Add ff2pam(1): convert farbfeld to 16-bit RGBA Portable Arbitrary Map

Laslo: Minor changes

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 74 insertions, 0 deletions

diff --git a/ff2pam.c b/ff2pam.c
new file mode 100644
index 0000000..93bd26c
--- /dev/null
+++ b/ff2pam.c
@@ -0,0 +1,74 @@
+/* See LICENSE file for copyright and license details. */
+#include <arpa/inet.h>
+
+#include <errno.h>
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+static char *argv0;
+
+int
+main(int argc, char *argv[])
+{
+	uint32_t hdr[4], width, height;
+	char buf[BUFSIZ];
+	size_t n, t;
+
+	argv0 = argv[0], argc--, argv++;
+
+	if (argc) {
+		fprintf(stderr, "usage: %s\n", argv0);
+		return 1;
+	}
+
+	/* header */
+	if (fread(hdr, sizeof(*hdr), 4, stdin) != 4) {
+		fprintf(stderr, "%s: file too short\n", argv0);
+		return 1;
+	}
+	if (memcmp("farbfeld", hdr, sizeof("farbfeld") - 1)) {
+		fprintf(stderr, "%s: invalid magic value\n", argv0);
+		return 1;
+	}
+	width = ntohl(hdr[2]);
+	height = ntohl(hdr[3]);
+
+	/* write header */
+	printf("P7\n"
+	       "WIDTH %" PRIu32 "\n"
+	       "HEIGHT %" PRIu32 "\n"
+	       "DEPTH 4\n" /* number of channels */
+	       "MAXVAL 65535\n"
+	       "TUPLTYPE RGB_ALPHA\n"
+	       "ENDHDR\n",
+	       width, height);
+
+	/* write image */
+	t = (size_t)width * (size_t)height * sizeof(uint16_t) * (sizeof("RGBA") - 1);
+	for (; (n = fread(buf, 1, sizeof(buf) <= t ? sizeof(buf) : t, stdin)); ) {
+		t -= n;
+		fwrite(buf, 1, n, stdout);
+
+		if (feof(stdin)) {
+			break;
+		}
+		if (ferror(stdin)) {
+			fprintf(stderr, "%s: read: %s\n", argv0, strerror(errno));
+			return 1;
+		}
+		if (ferror(stdout)) {
+			fprintf(stderr, "%s: write: %s\n", argv0, strerror(errno));
+			return 1;
+		}
+	}
+
+	if (t > 0) {
+		fprintf(stderr, "%s: file too short\n", argv0);
+		return 1;
+	}
+
+	return 0;
+}