diff --git a/vp9/encoder/vp9_encoder.c b/vp9/encoder/vp9_encoder.c
index f8f681a..a32b782 100644
--- a/vp9/encoder/vp9_encoder.c
+++ b/vp9/encoder/vp9_encoder.c
@@ -410,6 +410,9 @@
   memset(&cpi->svc.scaled_frames[0], 0,
          MAX_LAG_BUFFERS * sizeof(cpi->svc.scaled_frames[0]));
 
+  vpx_free_frame_buffer(&cpi->svc.scaled_temp);
+  memset(&cpi->svc.scaled_temp, 0, sizeof(cpi->svc.scaled_temp));
+
   vpx_free_frame_buffer(&cpi->svc.empty_frame.img);
   memset(&cpi->svc.empty_frame, 0, sizeof(cpi->svc.empty_frame));
 
@@ -3357,11 +3360,20 @@
   vpx_clear_system_state();
 
   set_frame_size(cpi);
-  cpi->Source = vp9_scale_if_required(cm,
-                                      cpi->un_scaled_source,
-                                      &cpi->scaled_source,
-                                      (cpi->oxcf.pass == 0));
 
+  if (is_one_pass_cbr_svc(cpi) &&
+      cpi->un_scaled_source->y_width == cm->width << 2 &&
+      cpi->un_scaled_source->y_height == cm->height << 2) {
+    cpi->Source = vp9_svc_twostage_scale(cm,
+                                         cpi->un_scaled_source,
+                                         &cpi->scaled_source,
+                                         &cpi->svc.scaled_temp);
+  } else {
+    cpi->Source = vp9_scale_if_required(cm,
+                                        cpi->un_scaled_source,
+                                        &cpi->scaled_source,
+                                        (cpi->oxcf.pass == 0));
+  }
   // Avoid scaling last_source unless its needed.
   // Last source is needed if vp9_avg_source_sad() is used, or if
   // partition_search_type == SOURCE_VAR_BASED_PARTITION, or if noise
@@ -3782,6 +3794,25 @@
   }
 }
 
+YV12_BUFFER_CONFIG *vp9_svc_twostage_scale(VP9_COMMON *cm,
+                                           YV12_BUFFER_CONFIG *unscaled,
+                                           YV12_BUFFER_CONFIG *scaled,
+                                           YV12_BUFFER_CONFIG *scaled_temp) {
+  if (cm->mi_cols * MI_SIZE != unscaled->y_width ||
+      cm->mi_rows * MI_SIZE != unscaled->y_height) {
+#if CONFIG_VP9_HIGHBITDEPTH
+      scale_and_extend_frame(unscaled, scaled_temp, (int)cm->bit_depth);
+      scale_and_extend_frame(scaled_temp, scaled, (int)cm->bit_depth);
+#else
+      vp9_scale_and_extend_frame(unscaled, scaled_temp);
+      vp9_scale_and_extend_frame(scaled_temp, scaled);
+#endif  // CONFIG_VP9_HIGHBITDEPTH
+    return scaled;
+  } else {
+    return unscaled;
+  }
+}
+
 YV12_BUFFER_CONFIG *vp9_scale_if_required(VP9_COMMON *cm,
                                           YV12_BUFFER_CONFIG *unscaled,
                                           YV12_BUFFER_CONFIG *scaled,
diff --git a/vp9/encoder/vp9_encoder.h b/vp9/encoder/vp9_encoder.h
index c486ac2..2def941 100644
--- a/vp9/encoder/vp9_encoder.h
+++ b/vp9/encoder/vp9_encoder.h
@@ -623,6 +623,11 @@
 
 void vp9_set_high_precision_mv(VP9_COMP *cpi, int allow_high_precision_mv);
 
+YV12_BUFFER_CONFIG *vp9_svc_twostage_scale(VP9_COMMON *cm,
+                                           YV12_BUFFER_CONFIG *unscaled,
+                                           YV12_BUFFER_CONFIG *scaled,
+                                           YV12_BUFFER_CONFIG *scaled_temp);
+
 YV12_BUFFER_CONFIG *vp9_scale_if_required(VP9_COMMON *cm,
                                           YV12_BUFFER_CONFIG *unscaled,
                                           YV12_BUFFER_CONFIG *scaled,
diff --git a/vp9/encoder/vp9_svc_layercontext.c b/vp9/encoder/vp9_svc_layercontext.c
index 1d56154..2c8bc46 100644
--- a/vp9/encoder/vp9_svc_layercontext.c
+++ b/vp9/encoder/vp9_svc_layercontext.c
@@ -43,6 +43,25 @@
     cpi->svc.ext_alt_fb_idx[sl] = 2;
   }
 
+  // For 1 pass cbr: allocate scaled_frame that may be used for 2 stage
+  // downsampling.
+  if (cpi->oxcf.pass == 0 && cpi->oxcf.rc_mode == VPX_CBR) {
+    if (vpx_realloc_frame_buffer(&cpi->svc.scaled_temp,
+                                 cpi->common.width >> 1,
+                                 cpi->common.height >> 1,
+                                 cpi->common.subsampling_x,
+                                 cpi->common.subsampling_y,
+#if CONFIG_VP9_HIGHBITDEPTH
+                                 cpi->common.use_highbitdepth,
+#endif
+                                 VP9_ENC_BORDER_IN_PIXELS,
+                                 cpi->common.byte_alignment,
+                                 NULL, NULL, NULL))
+      vpx_internal_error(&cpi->common.error, VPX_CODEC_MEM_ERROR,
+                         "Failed to allocate scaled_frame for svc ");
+  }
+
+
   if (cpi->oxcf.error_resilient_mode == 0 && cpi->oxcf.pass == 2) {
     if (vpx_realloc_frame_buffer(&cpi->svc.empty_frame.img,
                                  SMALL_FRAME_WIDTH, SMALL_FRAME_HEIGHT,
diff --git a/vp9/encoder/vp9_svc_layercontext.h b/vp9/encoder/vp9_svc_layercontext.h
index 4e18640..f1b8556 100644
--- a/vp9/encoder/vp9_svc_layercontext.h
+++ b/vp9/encoder/vp9_svc_layercontext.h
@@ -70,6 +70,8 @@
   // Store scaled source frames to be used for temporal filter to generate
   // a alt ref frame.
   YV12_BUFFER_CONFIG scaled_frames[MAX_LAG_BUFFERS];
+  // Temp buffer used for 2-stage down-sampling, for real-time mode.
+  YV12_BUFFER_CONFIG scaled_temp;
 
   // Layer context used for rate control in one pass temporal CBR mode or
   // two pass spatial mode.