Merge "Revert "[spatial svc]Another workaround to avoid using prev_mi""

9 files changed, 137 insertions, 144 deletions

diff --git a/test/svc_test.cc b/test/svc_test.cc
index 67e83e395..fdde702d2 100644
--- a/test/svc_test.cc
+++ b/test/svc_test.cc
@@ -225,9 +225,10 @@ class SvcTest : public ::testing::Test {
     EXPECT_EQ(received_frames, n);
   }
 
-  void DropEnhancementLayers(struct vpx_fixed_buf *const inputs,
-                             const int num_super_frames,
-                             const int remained_spatial_layers) {
+  void DropLayersAndMakeItVP9Comaptible(struct vpx_fixed_buf *const inputs,
+                                        const int num_super_frames,
+                                        const int remained_spatial_layers,
+                                        const bool is_multiple_frame_contexts) {
     ASSERT_TRUE(inputs != NULL);
     ASSERT_GT(num_super_frames, 0);
     ASSERT_GT(remained_spatial_layers, 0);
@@ -249,6 +250,45 @@ class SvcTest : public ::testing::Test {
       if (frame_count == 0) {
         // There's no super frame but only a single frame.
         ASSERT_EQ(1, remained_spatial_layers);
+        if (is_multiple_frame_contexts) {
+          // Make a new super frame.
+          uint8_t marker = 0xc1;
+          unsigned int mask;
+          int mag;
+
+          // Choose the magnitude.
+          for (mag = 0, mask = 0xff; mag < 4; ++mag) {
+            if (inputs[i].sz < mask)
+              break;
+            mask <<= 8;
+            mask |= 0xff;
+          }
+          marker |= mag << 3;
+          int index_sz = 2 + (mag + 1) * 2;
+
+          inputs[i].buf = realloc(inputs[i].buf, inputs[i].sz + index_sz + 16);
+          ASSERT_TRUE(inputs[i].buf != NULL);
+          uint8_t *frame_data = static_cast<uint8_t*>(inputs[i].buf);
+          frame_data[0] &= ~2;      // Set the show_frame flag to 0.
+          frame_data += inputs[i].sz;
+          // Add an one byte frame with show_existing_frame.
+          *frame_data++ = 0x88;
+
+          // Write the super frame index.
+          *frame_data++ = marker;
+
+          frame_sizes[0] = inputs[i].sz;
+          frame_sizes[1] = 1;
+          for (int j = 0; j < 2; ++j) {
+            unsigned int this_sz = frame_sizes[j];
+            for (int k = 0; k <= mag; k++) {
+              *frame_data++ = this_sz & 0xff;
+              this_sz >>= 8;
+            }
+          }
+          *frame_data++ = marker;
+          inputs[i].sz += index_sz + 1;
+        }
       } else {
         // Found a super frame.
         uint8_t *frame_data = static_cast<uint8_t*>(inputs[i].buf);
@@ -264,13 +304,16 @@ class SvcTest : public ::testing::Test {
         }
         ASSERT_LT(frame, frame_count) << "Couldn't find a visible frame. "
             << "remained_spatial_layers: " << remained_spatial_layers
-            << "    super_frame: " << i;
-        if (frame == frame_count - 1)
+            << "    super_frame: " << i
+            << "    is_multiple_frame_context: " << is_multiple_frame_contexts;
+        if (frame == frame_count - 1 && !is_multiple_frame_contexts)
           continue;
 
         frame_data += frame_sizes[frame];
 
         // We need to add one more frame for multiple frame contexts.
+        if (is_multiple_frame_contexts)
+          ++frame;
         uint8_t marker =
             static_cast<const uint8_t*>(inputs[i].buf)[inputs[i].sz - 1];
         const uint32_t mag = ((marker >> 3) & 0x3) + 1;
@@ -280,14 +323,35 @@ class SvcTest : public ::testing::Test {
         marker |= frame;
 
         // Copy existing frame sizes.
-        memmove(frame_data + 1, frame_start + inputs[i].sz - index_sz + 1,
-                new_index_sz - 2);
+        memmove(frame_data + (is_multiple_frame_contexts ? 2 : 1),
+                frame_start + inputs[i].sz - index_sz + 1, new_index_sz - 2);
+        if (is_multiple_frame_contexts) {
+          // Add a one byte frame with flag show_existing_frame.
+          *frame_data++ = 0x88 | (remained_spatial_layers - 1);
+        }
         // New marker.
         frame_data[0] = marker;
         frame_data += (mag * (frame + 1) + 1);
 
