// 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"

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

  int c;

  int quiet = 0;

  int ok = 1;

  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");

      return 0;

    } else {

      const char* const filename = 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) printf("[%s] ", 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);

    }

  }

  return ok ? 0 : 1;

}