/src/libvpx/vp8/encoder/picklpf.c

Source
/*
 *  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 "./vpx_dsp_rtcd.h"
#include "./vpx_scale_rtcd.h"
#include "vp8/common/onyxc_int.h"
#include "onyx_int.h"
#include "vp8/encoder/picklpf.h"
#include "vp8/encoder/quantize.h"
#include "vpx_mem/vpx_mem.h"
#include "vpx_scale/vpx_scale.h"
#include "vp8/common/alloccommon.h"
#include "vp8/common/loopfilter.h"
#if VPX_ARCH_ARM
#include "vpx_ports/arm.h"
#endif

extern int vp8_calc_ss_err(YV12_BUFFER_CONFIG *source,
                           YV12_BUFFER_CONFIG *dest);

static void yv12_copy_partial_frame(YV12_BUFFER_CONFIG *src_ybc,
                                    YV12_BUFFER_CONFIG *dst_ybc) {
  unsigned char *src_y, *dst_y;
  int yheight;
  int ystride;
  int yoffset;
  int linestocopy;

  yheight = src_ybc->y_height;
  ystride = src_ybc->y_stride;

  /* number of MB rows to use in partial filtering */
  linestocopy = (yheight >> 4) / PARTIAL_FRAME_FRACTION;
  linestocopy = linestocopy ? linestocopy << 4 : 16; /* 16 lines per MB */

  /* Copy extra 4 so that full filter context is available if filtering done
   * on the copied partial frame and not original. Partial filter does mb
   * filtering for top row also, which can modify3 pixels above.
   */
  linestocopy += 4;
  /* partial image starts at ~middle of frame (macroblock border)*/
  yoffset = ystride * (((yheight >> 5) * 16) - 4);
  src_y = src_ybc->y_buffer + yoffset;
  dst_y = dst_ybc->y_buffer + yoffset;

  // The border will be used in vp8_loop_filter_partial_frame so it needs to be
  // extended to avoid a valgrind warning.
  const unsigned char *const top_row = src_ybc->y_buffer;
  for (int i = yoffset; i < 0; i += ystride, --linestocopy) {
    memcpy(dst_y, top_row, ystride);
    dst_y += ystride;
    src_y += ystride;
  }
  memcpy(dst_y, src_y, ystride * linestocopy);
}

static int calc_partial_ssl_err(YV12_BUFFER_CONFIG *source,
                                YV12_BUFFER_CONFIG *dest) {
  int i, j;
  int Total = 0;
  int srcoffset, dstoffset;
  unsigned char *src = source->y_buffer;
  unsigned char *dst = dest->y_buffer;

  int linestocopy;

  /* number of MB rows to use in partial filtering */
  linestocopy = (source->y_height >> 4) / PARTIAL_FRAME_FRACTION;
  linestocopy = linestocopy ? linestocopy << 4 : 16; /* 16 lines per MB */

  /* partial image starts at ~middle of frame (macroblock border)*/
  srcoffset = source->y_stride * ((dest->y_height >> 5) * 16);
  dstoffset = dest->y_stride * ((dest->y_height >> 5) * 16);

  src += srcoffset;
  dst += dstoffset;

  /* Loop through the Y plane raw and reconstruction data summing
   * (square differences)
   */
  for (i = 0; i < linestocopy; i += 16) {
    for (j = 0; j < source->y_width; j += 16) {
      unsigned int sse;
      Total += vpx_mse16x16(src + j, source->y_stride, dst + j, dest->y_stride,
                            &sse);
    }

    src += 16 * source->y_stride;
    dst += 16 * dest->y_stride;
  }

  return Total;
}

/* Enforce a minimum filter level based upon baseline Q */
static int get_min_filter_level(VP8_COMP *cpi, int base_qindex) {
  int min_filter_level;

  if (cpi->source_alt_ref_active && cpi->common.refresh_golden_frame &&
      !cpi->common.refresh_alt_ref_frame) {
    min_filter_level = 0;
  } else {
    if (base_qindex <= 6) {
      min_filter_level = 0;
    } else if (base_qindex <= 16) {
      min_filter_level = 1;
    } else {
      min_filter_level = (base_qindex / 8);
    }
  }

  return min_filter_level;
}

/* Enforce a maximum filter level based upon baseline Q */
static int get_max_filter_level(VP8_COMP *cpi, int base_qindex) {
  /* PGW August 2006: Highest filter values almost always a bad idea */

