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bitreader.h (7170B)


      1 /*
      2 * Copyright (c) 2016, Alliance for Open Media. All rights reserved.
      3 *
      4 * This source code is subject to the terms of the BSD 2 Clause License and
      5 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
      6 * was not distributed with this source code in the LICENSE file, you can
      7 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
      8 * Media Patent License 1.0 was not distributed with this source code in the
      9 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
     10 */
     11 
     12 #ifndef AOM_AOM_DSP_BITREADER_H_
     13 #define AOM_AOM_DSP_BITREADER_H_
     14 
     15 #include <assert.h>
     16 #include <limits.h>
     17 
     18 #include "config/aom_config.h"
     19 
     20 #include "aom/aomdx.h"
     21 #include "aom/aom_integer.h"
     22 #include "aom_dsp/entdec.h"
     23 #include "aom_dsp/odintrin.h"
     24 #include "aom_dsp/prob.h"
     25 
     26 #if CONFIG_BITSTREAM_DEBUG
     27 #include "aom_util/debug_util.h"
     28 #endif  // CONFIG_BITSTREAM_DEBUG
     29 
     30 #if CONFIG_ACCOUNTING
     31 #include "av1/decoder/accounting.h"
     32 #define ACCT_STR_NAME acct_str
     33 #define ACCT_STR_PARAM , const char *ACCT_STR_NAME
     34 #define ACCT_STR_ARG(s) , s
     35 #else
     36 #define ACCT_STR_PARAM
     37 #define ACCT_STR_ARG(s)
     38 #endif
     39 
     40 #define aom_read(r, prob, ACCT_STR_NAME) \
     41  aom_read_(r, prob ACCT_STR_ARG(ACCT_STR_NAME))
     42 #define aom_read_bit(r, ACCT_STR_NAME) \
     43  aom_read_bit_(r ACCT_STR_ARG(ACCT_STR_NAME))
     44 #define aom_read_tree(r, tree, probs, ACCT_STR_NAME) \
     45  aom_read_tree_(r, tree, probs ACCT_STR_ARG(ACCT_STR_NAME))
     46 #define aom_read_literal(r, bits, ACCT_STR_NAME) \
     47  aom_read_literal_(r, bits ACCT_STR_ARG(ACCT_STR_NAME))
     48 #define aom_read_cdf(r, cdf, nsymbs, ACCT_STR_NAME) \
     49  aom_read_cdf_(r, cdf, nsymbs ACCT_STR_ARG(ACCT_STR_NAME))
     50 #define aom_read_symbol(r, cdf, nsymbs, ACCT_STR_NAME) \
     51  aom_read_symbol_(r, cdf, nsymbs ACCT_STR_ARG(ACCT_STR_NAME))
     52 
     53 #ifdef __cplusplus
     54 extern "C" {
     55 #endif
     56 
     57 struct aom_reader {
     58  const uint8_t *buffer;
     59  const uint8_t *buffer_end;
     60  od_ec_dec ec;
     61 #if CONFIG_ACCOUNTING
     62  Accounting *accounting;
     63 #endif
     64  uint8_t allow_update_cdf;
     65 };
     66 
     67 typedef struct aom_reader aom_reader;
     68 
     69 int aom_reader_init(aom_reader *r, const uint8_t *buffer, size_t size);
     70 
     71 const uint8_t *aom_reader_find_begin(aom_reader *r);
     72 
     73 const uint8_t *aom_reader_find_end(aom_reader *r);
     74 
     75 // Returns true if the bit reader has tried to decode more data from the buffer
     76 // than was actually provided.
     77 int aom_reader_has_overflowed(const aom_reader *r);
     78 
     79 // Returns the position in the bit reader in bits.
     80 uint32_t aom_reader_tell(const aom_reader *r);
     81 
     82 // Returns the position in the bit reader in 1/8th bits.
     83 uint32_t aom_reader_tell_frac(const aom_reader *r);
     84 
     85 #if CONFIG_ACCOUNTING
     86 static inline void aom_process_accounting(const aom_reader *r ACCT_STR_PARAM) {
     87  if (r->accounting != NULL) {
     88    uint32_t tell_frac;
     89    tell_frac = aom_reader_tell_frac(r);
     90    aom_accounting_record(r->accounting, ACCT_STR_NAME,
     91                          tell_frac - r->accounting->last_tell_frac);
     92    r->accounting->last_tell_frac = tell_frac;
     93  }
     94 }
     95 
     96 static inline void aom_update_symb_counts(const aom_reader *r, int is_binary) {
     97  if (r->accounting != NULL) {
     98    r->accounting->syms.num_multi_syms += !is_binary;
     99    r->accounting->syms.num_binary_syms += !!is_binary;
    100  }
    101 }
    102 #endif
    103 
    104 static inline int aom_read_(aom_reader *r, int prob ACCT_STR_PARAM) {
    105  int p = (0x7FFFFF - (prob << 15) + prob) >> 8;
    106  int bit = od_ec_decode_bool_q15(&r->ec, p);
    107 
    108 #if CONFIG_BITSTREAM_DEBUG
    109  {
    110    int i;
    111    int ref_bit, ref_nsymbs;
    112    aom_cdf_prob ref_cdf[16];
    113    const int queue_r = bitstream_queue_get_read();
    114    const int frame_idx = aom_bitstream_queue_get_frame_read();
