Fix issues with mixed ARF and GF groups.

This patch addresses two issues that can occur when the
encoder chooses to use a mixture of ARF and GF groups.

The first issue relates to a failure to reset the "ARF active" flag
correctly when transitioning from coding ARF groups to coding
GF groups. This caused some golden frames to be  encoded
with an incorrect bit rate target as if they were ARF overlay frames.

The second issue relates to the encoding of a single short GF group
just before a key frame.  Where the last group before a key frame
is an ARF group we expect the final frame before the key frame  to
be an low data rate overlay frame. However, when the last  group
is a GF group, the final frame before the key frame should be a normal
frame with a normal bit allocation. This issue had the potential to cause
a single poorly coded frame just before a key frame. If that key frame
were a forced key frame rather than a real scene cut, this might cause
pulsing.

Change-Id: Idf1eb5eaf63a231495a74de7899236e1ead9fb00

diff --git a/vp9/encoder/vp9_encoder.c b/vp9/encoder/vp9_encoder.c
index e89ee5eb7e19d66651e79567b75468f1157505c3..0add45ec5bc0ef5d0e0630fb8461763ea59cffcd 100644 (file)
--- a/vp9/encoder/vp9_encoder.c
+++ b/vp9/encoder/vp9_encoder.c
@@ -2795,7 +2795,7 @@ static void output_frame_level_debug_stats(VP9_COMP *cpi) {
   recon_err = vp9_get_y_sse(cpi->Source, get_frame_new_buffer(cm));
 
   if (cpi->twopass.total_left_stats.coded_error != 0.0)
-    fprintf(f, "%10u %dx%d %10d %10d %10d %10d"
+    fprintf(f, "%10u %dx%d %d %d %10d %10d %10d %10d"
         "%10"PRId64" %10"PRId64" %10"PRId64" %10"PRId64" %10d "
         "%7.2lf %7.2lf %7.2lf %7.2lf %7.2lf"
         "%6d %6d %5d %5d %5d "
@@ -2803,6 +2803,8 @@ static void output_frame_level_debug_stats(VP9_COMP *cpi) {
         "%10lf %8u %10"PRId64" %10d %10d\n",
         cpi->common.current_video_frame,
         cm->width, cm->height,
+        cpi->rc.source_alt_ref_pending,
+        cpi->rc.source_alt_ref_active,
         cpi->rc.this_frame_target,
         cpi->rc.projected_frame_size,
         cpi->rc.projected_frame_size / cpi->common.MBs,

diff --git a/vp9/encoder/vp9_firstpass.c b/vp9/encoder/vp9_firstpass.c
index 88b10307d40374d517b2aeb3cb6e3ebfaa49efa0..40f65c3e077e7ae3e22ffd1829dd03d0ce148b82 100644 (file)
--- a/vp9/encoder/vp9_firstpass.c
+++ b/vp9/encoder/vp9_firstpass.c
@@ -1696,7 +1696,7 @@ static void allocate_gf_group_bits(VP9_COMP *cpi, int64_t gf_group_bits,
   mid_frame_idx = frame_index + (rc->baseline_gf_interval >> 1) - 1;
 
   // Allocate bits to the other frames in the group.
-  for (i = 0; i < rc->baseline_gf_interval - 1; ++i) {
+  for (i = 0; i < rc->baseline_gf_interval - rc->source_alt_ref_pending; ++i) {
     int arf_idx = 0;
     if (EOF == input_stats(twopass, &frame_stats))
       break;
@@ -1934,8 +1934,26 @@ static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
   // Was the group length constrained by the requirement for a new KF?
   rc->constrained_gf_group = (i >= rc->frames_to_key) ? 1 : 0;
 
+  // Should we use the alternate reference frame.
+  if (allow_alt_ref &&
+    (i < cpi->oxcf.lag_in_frames) &&
+    (i >= rc->min_gf_interval)) {
+    // Calculate the boost for alt ref.
+    rc->gfu_boost = calc_arf_boost(cpi, 0, (i - 1), (i - 1), &f_boost,
+      &b_boost);
+    rc->source_alt_ref_pending = 1;
+
+    // Test to see if multi arf is appropriate.
+    cpi->multi_arf_enabled =
+      (cpi->multi_arf_allowed && (rc->baseline_gf_interval >= 6) &&
+      (zero_motion_accumulator < 0.995)) ? 1 : 0;
+  } else {
+    rc->gfu_boost = MAX((int)boost_score, MIN_ARF_GF_BOOST);
+    rc->source_alt_ref_pending = 0;
+  }
+
   // Set the interval until the next gf.
-  if (is_key_frame || rc->source_alt_ref_active)
+  if (is_key_frame || rc->source_alt_ref_pending)
     rc->baseline_gf_interval = i - 1;
   else
     rc->baseline_gf_interval = i;
@@ -1960,24 +1978,6 @@ static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
 
   rc->frames_till_gf_update_due = rc->baseline_gf_interval;
 
-  // Should we use the alternate reference frame.
-  if (allow_alt_ref &&
-      (i < cpi->oxcf.lag_in_frames) &&
-      (i >= rc->min_gf_interval)) {
-    // Calculate the boost for alt ref.
-    rc->gfu_boost = calc_arf_boost(cpi, 0, (i - 1), (i - 1), &f_boost,
-                                   &b_boost);
-    rc->source_alt_ref_pending = 1;
-
-    // Test to see if multi arf is appropriate.
-    cpi->multi_arf_enabled =
-      (cpi->multi_arf_allowed && (rc->baseline_gf_interval >= 6) &&
-      (zero_motion_accumulator < 0.995)) ? 1 : 0;
-  } else {
-    rc->gfu_boost = MAX((int)boost_score, MIN_ARF_GF_BOOST);
-    rc->source_alt_ref_pending = 0;
-  }
-
   // Reset the file position.
   reset_fpf_position(twopass, start_pos);
 

diff --git a/vp9/encoder/vp9_ratectrl.c b/vp9/encoder/vp9_ratectrl.c
index fabe362968847abec65a5c6380f0b209c3548579..7211e99920ab855f7c872a22e0fa97f989564da0 100644 (file)
--- a/vp9/encoder/vp9_ratectrl.c
+++ b/vp9/encoder/vp9_ratectrl.c
@@ -1207,11 +1207,9 @@ static void update_golden_frame_stats(VP9_COMP *cpi) {
     // this frame refreshes means next frames don't unless specified by user
     rc->frames_since_golden = 0;
 
-    if (cpi->oxcf.pass == 2) {
-      if (!rc->source_alt_ref_pending &&
-          cpi->twopass.gf_group.rf_level[0] == GF_ARF_STD)
-      rc->source_alt_ref_active = 0;
-    } else if (!rc->source_alt_ref_pending) {
+    // If we are not using alt ref in the up and coming group clear the arf
+    // active flag.
+    if (!rc->source_alt_ref_pending) {
       rc->source_alt_ref_active = 0;
     }