diff --git a/vp9/encoder/vp9_onyx_if.c b/vp9/encoder/vp9_onyx_if.c
index db6e03e06..e6e9cddd7 100644
--- a/vp9/encoder/vp9_onyx_if.c
+++ b/vp9/encoder/vp9_onyx_if.c
@@ -1187,6 +1187,38 @@ void vp9_alloc_compressor_data(VP9_COMP *cpi) {
 }
 
 
+static void update_frame_size(VP9_COMP *cpi) {
+  VP9_COMMON *cm = &cpi->common;
+
+  /* our internal buffers are always multiples of 16 */
+  int width = (cm->Width + 15) & ~15;
+  int height = (cm->Height + 15) & ~15;
+
+  cm->mb_rows = height >> 4;
+  cm->mb_cols = width >> 4;
+  cm->MBs = cm->mb_rows * cm->mb_cols;
+  cm->mode_info_stride = cm->mb_cols + 1;
+  memset(cm->mip, 0,
+        (cm->mb_cols + 1) * (cm->mb_rows + 1) * sizeof(MODE_INFO));
+  vp9_update_mode_info_border(cm, cm->mip);
+
+  cm->mi = cm->mip + cm->mode_info_stride + 1;
+  cm->prev_mi = cm->prev_mip + cm->mode_info_stride + 1;
+  vp9_update_mode_info_in_image(cm, cm->mi);
+
+  /* Update size of buffers local to this frame */
+  if (vp8_yv12_realloc_frame_buffer(&cpi->last_frame_uf,
+                                    width, height, VP9BORDERINPIXELS))
+    vpx_internal_error(&cpi->common.error, VPX_CODEC_MEM_ERROR,
+                       "Failed to reallocate last frame buffer");
+
+  if (vp8_yv12_realloc_frame_buffer(&cpi->scaled_source,
+                                    width, height, VP9BORDERINPIXELS))
+    vpx_internal_error(&cpi->common.error, VPX_CODEC_MEM_ERROR,
+                       "Failed to reallocate scaled source buffer");
+}
+
+
 // TODO perhaps change number of steps expose to outside world when setting
 // max and min limits. Also this will likely want refining for the extended Q
 // range.
@@ -1482,14 +1514,18 @@ void vp9_change_config(VP9_PTR ptr, VP9_CONFIG *oxcf) {
     cm->Height = (vs - 1 + cpi->oxcf.Height * vr) / vs;
   }
 
-  if (((cm->Width + 15) & 0xfffffff0) !=
-      cm->yv12_fb[cm->active_ref_idx[cpi->lst_fb_idx]].y_width ||
-      ((cm->Height + 15) & 0xfffffff0) !=
-      cm->yv12_fb[cm->active_ref_idx[cpi->lst_fb_idx]].y_height ||
-      cm->yv12_fb[cm->active_ref_idx[cpi->lst_fb_idx]].y_width == 0) {
+  // Increasing the size of the frame beyond the first seen frame, or some
+  // otherwise signalled maximum size, is not supported.
+  // TODO(jkoleszar): exit gracefully.
+  if (!cpi->initial_width) {
     alloc_raw_frame_buffers(cpi);
     vp9_alloc_compressor_data(cpi);
+    cpi->initial_width = cm->Width;
+    cpi->initial_height = cm->Height;
   }
+  assert(cm->Width <= cpi->initial_width);
+  assert(cm->Height <= cpi->initial_height);
+  update_frame_size(cpi);
 
   if (cpi->oxcf.fixed_q >= 0) {
     cpi->last_q[0] = cpi->oxcf.fixed_q;
@@ -3954,6 +3990,11 @@ int vp9_get_compressed_data(VP9_PTR ptr, unsigned int *frame_flags,
   cm->fb_idx_ref_cnt[cm->new_fb_idx]--;
   cm->new_fb_idx = get_free_fb(cm);
 
+  /* Reset the frame pointers to the current frame size */
+  vp8_yv12_realloc_frame_buffer(&cm->yv12_fb[cm->new_fb_idx],
+                                cm->mb_cols * 16, cm->mb_rows * 16,
+                                VP9BORDERINPIXELS);
+
   vp9_setup_interp_filters(&cpi->mb.e_mbd, DEFAULT_INTERP_FILTER, cm);
   if (cpi->pass == 1) {
     Pass1Encode(cpi, size, dest, frame_flags);
diff --git a/vp9/encoder/vp9_onyx_int.h b/vp9/encoder/vp9_onyx_int.h
index 4c1113ef2..c4442b4aa 100644
--- a/vp9/encoder/vp9_onyx_int.h
+++ b/vp9/encoder/vp9_onyx_int.h
@@ -677,6 +677,8 @@ typedef struct VP9_COMP {
   unsigned int mb_mv_ref_count[MAX_REF_FRAMES][MAX_MV_REF_CANDIDATES];
 #endif
 
+  int initial_width;
+  int initial_height;
 } VP9_COMP;
 
 void vp9_encode_frame(VP9_COMP *cpi);
diff --git a/vp9/encoder/vp9_picklpf.c b/vp9/encoder/vp9_picklpf.c
index b443ede6f..6f9333521 100644
--- a/vp9/encoder/vp9_picklpf.c
+++ b/vp9/encoder/vp9_picklpf.c
@@ -8,7 +8,7 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-
+#include <assert.h>
 #include "vp9/common/vp9_onyxc_int.h"
 #include "vp9/encoder/vp9_onyx_int.h"
 #include "vp9/encoder/vp9_picklpf.h"
@@ -27,6 +27,7 @@ void vp9_yv12_copy_partial_frame_c(YV12_BUFFER_CONFIG *src_ybc,
   int yoffset;
   int linestocopy;
 