+        if (is_multiple_frame_contexts) {
+          // Write the frame size for the one byte frame.
+          frame_data -= mag;
+          *frame_data++ = 1;
+          for (uint32_t j = 1; j < mag; ++j) {
+            *frame_data++ = 0;
+          }
+        }
+
         *frame_data++ = marker;
         inputs[i].sz = frame_data - frame_start;
+
+        if (is_multiple_frame_contexts) {
+          // Change the show frame flag to 0 for all frames.
+          for (int j = 0; j < frame; ++j) {
+            frame_start[0] &= ~2;
+            frame_start += frame_sizes[j];
+          }
+        }
       }
     }
   }
@@ -491,7 +555,7 @@ TEST_F(SvcTest, TwoPassEncode2SpatialLayersDecodeBaseLayerOnly) {
   vpx_fixed_buf outputs[10];
   memset(&outputs[0], 0, sizeof(outputs));
   Pass2EncodeNFrames(&stats_buf, 10, 2, &outputs[0]);
-  DropEnhancementLayers(&outputs[0], 10, 1);
+  DropLayersAndMakeItVP9Comaptible(&outputs[0], 10, 1, false);
   DecodeNFrames(&outputs[0], 10);
   FreeBitstreamBuffers(&outputs[0], 10);
 }
@@ -509,13 +573,13 @@ TEST_F(SvcTest, TwoPassEncode5SpatialLayersDecode54321Layers) {
   Pass2EncodeNFrames(&stats_buf, 10, 5, &outputs[0]);
 
   DecodeNFrames(&outputs[0], 10);
-  DropEnhancementLayers(&outputs[0], 10, 4);
+  DropLayersAndMakeItVP9Comaptible(&outputs[0], 10, 4, false);
   DecodeNFrames(&outputs[0], 10);
-  DropEnhancementLayers(&outputs[0], 10, 3);
+  DropLayersAndMakeItVP9Comaptible(&outputs[0], 10, 3, false);
   DecodeNFrames(&outputs[0], 10);
-  DropEnhancementLayers(&outputs[0], 10, 2);
+  DropLayersAndMakeItVP9Comaptible(&outputs[0], 10, 2, false);
   DecodeNFrames(&outputs[0], 10);
-  DropEnhancementLayers(&outputs[0], 10, 1);
+  DropLayersAndMakeItVP9Comaptible(&outputs[0], 10, 1, false);
   DecodeNFrames(&outputs[0], 10);
 
   FreeBitstreamBuffers(&outputs[0], 10);
@@ -552,9 +616,9 @@ TEST_F(SvcTest, TwoPassEncode3SNRLayersDecode321Layers) {
   memset(&outputs[0], 0, sizeof(outputs));
   Pass2EncodeNFrames(&stats_buf, 20, 3, &outputs[0]);
   DecodeNFrames(&outputs[0], 20);
-  DropEnhancementLayers(&outputs[0], 20, 2);
+  DropLayersAndMakeItVP9Comaptible(&outputs[0], 20, 2, false);
   DecodeNFrames(&outputs[0], 20);
-  DropEnhancementLayers(&outputs[0], 20, 1);
+  DropLayersAndMakeItVP9Comaptible(&outputs[0], 20, 1, false);
   DecodeNFrames(&outputs[0], 20);
 
