1 files changed, 203 insertions, 0 deletions
diff --git a/media/libvpx/libvpx/vp9/encoder/vp9_picklpf.c b/media/libvpx/libvpx/vp9/encoder/vp9_picklpf.c
new file mode 100644
index 0000000000..3a620df693
--- /dev/null
+++ b/media/libvpx/libvpx/vp9/encoder/vp9_picklpf.c
@@ -0,0 +1,203 @@
+/*
+ *  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.
+ */
+
+#include <assert.h>
+#include <limits.h>
+
+#include "./vpx_scale_rtcd.h"
+#include "vpx_dsp/psnr.h"
+#include "vpx_mem/vpx_mem.h"
+#include "vpx_ports/mem.h"
+
+#include "vp9/common/vp9_loopfilter.h"
+#include "vp9/common/vp9_onyxc_int.h"
+#include "vp9/common/vp9_quant_common.h"
+
+#include "vp9/encoder/vp9_encoder.h"
+#include "vp9/encoder/vp9_picklpf.h"
+#include "vp9/encoder/vp9_quantize.h"
+
+static unsigned int get_section_intra_rating(const VP9_COMP *cpi) {
+  unsigned int section_intra_rating;
+
+  section_intra_rating = (cpi->common.frame_type == KEY_FRAME)
+                             ? cpi->twopass.key_frame_section_intra_rating
+                             : cpi->twopass.section_intra_rating;
+
+  return section_intra_rating;
+}
+
+static int get_max_filter_level(const VP9_COMP *cpi) {
+  if (cpi->oxcf.pass == 2) {
+    unsigned int section_intra_rating = get_section_intra_rating(cpi);
+    return section_intra_rating > 8 ? MAX_LOOP_FILTER * 3 / 4 : MAX_LOOP_FILTER;
+  } else {
+    return MAX_LOOP_FILTER;
+  }
+}
+
+static int64_t try_filter_frame(const YV12_BUFFER_CONFIG *sd,
+                                VP9_COMP *const cpi, int filt_level,
+                                int partial_frame) {
+  VP9_COMMON *const cm = &cpi->common;
+  int64_t filt_err;
+
+  vp9_build_mask_frame(cm, filt_level, partial_frame);
+
+  if (cpi->num_workers > 1)
+    vp9_loop_filter_frame_mt(cm->frame_to_show, cm, cpi->td.mb.e_mbd.plane,
+                             filt_level, 1, partial_frame, cpi->workers,
+                             cpi->num_workers, &cpi->lf_row_sync);
+  else
+    vp9_loop_filter_frame(cm->frame_to_show, cm, &cpi->td.mb.e_mbd, filt_level,
+                          1, partial_frame);
+
+#if CONFIG_VP9_HIGHBITDEPTH
+  if (cm->use_highbitdepth) {
+    filt_err = vpx_highbd_get_y_sse(sd, cm->frame_to_show);
+  } else {
+    filt_err = vpx_get_y_sse(sd, cm->frame_to_show);
+  }
+#else
+  filt_err = vpx_get_y_sse(sd, cm->frame_to_show);
+#endif  // CONFIG_VP9_HIGHBITDEPTH
+
+  // Re-instate the unfiltered frame
+  vpx_yv12_copy_y(&cpi->last_frame_uf, cm->frame_to_show);
+
+  return filt_err;
+}
+
+static int search_filter_level(const YV12_BUFFER_CONFIG *sd, VP9_COMP *cpi,
+                               int partial_frame) {
+  const VP9_COMMON *const cm = &cpi->common;
+  const struct loopfilter *const lf = &cm->lf;
+  const int min_filter_level = 0;
+  const int max_filter_level = get_max_filter_level(cpi);
+  int filt_direction = 0;
+  int64_t best_err;
+  int filt_best;
+
+  // Start the search at the previous frame filter level unless it is now out of
+  // range.
+  int filt_mid = clamp(lf->last_filt_level, min_filter_level, max_filter_level);
+  int filter_step = filt_mid < 16 ? 4 : filt_mid / 4;
+  // Sum squared error at each filter level
+  int64_t ss_err[MAX_LOOP_FILTER + 1];
+  unsigned int section_intra_rating = get_section_intra_rating(cpi);
+
+  // Set each entry to -1
+  memset(ss_err, 0xFF, sizeof(ss_err));
+
+  //  Make a copy of the unfiltered / processed recon buffer
+  vpx_yv12_copy_y(cm->frame_to_show, &cpi->last_frame_uf);
+
+  best_err = try_filter_frame(sd, cpi, filt_mid, partial_frame);
+  filt_best = filt_mid;
+  ss_err[filt_mid] = best_err;
+
+  while (filter_step > 0) {
+    const int filt_high = VPXMIN(filt_mid + filter_step, max_filter_level);
+    const int filt_low = VPXMAX(filt_mid - filter_step, min_filter_level);
+
+    // Bias against raising loop filter in favor of lowering it.
