diff --git a/doc/APIchanges b/doc/APIchanges
index 2bde666c35..2c1358fe05 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -144,6 +144,9 @@ API changes, most recent first:
 2012-03-26 - a67d9cf - lavfi 2.66.100
   Add avfilter_fill_frame_from_{audio_,}buffer_ref() functions.
 
+2013-xx-xx - lavu 52.9.0 - pixdesc.h
+  Add av_pix_fmt_count_planes() function for counting planes in a pixel format.
+
 2013-xx-xx - lavfi 3.6.0
   Add AVFilterGraph.nb_filters, deprecate AVFilterGraph.filter_count.
 
diff --git a/libavformat/asfenc.c b/libavformat/asfenc.c
index 9a8a739d39..f3aec9c845 100644
--- a/libavformat/asfenc.c
+++ b/libavformat/asfenc.c
@@ -804,14 +804,6 @@ static int asf_write_packet(AVFormatContext *s, AVPacket *pkt)
         flags &= ~AV_PKT_FLAG_KEY;
 
     pts = (pkt->pts != AV_NOPTS_VALUE) ? pkt->pts : pkt->dts;
-
-    if (pts < 0) {
-        av_log(s, AV_LOG_ERROR,
-               "Negative dts not supported stream %d, dts %"PRId64"\n",
-               pkt->stream_index, pts);
-        return AVERROR(ENOSYS);
-    }
-
     assert(pts != AV_NOPTS_VALUE);
     pts *= 10000;
     asf->duration = FFMAX(asf->duration, pts + pkt->duration * 10000);
diff --git a/libavutil/pixdesc.c b/libavutil/pixdesc.c
index 1016dbaecb..31363cfb61 100644
--- a/libavutil/pixdesc.c
+++ b/libavutil/pixdesc.c
@@ -1791,3 +1791,18 @@ int av_pix_fmt_get_chroma_sub_sample(enum AVPixelFormat pix_fmt,
 
     return 0;
 }
+
+int av_pix_fmt_count_planes(enum AVPixelFormat pix_fmt)
+{
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
+    int i, planes[4] = { 0 }, ret = 0;
+
+    if (!desc)
+        return AVERROR(EINVAL);
+
+    for (i = 0; i < desc->nb_components; i++)
+        planes[desc->comp[i].plane] = 1;
+    for (i = 0; i < FF_ARRAY_ELEMS(planes); i++)
+        ret += planes[i];
+    return ret;
+}
diff --git a/libavutil/pixdesc.h b/libavutil/pixdesc.h
index 1042e1ed45..0947fd1f88 100644
--- a/libavutil/pixdesc.h
+++ b/libavutil/pixdesc.h
@@ -233,5 +233,11 @@ enum AVPixelFormat av_pix_fmt_desc_get_id(const AVPixFmtDescriptor *desc);
 int av_pix_fmt_get_chroma_sub_sample(enum AVPixelFormat pix_fmt,
                                      int *h_shift, int *v_shift);
 
+/**
+ * @return number of planes in pix_fmt, a negative AVERROR if pix_fmt is not a
+ * valid pixel format.
+ */
+int av_pix_fmt_count_planes(enum AVPixelFormat pix_fmt);
+
 
 #endif /* AVUTIL_PIXDESC_H */
diff --git a/libavutil/version.h b/libavutil/version.h
index b8f814f587..1ff9ffeb92 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -75,8 +75,8 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR  52
-#define LIBAVUTIL_VERSION_MINOR  19
-#define LIBAVUTIL_VERSION_MICRO 101
+#define LIBAVUTIL_VERSION_MINOR  20
+#define LIBAVUTIL_VERSION_MICRO 100
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
                                                LIBAVUTIL_VERSION_MINOR, \