  /* jbb chg: 20100118 - not so any more with this overquant stuff allow
   * high values with lots of intra coming in.
   */
  int max_filter_level = MAX_LOOP_FILTER;
  (void)base_qindex;

  if (cpi->twopass.section_intra_rating > 8) {
    max_filter_level = MAX_LOOP_FILTER * 3 / 4;
  }

  return max_filter_level;
}

void vp8cx_pick_filter_level_fast(YV12_BUFFER_CONFIG *sd, VP8_COMP *cpi) {
  VP8_COMMON *cm = &cpi->common;

  int best_err = 0;
  int filt_err = 0;
  int min_filter_level = get_min_filter_level(cpi, cm->base_qindex);
  int max_filter_level = get_max_filter_level(cpi, cm->base_qindex);
  int filt_val;
  int best_filt_val;
  YV12_BUFFER_CONFIG *saved_frame = cm->frame_to_show;

  /* Replace unfiltered frame buffer with a new one */
  cm->frame_to_show = &cpi->pick_lf_lvl_frame;

  if (cm->frame_type == KEY_FRAME) {
    cm->sharpness_level = 0;
  } else {
    cm->sharpness_level = cpi->oxcf.Sharpness;
  }

  if (cm->sharpness_level != cm->last_sharpness_level) {
    vp8_loop_filter_update_sharpness(&cm->lf_info, cm->sharpness_level);
    cm->last_sharpness_level = cm->sharpness_level;
  }

  /* Start the search at the previous frame filter level unless it is
   * now out of range.
   */
  if (cm->filter_level < min_filter_level) {
    cm->filter_level = min_filter_level;
  } else if (cm->filter_level > max_filter_level) {
    cm->filter_level = max_filter_level;
  }

  filt_val = cm->filter_level;
  best_filt_val = filt_val;

  /* Get the err using the previous frame's filter value. */

  /* Copy the unfiltered / processed recon buffer to the new buffer */
  yv12_copy_partial_frame(saved_frame, cm->frame_to_show);
  vp8_loop_filter_partial_frame(cm, &cpi->mb.e_mbd, filt_val);

  best_err = calc_partial_ssl_err(sd, cm->frame_to_show);

  filt_val -= 1 + (filt_val > 10);

  /* Search lower filter levels */
  while (filt_val >= min_filter_level) {
    /* Apply the loop filter */
    yv12_copy_partial_frame(saved_frame, cm->frame_to_show);
    vp8_loop_filter_partial_frame(cm, &cpi->mb.e_mbd, filt_val);

    /* Get the err for filtered frame */
    filt_err = calc_partial_ssl_err(sd, cm->frame_to_show);

    /* Update the best case record or exit loop. */
    if (filt_err < best_err) {
      best_err = filt_err;
      best_filt_val = filt_val;
    } else {
      break;
    }

    /* Adjust filter level */
    filt_val -= 1 + (filt_val > 10);
  }

  /* Search up (note that we have already done filt_val = cm->filter_level) */
  filt_val = cm->filter_level + 1 + (filt_val > 10);

  if (best_filt_val == cm->filter_level) {
    /* Resist raising filter level for very small gains */
    best_err -= (best_err >> 10);

    while (filt_val < max_filter_level) {
      /* Apply the loop filter */
      yv12_copy_partial_frame(saved_frame, cm->frame_to_show);

      vp8_loop_filter_partial_frame(cm, &cpi->mb.e_mbd, filt_val);

      /* Get the err for filtered frame */
      filt_err = calc_partial_ssl_err(sd, cm->frame_to_show);

      /* Update the best case record or exit loop. */
      if (filt_err < best_err) {
        /* Do not raise filter level if improvement is < 1 part
         * in 4096
         */
        best_err = filt_err - (filt_err >> 10);

        best_filt_val = filt_val;
      } else {
        break;
      }

      /* Adjust filter level */
      filt_val += 1 + (filt_val > 10);
    }
  }

  cm->filter_level = best_filt_val;

  if (cm->filter_level < min_filter_level) cm->filter_level = min_filter_level;

  if (cm->filter_level > max_filter_level) cm->filter_level = max_filter_level;

