ffmpeg: print frame decoding error statistic

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

ffmpeg.c

@@ -3361,6 +3361,8 @@ int main(int argc, char **argv)
     if (do_benchmark) {
         printf("bench: utime=%0.3fs\n", ti / 1000000.0);
     }
+    av_log(NULL, AV_LOG_DEBUG, "%"PRIu64" frames successfully decoded, %"PRIu64" decoding errors\n",
+           decode_error_stat[0], decode_error_stat[1]);
     if (2*decode_error_stat[0] < decode_error_stat[1])
         exit(254);