vp9: Small refactor on overshoot detection, for cbr real-time.

Change-Id: I70997d35a2371bb4614d716ef0c587fa12ea0f4a

4 files changed, 27 insertions, 18 deletions

diff --git a/vp9/encoder/vp9_encoder.c b/vp9/encoder/vp9_encoder.c
index 40ea13a9c..56dca855c 100644
--- a/vp9/encoder/vp9_encoder.c
+++ b/vp9/encoder/vp9_encoder.c
@@ -3988,7 +3988,7 @@ static int encode_without_recode_loop(VP9_COMP *cpi, size_t *size,
   // Check if this high_source_sad (scene/slide change) frame should be
   // encoded at high/max QP, and if so, set the q and adjust some rate
   // control parameters.
-  if (cpi->sf.overshoot_detection_rt == 1 &&
+  if (cpi->sf.overshoot_detection_cbr_rt == FAST_DETECTION_MAXQ &&
       (cpi->rc.high_source_sad ||
        (cpi->use_svc && cpi->svc.high_source_sad_superframe))) {
     if (vp9_encodedframe_overshoot(cpi, -1, &q)) {
@@ -4023,7 +4023,7 @@ static int encode_without_recode_loop(VP9_COMP *cpi, size_t *size,
   // overshoot based on the encoded frame size. Only for frames where
   // high temporal-source SAD is detected.
   // For SVC: all spatial layers are checked for re-encoding.
-  if (cpi->sf.overshoot_detection_rt == 2 &&
+  if (cpi->sf.overshoot_detection_cbr_rt == RE_ENCODE_MAXQ &&
       (cpi->rc.high_source_sad ||
        (cpi->use_svc && cpi->svc.high_source_sad_superframe))) {
     int frame_size = 0;
diff --git a/vp9/encoder/vp9_ratectrl.c b/vp9/encoder/vp9_ratectrl.c
index 64db18f09..a1a32f192 100644
--- a/vp9/encoder/vp9_ratectrl.c
+++ b/vp9/encoder/vp9_ratectrl.c
@@ -2825,11 +2825,13 @@ int vp9_encodedframe_overshoot(VP9_COMP *cpi, int frame_size, int *q) {
   if (cpi->oxcf.content != VP9E_CONTENT_SCREEN)
     thresh_qp = rc->worst_quality >> 1;
   // If this decision is not based on an encoded frame size but just on
-  // scene/slide change detection (i.e., re_encode_overshoot_rt = 1),
-  // for now skip the (frame_size > thresh_rate) condition in this case.
+  // scene/slide change detection (i.e., re_encode_overshoot_cbr_rt ==
+  // FAST_DETECTION_MAXQ), for now skip the (frame_size > thresh_rate)
+  // condition in this case.
   // TODO(marpan): Use a better size/rate condition for this case and
   // adjust thresholds.
-  if ((sf->overshoot_detection_rt == 1 || frame_size > thresh_rate) &&
+  if ((sf->overshoot_detection_cbr_rt == FAST_DETECTION_MAXQ ||
+       frame_size > thresh_rate) &&
       cm->base_qindex < thresh_qp) {
     double rate_correction_factor =
         cpi->rc.rate_correction_factors[INTER_NORMAL];
@@ -2846,8 +2848,8 @@ int vp9_encodedframe_overshoot(VP9_COMP *cpi, int frame_size, int *q) {
     // and the encoded frame used alot of Intra modes, then force hybrid_intra
     // encoding for the re-encode on this scene change. hybrid_intra will
     // use rd-based intra mode selection for small blocks.
-    if (sf->overshoot_detection_rt == 2 && frame_size > (thresh_rate << 1) &&
-        cpi->svc.spatial_layer_id == 0) {
+    if (sf->overshoot_detection_cbr_rt == RE_ENCODE_MAXQ &&
+        frame_size > (thresh_rate << 1) && cpi->svc.spatial_layer_id == 0) {
       MODE_INFO **mi = cm->mi_grid_visible;
       int sum_intra_usage = 0;
       int mi_row, mi_col;
diff --git a/vp9/encoder/vp9_speed_features.c b/vp9/encoder/vp9_speed_features.c
index 107da2194..d522a623b 100644
--- a/vp9/encoder/vp9_speed_features.c
+++ b/vp9/encoder/vp9_speed_features.c
@@ -405,7 +405,7 @@ static void set_rt_speed_feature_framesize_independent(
   sf->use_compound_nonrd_pickmode = 0;
   sf->nonrd_keyframe = 0;
   sf->svc_use_lowres_part = 0;
-  sf->overshoot_detection_rt = 0;
+  sf->overshoot_detection_cbr_rt = NO_DETECTION;
   sf->disable_16x16part_nonkey = 0;
   sf->disable_golden_ref = 0;
   sf->enable_tpl_model = 0;
@@ -572,7 +572,7 @@ static void set_rt_speed_feature_framesize_independent(
     if (cpi->use_svc && cpi->svc.spatial_layer_id > 0) sf->nonrd_keyframe = 1;
     if (cm->frame_type != KEY_FRAME && cpi->resize_state == ORIG &&
         cpi->oxcf.rc_mode == VPX_CBR)
-      sf->overshoot_detection_rt = 1;
+      sf->overshoot_detection_cbr_rt = FAST_DETECTION_MAXQ;
     if (cpi->oxcf.rc_mode == VPX_VBR && cpi->oxcf.lag_in_frames > 0 &&
         cm->width <= 1280 && cm->height <= 720) {
       sf->use_altref_onepass = 1;
diff --git a/vp9/encoder/vp9_speed_features.h b/vp9/encoder/vp9_speed_features.h
index 7430f0a33..331ca49d7 100644
--- a/vp9/encoder/vp9_speed_features.h
+++ b/vp9/encoder/vp9_speed_features.h
@@ -222,6 +222,21 @@ typedef struct MESH_PATTERN {
   int interval;
 } MESH_PATTERN;
 
+typedef enum {
+  // No reaction to rate control on a detected slide/scene change.
+  NO_DETECTION = 0,
+
+  // Set to larger Q (max_q set by user) based only on the
+  // detected slide/scene change and current/past Q.
+  FAST_DETECTION_MAXQ = 1,
+
+  // Based on (first pass) encoded frame, if large frame size is detected
+  // then set to higher Q for the second re-encode. This involves 2 pass
+  // encoding on slide change, so slower than 1, but more accurate for
+  // detecting overshoot.
+  RE_ENCODE_MAXQ = 2
+} OVERSHOOT_DETECTION_CBR_RT;
+
 typedef struct SPEED_FEATURES {
   MV_SPEED_FEATURES mv;
 
@@ -544,15 +559,7 @@ typedef struct SPEED_FEATURES {
 
   // Flag to indicate process for handling overshoot on slide/scene change,
   // for real-time CBR mode.
-  // 0: no reaction to rate control on a detected slide/scene change
-  // (prior to encoding the frame).
-  // 1: set to larger Q based only on the detected slide/scene change
-  // and current/past Q. No second pass encoding, so faster than option 2.
-  // 2: based on (first pass) encoded frame, if large frame size is detected
-  // then set to higher Q for second encode. This involves 2 pass encoding
-  // on slide change, so slower than 1, but more accurate for detecting
-  // overshoot.
-  int overshoot_detection_rt;
+  OVERSHOOT_DETECTION_CBR_RT overshoot_detection_cbr_rt;
 
   // Disable partitioning of 16x16 blocks.
   int disable_16x16part_nonkey;