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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Provide a simple API around the Wuffs JPEG decoder.
*/
#include <stdint.h>
#include "jpeg.h"
#define WUFFS_CONFIG__AVOID_CPU_ARCH
#define WUFFS_CONFIG__MODULES
#define WUFFS_CONFIG__MODULE__BASE
#define WUFFS_CONFIG__MODULE__JPEG
#define WUFFS_CONFIG__STATIC_FUNCTIONS
#define WUFFS_IMPLEMENTATION
#include "../vendorcode/wuffs/wuffs-v0.4.c"
/* ~16K is big enough to move this off the stack */
static wuffs_jpeg__decoder dec;
int jpeg_fetch_size(unsigned char *filedata, size_t filesize, unsigned int *width,
unsigned int *height)
{
if (!width || !height) {
return JPEG_DECODE_FAILED;
}
wuffs_base__status status = wuffs_jpeg__decoder__initialize(
&dec, sizeof(dec), WUFFS_VERSION, WUFFS_INITIALIZE__DEFAULT_OPTIONS);
if (status.repr) {
return JPEG_DECODE_FAILED;
}
wuffs_base__image_config imgcfg;
wuffs_base__io_buffer src = wuffs_base__ptr_u8__reader(filedata, filesize, true);
status = wuffs_jpeg__decoder__decode_image_config(&dec, &imgcfg, &src);
if (status.repr) {
return JPEG_DECODE_FAILED;
}
*width = wuffs_base__pixel_config__width(&imgcfg.pixcfg);
*height = wuffs_base__pixel_config__height(&imgcfg.pixcfg);
return 0;
}
int jpeg_decode(unsigned char *filedata, size_t filesize, unsigned char *pic,
unsigned int width, unsigned int height, unsigned int bytes_per_line,
unsigned int depth)
{
if (!filedata || !pic) {
return JPEG_DECODE_FAILED;
}
/* Relatively arbitrary limit that shouldn't hurt anybody.
* 300M (10k*10k*3bytes/pixel) is already larger than our heap, so
* it's on the safe side.
* This avoids overflows when width or height are used for
* calculations in this function.
*/
if ((width > 10000) || (height > 10000)) {
return JPEG_DECODE_FAILED;
}
uint32_t pixfmt;
switch (depth) {
case 16:
pixfmt = WUFFS_BASE__PIXEL_FORMAT__BGR_565;
break;
case 24:
pixfmt = WUFFS_BASE__PIXEL_FORMAT__BGR;
break;
case 32:
pixfmt = WUFFS_BASE__PIXEL_FORMAT__BGRA_NONPREMUL;
break;
default:
return JPEG_DECODE_FAILED;
}
wuffs_base__status status = wuffs_jpeg__decoder__initialize(
&dec, sizeof(dec), WUFFS_VERSION, WUFFS_INITIALIZE__DEFAULT_OPTIONS);
if (status.repr) {
return JPEG_DECODE_FAILED;
}
/* Opting in to lower quality means that we can pass an empty slice as the
* "work buffer" argument to wuffs_jpeg__decoder__decode_frame below.
*
* Decoding progressive (not sequential) JPEGs would still require dynamic
* memory allocation (and the amount of work buffer required depends on the
* image dimensions), but we choose to just reject progressive JPEGs. It is
* simpler than sometimes calling malloc (which can fail, especially for
* large allocations) and free.
*
* More commentary about these quirks is at
* https://github.com/google/wuffs/blob/beaf45650085a16780b5f708b72daaeb1aa865c8/std/jpeg/decode_quirks.wuffs
*/
wuffs_jpeg__decoder__set_quirk(
&dec, WUFFS_BASE__QUIRK_QUALITY,
WUFFS_BASE__QUIRK_QUALITY__VALUE__LOWER_QUALITY);
wuffs_jpeg__decoder__set_quirk(
&dec, WUFFS_JPEG__QUIRK_REJECT_PROGRESSIVE_JPEGS, 1);
wuffs_base__image_config imgcfg;
wuffs_base__io_buffer src = wuffs_base__ptr_u8__reader(filedata, filesize, true);
status = wuffs_jpeg__decoder__decode_image_config(&dec, &imgcfg, &src);
if (status.repr) {
return JPEG_DECODE_FAILED;
}
wuffs_base__pixel_config pixcfg;
wuffs_base__pixel_config__set(&pixcfg, pixfmt, 0, width, height);
wuffs_base__pixel_buffer pixbuf;
status = wuffs_base__pixel_buffer__set_interleaved(
&pixbuf, &pixcfg,
wuffs_base__make_table_u8(pic, width * (depth / 8), height, bytes_per_line),
wuffs_base__empty_slice_u8());
if (status.repr) {
return JPEG_DECODE_FAILED;
}
status = wuffs_jpeg__decoder__decode_frame(&dec, &pixbuf, &src,
WUFFS_BASE__PIXEL_BLEND__SRC,
wuffs_base__empty_slice_u8(), NULL);
if (status.repr) {
return JPEG_DECODE_FAILED;
}
return 0;
}
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