commit 9f7647d61eb07195fc46cd4d9ad73aab06f2f779
parent a18c512a46c9dfe6f24e3ff1ad07318cd3fd4667
Author: sin <sin@2f30.org>
Date: Tue, 29 Jul 2014 17:25:22 +0100
Revert "Fix endianness in header"
The previous behaviour was correct. A width of 1900 pixels which is
0x00000640 in hex was stored on disk as:
00 00 06 40
That's BE order which is what we want.
Reading this uint32_t on an LE machine we get:
width = 0x40060000 and converting from BE to LE
we get the correct 0x640 value.
Reading on a BE machine we get the correct value
and the swap is a no-op.
Diffstat:
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/if2png.c b/if2png.c
@@ -46,8 +46,8 @@ main(int argc, char *argv[])
fprintf(stderr, "invalid magic in header\n");
return EXIT_FAILURE;
}
- width = ntohl((hdr[9] << 24) | (hdr[10] << 16) | (hdr[11] << 8) | (hdr[12] << 0));
- height = ntohl((hdr[13] << 24) | (hdr[14] << 16) | (hdr[15] << 8) | (hdr[16] << 0));
+ width = ntohl((hdr[9] << 0) | (hdr[10] << 8) | (hdr[11] << 16) | (hdr[12] << 24));
+ height = ntohl((hdr[13] << 0) | (hdr[14] << 8) | (hdr[15] << 16) | (hdr[16] << 24));
/* load png */
png_struct_p = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
diff --git a/png2if.c b/png2if.c
@@ -57,8 +57,10 @@ main(int argc, char *argv[])
/* write header with big endian width and height-values */
fprintf(stdout, "imagefile");
- fwrite(&width, sizeof(uint32_t), 1, stdout);
- fwrite(&height, sizeof(uint32_t), 1, stdout);
+ val_be = htonl(width);
+ fwrite(&val_be, sizeof(uint32_t), 1, stdout);
+ val_be = htonl(height);
+ fwrite(&val_be, sizeof(uint32_t), 1, stdout);
/* write data */
for (i = 0; i < height; i++) {
