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// Copyright 2010 Google Inc.
//
// This code is licensed under the same terms as WebM:
// Software License Agreement: http://www.webmproject.org/license/software/
// Additional IP Rights Grant: http://www.webmproject.org/license/additional/
// -----------------------------------------------------------------------------
//
// simple command-line example calling libwebpdecode to
// decode a WebP image into a PPM image.
//
// Compile with: gcc -o dwebp dwebp.c -lwebpdecode
//
// Author: Skal (pascal.massimino@gmail.com)
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "webp/decode.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
//-----------------------------------------------------------------------------
static void help(const char *s) {
printf("Usage: dwebp "
"[options] [in_file] [-h] [-raw] [-o ppm_file]\n\n"
" -raw: save the raw YUV samples as a grayscale PGM\n"
" file with IMC4 layout.\n"
);
}
int main(int argc, char *argv[]) {
const char *in_file = NULL;
const char *out_file = NULL;
int raw_output = 0;
int width, height, stride, uv_stride;
uint8_t* out = NULL, *u = NULL, *v = NULL;
int c;
for (c = 1; c < argc; ++c) {
if (!strcmp(argv[c], "-h")) {
help(argv[0]);
return 0;
} else if (!strcmp(argv[c], "-o") && c < argc - 1) {
out_file = argv[++c];
} else if (!strcmp(argv[c], "-raw")) {
raw_output = 1;
} else if (argv[c][0] == '-') {
printf("Unknown option '%s'\n", argv[c]);
help(argv[0]);
return -1;
} else {
in_file = argv[c];
}
}
if (in_file == NULL) {
printf("missing input file!!\n");
help(argv[0]);
return -1;
}
{
uint32_t data_size = 0;
void* data = NULL;
FILE* const in = fopen(in_file, "rb");
if (!in) {
printf("cannot open input file '%s'\n", in_file);
return 1;
}
fseek(in, 0, SEEK_END);
data_size = ftell(in);
fseek(in, 0, SEEK_SET);
data = malloc(data_size);
const int ok = (fread(data, data_size, 1, in) == 1);
fclose(in);
if (!ok) {
free(data);
return -1;
}
if (!raw_output) {
out = WebPDecodeRGB(data, data_size, &width, &height);
} else {
out = WebPDecodeYUV(data, data_size, &width, &height,
&u, &v, &stride, &uv_stride);
}
free(data);
}
if (!out) {
printf("Decoding of %s failed.\n", in_file);
return -1;
}
if (out_file) {
FILE* const fout = fopen(out_file, "wb");
if (fout) {
int ok = 1;
if (!raw_output) {
fprintf(fout, "P6\n%d %d\n255\n", width, height);
ok &= (fwrite(out, width * height, 3, fout) == 3);
} else {
// Save a grayscale PGM file using the IMC4 layout
// (http://www.fourcc.org/yuv.php#IMC4). This is a very
// convenient format for viewing the samples, esp. for
// odd dimensions.
int y;
const int uv_width = (width + 1) / 2;
const int uv_height = (height + 1) / 2;
const int out_stride = (width + 1) & ~1;
fprintf(fout, "P5\n%d %d\n255\n", out_stride, height + uv_height);
for (y = 0; ok && y < height; ++y) {
ok &= (fwrite(out + y * stride, width, 1, fout) == 1);
if (width & 1) fputc(0, fout); // padding byte
}
for (y = 0; ok && y < uv_height; ++y) {
ok &= (fwrite(u + y * uv_stride, uv_width, 1, fout) == 1);
ok &= (fwrite(v + y * uv_stride, uv_width, 1, fout) == 1);
}
}
fclose(fout);
if (ok) {
printf("Saved file %s\n", out_file);
} else {
printf("Error writing file %s !!\n", out_file);
}
} else {
printf("Error opening output file %s\n", out_file);
}
}
printf("Decoded %s. Dimensions: %d x %d.\n", in_file, width, height);
free(out);
return 0;
}
//-----------------------------------------------------------------------------
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
#endif
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