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| author | Andreas Rheinhardt <andreas.rheinhardt@outlook.com> | 2024-03-06 22:49:54 +0100 |
|---|---|---|
| committer | Andreas Rheinhardt <andreas.rheinhardt@outlook.com> | 2024-03-10 13:51:37 +0100 |
| commit | 0b2ed7f6c7e44c9dbf6b79aa36b8db033d192760 (patch) | |
| tree | eb2fcb7cd394c73f81e6889e10d087364513ec4a /libavcodec | |
| parent | 8fb89790af0ac6de08be7faaa92c41db98358063 (diff) | |
avcodec/xbmdec: Use LUT for hex char->number conversion
Improves performance by about 30%.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/xbmdec.c | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/libavcodec/xbmdec.c b/libavcodec/xbmdec.c index ecfc957a3f..2d84327e02 100644 --- a/libavcodec/xbmdec.c +++ b/libavcodec/xbmdec.c @@ -28,17 +28,22 @@ static int get_nibble(uint8_t x) { - int ret = 255; - - if (x <= '9') { - if (x >= '0') - ret = x - '0'; - } else if (x >= 'a') { - if (x <= 'f') - ret = x - ('a' - 10); - } else if (x >= 'A' && x <= 'F') - ret = x - ('A' - 10); - return ret; +#define TIMES256(idx) \ +TIMES64(4 * (idx)) TIMES64(4 * (idx) + 1) TIMES64(4 * (idx) + 2) TIMES64(4 * (idx) + 3) +#define TIMES64(idx) \ +TIMES16(4 * (idx)) TIMES16(4 * (idx) + 1) TIMES16(4 * (idx) + 2) TIMES16(4 * (idx) + 3) +#define TIMES16(idx) \ +TIMES4(4 * (idx)) TIMES4(4 * (idx) + 1) TIMES4(4 * (idx) + 2) TIMES4(4 * (idx) + 3) +#define TIMES4(idx) \ +ENTRY(4 * (idx)) ENTRY(4 * (idx) + 1) ENTRY(4 * (idx) + 2) ENTRY(4 * (idx) + 3) +#define ENTRY(x) [x] = ((x) >= 'a' && (x) <= 'f') ? (x) - ('a' - 10) : \ + ((x) >= 'A' && (x) <= 'F') ? (x) - ('A' - 10) : \ + ((x) >= '0' && (x) <= '9') ? (x) - '0' : 255, + + static const uint8_t lut[] = { + TIMES256(0) + }; + return lut[x]; } static int parse_str_int(const uint8_t *p, const uint8_t *end, const uint8_t *key) |