Do not suggest to increase probesize for image2 files.

libavformat/utils.c

@@ -2779,7 +2779,8 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
             av_log(ic, AV_LOG_DEBUG, "Probe buffer size limit of %d bytes reached\n", ic->probesize);
             for (i = 0; i < ic->nb_streams; i++)
                 if (!ic->streams[i]->r_frame_rate.num &&
-                    ic->streams[i]->info->duration_count <= 1)
+                    ic->streams[i]->info->duration_count <= 1 &&
+                    strcmp(ic->iformat->name, "image2"))
                     av_log(ic, AV_LOG_WARNING,
                            "Stream #%d: not enough frames to estimate rate; "
                            "consider increasing probesize\n", i);