ffmpeg/FFmpeg
1
0
Fork 0
mirror of https://git.ffmpeg.org/ffmpeg.git synced 2024-09-20 05:16:38 +00:00
Code Issues Packages Projects Releases Wiki Activity

avcodec/lagarithrac: increase LUT from 256 to 1024 bytes

Browse Source 
about 2 cycles (~1%) faster lag_get_rac()

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2014-05-27 01:33:59 +02:00
parent 4fb4bf7289
commit d8ae0dfd99
2 changed files with 3 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
libavcodec/lagarithrac.c
View File

@ -45,9 +45,9 @@ void ff_lag_rac_init(lag_rac *l, GetBitContext *gb, int length)
l->range = 0x80;
l->low = *l->bytestream >> 1;
l->hash_shift = FFMAX((int)l->scale - 8, 0);
l->hash_shift = FFMAX((int)l->scale - 10, 0);
for (i = j = 0; i < 256; i++) {
for (i = j = 0; i < 1024; i++) {
unsigned r = i << l->hash_shift;
while (l->prob[j + 1] <= r)
j++;

2
libavcodec/lagarithrac.h
View File

@ -48,7 +48,7 @@ typedef struct lag_rac {
const uint8_t *bytestream_end; /**< End position of input bytestream. */
uint32_t prob[258]; /**< Table of cumulative probability for each symbol. */
uint8_t range_hash[256]; /**< Hash table mapping upper byte to approximate symbol. */
uint8_t range_hash[1024]; /**< Hash table mapping upper byte to approximate symbol. */
} lag_rac;
void ff_lag_rac_init(lag_rac *l, GetBitContext *gb, int length);