    115    bitstream_queue_pop(&ref_bit, ref_cdf, &ref_nsymbs);
    116    if (ref_nsymbs != 2) {
    117      fprintf(stderr,
    118              "\n *** [bit] nsymbs error, frame_idx_r %d nsymbs %d ref_nsymbs "
    119              "%d queue_r %d\n",
    120              frame_idx, 2, ref_nsymbs, queue_r);
    121      assert(0);
    122    }
    123    if ((ref_nsymbs != 2) || (ref_cdf[0] != (aom_cdf_prob)p) ||
    124        (ref_cdf[1] != 32767)) {
    125      fprintf(stderr,
    126              "\n *** [bit] cdf error, frame_idx_r %d cdf {%d, %d} ref_cdf {%d",
    127              frame_idx, p, 32767, ref_cdf[0]);
    128      for (i = 1; i < ref_nsymbs; ++i) fprintf(stderr, ", %d", ref_cdf[i]);
    129      fprintf(stderr, "} queue_r %d\n", queue_r);
    130      assert(0);
    131    }
    132    if (bit != ref_bit) {
    133      fprintf(stderr,
    134              "\n *** [bit] symb error, frame_idx_r %d symb %d ref_symb %d "
    135              "queue_r %d\n",
    136              frame_idx, bit, ref_bit, queue_r);
    137      assert(0);
    138    }
    139  }
    140 #endif
    141 
    142 #if CONFIG_ACCOUNTING
    143  if (ACCT_STR_NAME) aom_process_accounting(r, ACCT_STR_NAME);
    144  aom_update_symb_counts(r, 1);
    145 #endif
    146  return bit;
    147 }
    148 
    149 static inline int aom_read_bit_(aom_reader *r ACCT_STR_PARAM) {
    150  int ret;
    151  ret = aom_read(r, 128, NULL);  // aom_prob_half
    152 #if CONFIG_ACCOUNTING
    153  if (ACCT_STR_NAME) aom_process_accounting(r, ACCT_STR_NAME);
    154 #endif
    155  return ret;
    156 }
    157 
    158 static inline int aom_read_literal_(aom_reader *r, int bits ACCT_STR_PARAM) {
    159  int literal = 0, bit;
    160 
    161  for (bit = bits - 1; bit >= 0; bit--) literal |= aom_read_bit(r, NULL) << bit;
    162 #if CONFIG_ACCOUNTING
    163  if (ACCT_STR_NAME) aom_process_accounting(r, ACCT_STR_NAME);
    164 #endif
    165  return literal;
    166 }
    167 
    168 static inline int aom_read_cdf_(aom_reader *r, const aom_cdf_prob *cdf,
    169                                int nsymbs ACCT_STR_PARAM) {
    170  int symb;
    171  assert(cdf != NULL);
    172  symb = od_ec_decode_cdf_q15(&r->ec, cdf, nsymbs);
    173 
    174 #if CONFIG_BITSTREAM_DEBUG
    175  {
    176    int i;
    177    int cdf_error = 0;
    178    int ref_symb, ref_nsymbs;
    179    aom_cdf_prob ref_cdf[16];
    180    const int queue_r = bitstream_queue_get_read();
    181    const int frame_idx = aom_bitstream_queue_get_frame_read();
    182    bitstream_queue_pop(&ref_symb, ref_cdf, &ref_nsymbs);
    183    if (nsymbs != ref_nsymbs) {
    184      fprintf(stderr,
    185              "\n *** nsymbs error, frame_idx_r %d nsymbs %d ref_nsymbs %d "
    186              "queue_r %d\n",
    187              frame_idx, nsymbs, ref_nsymbs, queue_r);
    188      cdf_error = 0;
    189      assert(0);
    190    } else {
    191      for (i = 0; i < nsymbs; ++i)
    192        if (cdf[i] != ref_cdf[i]) cdf_error = 1;
    193    }
    194    if (cdf_error) {
    195      fprintf(stderr, "\n *** cdf error, frame_idx_r %d cdf {%d", frame_idx,
    196              cdf[0]);
    197      for (i = 1; i < nsymbs; ++i) fprintf(stderr, ", %d", cdf[i]);
    198      fprintf(stderr, "} ref_cdf {%d", ref_cdf[0]);
    199      for (i = 1; i < ref_nsymbs; ++i) fprintf(stderr, ", %d", ref_cdf[i]);
    200      fprintf(stderr, "} queue_r %d\n", queue_r);
    201      assert(0);
    202    }
    203    if (symb != ref_symb) {
    204      fprintf(
    205          stderr,
    206          "\n *** symb error, frame_idx_r %d symb %d ref_symb %d queue_r %d\n",
    207          frame_idx, symb, ref_symb, queue_r);
    208      assert(0);
    209    }
    210  }
    211 #endif
    212 
    213 #if CONFIG_ACCOUNTING
    214  if (ACCT_STR_NAME) aom_process_accounting(r, ACCT_STR_NAME);
    215  aom_update_symb_counts(r, (nsymbs == 2));
    216 #endif
    217  return symb;
    218 }
    219 
    220 static inline int aom_read_symbol_(aom_reader *r, aom_cdf_prob *cdf,
    221                                   int nsymbs ACCT_STR_PARAM) {
    222  int ret;
    223  ret = aom_read_cdf(r, cdf, nsymbs, ACCT_STR_NAME);
    224  if (r->allow_update_cdf) update_cdf(cdf, ret, nsymbs);
    225  return ret;
    226 }
    227 
    228 #ifdef __cplusplus
    229 }  // extern "C"
    230 #endif
    231 
    232 #endif  // AOM_AOM_DSP_BITREADER_H_