/*
  * exp golomb vlc stuff
  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>

  * Copyright (c) 2004 Alex Beregszaszi

  *

  * 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

  * @brief

  *     exp golomb vlc stuff

  * @author Michael Niedermayer <michaelni@gmx.at> and Alex Beregszaszi

  */
 

 #ifndef AVCODEC_GOLOMB_H
 #define AVCODEC_GOLOMB_H

 #include <stdint.h>

 #include "get_bits.h"

 #include "put_bits.h"

 #define INVALID_VLC           0x80000000
 

 extern const uint8_t ff_golomb_vlc_len[512];
 extern const uint8_t ff_ue_golomb_vlc_code[512];
 extern const  int8_t ff_se_golomb_vlc_code[512];
 extern const uint8_t ff_ue_golomb_len[256];
 

 extern const uint8_t ff_interleaved_golomb_vlc_len[256];
 extern const uint8_t ff_interleaved_ue_golomb_vlc_code[256];
 extern const  int8_t ff_interleaved_se_golomb_vlc_code[256];

 extern const uint8_t ff_interleaved_dirac_golomb_vlc_code[256];

  /**
  * read unsigned exp golomb code.
  */
 static inline int get_ue_golomb(GetBitContext *gb){
     unsigned int buf;
     int log;

     OPEN_READER(re, gb);
     UPDATE_CACHE(re, gb);
     buf=GET_CACHE(re, gb);

     if(buf >= (1<<27)){
         buf >>= 32 - 9;
         LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
         CLOSE_READER(re, gb);

         return ff_ue_golomb_vlc_code[buf];
     }else{
         log= 2*av_log2(buf) - 31;
         buf>>= log;
         buf--;
         LAST_SKIP_BITS(re, gb, 32 - log);
         CLOSE_READER(re, gb);

         return buf;
     }
 }
 

 /**
  * Read an unsigned Exp-Golomb code in the range 0 to UINT32_MAX-1.
  */
 static inline unsigned get_ue_golomb_long(GetBitContext *gb)
 {
     unsigned buf, log;
 
     buf = show_bits_long(gb, 32);
     log = 31 - av_log2(buf);
     skip_bits_long(gb, log);
 
     return get_bits_long(gb, log + 1) - 1;
 }
 

  /**

  * read unsigned exp golomb code, constraint to a max of 31.
  * the return value is undefined if the stored value exceeds 31.

  */
 static inline int get_ue_golomb_31(GetBitContext *gb){
     unsigned int buf;
 
     OPEN_READER(re, gb);
     UPDATE_CACHE(re, gb);
     buf=GET_CACHE(re, gb);
 
     buf >>= 32 - 9;
     LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
     CLOSE_READER(re, gb);
 
     return ff_ue_golomb_vlc_code[buf];
 }
 

 static inline int svq3_get_ue_golomb(GetBitContext *gb){

     uint32_t buf;

 
     OPEN_READER(re, gb);
     UPDATE_CACHE(re, gb);

     buf=GET_CACHE(re, gb);

     if(buf&0xAA800000){
         buf >>= 32 - 8;
         LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
         CLOSE_READER(re, gb);

         return ff_interleaved_ue_golomb_vlc_code[buf];
     }else{

         int ret = 1;
 
         while (1) {
             buf >>= 32 - 8;
             LAST_SKIP_BITS(re, gb, FFMIN(ff_interleaved_golomb_vlc_len[buf], 8));
 
             if (ff_interleaved_golomb_vlc_len[buf] != 9){
                 ret <<= (ff_interleaved_golomb_vlc_len[buf] - 1) >> 1;
                 ret |= ff_interleaved_dirac_golomb_vlc_code[buf];
                 break;
             }
             ret = (ret << 4) | ff_interleaved_dirac_golomb_vlc_code[buf];
             UPDATE_CACHE(re, gb);
             buf = GET_CACHE(re, gb);

         }

         CLOSE_READER(re, gb);

         return ret - 1;

     }

 }
 

 /**
  * read unsigned truncated exp golomb code.
  */
 static inline int get_te0_golomb(GetBitContext *gb, int range){
     assert(range >= 1);

     if(range==1)      return 0;

     else if(range==2) return get_bits1(gb)^1;

     else              return get_ue_golomb(gb);
 }
 
 /**
  * read unsigned truncated exp golomb code.
  */
 static inline int get_te_golomb(GetBitContext *gb, int range){
     assert(range >= 1);

     if(range==2) return get_bits1(gb)^1;

     else         return get_ue_golomb(gb);
 }
 
 
 /**
  * read signed exp golomb code.
  */
 static inline int get_se_golomb(GetBitContext *gb){
     unsigned int buf;
     int log;

