeCoder *c, int prob)
 {
     unsigned long code_word = vp56_rac_renorm(c);
     unsigned low = 1 + (((c->high - 1) * prob) >> 8);

     unsigned low_shift = low << 16;

 
     if (code_word >= low_shift) {
         c->high     -= low;
         c->code_word = code_word - low_shift;
         return 1;
     }
 
     c->high = low;
     c->code_word = code_word;
     return 0;
 }

 #endif

 static av_always_inline int vp56_rac_get(VP56RangeCoder *c)

 {

     unsigned int code_word = vp56_rac_renorm(c);

     /* equiprobable */
     int low = (c->high + 1) >> 1;

     unsigned int low_shift = low << 16;

     int bit = code_word >= low_shift;

     if (bit) {

         c->high   -= low;
         code_word -= low_shift;

     } else {

         c->high = low;

     }
 

     c->code_word = code_word;

     return bit;
 }
 

 // rounding is different than vp56_rac_get, is vp56_rac_get wrong?

 static av_always_inline int vp8_rac_get(VP56RangeCoder *c)

 {
     return vp56_rac_get_prob(c, 128);
 }
 

 static av_unused int vp56_rac_gets(VP56RangeCoder *c, int bits)

 {
     int value = 0;
 
     while (bits--) {
         value = (value << 1) | vp56_rac_get(c);
     }
 
     return value;
 }
 

 static av_unused int vp8_rac_get_uint(VP56RangeCoder *c, int bits)

 {
     int value = 0;
 
     while (bits--) {
         value = (value << 1) | vp8_rac_get(c);
     }
 
     return value;
 }
 
 // fixme: add 1 bit to all the calls to this?

 static av_unused int vp8_rac_get_sint(VP56RangeCoder *c, int bits)

 {
     int v;
 
     if (!vp8_rac_get(c))
         return 0;
 
     v = vp8_rac_get_uint(c, bits);
 
     if (vp8_rac_get(c))
         v = -v;
 
     return v;
 }
 
 // P(7)

 static av_unused int vp56_rac_gets_nn(VP56RangeCoder *c, int bits)

 {
     int v = vp56_rac_gets(c, 7) << 1;
     return v + !v;
 }
 

 static av_unused int vp8_rac_get_nn(VP56RangeCoder *c)

 {
     int v = vp8_rac_get_uint(c, 7) << 1;
     return v + !v;
 }
 

 static av_always_inline
 int vp56_rac_get_tree(VP56RangeCoder *c,
                       const VP56Tree *tree,
                       const uint8_t *probs)

 {
     while (tree->val > 0) {
         if (vp56_rac_get_prob(c, probs[tree->prob_idx]))
             tree += tree->val;
         else
             tree++;
     }
     return -tree->val;
 }
 

 /**
  * This is identical to vp8_rac_get_tree except for the possibility of starting
  * on a node other than the root node, needed for coeff decode where this is
  * used to save a bit after a 0 token (by disallowing EOB to immediately follow.)
  */

 static av_always_inline
 int vp8_rac_get_tree_with_offset(VP56RangeCoder *c, const int8_t (*tree)[2],
                                  const uint8_t *probs, int i)

 {
     do {
         i = tree[i][vp56_rac_get_prob(c, probs[i])];
     } while (i > 0);
 
     return -i;
 }
 
 // how probabilities are associated with decisions is different I think
 // well, the new scheme fits in the old but this way has one fewer branches per decision

 static av_always_inline
 int vp8_rac_get_tree(VP56RangeCoder *c, const int8_t (*tree)[2],
                      const uint8_t *probs)

 {
     return vp8_rac_get_tree_with_offset(c, tree, probs, 0);
 }
 
 // DCTextra

 static av_always_inline int vp8_rac_get_coeff(VP56RangeCoder *c, const uint8_t *prob)

 {
     int v = 0;
 
     do {
         v = (v<<1) + vp56_rac_get_prob(c, *prob++);
     } while (*prob);
 
     return v;
 }
 

 #endif /* AVCODEC_VP56_H */