1.12x faster overall in palettegen on my machine.
Showing the changes to libavfilter (1 of 1 file). Show all
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| @@ -63,8 +63,7 @@ enum { · 62 unmodified lines | ||
| 63 | 63 | NB_STATS_MODE |
| 64 | 64 | }; |
| 65 | 65 | |
| 66 | −#define NBITS 5 | |
| 67 | −#define HIST_SIZE (1<<(3*NBITS)) | |
| 66 | +#define HIST_SIZE (1<<15) | |
| 68 | 67 | |
| 69 | 68 | typedef struct PaletteGenContext { |
| 70 | 69 | const AVClass *class; |
| @@ -387,27 +386,13 @@ static AVFrame *get_palette_frame(AVFilterContext *ctx) · 316 unmodified lines | ||
| 387 | 386 | return out; |
| 388 | 387 | } |
| 389 | 388 | |
| 390 | −/** | |
| 391 | − * Hashing function for the color. | |
| 392 | − * It keeps the NBITS least significant bit of each component to make it | |
| 393 | − * "random" even if the scene doesn't have much different colors. | |
| 394 | − */ | |
| 395 | −static inline unsigned color_hash(uint32_t color) | |
| 396 | −{ | |
| 397 | − const uint8_t r = color >> 16 & ((1<<NBITS)-1); | |
| 398 | − const uint8_t g = color >> 8 & ((1<<NBITS)-1); | |
| 399 | − const uint8_t b = color & ((1<<NBITS)-1); | |
| 400 | − | |
| 401 | − return r << (NBITS * 2) | g << NBITS | b; | |
| 402 | −} | |
| 403 | − | |
| 404 | 389 | /** |
| 405 | 390 | * Locate the color in the hash table and increment its counter. |
| 406 | 391 | */ |
| 407 | 392 | static int color_inc(struct hist_node *hist, uint32_t color) |
| 408 | 393 | { |
| 409 | 394 | int i; |
| 410 | − const unsigned hash = color_hash(color); | |
| 395 | + const uint32_t hash = ff_lowbias32(color) & (HIST_SIZE - 1); | |
| 411 | 396 | struct hist_node *node = &hist[hash]; |
| 412 | 397 | struct color_ref *e; |
| 413 | 398 | |