  /* restore unfiltered frame pointer */
  cm->frame_to_show = saved_frame;
}

/* Stub function for now Alt LF not used */
void vp8cx_set_alt_lf_level(VP8_COMP *cpi, int filt_val) {
  MACROBLOCKD *mbd = &cpi->mb.e_mbd;
  (void)filt_val;

  mbd->segment_feature_data[MB_LVL_ALT_LF][0] =
      cpi->segment_feature_data[MB_LVL_ALT_LF][0];
  mbd->segment_feature_data[MB_LVL_ALT_LF][1] =
      cpi->segment_feature_data[MB_LVL_ALT_LF][1];
  mbd->segment_feature_data[MB_LVL_ALT_LF][2] =
      cpi->segment_feature_data[MB_LVL_ALT_LF][2];
  mbd->segment_feature_data[MB_LVL_ALT_LF][3] =
      cpi->segment_feature_data[MB_LVL_ALT_LF][3];
}

void vp8cx_pick_filter_level(YV12_BUFFER_CONFIG *sd, VP8_COMP *cpi) {
  VP8_COMMON *cm = &cpi->common;

  int best_err = 0;
  int filt_err = 0;
  int min_filter_level = get_min_filter_level(cpi, cm->base_qindex);
  int max_filter_level = get_max_filter_level(cpi, cm->base_qindex);

  int filter_step;
  int filt_high = 0;
  int filt_mid;
  int filt_low = 0;
  int filt_best;
  int filt_direction = 0;

  /* Bias against raising loop filter and in favor of lowering it */
  int Bias = 0;

  int ss_err[MAX_LOOP_FILTER + 1];

  YV12_BUFFER_CONFIG *saved_frame = cm->frame_to_show;

  memset(ss_err, 0, sizeof(ss_err));

  /* Replace unfiltered frame buffer with a new one */
  cm->frame_to_show = &cpi->pick_lf_lvl_frame;

  if (cm->frame_type == KEY_FRAME) {
    cm->sharpness_level = 0;
  } else {
    cm->sharpness_level = cpi->oxcf.Sharpness;
  }

  /* Start the search at the previous frame filter level unless it is
   * now out of range.
   */
  filt_mid = cm->filter_level;

  if (filt_mid < min_filter_level) {
    filt_mid = min_filter_level;
  } else if (filt_mid > max_filter_level) {
    filt_mid = max_filter_level;
  }

  /* Define the initial step size */
  filter_step = (filt_mid < 16) ? 4 : filt_mid / 4;

  /* Get baseline error score */

  /* Copy the unfiltered / processed recon buffer to the new buffer */
  vpx_yv12_copy_y(saved_frame, cm->frame_to_show);

  vp8cx_set_alt_lf_level(cpi, filt_mid);
  vp8_loop_filter_frame_yonly(cm, &cpi->mb.e_mbd, filt_mid);

  best_err = vp8_calc_ss_err(sd, cm->frame_to_show);

  ss_err[filt_mid] = best_err;

  filt_best = filt_mid;

  while (filter_step > 0) {
    Bias = (best_err >> (15 - (filt_mid / 8))) * filter_step;

    if (cpi->twopass.section_intra_rating < 20) {
      Bias = Bias * cpi->twopass.section_intra_rating / 20;
    }

    filt_high = ((filt_mid + filter_step) > max_filter_level)
                    ? max_filter_level
                    : (filt_mid + filter_step);
    filt_low = ((filt_mid - filter_step) < min_filter_level)
                   ? min_filter_level
                   : (filt_mid - filter_step);

    if ((filt_direction <= 0) && (filt_low != filt_mid)) {
      if (ss_err[filt_low] == 0) {
        /* Get Low filter error score */
        vpx_yv12_copy_y(saved_frame, cm->frame_to_show);
        vp8cx_set_alt_lf_level(cpi, filt_low);
        vp8_loop_filter_frame_yonly(cm, &cpi->mb.e_mbd, filt_low);

        filt_err = vp8_calc_ss_err(sd, cm->frame_to_show);
        ss_err[filt_low] = filt_err;
      } else {
        filt_err = ss_err[filt_low];
      }

