[PATCH 1/2] apps: common: dng_writer: Fix thumbnail generation on BE machines

[Stefan Klug]

Hi Laurent,

Thanks for the patch.

On Sat, Jun 29, 2024 at 12:35:34AM +0300, Laurent Pinchart wrote:
> The 16-bit padded raw 10 and raw 12 formats are stored in memory in
> little endian order, regardless of the machine's endianness. Swap the
> 16-bit values on big-endian machines when reading pixels from memory to
> generate thumbnails.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

Signed-off-by: Stefan Klug <stefan.klug at ideasonboard.com> 

Regards,
Stefan

> ---
>  src/apps/common/dng_writer.cpp | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/src/apps/common/dng_writer.cpp b/src/apps/common/dng_writer.cpp
> index 9241f23fb806..50db5eb33c83 100644
> --- a/src/apps/common/dng_writer.cpp
> +++ b/src/apps/common/dng_writer.cpp
> @@ -8,6 +8,7 @@
>  #include "dng_writer.h"
>  
>  #include <algorithm>
> +#include <endian.h>
>  #include <iostream>
>  #include <map>
>  
> @@ -185,7 +186,8 @@ void thumbScanlineRaw(const FormatInfo &info, void *output, const void *input,
>  
>  	/* Simple averaging that produces greyscale RGB values. */
>  	for (unsigned int x = 0; x < width; x++) {
> -		uint16_t value = (in[0] + in[1] + in2[0] + in2[1]) >> 2;
> +		uint16_t value = (le16toh(in[0]) + le16toh(in[1]) +
> +				  le16toh(in2[0]) + le16toh(in2[1])) >> 2;
>  		value = value >> shift;
>  		*out++ = value;
>  		*out++ = value;
> -- 
> Regards,
> 
> Laurent Pinchart
>