ryan/mozjpeg
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

example.c: Fix 12-bit PPM write w/ big endian CPUs

Browse Source
This commit is contained in:
DRC
2023-10-11 15:02:33 -04:00
parent 5b2beb4bc4
commit ec32420f6b
1 changed files with 8 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
example.c
View File

@@ -4,7 +4,7 @@
* This file was part of the Independent JPEG Group's software. * This file was part of the Independent JPEG Group's software.
* Copyright (C) 1992-1996, Thomas G. Lane. * Copyright (C) 1992-1996, Thomas G. Lane.
* libjpeg-turbo Modifications: * libjpeg-turbo Modifications:
* Copyright (C) 2017, 2019, 2022, D. R. Commander. * Copyright (C) 2017, 2019, 2022-2023, D. R. Commander.
* For conditions of distribution and use, see the accompanying README.ijg * For conditions of distribution and use, see the accompanying README.ijg
* file. * file.
* *
@@ -398,6 +398,7 @@ do_read_JPEG_file(struct jpeg_decompress_struct *cinfo, char *infilename,
J12SAMPARRAY buffer12 = NULL; /* 12-bit output row buffer */ J12SAMPARRAY buffer12 = NULL; /* 12-bit output row buffer */
int col; int col;
int row_stride; /* physical row width in output buffer */ int row_stride; /* physical row width in output buffer */
int little_endian = 1;
/* In this example we want to open the input and output files before doing /* In this example we want to open the input and output files before doing
* anything else, so that the setjmp() error recovery below can assume the * anything else, so that the setjmp() error recovery below can assume the
@@ -494,10 +495,12 @@ do_read_JPEG_file(struct jpeg_decompress_struct *cinfo, char *infilename,
* more than one scanline at a time if that's more convenient. * more than one scanline at a time if that's more convenient.
*/ */
(void)jpeg12_read_scanlines(cinfo, buffer12, 1); (void)jpeg12_read_scanlines(cinfo, buffer12, 1);
if (*(char *)&little_endian == 1) {
/* Swap MSB and LSB in each sample */ /* Swap MSB and LSB in each sample */
for (col = 0; col < row_stride; col++) for (col = 0; col < row_stride; col++)
buffer12[0][col] = ((buffer12[0][col] & 0xFF) << 8) | buffer12[0][col] = ((buffer12[0][col] & 0xFF) << 8) |
((buffer12[0][col] >> 8) & 0xFF); ((buffer12[0][col] >> 8) & 0xFF);
}
fwrite(buffer12[0], 1, row_stride * sizeof(J12SAMPLE), outfile); fwrite(buffer12[0], 1, row_stride * sizeof(J12SAMPLE), outfile);
} }
} else { } else {