      /* If value is close to the best so far then bias towards a
       * lower loop filter value.
       */
      if ((filt_err - Bias) < best_err) {
        /* Was it actually better than the previous best? */
        if (filt_err < best_err) best_err = filt_err;

        filt_best = filt_low;
      }
    }

    /* Now look at filt_high */
    if ((filt_direction >= 0) && (filt_high != filt_mid)) {
      if (ss_err[filt_high] == 0) {
        vpx_yv12_copy_y(saved_frame, cm->frame_to_show);
        vp8cx_set_alt_lf_level(cpi, filt_high);
        vp8_loop_filter_frame_yonly(cm, &cpi->mb.e_mbd, filt_high);

        filt_err = vp8_calc_ss_err(sd, cm->frame_to_show);
        ss_err[filt_high] = filt_err;
      } else {
        filt_err = ss_err[filt_high];
      }

      /* Was it better than the previous best? */
      if (filt_err < (best_err - Bias)) {
        best_err = filt_err;
        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 = filter_step / 2;
      filt_direction = 0;
    } else {
      filt_direction = (filt_best < filt_mid) ? -1 : 1;
      filt_mid = filt_best;
    }
  }

  cm->filter_level = filt_best;

  /* restore unfiltered frame pointer */
  cm->frame_to_show = saved_frame;
}

Coverage Report

Created: 2026-01-16 07:48

Line	Count	Source
1		/*
2		* Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3		*
4		* Use of this source code is governed by a BSD-style license
5		* that can be found in the LICENSE file in the root of the source
6		* tree. An additional intellectual property rights grant can be found
7		* in the file PATENTS. All contributing project authors may
8		* be found in the AUTHORS file in the root of the source tree.
9		*/
10
11		#include "./vpx_dsp_rtcd.h"
12		#include "./vpx_scale_rtcd.h"
13		#include "vp8/common/onyxc_int.h"
14		#include "onyx_int.h"
15		#include "vp8/encoder/picklpf.h"
16		#include "vp8/encoder/quantize.h"
17		#include "vpx_mem/vpx_mem.h"
18		#include "vpx_scale/vpx_scale.h"
19		#include "vp8/common/alloccommon.h"
20		#include "vp8/common/loopfilter.h"
21		#if VPX_ARCH_ARM
22		#include "vpx_ports/arm.h"
23		#endif
24
25		extern int vp8_calc_ss_err(YV12_BUFFER_CONFIG *source,
26		YV12_BUFFER_CONFIG *dest);
27
28		static void yv12_copy_partial_frame(YV12_BUFFER_CONFIG *src_ybc,
29	2	YV12_BUFFER_CONFIG *dst_ybc) {
30	2	unsigned char src_y, dst_y;
31	2	int yheight;
32	2	int ystride;
33	2	int yoffset;
34	2	int linestocopy;
35
36	2	yheight = src_ybc->y_height;
37	2	ystride = src_ybc->y_stride;
38
39		/* number of MB rows to use in partial filtering */
40	2	linestocopy = (yheight >> 4) / PARTIAL_FRAME_FRACTION;
41	2	linestocopy = linestocopy ? linestocopy << 4 : 16; /* 16 lines per MB */
42
43		/* Copy extra 4 so that full filter context is available if filtering done
44		* on the copied partial frame and not original. Partial filter does mb
45		* filtering for top row also, which can modify3 pixels above.
46		*/
47	2	linestocopy += 4;
48		/* partial image starts at ~middle of frame (macroblock border)*/
49	2	yoffset = ystride * (((yheight >> 5) * 16) - 4);
50	2	src_y = src_ybc->y_buffer + yoffset;
51	2	dst_y = dst_ybc->y_buffer + yoffset;
52
53		// The border will be used in vp8_loop_filter_partial_frame so it needs to be
54		// extended to avoid a valgrind warning.
55	2	const unsigned char *const top_row = src_ybc->y_buffer;
56	2	for (int i = yoffset; i < 0; i += ystride, --linestocopy) {
