Move tile_ctx init & fix_interp_filter to finalize

Move initialisation of tile_ctx and fix_interp_filter() from bitstream
writer to finalize_encoded_frame in encoder.c

This forms part of my efforts to remove implicit outputs from and
side-effects of av1_pack_bitstream.  This is part of wider restructuring
and refactoring in order to achieve a clean API separation at the entry
to the low-level encoder.

BUG=aomedia:2244

Change-Id: Idacba15e5d0956772fa66e0b8ae13ae4e64f9d28

av1/encoder/bitstream.c

diff --git a/av1/encoder/bitstream.c b/av1/encoder/bitstream.c
index 0adc212..38d5315 100644
--- a/av1/encoder/bitstream.c
+++ b/av1/encoder/bitstream.c
@@ -1178,7 +1178,6 @@
         }
       }
     }
-
     write_mb_interp_filter(cpi, xd, w);
   }
 }
@@ -2073,29 +2072,6 @@
     aom_wb_write_literal(wb, filter, LOG_SWITCHABLE_FILTERS);
 }
 
-static void fix_interp_filter(AV1_COMMON *cm, FRAME_COUNTS *counts) {
-  if (cm->interp_filter == SWITCHABLE) {
-    // Check to see if only one of the filters is actually used
-    int count[SWITCHABLE_FILTERS];
-    int i, j, c = 0;
-    for (i = 0; i < SWITCHABLE_FILTERS; ++i) {
-      count[i] = 0;
-      for (j = 0; j < SWITCHABLE_FILTER_CONTEXTS; ++j)
-        count[i] += counts->switchable_interp[j][i];
-      c += (count[i] > 0);
-    }
-    if (c == 1) {
-      // Only one filter is used. So set the filter at frame level
-      for (i = 0; i < SWITCHABLE_FILTERS; ++i) {
-        if (count[i]) {
-          if (i == EIGHTTAP_REGULAR) cm->interp_filter = i;
-          break;
-        }
-      }
-    }
-  }
-}
-
 // Same function as write_uniform but writing to uncompresses header wb
 static void wb_write_uniform(struct aom_write_bit_buffer *wb, int n, int v) {
   const int l = get_unsigned_bits(n);
@@ -3041,7 +3017,6 @@
 
       if (!cm->cur_frame_force_integer_mv)
         aom_wb_write_bit(wb, cm->allow_high_precision_mv);
-      fix_interp_filter(cm, cpi->td.counts);
       write_frame_interp_filter(cm->interp_filter, wb);
       aom_wb_write_bit(wb, cm->switchable_motion_mode);
       if (frame_might_allow_ref_frame_mvs(cm)) {
@@ -3507,8 +3482,6 @@
         // Is CONFIG_EXT_TILE = 1, every tile in the row has a header,
         // even for the last one, unless no tiling is used at all.
         total_size += data_offset;
-        // Initialise tile context from the frame context
-        this_tile->tctx = *cm->fc;
         cpi->td.mb.e_mbd.tile_ctx = &this_tile->tctx;
         mode_bc.allow_update_cdf = !cm->large_scale_tile;
         mode_bc.allow_update_cdf =
@@ -3648,8 +3621,6 @@
       // The last tile of the tile group does not have a header.
       if (!is_last_tile_in_tg) total_size += 4;
 
-      // Initialise tile context from the frame context
-      this_tile->tctx = *cm->fc;
       cpi->td.mb.e_mbd.tile_ctx = &this_tile->tctx;
       mode_bc.allow_update_cdf = 1;
       mode_bc.allow_update_cdf =

av1/encoder/encoder.c

diff --git a/av1/encoder/encoder.c b/av1/encoder/encoder.c
index 2202bbb..af7d6e1 100644
--- a/av1/encoder/encoder.c
+++ b/av1/encoder/encoder.c
@@ -4543,6 +4543,29 @@
   return refresh_mask;
 }
 
+static void fix_interp_filter(InterpFilter *const interp_filter,
+                              const FRAME_COUNTS *const counts) {
+  if (*interp_filter == SWITCHABLE) {
+    // Check to see if only one of the filters is actually used
+    int count[SWITCHABLE_FILTERS] = { 0 };
+    int num_filters_used = 0;
+    for (int i = 0; i < SWITCHABLE_FILTERS; ++i) {
+      for (int j = 0; j < SWITCHABLE_FILTER_CONTEXTS; ++j)
+        count[i] += counts->switchable_interp[j][i];
+      num_filters_used += (count[i] > 0);
+    }
+    if (num_filters_used == 1) {
+      // Only one filter is used. So set the filter at frame level
+      for (int i = 0; i < SWITCHABLE_FILTERS; ++i) {
+        if (count[i]) {
+          if (i == EIGHTTAP_REGULAR) *interp_filter = i;
+          break;
+        }
+      }
+    }
+  }
+}
+
 static void finalize_encoded_frame(AV1_COMP *const cpi) {
   AV1_COMMON *const cm = &cpi->common;
   CurrentFrame *const current_frame = &cm->current_frame;
@@ -4602,6 +4625,16 @@
     if (cm->film_grain_params.random_seed == 0)
       cm->film_grain_params.random_seed = 7391;
   }
+
+  // Initialise all tiles' contexts from the global frame context
+  for (int tile_col = 0; tile_col < cm->tile_cols; tile_col++) {
+    for (int tile_row = 0; tile_row < cm->tile_rows; tile_row++) {
+      const int tile_idx = tile_row * cm->tile_cols + tile_col;
+      cpi->tile_data[tile_idx].tctx = *cm->fc;
+    }
+  }
+
+  fix_interp_filter(&cm->interp_filter, cpi->td.counts);
 }
 
 // Called after encode_with_recode_loop() has just encoded a frame and packed