   FreeBitstreamBuffers(&outputs[0], 20);
@@ -585,6 +649,7 @@ TEST_F(SvcTest, TwoPassEncode2SpatialLayersWithMultipleFrameContexts) {
   vpx_fixed_buf outputs[10];
   memset(&outputs[0], 0, sizeof(outputs));
   Pass2EncodeNFrames(&stats_buf, 10, 2, &outputs[0]);
+  DropLayersAndMakeItVP9Comaptible(&outputs[0], 10, 2, true);
   DecodeNFrames(&outputs[0], 10);
   FreeBitstreamBuffers(&outputs[0], 10);
 }
@@ -602,7 +667,7 @@ TEST_F(SvcTest,
   vpx_fixed_buf outputs[10];
   memset(&outputs[0], 0, sizeof(outputs));
   Pass2EncodeNFrames(&stats_buf, 10, 2, &outputs[0]);
-  DropEnhancementLayers(&outputs[0], 10, 1);
+  DropLayersAndMakeItVP9Comaptible(&outputs[0], 10, 1, true);
   DecodeNFrames(&outputs[0], 10);
   FreeBitstreamBuffers(&outputs[0], 10);
 }
@@ -621,6 +686,7 @@ TEST_F(SvcTest, TwoPassEncode2SNRLayersWithMultipleFrameContexts) {
   vpx_fixed_buf outputs[10];
   memset(&outputs[0], 0, sizeof(outputs));
   Pass2EncodeNFrames(&stats_buf, 10, 2, &outputs[0]);
+  DropLayersAndMakeItVP9Comaptible(&outputs[0], 10, 2, true);
   DecodeNFrames(&outputs[0], 10);
   FreeBitstreamBuffers(&outputs[0], 10);
 }
@@ -641,13 +707,32 @@ TEST_F(SvcTest,
   memset(&outputs[0], 0, sizeof(outputs));
   Pass2EncodeNFrames(&stats_buf, 10, 3, &outputs[0]);
 
-  DecodeNFrames(&outputs[0], 10);
-  DropEnhancementLayers(&outputs[0], 10, 2);
-  DecodeNFrames(&outputs[0], 10);
-  DropEnhancementLayers(&outputs[0], 10, 1);
-  DecodeNFrames(&outputs[0], 10);
+  vpx_fixed_buf outputs_new[10];
+  for (int i = 0; i < 10; ++i) {
+    outputs_new[i].buf = malloc(outputs[i].sz + 16);
+    ASSERT_TRUE(outputs_new[i].buf != NULL);
+    memcpy(outputs_new[i].buf, outputs[i].buf, outputs[i].sz);
+    outputs_new[i].sz = outputs[i].sz;
+  }
+  DropLayersAndMakeItVP9Comaptible(&outputs_new[0], 10, 3, true);
+  DecodeNFrames(&outputs_new[0], 10);
+
+  for (int i = 0; i < 10; ++i) {
+    memcpy(outputs_new[i].buf, outputs[i].buf, outputs[i].sz);
+    outputs_new[i].sz = outputs[i].sz;
+  }
+  DropLayersAndMakeItVP9Comaptible(&outputs_new[0], 10, 2, true);
+  DecodeNFrames(&outputs_new[0], 10);
+
+  for (int i = 0; i < 10; ++i) {
+    memcpy(outputs_new[i].buf, outputs[i].buf, outputs[i].sz);
+    outputs_new[i].sz = outputs[i].sz;
+  }
+  DropLayersAndMakeItVP9Comaptible(&outputs_new[0], 10, 1, true);
+  DecodeNFrames(&outputs_new[0], 10);
 
   FreeBitstreamBuffers(&outputs[0], 10);
+  FreeBitstreamBuffers(&outputs_new[0], 10);
 }
 
 TEST_F(SvcTest, TwoPassEncode2TemporalLayers) {
@@ -684,6 +769,7 @@ TEST_F(SvcTest, TwoPassEncode2TemporalLayersWithMultipleFrameContexts) {
   vpx_fixed_buf outputs[10];
   memset(&outputs[0], 0, sizeof(outputs));
   Pass2EncodeNFrames(&stats_buf, 10, 1, &outputs[0]);
+  DropLayersAndMakeItVP9Comaptible(&outputs[0], 10, 1, true);
   DecodeNFrames(&outputs[0], 10);
   FreeBitstreamBuffers(&outputs[0], 10);
 }
@@ -728,6 +814,7 @@ TEST_F(SvcTest,
   vpx_fixed_buf outputs[10];
   memset(&outputs[0], 0, sizeof(outputs));
   Pass2EncodeNFrames(&stats_buf, 10, 1, &outputs[0]);
+  DropLayersAndMakeItVP9Comaptible(&outputs[0], 10, 1, true);
 