57	0	memcpy(dst_y, top_row, ystride);
58	0	dst_y += ystride;
59	0	src_y += ystride;
60	0	}
61	2	memcpy(dst_y, src_y, ystride * linestocopy);
62	2	}
63
64		static int calc_partial_ssl_err(YV12_BUFFER_CONFIG *source,
65	2	YV12_BUFFER_CONFIG *dest) {
66	2	int i, j;
67	2	int Total = 0;
68	2	int srcoffset, dstoffset;
69	2	unsigned char *src = source->y_buffer;
70	2	unsigned char *dst = dest->y_buffer;
71
72	2	int linestocopy;
73
74		/* number of MB rows to use in partial filtering */
75	2	linestocopy = (source->y_height >> 4) / PARTIAL_FRAME_FRACTION;
76	2	linestocopy = linestocopy ? linestocopy << 4 : 16; /* 16 lines per MB */
77
78		/* partial image starts at ~middle of frame (macroblock border)*/
79	2	srcoffset = source->y_stride * ((dest->y_height >> 5) * 16);
80	2	dstoffset = dest->y_stride * ((dest->y_height >> 5) * 16);
81
82	2	src += srcoffset;
83	2	dst += dstoffset;
84
85		/* Loop through the Y plane raw and reconstruction data summing
86		* (square differences)
87		*/
88	18	for (i = 0; i < linestocopy; i += 16) {
89	272	for (j = 0; j < source->y_width; j += 16) {
90	256	unsigned int sse;
91	256	Total += vpx_mse16x16(src + j, source->y_stride, dst + j, dest->y_stride,
92	256	&sse);
93	256	}
94
95	16	src += 16 * source->y_stride;
96	16	dst += 16 * dest->y_stride;
97	16	}
98
99	2	return Total;
100	2	}
101
102		/* Enforce a minimum filter level based upon baseline Q */
103	110k	static int get_min_filter_level(VP8_COMP *cpi, int base_qindex) {
104	110k	int min_filter_level;
105
106	110k	if (cpi->source_alt_ref_active && cpi->common.refresh_golden_frame &&
107	0	!cpi->common.refresh_alt_ref_frame) {
108	0	min_filter_level = 0;
109	110k	} else {
110	110k	if (base_qindex <= 6) {
111	47.4k	min_filter_level = 0;
112	62.7k	} else if (base_qindex <= 16) {
113	3.54k	min_filter_level = 1;
114	59.1k	} else {
115	59.1k	min_filter_level = (base_qindex / 8);
116	59.1k	}
117	110k	}
118
119	110k	return min_filter_level;
120	110k	}
121
122		/* Enforce a maximum filter level based upon baseline Q */
123	110k	static int get_max_filter_level(VP8_COMP *cpi, int base_qindex) {
124		/* PGW August 2006: Highest filter values almost always a bad idea */
125
126		/* jbb chg: 20100118 - not so any more with this overquant stuff allow
127		* high values with lots of intra coming in.
128		*/
129	110k	int max_filter_level = MAX_LOOP_FILTER;
130	110k	(void)base_qindex;
131
132	110k	if (cpi->twopass.section_intra_rating > 8) {
133	0	max_filter_level = MAX_LOOP_FILTER * 3 / 4;
134	0	}
135
136	110k	return max_filter_level;
137	110k	}
138
139	1	void vp8cx_pick_filter_level_fast(YV12_BUFFER_CONFIG sd, VP8_COMP cpi) {
140	1	VP8_COMMON *cm = &cpi->common;
141
142	1	int best_err = 0;
143	1	int filt_err = 0;
144	1	int min_filter_level = get_min_filter_level(cpi, cm->base_qindex);
145	1	int max_filter_level = get_max_filter_level(cpi, cm->base_qindex);
146	1	int filt_val;
147	1	int best_filt_val;
148	1	YV12_BUFFER_CONFIG *saved_frame = cm->frame_to_show;
149
150		/* Replace unfiltered frame buffer with a new one */
151	1	cm->frame_to_show = &cpi->pick_lf_lvl_frame;
152
153	1	if (cm->frame_type == KEY_FRAME) {
154	0	cm->sharpness_level = 0;
155	1	} else {
156	1	cm->sharpness_level = cpi->oxcf.Sharpness;
157	1	}
158
159	1	if (cm->sharpness_level != cm->last_sharpness_level) {
160	0	vp8_loop_filter_update_sharpness(&cm->lf_info, cm->sharpness_level);
161	0	cm->last_sharpness_level = cm->sharpness_level;
