diff options
| author | Andreas Rheinhardt <andreas.rheinhardt@outlook.com> | 2024-03-06 23:16:22 +0100 |
|---|---|---|
| committer | Andreas Rheinhardt <andreas.rheinhardt@outlook.com> | 2024-03-10 13:51:37 +0100 |
| commit | 9e36e2fb7b0153e3e216870e8d88018f0546f8e6 (patch) | |
| tree | fca583687572fc30a03fa5ecc6172ee14ec383db /libavcodec | |
| parent | 0b2ed7f6c7e44c9dbf6b79aa36b8db033d192760 (diff) | |
avcodec/xpmdec: Use LUT for hex char->number conversion
Speeds up decoding and also reduces binary size.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/xpmdec.c | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/libavcodec/xpmdec.c b/libavcodec/xpmdec.c index e7f8a90fdc..b915abe0bf 100644 --- a/libavcodec/xpmdec.c +++ b/libavcodec/xpmdec.c @@ -193,15 +193,22 @@ static const ColorEntry color_table[] = { static unsigned hex_char_to_number(uint8_t x) { - if (x >= 'a' && x <= 'f') - x -= 'a' - 10; - else if (x >= 'A' && x <= 'F') - x -= 'A' - 10; - else if (x >= '0' && x <= '9') - x -= '0'; - else - x = 0; - return x; +#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' : 0, + + static const uint8_t lut[] = { + TIMES256(0) + }; + return lut[x]; } /* |