   vpx_fixed_buf base_layer[5];
   for (int i = 0; i < 5; ++i)
diff --git a/vp9/encoder/vp9_bitstream.c b/vp9/encoder/vp9_bitstream.c
index 3954fe6a7..694cac76f 100644
--- a/vp9/encoder/vp9_bitstream.c
+++ b/vp9/encoder/vp9_bitstream.c
@@ -1013,11 +1013,7 @@ static void write_frame_size_with_refs(VP9_COMP *cpi,
         ((cpi->svc.number_temporal_layers > 1 &&
          cpi->oxcf.rc_mode == VPX_CBR) ||
         (cpi->svc.number_spatial_layers > 1 &&
-         cpi->svc.layer_context[cpi->svc.spatial_layer_id].is_key_frame) ||
-        (is_two_pass_svc(cpi) &&
-         cpi->svc.encode_empty_frame_state == ENCODING &&
-         cpi->svc.layer_context[0].frames_from_key_frame <
-         cpi->svc.number_temporal_layers + 1))) {
+         cpi->svc.layer_context[cpi->svc.spatial_layer_id].is_key_frame))) {
       found = 0;
     }
     vp9_wb_write_bit(wb, found);
@@ -1109,7 +1105,8 @@ static void write_uncompressed_header(VP9_COMP *cpi,
     // will change to show_frame flag to 0, then add an one byte frame with
     // show_existing_frame flag which tells the decoder which frame we want to
     // show.
-    if (!cm->show_frame)
+    if (!cm->show_frame ||
+        (is_two_pass_svc(cpi) && cm->error_resilient_mode == 0))
       vp9_wb_write_bit(wb, cm->intra_only);
 
     if (!cm->error_resilient_mode)
diff --git a/vp9/encoder/vp9_encoder.c b/vp9/encoder/vp9_encoder.c
index 0928c0bb7..dea93062b 100644
--- a/vp9/encoder/vp9_encoder.c
+++ b/vp9/encoder/vp9_encoder.c
@@ -225,9 +225,6 @@ static void dealloc_compressor_data(VP9_COMP *cpi) {
   }
   vpx_memset(&cpi->svc.scaled_frames[0], 0,
              MAX_LAG_BUFFERS * sizeof(cpi->svc.scaled_frames[0]));
-
-  vp9_free_frame_buffer(&cpi->svc.empty_frame.img);
-  vpx_memset(&cpi->svc.empty_frame, 0, sizeof(cpi->svc.empty_frame));
 }
 
 static void save_coding_context(VP9_COMP *cpi) {
@@ -2638,10 +2635,7 @@ void set_frame_size(VP9_COMP *cpi) {
 
   // For two pass encodes analyse the first pass stats and determine
   // the bit allocation and other parameters for this frame / group of frames.
-  if ((oxcf->pass == 2) &&
-      (!cpi->use_svc ||
-       (is_two_pass_svc(cpi) &&
-        cpi->svc.encode_empty_frame_state != ENCODING))) {
+  if ((oxcf->pass == 2) && (!cpi->use_svc || is_two_pass_svc(cpi))) {
     vp9_rc_get_second_pass_params(cpi);
   }
 
@@ -3140,9 +3134,7 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi,
     }
   }
   if (is_two_pass_svc(cpi) && cm->error_resilient_mode == 0) {
-    // Use the last frame context for the empty frame.
     cm->frame_context_idx =
-        (cpi->svc.encode_empty_frame_state == ENCODING) ? FRAME_CONTEXTS - 1 :
         cpi->svc.spatial_layer_id * cpi->svc.number_temporal_layers +
         cpi->svc.temporal_layer_id;
 
@@ -3277,9 +3269,7 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi,
   cpi->ref_frame_flags = get_ref_frame_flags(cpi);
 
   cm->last_frame_type = cm->frame_type;
-
-  if (!(is_two_pass_svc(cpi) && cpi->svc.encode_empty_frame_state == ENCODING))
-    vp9_rc_postencode_update(cpi, *size);
+  vp9_rc_postencode_update(cpi, *size);
 
 #if 0
   output_frame_level_debug_stats(cpi);
@@ -3303,8 +3293,12 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi,
   cm->last_height = cm->height;
 
   // reset to normal state now that we are done.
-  if (!cm->show_existing_frame)
-    cm->last_show_frame = cm->show_frame;
+  if (!cm->show_existing_frame) {
+    if (is_two_pass_svc(cpi) && cm->error_resilient_mode == 0)
+      cm->last_show_frame = 0;
+    else
+      cm->last_show_frame = cm->show_frame;
+  }
 
