// Simple tool to roughly evaluate the quality encoding of a webp bitstream

//

// Result is a *rough* estimation of the quality. You should just consider

// the bucket it's in (q > 80? > 50? > 20?) and not take it for face value.

/*

gcc -o webp_quality webp_quality.c -O3 -I../ -L. -L../imageio \

-limageio_util -lwebpextras -lwebp -lm -lpthread

*/

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "extras/extras.h"

#include "imageio/imageio_util.h"

#include "../examples/unicode.h"

int main(int argc, const char *argv[]) {

int c;

int quiet = 0;

int ok = 1;

INIT_WARGV(argc, argv);

for (c = 1; ok && c < argc; ++c) {

if (!strcmp(argv[c], "-quiet")) {

quiet = 1;

} else if (!strcmp(argv[c], "-help") || !strcmp(argv[c], "-h")) {

printf("webp_quality [-h][-quiet] webp_files...\n");

FREE_WARGV_AND_RETURN(0);

} else {

const char* const filename = (const char*)GET_WARGV(argv, c);

const uint8_t* data = NULL;

size_t data_size = 0;

int q;

ok = ImgIoUtilReadFile(filename, &data, &data_size);

if (!ok) break;

q = VP8EstimateQuality(data, data_size);

if (!quiet) WPRINTF("[%s] ", (const W_CHAR*)filename);

if (q < 0) {

fprintf(stderr, "Not a WebP file, or not a lossy WebP file.\n");

ok = 0;

} else {

if (!quiet) {

printf("Estimated quality factor: %d\n", q);

} else {

printf("%d\n", q); // just print the number

}

}

free((void*)data);

}

}

FREE_WARGV_AND_RETURN(ok ? 0 : 1);

}