     OPEN_READER(re, gb);
     UPDATE_CACHE(re, gb);
     buf=GET_CACHE(re, gb);

     if(buf >= (1<<27)){
         buf >>= 32 - 9;
         LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
         CLOSE_READER(re, gb);

         return ff_se_golomb_vlc_code[buf];
     }else{
         log= 2*av_log2(buf) - 31;
         buf>>= log;

         LAST_SKIP_BITS(re, gb, 32 - log);
         CLOSE_READER(re, gb);

         if(buf&1) buf= -(buf>>1);
         else      buf=  (buf>>1);
 
         return buf;
     }
 }
 

 static inline int svq3_get_se_golomb(GetBitContext *gb){
     unsigned int buf;
     int log;
 
     OPEN_READER(re, gb);
     UPDATE_CACHE(re, gb);

     buf=GET_CACHE(re, gb);

     if(buf&0xAA800000){
         buf >>= 32 - 8;
         LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
         CLOSE_READER(re, gb);

         return ff_interleaved_se_golomb_vlc_code[buf];
     }else{

         LAST_SKIP_BITS(re, gb, 8);
         UPDATE_CACHE(re, gb);
         buf |= 1 | (GET_CACHE(re, gb) >> 8);
 

         if((buf & 0xAAAAAAAA) == 0)
             return INVALID_VLC;

         for(log=31; (buf & 0x80000000) == 0; log--){
             buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
         }

         LAST_SKIP_BITS(re, gb, 63 - 2*log - 8);

         CLOSE_READER(re, gb);

         return (signed) (((((buf << log) >> log) - 1) ^ -(buf & 0x1)) + 1) >> 1;
     }

 }
 

 static inline int dirac_get_se_golomb(GetBitContext *gb){
     uint32_t buf;
     uint32_t ret;
 
     ret = svq3_get_ue_golomb(gb);
 
     if (ret) {
         OPEN_READER(re, gb);
         UPDATE_CACHE(re, gb);
         buf = SHOW_SBITS(re, gb, 1);
         LAST_SKIP_BITS(re, gb, 1);
         ret = (ret ^ buf) - buf;
         CLOSE_READER(re, gb);
     }
 
     return ret;
 }
 

 /**

  * read unsigned golomb rice code (ffv1).

  */
 static inline int get_ur_golomb(GetBitContext *gb, int k, int limit, int esc_len){
     unsigned int buf;
     int log;

     OPEN_READER(re, gb);
     UPDATE_CACHE(re, gb);
     buf=GET_CACHE(re, gb);
 
     log= av_log2(buf);

     if(log > 31-limit){
         buf >>= log - k;
         buf += (30-log)<<k;
         LAST_SKIP_BITS(re, gb, 32 + k - log);
         CLOSE_READER(re, gb);

         return buf;

     }else{

         LAST_SKIP_BITS(re, gb, limit);
         UPDATE_CACHE(re, gb);
 
         buf = SHOW_UBITS(re, gb, esc_len);
 
         LAST_SKIP_BITS(re, gb, esc_len);

         CLOSE_READER(re, gb);

         return buf + limit - 1;
     }
 }
 
 /**
  * read unsigned golomb rice code (jpegls).
  */
 static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit, int esc_len){
     unsigned int buf;
     int log;

     OPEN_READER(re, gb);
     UPDATE_CACHE(re, gb);
     buf=GET_CACHE(re, gb);
 
     log= av_log2(buf);

     if(log - k >= 32-MIN_CACHE_BITS+(MIN_CACHE_BITS==32) && 32-log < limit){

         buf >>= log - k;
         buf += (30-log)<<k;
         LAST_SKIP_BITS(re, gb, 32 + k - log);
         CLOSE_READER(re, gb);

         return buf;
     }else{
         int i;
         for(i=0; SHOW_UBITS(re, gb, 1) == 0; i++){
             LAST_SKIP_BITS(re, gb, 1);
             UPDATE_CACHE(re, gb);
         }
         SKIP_BITS(re, gb, 1);
 
         if(i < limit - 1){
             if(k){
                 buf = SHOW_UBITS(re, gb, k);
                 LAST_SKIP_BITS(re, gb, k);
             }else{
                 buf=0;
             }
 
             CLOSE_READER(re, gb);
             return buf + (i<<k);
         }else if(i == limit - 1){
             buf = SHOW_UBITS(re, gb, esc_len);
             LAST_SKIP_BITS(re, gb, esc_len);
             CLOSE_READER(re, gb);

             return buf + 1;
         }else
             return -1;
     }

 }
 

 /**

  * read signed golomb rice code (ffv1).
  */

 static inline int get_sr_golomb(GetBitContext *gb, int k, int limit, int esc_len){

     int v= get_ur_golomb(gb, k, limit, esc_len);

     v++;
     if (v&1) return v>>1;
     else return -(v>>1);

 //    return (v>>1) ^ -(v&1);
 }
 

 /**

  * read signed golomb rice code (flac).

