1 files changed, 181 insertions, 0 deletions
diff --git a/third_party/aom/aom_dsp/dkboolreader.h b/third_party/aom/aom_dsp/dkboolreader.h
new file mode 100644
index 0000000000..f0bc843813
--- /dev/null
+++ b/third_party/aom/aom_dsp/dkboolreader.h
@@ -0,0 +1,181 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#ifndef AOM_DSP_DKBOOLREADER_H_
+#define AOM_DSP_DKBOOLREADER_H_
+
+#include <assert.h>
+#include <stddef.h>
+#include <limits.h>
+
+#include "./aom_config.h"
+#if CONFIG_BITSTREAM_DEBUG
+#include <assert.h>
+#include <stdio.h>
+#include "aom_util/debug_util.h"
+#endif  // CONFIG_BITSTREAM_DEBUG
+
+#include "aom_ports/mem.h"
+#include "aom/aomdx.h"
+#include "aom/aom_integer.h"
+#include "aom_dsp/prob.h"
+#if CONFIG_ACCOUNTING
+#include "av1/decoder/accounting.h"
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef size_t BD_VALUE;
+
+#define BD_VALUE_SIZE ((int)sizeof(BD_VALUE) * CHAR_BIT)
+
+// This is meant to be a large, positive constant that can still be efficiently
+// loaded as an immediate (on platforms like ARM, for example).
+// Even relatively modest values like 100 would work fine.
+#define LOTS_OF_BITS 0x40000000
+
+struct aom_dk_reader {
+  // Be careful when reordering this struct, it may impact the cache negatively.
+  BD_VALUE value;
+  unsigned int range;
+  int count;
+  const uint8_t *buffer_start;
+  const uint8_t *buffer_end;
+  const uint8_t *buffer;
+  aom_decrypt_cb decrypt_cb;
+  void *decrypt_state;
+  uint8_t clear_buffer[sizeof(BD_VALUE) + 1];
+#if CONFIG_ACCOUNTING
+  Accounting *accounting;
+#endif
+};
+
+int aom_dk_reader_init(struct aom_dk_reader *r, const uint8_t *buffer,
+                       size_t size, aom_decrypt_cb decrypt_cb,
+                       void *decrypt_state);
+
+void aom_dk_reader_fill(struct aom_dk_reader *r);
+
+const uint8_t *aom_dk_reader_find_end(struct aom_dk_reader *r);
+
+static INLINE uint32_t aom_dk_reader_tell(const struct aom_dk_reader *r) {
+  const uint32_t bits_read =
+      (uint32_t)((r->buffer - r->buffer_start) * CHAR_BIT);
+  const int count =
+      (r->count < LOTS_OF_BITS) ? r->count : r->count - LOTS_OF_BITS;
+  assert(r->buffer >= r->buffer_start);
+  return bits_read - (count + CHAR_BIT);
+}
+
+/*The resolution of fractional-precision bit usage measurements, i.e.,
+   3 => 1/8th bits.*/
+#define DK_BITRES (3)
+
+static INLINE uint32_t aom_dk_reader_tell_frac(const struct aom_dk_reader *r) {
+  uint32_t num_bits;
+  uint32_t range;
+  int l;
+  int i;
+  num_bits = aom_dk_reader_tell(r) << DK_BITRES;
+  range = r->range;
+  l = 0;
+  for (i = DK_BITRES; i-- > 0;) {
+    int b;
+    range = range * range >> 7;
+    b = (int)(range >> 8);
+    l = l << 1 | b;
+    range >>= b;
+  }
+  return num_bits - l;
+}
+
+static INLINE int aom_dk_reader_has_error(struct aom_dk_reader *r) {
+  // Check if we have reached the end of the buffer.
+  //
+  // Variable 'count' stores the number of bits in the 'value' buffer, minus
+  // 8. The top byte is part of the algorithm, and the remainder is buffered
+  // to be shifted into it. So if count == 8, the top 16 bits of 'value' are
+  // occupied, 8 for the algorithm and 8 in the buffer.
+  //
+  // When reading a byte from the user's buffer, count is filled with 8 and
+  // one byte is filled into the value buffer. When we reach the end of the
+  // data, count is additionally filled with LOTS_OF_BITS. So when
+  // count == LOTS_OF_BITS - 1, the user's data has been exhausted.
+  //
+  // 1 if we have tried to decode bits after the end of stream was encountered.
+  // 0 No error.
+  return r->count > BD_VALUE_SIZE && r->count < LOTS_OF_BITS;
+}
+
+static INLINE int aom_dk_read(struct aom_dk_reader *r, int prob) {
+  unsigned int bit = 0;
+  BD_VALUE value;
+  BD_VALUE bigsplit;
+  int count;
+  unsigned int range;
+  unsigned int split = (r->range * prob + (256 - prob)) >> CHAR_BIT;
+
+  if (r->count < 0) aom_dk_reader_fill(r);
+
+  value = r->value;
+  count = r->count;
+
+  bigsplit = (BD_VALUE)split << (BD_VALUE_SIZE - CHAR_BIT);
+
+  range = split;
+
+  if (value >= bigsplit) {
+    range = r->range - split;
+    value = value - bigsplit;
+    bit = 1;
+  }
+
+  {
+    register int shift = aom_norm[range];
+    range <<= shift;
+    value <<= shift;
+    count -= shift;
+  }
+  r->value = value;
+  r->count = count;
+  r->range = range;
+
+#if CONFIG_BITSTREAM_DEBUG
+  {
+    int ref_bit, ref_prob;
+    const int queue_r = bitstream_queue_get_read();
+    const int frame_idx = bitstream_queue_get_frame_read();
+    bitstream_queue_pop(&ref_bit, &ref_prob);
+    if (prob != ref_prob) {
+      fprintf(
+          stderr,
+          "\n *** prob error, frame_idx_r %d prob %d ref_prob %d queue_r %d\n",
+          frame_idx, prob, ref_prob, queue_r);
+      assert(0);
+    }
+    if ((int)bit != ref_bit) {
+      fprintf(stderr, "\n *** bit error, frame_idx_r %d bit %d ref_bit %d\n",
+              frame_idx, bit, ref_bit);
+      assert(0);
+    }
+  }
+#endif  // CONFIG_BITSTREAM_DEBUG
+
+  return bit;
+}
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // AOM_DSP_DKBOOLREADER_H_