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diff --git a/.repos/farbfeld/farbfeld.5 b/.repos/farbfeld/farbfeld.5 new file mode 100644 index 0000000..55dc47c --- /dev/null +++ b/.repos/farbfeld/farbfeld.5 @@ -0,0 +1,177 @@ +.Dd 2018-04-11 +.Dt FARBFELD 5 +.Os suckless.org +.Sh NAME +.Nm farbfeld +.Nd suckless image format +.Sh DESCRIPTION +.Nm +is a +.Em lossless +image format which is easy to parse, pipe and compress. +It has the following format: +.Bd -literal -offset left +BYTES DESCRIPTION +8 "farbfeld" magic value +4 32-Bit BE unsigned integer (width) +4 32-Bit BE unsigned integer (height) +[2222] 4*16-Bit BE unsigned integers [RGBA] / pixel, row-major +.Ed +.Pp +The RGB-data should be sRGB for best interoperability and not +alpha-premultiplied. +.Sh USAGE +.Nm +provides the tools +.Xr 2ff 1 , +.Xr jpg2ff 1 , +.Xr png2ff 1 +and +.Xr ff2jpg 1 , +.Xr ff2pam 1 , +.Xr ff2png 1 , +.Xr ff2ppm 1 +to +.Em convert +to and from farbfeld images respectively. +.Pp +.Xr bzip2 1 +is recommended for +.Em compression , +giving results comparable with PNG for photographs and much better results +for other image types. +.sp +The +.Em file extension +is ".ff" and compression extensions shall be +appended (e.g. ".ff.bz2"). +.Sh MOTIVATION +.Nm +was created because the author was not satisfied with the boilerplate +and inherent complexity involved in handling common image formats +(PNG, JPEG, GIF,...), having to rely on bloated libraries while not being +able to focus on the task at hand for a given image processing problem. +.Sh EXAMPLES +The following code listing +.Em invert.c +is a ready-to-use color inverter with all necessary error handling and +reporting. This program can be integrated into a farbfeld pipeline as +follows: +.Pp +$ png2ff < image.png | invert | ff2png > image-inverted.png +.Pp +It shall be noted here that due to the simplicity of the format no +external libraries are needed to handle the farbfeld image data. The +0BSD-License gives you the freedom to throw away the license block and +just use the code as you wish. Happy hacking! +.Bd -literal -offset left +/* + * 0BSD-License + * + * (c) 2017 Laslo Hunhold <dev@frign.de> + * + * Permission to use, copy, modify, and/or distribute this software for + * any purpose with or without fee is hereby granted. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL + * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE + * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL + * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR + * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER + * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + * PERFORMANCE OF THIS SOFTWARE. + */ +#include <arpa/inet.h> + +#include <errno.h> +#include <stdint.h> +#include <stdio.h> +#include <string.h> + +#define LEN(x) (sizeof (x) / sizeof *(x)) + +static void +invert(uint16_t rgba[4]) +{ + rgba[0] = UINT16_MAX - rgba[0]; + rgba[1] = UINT16_MAX - rgba[1]; + rgba[2] = UINT16_MAX - rgba[2]; +} + +int +main(int argc, char *argv[]) +{ + uint32_t hdr[4], width, height, i, j, k; + uint16_t rgba[4]; + + /* arguments */ + if (argc != 1) { + fprintf(stderr, "usage: %s\\n", argv[0]); + return 1; + } + + /* read header */ + if (fread(hdr, sizeof(*hdr), LEN(hdr), stdin) != LEN(hdr)) { + goto readerr; + } + if (memcmp("farbfeld", hdr, sizeof("farbfeld") - 1)) { + fprintf(stderr, "%s: invalid magic value\\n", argv[0]); + return 1; + } + width = ntohl(hdr[2]); + height = ntohl(hdr[3]); + + /* write data */ + if (fwrite(hdr, sizeof(*hdr), LEN(hdr), stdout) != 4) { + goto writerr; + } + + for (i = 0; i < height; i++) { + for (j = 0; j < width; j++) { + if (fread(rgba, sizeof(*rgba), LEN(rgba), + stdin) != LEN(rgba)) { + goto readerr; + } + for (k = 0; k < 4; k++) { + rgba[k] = ntohs(rgba[k]); + } + + invert(rgba); + + for (k = 0; k < 4; k++) { + rgba[k] = htons(rgba[k]); + } + if (fwrite(rgba, sizeof(*rgba), LEN(rgba), + stdout) != LEN(rgba)) { + goto writerr; + } + } + } + + /* clean up */ + if (fclose(stdout)) { + fprintf(stderr, "%s: fclose: %s\\n", argv[0], + strerror(errno)); + return 1; + } + + return 0; +readerr: + fprintf(stderr, "%s: fread: Unexpected EOF\\n", argv[0]); + return 1; +writerr: + fprintf(stderr, "%s: fwrite: %s\\n", argv[0], strerror(errno)); + return 1; +} +.Ed +.Sh SEE ALSO +.Xr 2ff 1 , +.Xr ff2jpg 1 , +.Xr ff2pam 1 , +.Xr ff2png 1 , +.Xr ff2ppm 1 , +.Xr jpg2ff 1 , +.Xr png2ff 1 +.Sh AUTHORS +.An Laslo Hunhold Aq Mt dev@frign.de |