162	0	}
163
164		/* Start the search at the previous frame filter level unless it is
165		* now out of range.
166		*/
167	1	if (cm->filter_level < min_filter_level) {
168	1	cm->filter_level = min_filter_level;
169	1	} else if (cm->filter_level > max_filter_level) {
170	0	cm->filter_level = max_filter_level;
171	0	}
172
173	1	filt_val = cm->filter_level;
174	1	best_filt_val = filt_val;
175
176		/* Get the err using the previous frame's filter value. */
177
178		/* Copy the unfiltered / processed recon buffer to the new buffer */
179	1	yv12_copy_partial_frame(saved_frame, cm->frame_to_show);
180	1	vp8_loop_filter_partial_frame(cm, &cpi->mb.e_mbd, filt_val);
181
182	1	best_err = calc_partial_ssl_err(sd, cm->frame_to_show);
183
184	1	filt_val -= 1 + (filt_val > 10);
185
186		/* Search lower filter levels */
187	1	while (filt_val >= min_filter_level) {
188		/* Apply the loop filter */
189	0	yv12_copy_partial_frame(saved_frame, cm->frame_to_show);
190	0	vp8_loop_filter_partial_frame(cm, &cpi->mb.e_mbd, filt_val);
191
192		/* Get the err for filtered frame */
193	0	filt_err = calc_partial_ssl_err(sd, cm->frame_to_show);
194
195		/* Update the best case record or exit loop. */
196	0	if (filt_err < best_err) {
197	0	best_err = filt_err;
198	0	best_filt_val = filt_val;
199	0	} else {
200	0	break;
201	0	}
202
203		/* Adjust filter level */
204	0	filt_val -= 1 + (filt_val > 10);
205	0	}
206
207		/* Search up (note that we have already done filt_val = cm->filter_level) */
208	1	filt_val = cm->filter_level + 1 + (filt_val > 10);
209
210	1	if (best_filt_val == cm->filter_level) {
211		/* Resist raising filter level for very small gains */
212	1	best_err -= (best_err >> 10);
213
214	1	while (filt_val < max_filter_level) {
215		/* Apply the loop filter */
216	1	yv12_copy_partial_frame(saved_frame, cm->frame_to_show);
217
218	1	vp8_loop_filter_partial_frame(cm, &cpi->mb.e_mbd, filt_val);
219
220		/* Get the err for filtered frame */
221	1	filt_err = calc_partial_ssl_err(sd, cm->frame_to_show);
222
223		/* Update the best case record or exit loop. */
224	1	if (filt_err < best_err) {
225		/* Do not raise filter level if improvement is < 1 part
226		* in 4096
227		*/
228	0	best_err = filt_err - (filt_err >> 10);
229
230	0	best_filt_val = filt_val;
231	1	} else {
232	1	break;
233	1	}
234
235		/* Adjust filter level */
236	0	filt_val += 1 + (filt_val > 10);
237	0	}
238	1	}
239
240	1	cm->filter_level = best_filt_val;
241
242	1	if (cm->filter_level < min_filter_level) cm->filter_level = min_filter_level;
243
244	1	if (cm->filter_level > max_filter_level) cm->filter_level = max_filter_level;
245
246		/* restore unfiltered frame pointer */
247	1	cm->frame_to_show = saved_frame;
248	1	}
249
250		/* Stub function for now Alt LF not used */
251	848k	void vp8cx_set_alt_lf_level(VP8_COMP *cpi, int filt_val) {
252	848k	MACROBLOCKD *mbd = &cpi->mb.e_mbd;
253	848k	(void)filt_val;
254
255	848k	mbd->segment_feature_data[MB_LVL_ALT_LF][0] =
256	848k	cpi->segment_feature_data[MB_LVL_ALT_LF][0];
257	848k	mbd->segment_feature_data[MB_LVL_ALT_LF][1] =
258	848k	cpi->segment_feature_data[MB_LVL_ALT_LF][1];
259	848k	mbd->segment_feature_data[MB_LVL_ALT_LF][2] =
260	848k	cpi->segment_feature_data[MB_LVL_ALT_LF][2];
261	848k	mbd->segment_feature_data[MB_LVL_ALT_LF][3] =
262	848k	cpi->segment_feature_data[MB_LVL_ALT_LF][3];
263	848k	}
264
265	110k	void vp8cx_pick_filter_level(YV12_BUFFER_CONFIG sd, VP8_COMP cpi) {
