diff --git a/libavformat/utils.c b/libavformat/utils.c
index c4d09e99ac..04c10a072d 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -2382,7 +2382,9 @@ static void estimate_timings_from_pts(AVFormatContext *ic, int64_t old_offset)
 
     for (i = 0; i < ic->nb_streams; i++) {
         st = ic->streams[i];
-        if (st->start_time == AV_NOPTS_VALUE && st->first_dts == AV_NOPTS_VALUE)
+        if (st->start_time == AV_NOPTS_VALUE &&
+            st->first_dts == AV_NOPTS_VALUE &&
+            st->codec->codec_type != AVMEDIA_TYPE_UNKNOWN)
             av_log(st->codec, AV_LOG_WARNING,
                    "start time is not set in estimate_timings_from_pts\n");
 
@@ -3062,6 +3064,7 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
             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]->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
                     strcmp(ic->iformat->name, "image2"))
                     av_log(ic, AV_LOG_WARNING,
                            "Stream #%d: not enough frames to estimate rate; "