   if (cm->show_frame) {
     vp9_swap_mi_and_prev_mi(cm);
@@ -3341,9 +3335,7 @@ static void Pass2Encode(VP9_COMP *cpi, size_t *size,
                         uint8_t *dest, unsigned int *frame_flags) {
   cpi->allow_encode_breakout = ENCODE_BREAKOUT_ENABLED;
   encode_frame_to_data_rate(cpi, size, dest, frame_flags);
-
-  if (!(is_two_pass_svc(cpi) && cpi->svc.encode_empty_frame_state == ENCODING))
-    vp9_twopass_postencode_update(cpi);
+  vp9_twopass_postencode_update(cpi);
 }
 
 static void check_initial_width(VP9_COMP *cpi,
@@ -3521,9 +3513,6 @@ int vp9_get_compressed_data(VP9_COMP *cpi, unsigned int *frame_flags,
   if (is_two_pass_svc(cpi)) {
 #if CONFIG_SPATIAL_SVC
     vp9_svc_start_frame(cpi);
-    // Use a small empty frame instead of a real frame
-    if (cpi->svc.encode_empty_frame_state == ENCODING)
-      source = &cpi->svc.empty_frame;
 #endif
     if (oxcf->pass == 2)
       vp9_restore_layer_context(cpi);
@@ -3542,11 +3531,6 @@ int vp9_get_compressed_data(VP9_COMP *cpi, unsigned int *frame_flags,
 
   // Should we encode an arf frame.
   arf_src_index = get_arf_src_index(cpi);
-
-  // Skip alt frame if we encode the empty frame
-  if (is_two_pass_svc(cpi) && source != NULL)
-    arf_src_index = 0;
-
   if (arf_src_index) {
     assert(arf_src_index <= rc->frames_to_key);
 
@@ -3834,18 +3818,10 @@ int vp9_get_compressed_data(VP9_COMP *cpi, unsigned int *frame_flags,
 
 #endif
 
-  if (is_two_pass_svc(cpi)) {
-    if (cpi->svc.encode_empty_frame_state == ENCODING)
-      cpi->svc.encode_empty_frame_state = ENCODED;
-
-    if (cm->show_frame) {
-      ++cpi->svc.spatial_layer_to_encode;
-      if (cpi->svc.spatial_layer_to_encode >= cpi->svc.number_spatial_layers)
-        cpi->svc.spatial_layer_to_encode = 0;
-
-      // May need the empty frame after an visible frame.
-      cpi->svc.encode_empty_frame_state = NEED_TO_ENCODE;
-    }
+  if (is_two_pass_svc(cpi) && cm->show_frame) {
+    ++cpi->svc.spatial_layer_to_encode;
+    if (cpi->svc.spatial_layer_to_encode >= cpi->svc.number_spatial_layers)
+      cpi->svc.spatial_layer_to_encode = 0;
   }
   return 0;
 }
@@ -3936,6 +3912,10 @@ int vp9_set_size_literal(VP9_COMP *cpi, unsigned int width,
 
   if (width) {
     cm->width = width;
+    if (cm->width * 5 < cpi->initial_width) {
+      cm->width = cpi->initial_width / 5 + 1;
+      printf("Warning: Desired width too small, changed to %d\n", cm->width);
+    }
     if (cm->width > cpi->initial_width) {
       cm->width = cpi->initial_width;
       printf("Warning: Desired width too large, changed to %d\n", cm->width);
@@ -3944,6 +3924,10 @@ int vp9_set_size_literal(VP9_COMP *cpi, unsigned int width,
 
   if (height) {
     cm->height = height;
+    if (cm->height * 5 < cpi->initial_height) {
+      cm->height = cpi->initial_height / 5 + 1;
+      printf("Warning: Desired height too small, changed to %d\n", cm->height);
+    }
     if (cm->height > cpi->initial_height) {
       cm->height = cpi->initial_height;
       printf("Warning: Desired height too large, changed to %d\n", cm->height);
diff --git a/vp9/encoder/vp9_firstpass.c b/vp9/encoder/vp9_firstpass.c
index 760ec320c..9e204d7e9 100644
--- a/vp9/encoder/vp9_firstpass.c
+++ b/vp9/encoder/vp9_firstpass.c
@@ -2406,9 +2406,6 @@ void vp9_rc_get_second_pass_params(VP9_COMP *cpi) {
         cpi->ref_frame_flags &=
             (~VP9_LAST_FLAG & ~VP9_GOLD_FLAG & ~VP9_ALT_FLAG);
         lc->frames_from_key_frame = 0;
-        // Reset the empty frame resolution since we have a key frame.
-        cpi->svc.empty_frame_width = cm->width;
-        cpi->svc.empty_frame_height = cm->height;
       }
     } else {
       cm->frame_type = INTER_FRAME;
diff --git a/vp9/encoder/vp9_svc_layercontext.c b/vp9/encoder/vp9_svc_layercontext.c
index 1573557d4..eed681c96 100644
--- a/vp9/encoder/vp9_svc_layercontext.c
+++ b/vp9/encoder/vp9_svc_layercontext.c
@@ -14,8 +14,6 @@
 #include "vp9/encoder/vp9_svc_layercontext.h"
 #include "vp9/encoder/vp9_extend.h"
 
