generic-library/vpx
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Merge "Optimize bit_read_buffer."

Browse Source
This commit is contained in:
James Zern 2014-12-12 16:29:42 -08:00 committed by Gerrit Code Review
commit 089086bc25
1 changed files with 8 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
vp9/decoder/vp9_read_bit_buffer.c
View File

@ -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;
}
}