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author | Jim Bankoski <jimbankoski@google.com> | 2014-03-03 15:21:22 -0800 |
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committer | Jim Bankoski <jimbankoski@google.com> | 2014-03-03 15:21:22 -0800 |
commit | a1fbe1e15faa1fc4f53c2c2ad6c81b93d82797b6 (patch) | |
tree | 72a6fba9a8d8bd9065259c7c2752a5133fa25e3f /vp9/decoder/vp9_read_bit_buffer.c | |
parent | e5e9b05d6891969f27a3374a8eab005a568c81a1 (diff) | |
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vp9_read_bit_buffer.h convert header statics to global functions
Change-Id: Ibea71b22de898832320d9e49a711a0cb0092901b
Diffstat (limited to 'vp9/decoder/vp9_read_bit_buffer.c')
-rw-r--r-- | vp9/decoder/vp9_read_bit_buffer.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/vp9/decoder/vp9_read_bit_buffer.c b/vp9/decoder/vp9_read_bit_buffer.c new file mode 100644 index 000000000..778a635e3 --- /dev/null +++ b/vp9/decoder/vp9_read_bit_buffer.c @@ -0,0 +1,41 @@ +/* + * Copyright (c) 2013 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. + */ +#include "vp9/decoder/vp9_read_bit_buffer.h" + +size_t vp9_rb_bytes_read(struct vp9_read_bit_buffer *rb) { + return rb->bit_offset / CHAR_BIT + (rb->bit_offset % CHAR_BIT > 0); +} + +int vp9_rb_read_bit(struct vp9_read_bit_buffer *rb) { + const size_t off = rb->bit_offset; + const size_t p = off / CHAR_BIT; + const int q = CHAR_BIT - 1 - (int)off % CHAR_BIT; + if (rb->bit_buffer + p >= rb->bit_buffer_end) { + rb->error_handler(rb->error_handler_data); + return 0; + } else { + const int bit = (rb->bit_buffer[p] & (1 << q)) >> q; + rb->bit_offset = off + 1; + return bit; + } +} + +int vp9_rb_read_literal(struct vp9_read_bit_buffer *rb, int bits) { + int value = 0, bit; + for (bit = bits - 1; bit >= 0; bit--) + value |= vp9_rb_read_bit(rb) << bit; + return value; +} + +int vp9_rb_read_signed_literal(struct vp9_read_bit_buffer *rb, + int bits) { + const int value = vp9_rb_read_literal(rb, bits); + return vp9_rb_read_bit(rb) ? -value : value; +} |