+  assert(src_ybc->y_stride == dst_ybc->y_stride);
   yheight  = src_ybc->y_height;
   ystride  = src_ybc->y_stride;
 
diff --git a/vpx_scale/generic/yv12config.c b/vpx_scale/generic/yv12config.c
index 4cb2a4190..267d55f40 100644
--- a/vpx_scale/generic/yv12config.c
+++ b/vpx_scale/generic/yv12config.c
@@ -35,13 +35,8 @@ vp8_yv12_de_alloc_frame_buffer(YV12_BUFFER_CONFIG *ybf) {
   return 0;
 }
 
-/****************************************************************************
- *
- ****************************************************************************/
-int
-vp8_yv12_alloc_frame_buffer(YV12_BUFFER_CONFIG *ybf, int width, int height, int border) {
-  /*NOTE:*/
-
+int vp8_yv12_realloc_frame_buffer(YV12_BUFFER_CONFIG *ybf,
+                                  int width, int height, int border) {
   if (ybf) {
     int y_stride = ((width + 2 * border) + 31) & ~31;
     int yplane_size = (height + 2 * border) * y_stride;
@@ -51,8 +46,15 @@ vp8_yv12_alloc_frame_buffer(YV12_BUFFER_CONFIG *ybf, int width, int height, int
       *  uv_stride == y_stride/2, so enforce this here. */
     int uv_stride = y_stride >> 1;
     int uvplane_size = (uv_height + border) * uv_stride;
+    const int frame_size = yplane_size + 2 * uvplane_size;
 
-    vp8_yv12_de_alloc_frame_buffer(ybf);
+    if (!ybf->buffer_alloc) {
+      ybf->buffer_alloc = vpx_memalign(32, frame_size);
+      ybf->buffer_alloc_sz = frame_size;
+    }
+
+    if (!ybf->buffer_alloc || ybf->buffer_alloc_sz < frame_size)
+      return -1;
 
     /** Only support allocating buffers that have a height and width that
       *  are multiples of 16, and a border that's a multiple of 32.
@@ -72,21 +74,23 @@ vp8_yv12_alloc_frame_buffer(YV12_BUFFER_CONFIG *ybf, int width, int height, int
     ybf->uv_stride = uv_stride;
 
     ybf->border = border;
-    ybf->frame_size = yplane_size + 2 * uvplane_size;
-
-    ybf->buffer_alloc = (unsigned char *) vpx_memalign(32, ybf->frame_size);
-
-    if (ybf->buffer_alloc == NULL)
-      return -1;
+    ybf->frame_size = frame_size;
 
     ybf->y_buffer = ybf->buffer_alloc + (border * y_stride) + border;
     ybf->u_buffer = ybf->buffer_alloc + yplane_size + (border / 2  * uv_stride) + border / 2;
     ybf->v_buffer = ybf->buffer_alloc + yplane_size + uvplane_size + (border / 2  * uv_stride) + border / 2;
 
     ybf->corrupted = 0; /* assume not currupted by errors */
-  } else {
-    return -2;
+    return 0;
   }
-
-  return 0;
+  return -2;
+}
+
+int vp8_yv12_alloc_frame_buffer(YV12_BUFFER_CONFIG *ybf,
+                                int width, int height, int border) {
+  if (ybf) {
+    vp8_yv12_de_alloc_frame_buffer(ybf);
+    return vp8_yv12_realloc_frame_buffer(ybf, width, height, border);
+  }
+  return -2;
 }
diff --git a/vpx_scale/generic/yv12extend.c b/vpx_scale/generic/yv12extend.c
index 5a427356b..d733bd49d 100644
--- a/vpx_scale/generic/yv12extend.c
+++ b/vpx_scale/generic/yv12extend.c
@@ -8,7 +8,7 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-
+#include <assert.h>
 #include "vpx_scale/yv12config.h"
 #include "vpx_mem/vpx_mem.h"
 #include "vpx_scale/vpx_scale.h"
@@ -216,6 +216,9 @@ vp8_yv12_copy_frame_c(YV12_BUFFER_CONFIG *src_ybc,
   int row;
   unsigned char *source, *dest;
 
+  assert(src_ybc->y_width == dst_ybc->y_width);
+  assert(src_ybc->y_height == dst_ybc->y_height);
+
   source = src_ybc->y_buffer;
   dest = dst_ybc->y_buffer;
 
diff --git a/vpx_scale/yv12config.h b/vpx_scale/yv12config.h
index 23be8f3dd..45e57f401 100644
--- a/vpx_scale/yv12config.h
+++ b/vpx_scale/yv12config.h
@@ -55,6 +55,7 @@ extern "C" {
     uint8_t *v_buffer;
 
     uint8_t *buffer_alloc;
+    int buffer_alloc_sz;
     int border;
     int frame_size;
     YUV_TYPE clrtype;
@@ -65,6 +66,8 @@ extern "C" {
 
   int vp8_yv12_alloc_frame_buffer(YV12_BUFFER_CONFIG *ybf,
                                   int width, int height, int border);
+  int vp8_yv12_realloc_frame_buffer(YV12_BUFFER_CONFIG *ybf,
+                                    int width, int height, int border);
   int vp8_yv12_de_alloc_frame_buffer(YV12_BUFFER_CONFIG *ybf);
 
 #ifdef __cplusplus