Revert "Revert "Prevent double application of min rate in two pass.""

This rate control bug in the original patch is not the underlying cause
of the quality regression but simply unmasked a problem which stems
from applying 0 bits to the last frame in a short KF group at the start
of a chunk.

This reverts commit d10b1f233657054b1465d40f0b409c20029a540b.

Change-Id: I32c91a24a14d013853bb8e5587aa69600e6a0063

diff --git a/vp9/encoder/vp9_ratectrl.c b/vp9/encoder/vp9_ratectrl.c
index c0eafdebd1158d20ac17a23ad3f75b49733948ad..cc798e9f12bae47c1ad29b2e63402629f3b8a325 100644 (file)
--- a/vp9/encoder/vp9_ratectrl.c
+++ b/vp9/encoder/vp9_ratectrl.c
@@ -47,8 +47,6 @@
 #define MIN_BPB_FACTOR 0.005
 #define MAX_BPB_FACTOR 50
 
-#define FRAME_OVERHEAD_BITS 200
-
 #if CONFIG_VP9_HIGHBITDEPTH
 #define ASSIGN_MINQ_TABLE(bit_depth, name)       \
   do {                                           \
@@ -212,18 +210,23 @@ int vp9_estimate_bits_at_q(FRAME_TYPE frame_type, int q, int mbs,
 int vp9_rc_clamp_pframe_target_size(const VP9_COMP *const cpi, int target) {
   const RATE_CONTROL *rc = &cpi->rc;
   const VP9EncoderConfig *oxcf = &cpi->oxcf;
-  const int min_frame_target =
-      VPXMAX(rc->min_frame_bandwidth, rc->avg_frame_bandwidth >> 5);
-  if (target < min_frame_target) target = min_frame_target;
-  if (cpi->refresh_golden_frame && rc->is_src_frame_alt_ref) {
-    // If there is an active ARF at this location use the minimum
-    // bits on this frame even if it is a constructed arf.
-    // The active maximum quantizer insures that an appropriate
-    // number of bits will be spent if needed for constructed ARFs.
-    target = min_frame_target;
+
+  if (cpi->oxcf.pass != 2) {
+    const int min_frame_target =
+        VPXMAX(rc->min_frame_bandwidth, rc->avg_frame_bandwidth >> 5);
+    if (target < min_frame_target) target = min_frame_target;
+    if (cpi->refresh_golden_frame && rc->is_src_frame_alt_ref) {
+      // If there is an active ARF at this location use the minimum
+      // bits on this frame even if it is a constructed arf.
+      // The active maximum quantizer insures that an appropriate
+      // number of bits will be spent if needed for constructed ARFs.
+      target = min_frame_target;
+    }
   }
+
   // Clip the frame target to the maximum allowed value.
   if (target > rc->max_frame_bandwidth) target = rc->max_frame_bandwidth;
+
   if (oxcf->rc_max_inter_bitrate_pct) {
     const int max_rate =
         rc->avg_frame_bandwidth * oxcf->rc_max_inter_bitrate_pct / 100;

diff --git a/vp9/encoder/vp9_ratectrl.h b/vp9/encoder/vp9_ratectrl.h
index 87b1ec33e87a140bd2c814722fc6f6a381a30195..cf37117f964ccafaee859339a881ce5a698fd759 100644 (file)
--- a/vp9/encoder/vp9_ratectrl.h
+++ b/vp9/encoder/vp9_ratectrl.h
@@ -32,6 +32,8 @@ extern "C" {
 #define FIXED_GF_INTERVAL 8  // Used in some testing modes only
 #define ONEHALFONLY_RESIZE 0
 
+#define FRAME_OVERHEAD_BITS 200
+
 // Threshold used to define a KF group as static (e.g. a slide show).
 // Essentially this means that no frame in the group has more than 1% of MBs
 // that are not marked as coded with 0,0 motion in the first pass.