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cwebp: add webpdec

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simple webp decoding, no metadata support

Change-Id: I2752fd1442c87513922878cbf72f001d45b631bc
This commit is contained in:
James Zern
2014-04-22 19:30:27 -07:00
committed by Pascal Massimino
parent 4a0e73904d
commit ddeb6ac802
7 changed files with 123 additions and 12 deletions
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23
examples/cwebp.c
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@ -28,6 +28,7 @@
#include "./jpegdec.h"
#include "./pngdec.h"
#include "./tiffdec.h"
#include "./webpdec.h"
#include "./wicdec.h"
#ifndef WEBP_DLL
@ -106,26 +107,30 @@ typedef enum {
PNG_ = 0,
JPEG_,
TIFF_, // 'TIFF' clashes with libtiff
WEBP_,
UNSUPPORTED
} InputFileFormat;
static InputFileFormat GetImageType(FILE* in_file) {
InputFileFormat format = UNSUPPORTED;
uint32_t magic;
uint8_t buf[4];
uint32_t magic1, magic2;
uint8_t buf[12];
if ((fread(&buf[0], 4, 1, in_file) != 1) ||
if ((fread(&buf[0], 12, 1, in_file) != 1) ||
(fseek(in_file, 0, SEEK_SET) != 0)) {
return format;
}
magic = ((uint32_t)buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
if (magic == 0x89504E47U) {
magic1 = ((uint32_t)buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
magic2 = ((uint32_t)buf[8] << 24) | (buf[9] << 16) | (buf[10] << 8) | buf[11];
if (magic1 == 0x89504E47U) {
format = PNG_;
} else if (magic >= 0xFFD8FF00U && magic <= 0xFFD8FFFFU) {
} else if (magic1 >= 0xFFD8FF00U && magic1 <= 0xFFD8FFFFU) {
format = JPEG_;
} else if (magic == 0x49492A00 || magic == 0x4D4D002A) {
} else if (magic1 == 0x49492A00 || magic1 == 0x4D4D002A) {
format = TIFF_;
} else if (magic1 == 0x52494646 && magic2 == 0x57454250) {
format = WEBP_;
}
return format;
}
@ -148,6 +153,8 @@ static int ReadPicture(const char* const filename, WebPPicture* const pic,
ok = ReadJPEG(in_file, pic, metadata);
} else if (format == TIFF_) {
ok = ReadTIFF(filename, pic, keep_alpha, metadata);
} else if (format == WEBP_) {
ok = ReadWebP(filename, pic, keep_alpha, metadata);
}
} else {
// If image size is specified, infer it as YUV format.
@ -553,7 +560,7 @@ static void HelpLong(void) {
printf("Usage:\n");
printf(" cwebp [-preset <...>] [options] in_file [-o out_file]\n\n");
printf("If input size (-s) for an image is not specified, "
"it is assumed to be a PNG, JPEG or TIFF file.\n");
"it is assumed to be a PNG, JPEG, TIFF or WebP file.\n");
#ifdef HAVE_WINCODEC_H
printf("Windows builds can take as input any of the files handled by WIC\n");
#endif