add log 2

src/opencv/image_fingerprint.cpp

@@ -53,13 +53,15 @@ int fingerprintFromFFAVFrame(FILE *file, AVFrame *frame, char buf[64]) {
     SwsContext *conversion = sws_getContext(width, height, (AVPixelFormat) frame->format, width, height,
                                             AVPixelFormat::AV_PIX_FMT_BGR24, SWS_FAST_BILINEAR, NULL, NULL, NULL);
     if (conversion){
+        printf("fingerprintFromFFAVFrame -4\n");
         sws_scale(conversion, frame->data, frame->linesize, 0, height, &img.data, cvLinesizes);
+        printf("fingerprintFromFFAVFrame -5\n");
         sws_freeContext(conversion);
     } else {
         printf("sws_getContext init error .");
         return NULL;
     }
-    printf("fingerprintFromFFAVFrame -4\n");
+    printf("fingerprintFromFFAVFrame -6\n");
     if (img.empty()) {
         printf("image is empty.");
         return NULL;