blind-dissolve.c (1255B)
1 /* See LICENSE file for copyright and license details. */ 2 #include "common.h" 3 4 USAGE("[-r]") 5 6 static size_t fm; 7 static double fm_double; 8 static float fm_float; 9 static int reverse = 0; 10 11 #define PROCESS(TYPE)\ 12 do {\ 13 size_t i = (size_t)(stream->alpha_chan) * stream->chan_size;\ 14 TYPE a = fm ? (TYPE)(reverse ? f : fm - f) / fm_##TYPE : (TYPE)0.5;\ 15 for (; i < n; i += stream->pixel_size)\ 16 *(TYPE *)(stream->buf + i) *= a;\ 17 } while (0) 18 19 static void process_lf(struct stream *stream, size_t n, size_t f) {PROCESS(double);} 20 static void process_f (struct stream *stream, size_t n, size_t f) {PROCESS(float);} 21 22 int 23 main(int argc, char *argv[]) 24 { 25 struct stream stream; 26 void (*process)(struct stream *stream, size_t n, size_t f); 27 28 ARGBEGIN { 29 case 'r': 30 reverse = 1; 31 break; 32 default: 33 usage(); 34 } ARGEND; 35 36 if (argc) 37 usage(); 38 39 eopen_stream(&stream, NULL); 40 41 SELECT_PROCESS_FUNCTION(&stream); 42 CHECK_CHANS(&stream, != -1, == stream.luma_chan); 43 44 if (!stream.frames) 45 eprintf("video's length is not recorded"); 46 47 fprint_stream_head(stdout, &stream); 48 efflush(stdout, "<stdout>"); 49 fm_double = (double)(fm = stream.frames - 1); 50 fm_float = (float)fm_double; 51 process_each_frame_segmented(&stream, STDOUT_FILENO, "<stdout>", process); 52 return 0; 53 }