+    int64_t bias = (best_err >> (15 - (filt_mid / 8))) * filter_step;
+
+    if ((cpi->oxcf.pass == 2) && (section_intra_rating < 20))
+      bias = (bias * section_intra_rating) / 20;
+
+    // yx, bias less for large block size
+    if (cm->tx_mode != ONLY_4X4) bias >>= 1;
+
+    if (filt_direction <= 0 && filt_low != filt_mid) {
+      // Get Low filter error score
+      if (ss_err[filt_low] < 0) {
+        ss_err[filt_low] = try_filter_frame(sd, cpi, filt_low, partial_frame);
+      }
+      // If value is close to the best so far then bias towards a lower loop
+      // filter value.
+      if ((ss_err[filt_low] - bias) < best_err) {
+        // Was it actually better than the previous best?
+        if (ss_err[filt_low] < best_err) best_err = ss_err[filt_low];
+
+        filt_best = filt_low;
+      }
+    }
+
+    // Now look at filt_high
+    if (filt_direction >= 0 && filt_high != filt_mid) {
+      if (ss_err[filt_high] < 0) {
+        ss_err[filt_high] = try_filter_frame(sd, cpi, filt_high, partial_frame);
+      }
+      // Was it better than the previous best?
+      if (ss_err[filt_high] < (best_err - bias)) {
+        best_err = ss_err[filt_high];
+        filt_best = filt_high;
+      }
+    }
+
+    // Half the step distance if the best filter value was the same as last time
+    if (filt_best == filt_mid) {
+      filter_step /= 2;
+      filt_direction = 0;
+    } else {
+      filt_direction = (filt_best < filt_mid) ? -1 : 1;
+      filt_mid = filt_best;
+    }
+  }
+
+  return filt_best;
+}
+
+void vp9_pick_filter_level(const YV12_BUFFER_CONFIG *sd, VP9_COMP *cpi,
+                           LPF_PICK_METHOD method) {
+  VP9_COMMON *const cm = &cpi->common;
+  struct loopfilter *const lf = &cm->lf;
+
+  lf->sharpness_level = 0;
+
+  if (method == LPF_PICK_MINIMAL_LPF && lf->filter_level) {
+    lf->filter_level = 0;
+  } else if (method >= LPF_PICK_FROM_Q) {
+    const int min_filter_level = 0;
+    const int max_filter_level = get_max_filter_level(cpi);
+    const int q = vp9_ac_quant(cm->base_qindex, 0, cm->bit_depth);
+// These values were determined by linear fitting the result of the
+// searched level, filt_guess = q * 0.316206 + 3.87252
+#if CONFIG_VP9_HIGHBITDEPTH
+    int filt_guess;
+    switch (cm->bit_depth) {
+      case VPX_BITS_8:
+        filt_guess = ROUND_POWER_OF_TWO(q * 20723 + 1015158, 18);
+        break;
+      case VPX_BITS_10:
+        filt_guess = ROUND_POWER_OF_TWO(q * 20723 + 4060632, 20);
+        break;
+      default:
+        assert(cm->bit_depth == VPX_BITS_12);
+        filt_guess = ROUND_POWER_OF_TWO(q * 20723 + 16242526, 22);
+        break;
+    }
+#else
+    int filt_guess = ROUND_POWER_OF_TWO(q * 20723 + 1015158, 18);
+#endif  // CONFIG_VP9_HIGHBITDEPTH
+    if (cpi->oxcf.pass == 0 && cpi->oxcf.rc_mode == VPX_CBR &&
+        cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ && cm->seg.enabled &&
+        (cm->base_qindex < 200 || cm->width * cm->height > 320 * 240) &&
+        cpi->oxcf.content != VP9E_CONTENT_SCREEN && cm->frame_type != KEY_FRAME)
+      filt_guess = 5 * filt_guess >> 3;
+
+    if (cm->frame_type == KEY_FRAME) filt_guess -= 4;
+    lf->filter_level = clamp(filt_guess, min_filter_level, max_filter_level);
+  } else {
+    lf->filter_level =
+        search_filter_level(sd, cpi, method == LPF_PICK_FROM_SUBIMAGE);
+  }
+}