/*
  * 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;

     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 {

         int log = 2 * av_log2(buf) - 31;

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

         if (CONFIG_FTRAPV && log < 0) {
             av_log(0, AV_LOG_ERROR, "Invalid UE golomb code\n");
             return AVERROR_INVALIDDATA;
         }

         buf >>= log;

         buf--;

         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 unsigned 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 {

         unsigned ret = 1;

         do {

             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);

         } while (ret<0x8000000U && HAVE_BITS_REMAINING(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)
 {

     av_assert2(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)
 {

     av_assert2(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;

     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 {

         int log = av_log2(buf);

         LAST_SKIP_BITS(re, gb, 31 - log);
         UPDATE_CACHE(re, gb);
         buf = GET_CACHE(re, gb);
 

         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 get_se_golomb_long(GetBitContext *gb)
 {
     unsigned int buf = get_ue_golomb_long(gb);
 
     if (buf & 1)

         buf = (buf + 1) >> 1;

     else

         buf = -(buf >> 1);

 
     return buf;
 }
 

 static inline int svq3_get_se_golomb(GetBitContext *gb)
 {

     unsigned int 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_se_golomb_vlc_code[buf];

     } else {

         int log;

         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 ret = svq3_get_ue_golomb(gb);

 
     if (ret) {

         uint32_t buf;

         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; i < limit && SHOW_UBITS(re, gb, 1) == 0; i++) {

             if (gb->size_in_bits <= re_index)

                 return -1;

             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, const 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, const 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 /* TRACE */

 
 /**
  * write unsigned exp golomb code.
  */

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

     av_assert2(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 {

         int 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)
 {

     av_assert2(range >= 1);

     av_assert2(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 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;

     av_assert2(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;

     av_assert2(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 */