From 3cecce916b7a7bacbf6e19fdcec34bd9834a0923 Mon Sep 17 00:00:00 2001 From: hkuang Date: Fri, 12 Dec 2014 13:54:40 -0800 Subject: [PATCH] Optimize bit_read_buffer. Change-Id: Iee43c34909deec9787b29c1c33672213b9f049df --- vp9/decoder/vp9_read_bit_buffer.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/vp9/decoder/vp9_read_bit_buffer.c b/vp9/decoder/vp9_read_bit_buffer.c index 3eef728..c3b38a9 100644 --- a/vp9/decoder/vp9_read_bit_buffer.c +++ b/vp9/decoder/vp9_read_bit_buffer.c @@ -10,20 +10,20 @@ #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 - 1) / CHAR_BIT; + return (rb->bit_offset + 7) >> 3; } 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; + const size_t p = off >> 3; + const int q = 7 - (int)(off & 0x7); + if (rb->bit_buffer + p < rb->bit_buffer_end) { + const int bit = (rb->bit_buffer[p] >> q) & 1; rb->bit_offset = off + 1; return bit; + } else { + rb->error_handler(rb->error_handler_data); + return 0; } } -- 2.7.4