Cherry pick: VP8: For high overshoot, force drop frame and max-out QP.

source/libvpx/vp8/encoder/onyx_if.c

 /*
  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 569 matching lines @@
     int mbs_in_frame = cpi->common.mb_rows * cpi->common.mb_cols;
 
     cpi->cyclic_refresh_q = Q / 2;
 
     if (cpi->oxcf.screen_content_mode) {
       // Modify quality ramp-up based on Q. Above some Q level, increase the
       // number of blocks to be refreshed, and reduce it below the thredhold.
       // Turn-off under certain conditions (i.e., away from key frame, and if
       // we are at good quality (low Q) and most of the blocks were skipped-encoded
       // in previous frame.
-      if (Q >= 100) {
+      int qp_thresh = (cpi->oxcf.screen_content_mode == 2) ? 80 : 100;
+      if (Q >= qp_thresh) {
         cpi->cyclic_refresh_mode_max_mbs_perframe =
             (cpi->common.mb_rows * cpi->common.mb_cols) / 10;
       } else if (cpi->frames_since_key > 250 &&
                  Q < 20 &&
                  cpi->mb.skip_true_count > (int)(0.95 * mbs_in_frame)) {
         cpi->cyclic_refresh_mode_max_mbs_perframe = 0;
       } else {
         cpi->cyclic_refresh_mode_max_mbs_perframe =
             (cpi->common.mb_rows * cpi->common.mb_cols) / 20;
       }
@@ skipping 1403 matching lines @@
     /* Give a sensible default for the first frame. */
     cpi->frames_since_key = 8;
     cpi->key_frame_frequency = cpi->oxcf.key_freq;
     cpi->this_key_frame_forced = 0;
     cpi->next_key_frame_forced = 0;
 
     cpi->source_alt_ref_pending = 0;
     cpi->source_alt_ref_active = 0;
     cpi->common.refresh_alt_ref_frame = 0;
 
+    cpi->force_maxqp = 0;
+
     cpi->b_calculate_psnr = CONFIG_INTERNAL_STATS;
 #if CONFIG_INTERNAL_STATS
     cpi->b_calculate_ssimg = 0;
 
     cpi->count = 0;
     cpi->bytes = 0;
 
     if (cpi->b_calculate_psnr)
     {
         cpi->total_sq_error = 0.0;
@@ skipping 2153 matching lines @@
     }
     else
         zbin_oq_high = ZBIN_OQ_MAX;
 #endif
 
     /* Setup background Q adjustment for error resilient mode.
      * For multi-layer encodes only enable this for the base layer.
     */
     if (cpi->cyclic_refresh_mode_enabled)
     {
-      if (cpi->current_layer==0)
+      // Special case for screen_content_mode with golden frame updates.
+      int disable_cr_gf = (cpi->oxcf.screen_content_mode == 2 &&
+                           cm->refresh_golden_frame);
+      if (cpi->current_layer == 0 && cpi->force_maxqp == 0 && !disable_cr_gf)
         cyclic_background_refresh(cpi, Q, 0);
       else
         disable_segmentation(cpi);
     }
 
     vp8_compute_frame_size_bounds(cpi, &frame_under_shoot_limit, &frame_over_shoot_limit);
 
 #if !(CONFIG_REALTIME_ONLY)
     /* Limit Q range for the adaptive loop. */
     bottom_index = cpi->active_best_quality;
@@ skipping 201 matching lines @@
              * +pack coef partitions
              */
             vp8_encode_frame(cpi);
 
             /* cpi->projected_frame_size is not needed for RT mode */
         }
 #else
         /* transform / motion compensation build reconstruction frame */
         vp8_encode_frame(cpi);
 
+        if (cpi->oxcf.screen_content_mode == 2) {
+          if (vp8_drop_encodedframe_overshoot(cpi, Q))
+            return;
+        }
+
         cpi->projected_frame_size -= vp8_estimate_entropy_savings(cpi);
         cpi->projected_frame_size = (cpi->projected_frame_size > 0) ? cpi->projected_frame_size : 0;
 #endif
         vp8_clear_system_state();
 
         /* Test to see if the stats generated for this frame indicate that
          * we should have coded a key frame (assuming that we didn't)!
          */
 
         if (cpi->pass != 2 && cpi->oxcf.auto_key && cm->frame_type != KEY_FRAME
@@ skipping 1571 matching lines @@
     }
 
     return Total;
 }
 
 
 int vp8_get_quantizer(VP8_COMP *cpi)
 {
     return cpi->common.base_qindex;
 }