diff --git a/examples.mk b/examples.mk
index f1cc42bf7..28430a611 100644
--- a/examples.mk
+++ b/examples.mk
@@ -8,6 +8,12 @@
 ##  be found in the AUTHORS file in the root of the source tree.
 ##
 
+LIBYUV_SRCS +=  third_party/libyuv/include/libyuv/basic_types.h  \
+                third_party/libyuv/include/libyuv/cpu_id.h  \
+                third_party/libyuv/include/libyuv/scale.h  \
+                third_party/libyuv/source/row.h \
+                third_party/libyuv/source/scale.c  \
+                third_party/libyuv/source/cpu_id.c
 
 # List of examples to build. UTILS are files that are taken from the source
 # tree directly, and GEN_EXAMPLES are files that are created from the
@@ -36,6 +42,7 @@ vpxenc.SRCS                 += vpx_ports/vpx_timer.h
 vpxenc.SRCS                 += libmkv/EbmlIDs.h
 vpxenc.SRCS                 += libmkv/EbmlWriter.c
 vpxenc.SRCS                 += libmkv/EbmlWriter.h
+vpxenc.SRCS                 += $(LIBYUV_SRCS)
 vpxenc.GUID                  = 548DEC74-7A15-4B2B-AFC3-AA102E7C25C1
 vpxenc.DESCRIPTION           = Full featured encoder
 UTILS-$(CONFIG_VP8_ENCODER)    += vp8_scalable_patterns.c
@@ -99,13 +106,7 @@ vp8cx_set_ref.DESCRIPTION           = VP8 set encoder reference frame
 
 # C file is provided, not generated automatically.
 UTILS-$(CONFIG_MULTI_RES_ENCODING) += vp8_multi_resolution_encoder.c
-vp8_multi_resolution_encoder.SRCS  \
-                         += third_party/libyuv/include/libyuv/basic_types.h  \
-                            third_party/libyuv/include/libyuv/cpu_id.h  \
-                            third_party/libyuv/include/libyuv/scale.h  \
-                            third_party/libyuv/source/row.h \
-                            third_party/libyuv/source/scale.c  \
-                            third_party/libyuv/source/cpu_id.c
+vp8_multi_resolution_encoder.SRCS         += $(LIBYUV_SRCS)
 vp8_multi_resolution_encoder.GUID         = 04f8738e-63c8-423b-90fa-7c2703a374de
 vp8_multi_resolution_encoder.DESCRIPTION  = VP8 Multiple-resolution Encoding
 
diff --git a/vpxenc.c b/vpxenc.c
index 99d581c19..df7718b70 100644
--- a/vpxenc.c
+++ b/vpxenc.c
@@ -47,6 +47,7 @@
 #include "y4minput.h"
 #include "libmkv/EbmlWriter.h"
 #include "libmkv/EbmlIDs.h"
+#include "third_party/libyuv/include/libyuv/scale.h"
 
 /* Need special handling of these functions on Windows */
 #if defined(_MSC_VER)
@@ -1635,6 +1636,7 @@ struct stream_state {
   uint64_t                  cx_time;
   size_t                    nbytes;
   stats_io_t                stats;
+  struct vpx_image         *img;
   vpx_codec_ctx_t           decoder;
   vpx_ref_frame_t           ref_enc;
   vpx_ref_frame_t           ref_dec;
@@ -2050,11 +2052,15 @@ static void validate_stream_config(struct stream_state *stream) {
 static void set_stream_dimensions(struct stream_state *stream,
                                   unsigned int w,
                                   unsigned int h) {
-  if ((stream->config.cfg.g_w && stream->config.cfg.g_w != w)
-      || (stream->config.cfg.g_h && stream->config.cfg.g_h != h))
-    fatal("Stream %d: Resizing not yet supported", stream->index);
-  stream->config.cfg.g_w = w;
-  stream->config.cfg.g_h = h;
+  if (!stream->config.cfg.g_w) {
+    if (!stream->config.cfg.g_h)
+      stream->config.cfg.g_w = w;
+    else
+      stream->config.cfg.g_w = w * stream->config.cfg.g_h / h;
+  }
+  if (!stream->config.cfg.g_h) {
+    stream->config.cfg.g_h = h * stream->config.cfg.g_w / w;
+  }
 }
 
 
@@ -2244,6 +2250,28 @@ static void encode_frame(struct stream_state  *stream,
   next_frame_start = (cfg->g_timebase.den * (int64_t)(frames_in)
                       * global->framerate.den)
                      / cfg->g_timebase.num / global->framerate.num;
+
+  /* Scale if necessary */
+  if (img && (img->d_w != cfg->g_w || img->d_h != cfg->g_h)) {
+    if (!stream->img)
+      stream->img = vpx_img_alloc(NULL, VPX_IMG_FMT_I420,
+                                  cfg->g_w, cfg->g_h, 16);
+    I420Scale(img->planes[VPX_PLANE_Y], img->stride[VPX_PLANE_Y],
+              img->planes[VPX_PLANE_U], img->stride[VPX_PLANE_U],
+              img->planes[VPX_PLANE_V], img->stride[VPX_PLANE_V],
+              img->d_w, img->d_h,
+              stream->img->planes[VPX_PLANE_Y],
+              stream->img->stride[VPX_PLANE_Y],
+              stream->img->planes[VPX_PLANE_U],
+              stream->img->stride[VPX_PLANE_U],
+              stream->img->planes[VPX_PLANE_V],
+              stream->img->stride[VPX_PLANE_V],
+              stream->img->d_w, stream->img->d_h,
+              kFilterBox);
+
+    img = stream->img;
+  }
+
   vpx_usec_timer_start(&timer);
   vpx_codec_encode(&stream->encoder, img, frame_start,
                    (unsigned long)(next_frame_start - frame_start),
@@ -2500,6 +2528,9 @@ int main(int argc, const char **argv_) {
     });
 
     /* Update stream configurations from the input file's parameters */
+    if (!input.w || !input.h)
+      fatal("Specify stream dimensions with --width (-w) "
+            " and --height (-h)");
     FOREACH_STREAM(set_stream_dimensions(stream, input.w, input.h));
     FOREACH_STREAM(validate_stream_config(stream));