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author | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
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committer | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
commit | 5f8de423f190bbb79a62f804151bc24824fa32d8 (patch) | |
tree | 10027f336435511475e392454359edea8e25895d /media/libvpx/vp9/decoder/vp9_reader.h | |
parent | 49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff) | |
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Add m-esr52 at 52.6.0
Diffstat (limited to 'media/libvpx/vp9/decoder/vp9_reader.h')
-rw-r--r-- | media/libvpx/vp9/decoder/vp9_reader.h | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/media/libvpx/vp9/decoder/vp9_reader.h b/media/libvpx/vp9/decoder/vp9_reader.h new file mode 100644 index 000000000..a68a1d592 --- /dev/null +++ b/media/libvpx/vp9/decoder/vp9_reader.h @@ -0,0 +1,120 @@ +/* + * Copyright (c) 2010 The WebM project authors. All Rights Reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +#ifndef VP9_DECODER_VP9_READER_H_ +#define VP9_DECODER_VP9_READER_H_ + +#include <stddef.h> +#include <limits.h> + +#include "./vpx_config.h" +#include "vpx_ports/mem.h" +#include "vpx/vp8dx.h" +#include "vpx/vpx_integer.h" + +#include "vp9/common/vp9_prob.h" + +#ifdef __cplusplus +extern "C" { +#endif + +typedef size_t BD_VALUE; + +#define BD_VALUE_SIZE ((int)sizeof(BD_VALUE) * CHAR_BIT) + +typedef struct { + // Be careful when reordering this struct, it may impact the cache negatively. + BD_VALUE value; + unsigned int range; + int count; + const uint8_t *buffer_end; + const uint8_t *buffer; + vpx_decrypt_cb decrypt_cb; + void *decrypt_state; + uint8_t clear_buffer[sizeof(BD_VALUE) + 1]; +} vp9_reader; + +int vp9_reader_init(vp9_reader *r, + const uint8_t *buffer, + size_t size, + vpx_decrypt_cb decrypt_cb, + void *decrypt_state); + +void vp9_reader_fill(vp9_reader *r); + +int vp9_reader_has_error(vp9_reader *r); + +const uint8_t *vp9_reader_find_end(vp9_reader *r); + +static INLINE int vp9_read(vp9_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) + vp9_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 unsigned int shift = vp9_norm[range]; + range <<= shift; + value <<= shift; + count -= shift; + } + r->value = value; + r->count = count; + r->range = range; + + return bit; +} + +static INLINE int vp9_read_bit(vp9_reader *r) { + return vp9_read(r, 128); // vp9_prob_half +} + +static INLINE int vp9_read_literal(vp9_reader *r, int bits) { + int literal = 0, bit; + + for (bit = bits - 1; bit >= 0; bit--) + literal |= vp9_read_bit(r) << bit; + + return literal; +} + +static INLINE int vp9_read_tree(vp9_reader *r, const vp9_tree_index *tree, + const vp9_prob *probs) { + vp9_tree_index i = 0; + + while ((i = tree[i + vp9_read(r, probs[i >> 1])]) > 0) + continue; + + return -i; +} + +#ifdef __cplusplus +} // extern "C" +#endif + +#endif // VP9_DECODER_VP9_READER_H_ |