Use background segmentation mask with ROI

RTC sample encoder vpx_temporal_svc_encoder can take mask files as input
when ROI_MAP is set to 1.

Uses ROI and segmentation of vp9 to skip background encoding when
source_sad is low and the correspond block in previous frame is also
skipped.

Change-Id: I8590e6f9a88cecfa1d7f375d4cc480f0f2af87b6

4 files changed, 55 insertions, 15 deletions

diff --git a/vp9/common/vp9_seg_common.h b/vp9/common/vp9_seg_common.h
index b63e4f499..5e71c2fca 100644
--- a/vp9/common/vp9_seg_common.h
+++ b/vp9/common/vp9_seg_common.h
@@ -25,6 +25,11 @@ extern "C" {
 
 #define PREDICTION_PROBS 3
 
+// Segment ID used to skip background encoding
+#define BACKGROUND_SEG_SKIP_ID 3
+// Number of frames that don't skip after a key frame
+#define FRAMES_NO_SKIPPING_AFTER_KEY 20
+
 // Segment level features.
 typedef enum {
   SEG_LVL_ALT_Q = 0,      // Use alternate Quantizer ....
diff --git a/vp9/encoder/vp9_aq_cyclicrefresh.c b/vp9/encoder/vp9_aq_cyclicrefresh.c
index f06fe4726..e336179e9 100644
--- a/vp9/encoder/vp9_aq_cyclicrefresh.c
+++ b/vp9/encoder/vp9_aq_cyclicrefresh.c
@@ -497,7 +497,9 @@ void vp9_cyclic_refresh_update_parameters(VP9_COMP *const cpi) {
        rc->avg_frame_low_motion < thresh_low_motion &&
        rc->frames_since_key > 40) ||
       (!cpi->use_svc && rc->avg_frame_qindex[INTER_FRAME] > qp_max_thresh &&
-       rc->frames_since_key > 20)) {
+       rc->frames_since_key > 20) ||
+      (cpi->roi.enabled && cpi->roi.skip[BACKGROUND_SEG_SKIP_ID] &&
+       rc->frames_since_key > FRAMES_NO_SKIPPING_AFTER_KEY)) {
     cr->apply_cyclic_refresh = 0;
     return;
   }
diff --git a/vp9/encoder/vp9_encodeframe.c b/vp9/encoder/vp9_encodeframe.c
index 131c4887f..fc4089865 100644
--- a/vp9/encoder/vp9_encodeframe.c
+++ b/vp9/encoder/vp9_encodeframe.c
@@ -5513,16 +5513,6 @@ static void encode_nonrd_sb_row(VP9_COMP *cpi, ThreadData *td,
     x->arf_frame_usage = 0;
     x->lastgolden_frame_usage = 0;
 
-    if (seg->enabled) {
-      const uint8_t *const map =
-          seg->update_map ? cpi->segmentation_map : cm->last_frame_seg_map;
-      int segment_id = get_segment_id(cm, map, BLOCK_64X64, mi_row, mi_col);
-      seg_skip = segfeature_active(seg, segment_id, SEG_LVL_SKIP);
-      if (seg_skip) {
-        partition_search_type = FIXED_PARTITION;
-      }
-    }
-
     if (cpi->compute_source_sad_onepass && cpi->sf.use_source_sad) {
       int shift = cpi->Source->y_stride * (mi_row << 3) + (mi_col << 3);
       int sb_offset2 = ((cm->mi_cols + 7) >> 3) * (mi_row >> 3) + (mi_col >> 3);
@@ -5534,6 +5524,38 @@ static void encode_nonrd_sb_row(VP9_COMP *cpi, ThreadData *td,
         partition_search_type = REFERENCE_PARTITION;
     }
 
+    if (seg->enabled) {
+      const uint8_t *const map =
+          seg->update_map ? cpi->segmentation_map : cm->last_frame_seg_map;
+      int segment_id = get_segment_id(cm, map, BLOCK_64X64, mi_row, mi_col);
+      seg_skip = segfeature_active(seg, segment_id, SEG_LVL_SKIP);
+
+      if (cpi->roi.enabled && cpi->roi.skip[BACKGROUND_SEG_SKIP_ID] &&
+          cpi->rc.frames_since_key > FRAMES_NO_SKIPPING_AFTER_KEY &&
+          x->content_state_sb > kLowSadLowSumdiff) {
+        // For ROI with skip, force segment = 0 (no skip) over whole
+        // superblock to avoid artifacts if temporal change in source_sad is
+        // not 0.
+        int xi, yi;
+        const int bw = num_8x8_blocks_wide_lookup[BLOCK_64X64];
+        const int bh = num_8x8_blocks_high_lookup[BLOCK_64X64];
+        const int xmis = VPXMIN(cm->mi_cols - mi_col, bw);
+        const int ymis = VPXMIN(cm->mi_rows - mi_row, bh);
+        const int block_index = mi_row * cm->mi_cols + mi_col;
+        set_mode_info_offsets(cm, x, xd, mi_row, mi_col);
+        for (yi = 0; yi < ymis; yi++)
+          for (xi = 0; xi < xmis; xi++) {
+            int map_offset = block_index + yi * cm->mi_cols + xi;
+            cpi->segmentation_map[map_offset] = 0;
+          }
+        set_segment_index(cpi, x, mi_row, mi_col, BLOCK_64X64, 0);
+        seg_skip = 0;
+      }
+      if (seg_skip) {
+        partition_search_type = FIXED_PARTITION;
+      }
+    }
+
     // Set the partition type of the 64X64 block
     switch (partition_search_type) {
       case VAR_BASED_PARTITION:
diff --git a/vp9/encoder/vp9_encoder.c b/vp9/encoder/vp9_encoder.c
index 7e80835f6..ac0efced7 100644
--- a/vp9/encoder/vp9_encoder.c
+++ b/vp9/encoder/vp9_encoder.c
@@ -618,7 +618,7 @@ static void apply_roi_map(VP9_COMP *cpi) {
     }
     if (skip[i] != 0) {
       vp9_enable_segfeature(seg, i, SEG_LVL_SKIP);
-      vp9_set_segdata(seg, i, SEG_LVL_SKIP, skip[i]);
+      vp9_set_segdata(seg, i, SEG_LVL_SKIP, 0);
     }
     if (ref_frame[i] >= 0) {
       int valid_ref = 1;
@@ -4137,11 +4137,22 @@ static int encode_without_recode_loop(VP9_COMP *cpi, size_t *size,
     vp9_alt_ref_aq_setup_map(cpi->alt_ref_aq, cpi);
   } else {
 #endif
-    if (cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ) {
+    // If ROI is enabled and skip feature is used for segmentation, apply cyclic
+    // refresh but not apply ROI for skip for the first 20 frames (defined by
+    // FRAMES_NO_SKIPPING_AFTER_KEY) after key frame to improve quality.
+    if (cpi->roi.enabled && !frame_is_intra_only(cm)) {
+      if (cpi->roi.skip[BACKGROUND_SEG_SKIP_ID]) {
+        if (cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ)
+          vp9_cyclic_refresh_setup(cpi);
+        if (cpi->rc.frames_since_key > FRAMES_NO_SKIPPING_AFTER_KEY)
+          apply_roi_map(cpi);
+      } else {
+        apply_roi_map(cpi);
+      }
+    } else if (cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ) {
       vp9_cyclic_refresh_setup(cpi);
-    } else if (cpi->roi.enabled && !frame_is_intra_only(cm)) {
-      apply_roi_map(cpi);
     }
+
 #if !CONFIG_REALTIME_ONLY
   }
 #endif