/*
  * FFV1 codec for libavcodec
  *
  * Copyright (c) 2003-2012 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_FFV1_H
 #define AVCODEC_FFV1_H
 
 /**
  * @file
  * FF Video Codec 1 (a lossless codec)
  */
 
 #include "libavutil/avassert.h"
 #include "libavutil/crc.h"
 #include "libavutil/opt.h"
 #include "libavutil/imgutils.h"
 #include "libavutil/pixdesc.h"
 #include "libavutil/timer.h"
 #include "avcodec.h"

 #include "get_bits.h"

 #include "internal.h"

 #include "mathops.h"

 #include "put_bits.h"
 #include "rangecoder.h"

 #include "thread.h"

 
 #ifdef __INTEL_COMPILER
 #undef av_flatten
 #define av_flatten
 #endif
 
 #define MAX_PLANES 4
 #define CONTEXT_SIZE 32
 
 #define MAX_QUANT_TABLES 8
 #define MAX_CONTEXT_INPUTS 5
 
 typedef struct VlcState {
     int16_t drift;
     uint16_t error_sum;
     int8_t bias;
     uint8_t count;
 } VlcState;
 
 typedef struct PlaneContext {
     int16_t quant_table[MAX_CONTEXT_INPUTS][256];
     int quant_table_index;
     int context_count;
     uint8_t (*state)[CONTEXT_SIZE];
     VlcState *vlc_state;
     uint8_t interlace_bit_state[2];
 } PlaneContext;
 
 #define MAX_SLICES 256
 
 typedef struct FFV1Context {
     AVClass *class;
     AVCodecContext *avctx;
     RangeCoder c;
     GetBitContext gb;
     PutBitContext pb;
     uint64_t rc_stat[256][2];
     uint64_t (*rc_stat2[MAX_QUANT_TABLES])[32][2];
     int version;

     int micro_version;

     int width, height;
     int chroma_planes;

     int chroma_h_shift, chroma_v_shift;

     int transparency;
     int flags;
     int picture_number;

     ThreadFrame picture, last_picture;

     struct FFV1Context *fsrc;

 
     AVFrame *cur;

     int plane_count;
     int ac;                              ///< 1=range coder <-> 0=golomb rice
     int ac_byte_count;                   ///< number of bytes used for AC coding
     PlaneContext plane[MAX_PLANES];
     int16_t quant_table[MAX_CONTEXT_INPUTS][256];
     int16_t quant_tables[MAX_QUANT_TABLES][MAX_CONTEXT_INPUTS][256];
     int context_count[MAX_QUANT_TABLES];
     uint8_t state_transition[256];
     uint8_t (*initial_states[MAX_QUANT_TABLES])[32];
     int run_index;
     int colorspace;
     int16_t *sample_buffer;

     int ec;

     int intra;

     int slice_damaged;
     int key_frame_ok;
 

     int bits_per_raw_sample;
     int packed_at_lsb;
 
     int gob_count;

     int quant_table_count;
 
     struct FFV1Context *slice_context[MAX_SLICES];
     int slice_count;

     int max_slice_count;

     int num_v_slices;
     int num_h_slices;
     int slice_width;
     int slice_height;
     int slice_x;
     int slice_y;

     int slice_reset_contexts;
     int slice_coding_mode;

     int slice_rct_by_coef;
     int slice_rct_ry_coef;

 } FFV1Context;
 
 int ffv1_common_init(AVCodecContext *avctx);
 int ffv1_init_slice_state(FFV1Context *f, FFV1Context *fs);
 int ffv1_init_slices_state(FFV1Context *f);
 int ffv1_init_slice_contexts(FFV1Context *f);
 int ffv1_allocate_initial_states(FFV1Context *f);
 void ffv1_clear_slice_state(FFV1Context *f, FFV1Context *fs);

 int ffv1_close(AVCodecContext *avctx);

 
 static av_always_inline int fold(int diff, int bits)
 {
     if (bits == 8)
         diff = (int8_t)diff;
     else {
         diff +=  1 << (bits  - 1);
         diff &= (1 <<  bits) - 1;
         diff -=  1 << (bits  - 1);
     }
 
     return diff;
 }
 
 static inline int predict(int16_t *src, int16_t *last)
 {
     const int LT = last[-1];
     const int T  = last[0];
     const int L  = src[-1];
 
     return mid_pred(L, L + T - LT, T);
 }
 
 static inline int get_context(PlaneContext *p, int16_t *src,
                               int16_t *last, int16_t *last2)
 {
     const int LT = last[-1];
     const int T  = last[0];
     const int RT = last[1];
     const int L  = src[-1];
 
     if (p->quant_table[3][127]) {
         const int TT = last2[0];
         const int LL = src[-2];
         return p->quant_table[0][(L - LT) & 0xFF] +
                p->quant_table[1][(LT - T) & 0xFF] +
                p->quant_table[2][(T - RT) & 0xFF] +
                p->quant_table[3][(LL - L) & 0xFF] +
                p->quant_table[4][(TT - T) & 0xFF];
     } else
         return p->quant_table[0][(L - LT) & 0xFF] +
                p->quant_table[1][(LT - T) & 0xFF] +
                p->quant_table[2][(T - RT) & 0xFF];
 }
 
 static inline void update_vlc_state(VlcState *const state, const int v)
 {
     int drift = state->drift;
     int count = state->count;
     state->error_sum += FFABS(v);
     drift            += v;
 
     if (count == 128) { // FIXME: variable
         count            >>= 1;
         drift            >>= 1;
         state->error_sum >>= 1;
     }
     count++;
 
     if (drift <= -count) {
         if (state->bias > -128)
             state->bias--;
 
         drift += count;
         if (drift <= -count)
             drift = -count + 1;
     } else if (drift > 0) {
         if (state->bias < 127)
             state->bias++;
 
         drift -= count;
         if (drift > 0)
             drift = 0;
     }
 
     state->drift = drift;
     state->count = count;
 }
 
 #endif /* AVCODEC_FFV1_H */