The Tor Browser / file comparison
comparison: media/libvpx/vp9/decoder/vp9_dboolhuff.h
media/libvpx/vp9/decoder/vp9_dboolhuff.h
- branch
- TOR_BUG_9701
- changeset 10
- ac0c01689b40
equal
deleted
inserted
replaced
| -1:000000000000 | 0:56547b6530ba |
|---|---|
| 1 /* | |
| 2 * Copyright (c) 2010 The WebM project authors. All Rights Reserved. | |
| 3 * | |
| 4 * Use of this source code is governed by a BSD-style license | |
| 5 * that can be found in the LICENSE file in the root of the source | |
| 6 * tree. An additional intellectual property rights grant can be found | |
| 7 * in the file PATENTS. All contributing project authors may | |
| 8 * be found in the AUTHORS file in the root of the source tree. | |
| 9 */ | |
| 10 | |
| 11 #ifndef VP9_DECODER_VP9_DBOOLHUFF_H_ | |
| 12 #define VP9_DECODER_VP9_DBOOLHUFF_H_ | |
| 13 | |
| 14 #include <stddef.h> | |
| 15 #include <limits.h> | |
| 16 | |
| 17 #include "./vpx_config.h" | |
| 18 #include "vpx_ports/mem.h" | |
| 19 #include "vpx/vpx_integer.h" | |
| 20 | |
| 21 typedef size_t VP9_BD_VALUE; | |
| 22 | |
| 23 #define BD_VALUE_SIZE ((int)sizeof(VP9_BD_VALUE)*CHAR_BIT) | |
| 24 | |
| 25 typedef struct { | |
| 26 const uint8_t *buffer_end; | |
| 27 const uint8_t *buffer; | |
| 28 VP9_BD_VALUE value; | |
| 29 int count; | |
| 30 unsigned int range; | |
| 31 } vp9_reader; | |
| 32 | |
| 33 DECLARE_ALIGNED(16, extern const uint8_t, vp9_norm[256]); | |
| 34 | |
| 35 int vp9_reader_init(vp9_reader *r, const uint8_t *buffer, size_t size); | |
| 36 | |
| 37 void vp9_reader_fill(vp9_reader *r); | |
| 38 | |
| 39 const uint8_t *vp9_reader_find_end(vp9_reader *r); | |
| 40 | |
| 41 static int vp9_read(vp9_reader *br, int probability) { | |
| 42 unsigned int bit = 0; | |
| 43 VP9_BD_VALUE value; | |
| 44 VP9_BD_VALUE bigsplit; | |
| 45 int count; | |
| 46 unsigned int range; | |
| 47 unsigned int split = ((br->range * probability) + (256 - probability)) >> 8; | |
| 48 | |
| 49 if (br->count < 0) | |
| 50 vp9_reader_fill(br); | |
| 51 | |
| 52 value = br->value; | |
| 53 count = br->count; | |
| 54 | |
| 55 bigsplit = (VP9_BD_VALUE)split << (BD_VALUE_SIZE - 8); | |
| 56 | |
| 57 range = split; | |
| 58 | |
| 59 if (value >= bigsplit) { | |
| 60 range = br->range - split; | |
| 61 value = value - bigsplit; | |
| 62 bit = 1; | |
| 63 } | |
| 64 | |
| 65 { | |
| 66 register unsigned int shift = vp9_norm[range]; | |
| 67 range <<= shift; | |
| 68 value <<= shift; | |
| 69 count -= shift; | |
| 70 } | |
| 71 br->value = value; | |
| 72 br->count = count; | |
| 73 br->range = range; | |
| 74 | |
| 75 return bit; | |
| 76 } | |
| 77 | |
| 78 static int vp9_read_bit(vp9_reader *r) { | |
| 79 return vp9_read(r, 128); // vp9_prob_half | |
| 80 } | |
| 81 | |
| 82 static int vp9_read_literal(vp9_reader *br, int bits) { | |
| 83 int z = 0, bit; | |
| 84 | |
| 85 for (bit = bits - 1; bit >= 0; bit--) | |
| 86 z |= vp9_read_bit(br) << bit; | |
| 87 | |
| 88 return z; | |
| 89 } | |
| 90 | |
| 91 int vp9_reader_has_error(vp9_reader *r); | |
| 92 | |
| 93 #endif // VP9_DECODER_VP9_DBOOLHUFF_H_ |