-#define SMALL_FRAME_FB_IDX 7
-
 void vp9_init_layer_context(VP9_COMP *const cpi) {
   SVC *const svc = &cpi->svc;
   const VP9EncoderConfig *const oxcf = &cpi->oxcf;
@@ -30,25 +28,6 @@ void vp9_init_layer_context(VP9_COMP *const cpi) {
     layer_end = svc->number_temporal_layers;
   } else {
     layer_end = svc->number_spatial_layers;
-
-    if (cpi->oxcf.error_resilient_mode == 0 && cpi->oxcf.pass == 2) {
-      if (vp9_realloc_frame_buffer(&cpi->svc.empty_frame.img,
-                                   cpi->common.width, cpi->common.height,
-                                   cpi->common.subsampling_x,
-                                   cpi->common.subsampling_y,
-#if CONFIG_VP9_HIGHBITDEPTH
-                                 cpi->common.use_highbitdepth,
-#endif
-                                 VP9_ENC_BORDER_IN_PIXELS, NULL, NULL, NULL))
-        vpx_internal_error(&cpi->common.error, VPX_CODEC_MEM_ERROR,
-                           "Failed to allocate empty frame for multiple frame "
-                           "contexts");
-
-      vpx_memset(cpi->svc.empty_frame.img.buffer_alloc, 0x80,
-                 cpi->svc.empty_frame.img.buffer_alloc_sz);
-      cpi->svc.empty_frame_width = cpi->common.width;
-      cpi->svc.empty_frame_height = cpi->common.height;
-    }
   }
 
   for (layer = 0; layer < layer_end; ++layer) {
@@ -331,47 +310,6 @@ int vp9_svc_start_frame(VP9_COMP *const cpi) {
   get_layer_resolution(cpi->oxcf.width, cpi->oxcf.height,
                        lc->scaling_factor_num, lc->scaling_factor_den,
                        &width, &height);
-
-  // Workaround for multiple frame contexts. In some frames we can't use prev_mi
-  // since its previous frame could be changed during decoding time. The idea is
-  // we put a empty invisible frame in front of them, then we will not use
-  // prev_mi when encoding these frames.
-  if (cpi->oxcf.error_resilient_mode == 0 && cpi->oxcf.pass == 2 &&
-      cpi->svc.encode_empty_frame_state == NEED_TO_ENCODE) {
-    if ((cpi->svc.number_temporal_layers > 1 &&
-         cpi->svc.temporal_layer_id < cpi->svc.number_temporal_layers - 1) ||
-        (cpi->svc.number_spatial_layers > 1 &&
-         cpi->svc.spatial_layer_id == 0)) {
-      struct lookahead_entry *buf = vp9_lookahead_peek(cpi->lookahead, 0);
-
-      if (buf != NULL) {
-        cpi->svc.empty_frame.ts_start = buf->ts_start;
-        cpi->svc.empty_frame.ts_end = buf->ts_end;
-        cpi->svc.encode_empty_frame_state = ENCODING;
-        cpi->common.show_frame = 0;
-        cpi->ref_frame_flags = 0;
-        cpi->common.frame_type = INTER_FRAME;
-        cpi->lst_fb_idx =
-            cpi->gld_fb_idx = cpi->alt_fb_idx = SMALL_FRAME_FB_IDX;
-
-        // Gradually make the empty frame smaller to save bits. Make it half of
-        // its previous size because of the scaling factor restriction.
-        cpi->svc.empty_frame_width >>= 1;
-        cpi->svc.empty_frame_width = (cpi->svc.empty_frame_width + 1) & ~1;
-        if (cpi->svc.empty_frame_width < 16)
-          cpi->svc.empty_frame_width = 16;
-
-        cpi->svc.empty_frame_height >>= 1;
-        cpi->svc.empty_frame_height = (cpi->svc.empty_frame_height + 1) & ~1;
-        if (cpi->svc.empty_frame_height < 16)
-          cpi->svc.empty_frame_height = 16;
-
-        width = cpi->svc.empty_frame_width;
-        height = cpi->svc.empty_frame_height;
-      }
-    }
-  }
-
   if (vp9_set_size_literal(cpi, width, height) != 0)
     return VPX_CODEC_INVALID_PARAM;
 
