blind-temporal-arithm.c - blind - suckless command-line video editing utility
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       ---
       blind-temporal-arithm.c (2413B)
       ---
            1 /* See LICENSE file for copyright and license details. */
            2 #include "common.h"
            3 
            4 USAGE("operation")
            5 
            6 /* Because the syntax for a function returning a function pointer is disgusting. */
            7 typedef void (*process_func)(struct stream *stream, void *image);
            8 
            9 #define LIST_OPERATORS(PIXFMT, TYPE)\
           10         X(add, *img + *buf,     PIXFMT, TYPE)\
           11         X(mul, *img * *buf,     PIXFMT, TYPE)\
           12         X(min, MIN(*img, *buf), PIXFMT, TYPE)\
           13         X(max, MAX(*img, *buf), PIXFMT, TYPE)
           14 
           15 #define X(NAME, ALGO, PIXFMT, TYPE)\
           16         static void\
           17         process_##PIXFMT##_##NAME(struct stream *stream, void *image)\
           18         {\
           19                 TYPE *buf, *img = image;\
           20                 size_t i, n, j = 0, m = stream->frame_size / sizeof(TYPE);\
           21                 do {\
           22                         n = stream->ptr / sizeof(TYPE);\
           23                         buf = (TYPE *)(stream->buf);\
           24                         for (i = 0; i < n; i++, buf++) {\
           25                                 *img = ALGO;\
           26                                 if (++j == m) {\
           27                                         j = 0;\
           28                                         img = image;\
           29                                 } else {\
           30                                         img++;\
           31                                 }\
           32                         }\
           33                         n *= sizeof(TYPE);\
           34                         memmove(stream->buf, stream->buf + n, stream->ptr -= n);\
           35                 } while (eread_stream(stream, SIZE_MAX));\
           36         }
           37 LIST_OPERATORS(lf, double)
           38 LIST_OPERATORS(f, float)
           39 #undef X
           40 
           41 static process_func
           42 get_process_lf(const char *operation)
           43 {
           44 #define X(NAME, _ALGO, PIXFMT, TYPE)\
           45         if (!strcmp(operation, #NAME)) return process_##PIXFMT##_##NAME;
           46         LIST_OPERATORS(lf, double)
           47 #undef X
           48         eprintf("algorithm not recognised: %s\n", operation);
           49         return NULL;
           50 }
           51 
           52 static process_func
           53 get_process_f(const char *operation)
           54 {
           55 #define X(NAME, _ALGO, PIXFMT, TYPE)\
           56         if (!strcmp(operation, #NAME)) return process_##PIXFMT##_##NAME;
           57         LIST_OPERATORS(f, float)
           58 #undef X
           59         eprintf("algorithm not recognised: %s\n", operation);
           60         return NULL;
           61 }
           62 
           63 int
           64 main(int argc, char *argv[])
           65 {
           66         struct stream stream;
           67         process_func process;
           68         char *img;
           69 
           70         UNOFLAGS(argc != 1);
           71 
           72         eopen_stream(&stream, NULL);
           73 
           74         if (stream.encoding == DOUBLE)
           75                 process = get_process_lf(argv[0]);
           76         else if (stream.encoding == FLOAT)
           77                 process = get_process_f(argv[0]);
           78         else
           79                 eprintf("pixel format %s is not supported, try xyza\n", stream.pixfmt);
           80 
           81         echeck_dimensions(&stream, WIDTH | HEIGHT, NULL);
           82         img = emalloc(stream.frame_size);
           83         if (!eread_frame(&stream, img))
           84                 eprintf("video has no frames\n");
           85 
           86         process(&stream, img);
           87         if (stream.ptr)
           88                 eprintf("%s: incomplete frame\n", stream.file);
           89 
           90         stream.frames = 1;
           91         fprint_stream_head(stdout, &stream);
           92         efflush(stdout, "<stdout>");
           93         ewriteall(STDOUT_FILENO, img, stream.frame_size, "<stdout>");
           94         free(img);
           95         return 0;
           96 }