diff --git a/libavformat/r3d.c b/libavformat/r3d.c
index 2674578aa0..cf6d7debbf 100644
--- a/libavformat/r3d.c
+++ b/libavformat/r3d.c
@@ -57,6 +57,7 @@ static int r3d_read_red1(AVFormatContext *s)
     char filename[258];
     int tmp;
     int av_unused tmp2;
+    AVRational framerate;
 
     if (!st)
         return AVERROR(ENOMEM);
@@ -84,8 +85,10 @@ static int r3d_read_red1(AVFormatContext *s)
     tmp = avio_rb16(s->pb); // unknown
     av_dlog(s, "unknown2 %d\n", tmp);
 
-    st->codec->time_base.den = avio_rb16(s->pb);
-    st->codec->time_base.num = avio_rb16(s->pb);
+    framerate.num = avio_rb16(s->pb);
+    framerate.den = avio_rb16(s->pb);
+    if (framerate.num && framerate.den)
+        st->r_frame_rate = st->avg_frame_rate = framerate;
 
     tmp = avio_r8(s->pb); // audio channels
     av_dlog(s, "audio channels %d\n", tmp);
@@ -107,7 +110,7 @@ static int r3d_read_red1(AVFormatContext *s)
     av_dlog(s, "resolution %dx%d\n", st->codec->width, st->codec->height);
     av_dlog(s, "timescale %d\n", st->time_base.den);
     av_dlog(s, "frame rate %d/%d\n",
-            st->codec->time_base.num, st->codec->time_base.den);
+            framerate.num, framerate.den);
 
     return 0;
 }
@@ -132,9 +135,11 @@ static int r3d_read_rdvo(AVFormatContext *s, Atom *atom)
         av_dlog(s, "video offset %d: %#x\n", i, r3d->video_offsets[i]);
     }
 
-    if (st->codec->time_base.den)
-        st->duration = (uint64_t)r3d->video_offsets_count*
-            st->time_base.den*st->codec->time_base.num/st->codec->time_base.den;
+    if (st->r_frame_rate.num)
+        st->duration = av_rescale_q(r3d->video_offsets_count,
+                                    (AVRational){st->r_frame_rate.den,
+                                                 st->r_frame_rate.num},
+                                    st->time_base);
     av_dlog(s, "duration %"PRId64"\n", st->duration);
 
     return 0;
@@ -257,9 +262,9 @@ static int r3d_read_redv(AVFormatContext *s, AVPacket *pkt, Atom *atom)
 
     pkt->stream_index = 0;
     pkt->dts = dts;
-    if (st->codec->time_base.den)
+    if (st->r_frame_rate.num)
         pkt->duration = (uint64_t)st->time_base.den*
-            st->codec->time_base.num/st->codec->time_base.den;
+            st->r_frame_rate.den/st->r_frame_rate.num;
     av_dlog(s, "pkt dts %"PRId64" duration %d\n", pkt->dts, pkt->duration);
 
     return 0;
@@ -357,11 +362,11 @@ static int r3d_seek(AVFormatContext *s, int stream_index, int64_t sample_time, i
     R3DContext *r3d = s->priv_data;
     int frame_num;
 
-    if (!st->codec->time_base.num || !st->time_base.den)
+    if (!st->r_frame_rate.num)
         return -1;
 
-    frame_num = sample_time*st->codec->time_base.den/
-        ((int64_t)st->codec->time_base.num*st->time_base.den);
+    frame_num = av_rescale_q(sample_time, st->time_base,
+                             (AVRational){st->r_frame_rate.den, st->r_frame_rate.num});
     av_dlog(s, "seek frame num %d timestamp %"PRId64"\n",
             frame_num, sample_time);