  */
 static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit, int esc_len){
     int v= get_ur_golomb_jpegls(gb, k, limit, esc_len);
     return (v>>1) ^ -(v&1);
 }
 

 /**
  * read unsigned golomb rice code (shorten).
  */
 static inline unsigned int get_ur_golomb_shorten(GetBitContext *gb, int k){

         return get_ur_golomb_jpegls(gb, k, INT_MAX, 0);

 }
 
 /**
  * read signed golomb rice code (shorten).
  */
 static inline int get_sr_golomb_shorten(GetBitContext* gb, int k)
 {
     int uvar = get_ur_golomb_jpegls(gb, k + 1, INT_MAX, 0);
     if (uvar & 1)
         return ~(uvar >> 1);
     else
         return uvar >> 1;
 }
 
 
 

 #ifdef TRACE
 

 static inline int get_ue(GetBitContext *s, char *file, const char *func, int line){

     int show= show_bits(s, 24);
     int pos= get_bits_count(s);
     int i= get_ue_golomb(s);
     int len= get_bits_count(s) - pos;
     int bits= show>>(24-len);

     print_bin(bits, len);

     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d ue  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);

     return i;
 }
 

 static inline int get_se(GetBitContext *s, char *file, const char *func, int line){

     int show= show_bits(s, 24);
     int pos= get_bits_count(s);
     int i= get_se_golomb(s);
     int len= get_bits_count(s) - pos;
     int bits= show>>(24-len);

     print_bin(bits, len);

     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d se  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);

     return i;
 }
 

 static inline int get_te(GetBitContext *s, int r, char *file, const char *func, int line){

     int show= show_bits(s, 24);
     int pos= get_bits_count(s);
     int i= get_te0_golomb(s, r);
     int len= get_bits_count(s) - pos;
     int bits= show>>(24-len);

     print_bin(bits, len);

     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d te  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);

     return i;
 }
 
 #define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 #define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 #define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 #define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 
 #endif
 
 /**
  * write unsigned exp golomb code.
  */
 static inline void set_ue_golomb(PutBitContext *pb, int i){
     int e;

     assert(i>=0);
 
 #if 0
     if(i=0){
         put_bits(pb, 1, 1);
         return;
     }
 #endif
     if(i<256)
         put_bits(pb, ff_ue_golomb_len[i], i+1);
     else{
         e= av_log2(i+1);

         put_bits(pb, 2*e+1, i+1);
     }
 }
 
 /**
  * write truncated unsigned exp golomb code.
  */
 static inline void set_te_golomb(PutBitContext *pb, int i, int range){
     assert(range >= 1);
     assert(i<=range);
 

     if(range==2) put_bits(pb, 1, i^1);

     else         set_ue_golomb(pb, i);
 }
 
 /**

  * write signed exp golomb code. 16 bits at most.

  */
 static inline void set_se_golomb(PutBitContext *pb, int i){

 //    if (i>32767 || i<-32767)

 //        av_log(NULL,AV_LOG_ERROR,"value out of range %d\n", i);

 #if 0

     if(i<=0) i= -2*i;
     else     i=  2*i-1;
 #elif 1
     i= 2*i-1;
     if(i<0) i^= -1; //FIXME check if gcc does the right thing
 #else
     i= 2*i-1;
     i^= (i>>31);
 #endif
     set_ue_golomb(pb, i);
 }

 
 /**

  * write unsigned golomb rice code (ffv1).

  */
 static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
     int e;

     assert(i>=0);

     e= i>>k;
     if(e<limit){
         put_bits(pb, e + k + 1, (1<<k) + (i&((1<<k)-1)));
     }else{

         put_bits(pb, limit + esc_len, i - limit + 1);
     }
 }
 
 /**
  * write unsigned golomb rice code (jpegls).
  */
 static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k, int limit, int esc_len){
     int e;

     assert(i>=0);

     e= (i>>k) + 1;
     if(e<limit){

         while(e > 31) {
             put_bits(pb, 31, 0);
             e -= 31;
         }

         put_bits(pb, e, 1);

         if(k)

             put_sbits(pb, k, i);

     }else{

         while(limit > 31) {
             put_bits(pb, 31, 0);
             limit -= 31;
         }

         put_bits(pb, limit  , 1);
         put_bits(pb, esc_len, i - 1);

     }
 }

 
 /**
  * write signed golomb rice code (ffv1).
  */

 static inline void set_sr_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){

     int v;
 
     v = -2*i-1;
     v ^= (v>>31);
 
     set_ur_golomb(pb, v, k, limit, esc_len);
 }
 
 /**
  * write signed golomb rice code (flac).
  */
 static inline void set_sr_golomb_flac(PutBitContext *pb, int i, int k, int limit, int esc_len){
     int v;
 
     v = -2*i-1;
     v ^= (v>>31);
 
     set_ur_golomb_jpegls(pb, v, k, limit, esc_len);
 }

 #endif /* AVCODEC_GOLOMB_H */