GopherProxy

	ff2jpg.c - farbfeld - suckless image format with conversion tools
	git clone git://git.suckless.org/farbfeld
	Log
	Files
	Refs
	README
	LICENSE
	---
	ff2jpg.c (2477B)
	---
	1 /* See LICENSE file for copyright and license details. */
	2 #include <arpa/inet.h>
	3
	4 #include <errno.h>
	5 #include <inttypes.h>
	6 #include <stdint.h>
	7 #include <stdio.h>
	8 #include <stdlib.h>
	9 #include <string.h>
	10
	11 #include <jpeglib.h>
	12
	13 #include "arg.h"
	14 #include "util.h"
	15
	16 static void
	17 jpeg_error(j_common_ptr js)
	18 {
	19 fprintf(stderr, "%s: libjpeg: ", argv0);
	20 (*js->err->output_message)(js);
	21 exit(1);
	22 }
	23
	24 static void
	25 jpeg_setup_writer(struct jpeg_compress_struct *s, struct jpeg_error_mgr …
	26 uint32_t w, uint32_t h, int quality, int opt)
	27 {
	28 jpeg_create_compress(s);
	29 e->error_exit = jpeg_error;
	30 s->err = jpeg_std_error(e);
	31
	32 jpeg_stdio_dest(s, stdout);
	33 s->image_width = w;
	34 s->image_height = h;
	35 s->input_components = 3; /* color components per pixel */
	36 s->in_color_space = JCS_RGB; /* output color space */
	37 jpeg_set_defaults(s);
	38
	39 if (opt) {
	40 s->optimize_coding = 1;
	41 }
	42 jpeg_set_quality(s, quality, 1);
	43
	44 jpeg_start_compress(s, 1);
	45 }
	46
	47 static void
	48 usage(void)
	49 {
	50 die("usage: %s [-b colour] [-o] [-q quality]", argv0);
	51 }
	52
	53 int
	54 main(int argc, char *argv[])
	55 {
	56 struct jpeg_compress_struct jcomp;
	57 struct jpeg_error_mgr jerr;
	58 size_t rowlen;
	59 uint64_t a;
	60 uint32_t width, height, i, j, k, l;
	61 uint16_t *row, mask[3] = { 0xffff, 0xffff, 0xffff };
	62 uint8_t *rowout;
	63 int optimize = 0, quality = 85;
	64
	65 /* arguments */
	66 ARGBEGIN {
	67 case 'b':
	68 if (parse_mask(EARGF(usage()), mask)) {
	69 usage();
	70 }
	71 break;
	72 case 'o':
	73 optimize = 1;
	74 break;
	75 case 'q':
	76 quality = estrtonum(EARGF(usage()), 0, 100);
	77 break;
	78 default:
	79 usage();
	80 } ARGEND
	81
	82 if (argc) {
	83 usage();
	84 }
	85
	86 /* prepare */
	87 ff_read_header(&width, &height);
	88 jpeg_setup_writer(&jcomp, &jerr, width, height, quality, optimiz…
	89 row = ereallocarray(NULL, width, (sizeof("RGBA") - 1) * sizeof(u…
	90 rowlen = width * (sizeof("RGBA") - 1);
	91 rowout = ereallocarray(NULL, width, (sizeof("RGB") - 1) * sizeof…
	92
	93 /* write data */
	94 for (i = 0; i < height; ++i) {
	95 efread(row, sizeof(uint16_t), rowlen, stdin);
	96 for (j = 0, k = 0; j < rowlen; j += 4, k += 3) {
	97 a = ntohs(row[j + 3]);
	98 for (l = 0; l < 3; l++) {
	99 /* alpha blending and 8-bit-reduction */
	100 rowout[k + l] = (a * ntohs(row[j + l]) +
	101 (UINT16_MAX - a) * mask…
	102 (UINT16_MAX *
	103 (UINT16_MAX / UINT8_MAX…
	104 }
	105 }
	106 jpeg_write_scanlines(&jcomp, &rowout, 1);
	107 }
	108
	109 /* clean up */
	110 jpeg_finish_compress(&jcomp);
	111 jpeg_destroy_compress(&jcomp);
	112
	113 return fshut(stdout, "<stdout>");
	114 }