@@ -379,6 +317,7 @@ int vp9_svc_start_frame(VP9_COMP *const cpi) {
   cpi->oxcf.best_allowed_q = vp9_quantizer_to_qindex(lc->min_q);
 
   vp9_change_config(cpi, &cpi->oxcf);
+
   vp9_set_high_precision_mv(cpi, 1);
 
   cpi->alt_ref_source = get_layer_context(cpi)->alt_ref_source;
diff --git a/vp9/encoder/vp9_svc_layercontext.h b/vp9/encoder/vp9_svc_layercontext.h
index e9645ce9f..47a5456b6 100644
--- a/vp9/encoder/vp9_svc_layercontext.h
+++ b/vp9/encoder/vp9_svc_layercontext.h
@@ -50,16 +50,6 @@ typedef struct {
 
   int spatial_layer_to_encode;
 
-  // Workaround for multiple frame contexts
-  enum {
-    ENCODED = 0,
-    ENCODING,
-    NEED_TO_ENCODE
-  }encode_empty_frame_state;
-  struct lookahead_entry empty_frame;
-  int empty_frame_width;
-  int empty_frame_height;
-
   // Store scaled source frames to be used for temporal filter to generate
   // a alt ref frame.
   YV12_BUFFER_CONFIG scaled_frames[MAX_LAG_BUFFERS];
diff --git a/vp9/encoder/vp9_temporal_filter.c b/vp9/encoder/vp9_temporal_filter.c
index 5599227ce..9ae81e761 100644
--- a/vp9/encoder/vp9_temporal_filter.c
+++ b/vp9/encoder/vp9_temporal_filter.c
@@ -719,9 +719,6 @@ void vp9_temporal_filter(VP9_COMP *cpi, int distance) {
           ++frame_used;
         }
       }
-      cm->mi = cm->mip + cm->mi_stride + 1;
-      cpi->mb.e_mbd.mi = cm->mi;
-      cpi->mb.e_mbd.mi[0].src_mi = &cpi->mb.e_mbd.mi[0];
     } else {
       // ARF is produced at the native frame size and resized when coded.
 #if CONFIG_VP9_HIGHBITDEPTH
diff --git a/vp9/vp9_cx_iface.c b/vp9/vp9_cx_iface.c
index d0ca5242c..041ba27da 100644
--- a/vp9/vp9_cx_iface.c
+++ b/vp9/vp9_cx_iface.c
@@ -188,9 +188,11 @@ static vpx_codec_err_t validate_config(vpx_codec_alg_priv_t *ctx,
     }
     if (alt_ref_sum > REF_FRAMES - cfg->ss_number_layers)
       ERROR("Not enough ref buffers for svc alt ref frames");
-    if (cfg->ss_number_layers * cfg->ts_number_layers > 3 &&
+    if ((cfg->ss_number_layers > 3 ||
+         cfg->ss_number_layers * cfg->ts_number_layers > 4) &&
         cfg->g_error_resilient == 0)
-    ERROR("Multiple frame context are not supported for more than 3 layers");
+    ERROR("Multiple frame context are not supported for more than 3 spatial "
+          "layers or more than 4 spatial x temporal layers");
   }
 #endif
 
diff --git a/vpx/src/svc_encodeframe.c b/vpx/src/svc_encodeframe.c
index fa3409c69..773087ddc 100644
--- a/vpx/src/svc_encodeframe.c
+++ b/vpx/src/svc_encodeframe.c
@@ -350,7 +350,7 @@ void assign_layer_bitrates(const SvcContext *svc_ctx,
       }
     }
 
-    for (i = 0; i < VPX_SS_MAX_LAYERS; ++i) {
+    for (i = 0; i < svc_ctx->spatial_layers; ++i) {
       if (total > 0) {
         enc_cfg->ss_target_bitrate[i] = (unsigned int)
             (enc_cfg->rc_target_bitrate * alloc_ratio[i] / total);