* Count up to 127 consecutive pixels which are either all the same or * all differ from the previous and next pixels. * @param start Pointer to the first pixel * @param len Maximum number of pixels * @param bpp Bytes per pixel * @param same 1 if searching for identical pixel values. 0 for differing * @return Number of matching consecutive pixels found */
| 31 | * @return Number of matching consecutive pixels found |
| 32 | */ |
| 33 | static int count_pixels(const uint8_t *start, int len, int bpp, int same) |
| 34 | { |
| 35 | const uint8_t *pos; |
| 36 | int count = 1; |
| 37 | |
| 38 | for(pos = start + bpp; count < FFMIN(127, len); pos += bpp, count ++) { |
| 39 | if(same != !memcmp(pos-bpp, pos, bpp)) { |
| 40 | if(!same) { |
| 41 | /* if bpp == 1, then 0 1 1 0 is more efficiently encoded as a single |
| 42 | * raw block of pixels. for larger bpp, RLE is as good or better */ |
| 43 | if(bpp == 1 && count + 1 < FFMIN(127, len) && *pos != *(pos+1)) |
| 44 | continue; |
| 45 | |
| 46 | /* if RLE can encode the next block better than as a raw block, |
| 47 | * back up and leave _all_ the identical pixels for RLE */ |
| 48 | count --; |
| 49 | } |
| 50 | break; |
| 51 | } |
| 52 | } |
| 53 | |
| 54 | return count; |
| 55 | } |
| 56 | |
| 57 | int ff_rle_encode(uint8_t *outbuf, int out_size, const uint8_t *ptr , int bpp, int w, |
| 58 | int add_rep, int xor_rep, int add_raw, int xor_raw) |