// 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 \ -lexample_util -limagedec -lwebpextras -lwebp -L/opt/local/lib \ -lpng -lz -ljpeg -ltiff -lm -lpthread */ #include #include #include #include "./extras.h" #include "../imageio/imageio_util.h" int main(int argc, const char *argv[]) { int c; int quiet = 0; for (c = 1; 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 1; } else { const char* const filename = argv[c]; const uint8_t* data = NULL; size_t data_size = 0; int q; const int ok = ImgIoUtilReadFile(filename, &data, &data_size); if (!ok) continue; 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"); } else { if (!quiet) { printf("Estimated quality factor: %d\n", q); } else { printf("%d\n", q); // just print the number } } free((void*)data); } } return 1; }