vp9_picklpf.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.
 */

#include <assert.h>
#include <limits.h>

#include "./vpx_scale_rtcd.h"

#include "vpx_mem/vpx_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 int get_max_filter_level(const VP9_COMP *cpi) {
  if (cpi->pass == 2) {
    return cpi->twopass.section_intra_rating > 8 ? MAX_LOOP_FILTER * 3 / 4
                                                 : MAX_LOOP_FILTER;
  } else {
    return MAX_LOOP_FILTER;
  }
}


static int try_filter_frame(const YV12_BUFFER_CONFIG *sd, VP9_COMP *const cpi,
                            int filt_level, int partial_frame) {
  VP9_COMMON *const cm = &cpi->common;
  int filt_err;

  vp9_loop_filter_frame(cm->frame_to_show, cm, &cpi->mb.e_mbd, filt_level, 1,
                        partial_frame);
  filt_err = vp9_get_y_sse(sd, cm->frame_to_show);

  // 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;
  int best_err, filt_best;

  // Start the search at the previous frame filter level unless it is now out of
  // range.
  int filt_mid = clamp(lf->filter_level, min_filter_level, max_filter_level);
  int filter_step = filt_mid < 16 ? 4 : filt_mid / 4;
  // Sum squared error at each filter level
  int ss_err[MAX_LOOP_FILTER + 1];

  // Set each entry to -1
  vpx_memset(ss_err, 0xFF, sizeof(ss_err));

  //  Make a copy of the unfiltered / processed recon buffer