266	110k	VP8_COMMON *cm = &cpi->common;
267
268	110k	int best_err = 0;
269	110k	int filt_err = 0;
270	110k	int min_filter_level = get_min_filter_level(cpi, cm->base_qindex);
271	110k	int max_filter_level = get_max_filter_level(cpi, cm->base_qindex);
272
273	110k	int filter_step;
274	110k	int filt_high = 0;
275	110k	int filt_mid;
276	110k	int filt_low = 0;
277	110k	int filt_best;
278	110k	int filt_direction = 0;
279
280		/* Bias against raising loop filter and in favor of lowering it */
281	110k	int Bias = 0;
282
283	110k	int ss_err[MAX_LOOP_FILTER + 1];
284
285	110k	YV12_BUFFER_CONFIG *saved_frame = cm->frame_to_show;
286
287	110k	memset(ss_err, 0, sizeof(ss_err));
288
289		/* Replace unfiltered frame buffer with a new one */
290	110k	cm->frame_to_show = &cpi->pick_lf_lvl_frame;
291
292	110k	if (cm->frame_type == KEY_FRAME) {
293	18.6k	cm->sharpness_level = 0;
294	91.4k	} else {
295	91.4k	cm->sharpness_level = cpi->oxcf.Sharpness;
296	91.4k	}
297
298		/* Start the search at the previous frame filter level unless it is
299		* now out of range.
300		*/
301	110k	filt_mid = cm->filter_level;
302
303	110k	if (filt_mid < min_filter_level) {
304	5.21k	filt_mid = min_filter_level;
305	104k	} else if (filt_mid > max_filter_level) {
306	0	filt_mid = max_filter_level;
307	0	}
308
309		/* Define the initial step size */
310	110k	filter_step = (filt_mid < 16) ? 4 : filt_mid / 4;
311
312		/* Get baseline error score */
313
314		/* Copy the unfiltered / processed recon buffer to the new buffer */
315	110k	vpx_yv12_copy_y(saved_frame, cm->frame_to_show);
316
317	110k	vp8cx_set_alt_lf_level(cpi, filt_mid);
318	110k	vp8_loop_filter_frame_yonly(cm, &cpi->mb.e_mbd, filt_mid);
319
320	110k	best_err = vp8_calc_ss_err(sd, cm->frame_to_show);
321
322	110k	ss_err[filt_mid] = best_err;
323
324	110k	filt_best = filt_mid;
325
326	544k	while (filter_step > 0) {
327	433k	Bias = (best_err >> (15 - (filt_mid / 8))) * filter_step;
328
329	433k	if (cpi->twopass.section_intra_rating < 20) {
330	433k	Bias = Bias * cpi->twopass.section_intra_rating / 20;
331	433k	}
332
333	433k	filt_high = ((filt_mid + filter_step) > max_filter_level)
334	433k	? max_filter_level
335	433k	: (filt_mid + filter_step);
336	433k	filt_low = ((filt_mid - filter_step) < min_filter_level)
337	433k	? min_filter_level
338	433k	: (filt_mid - filter_step);
339
340	433k	if ((filt_direction <= 0) && (filt_low != filt_mid)) {
341	312k	if (ss_err[filt_low] == 0) {
342		/* Get Low filter error score */
343	282k	vpx_yv12_copy_y(saved_frame, cm->frame_to_show);
344	282k	vp8cx_set_alt_lf_level(cpi, filt_low);
345	282k	vp8_loop_filter_frame_yonly(cm, &cpi->mb.e_mbd, filt_low);
346
347	282k	filt_err = vp8_calc_ss_err(sd, cm->frame_to_show);
348	282k	ss_err[filt_low] = filt_err;
349	282k	} else {
350	29.8k	filt_err = ss_err[filt_low];
351	29.8k	}
352
353		/* If value is close to the best so far then bias towards a
354		* lower loop filter value.
355		*/
356	312k	if ((filt_err - Bias) < best_err) {
357		/* Was it actually better than the previous best? */
358	26.4k	if (filt_err < best_err) best_err = filt_err;
359
360	26.4k	filt_best = filt_low;
361	26.4k	}
362	312k	}
363
364		/* Now look at filt_high */
365	433k	if ((filt_direction >= 0) && (filt_high != filt_mid)) {
366	380k	if (ss_err[filt_high] == 0) {
367	356k	vpx_yv12_copy_y(saved_frame, cm->frame_to_show);
368	356k	vp8cx_set_alt_lf_level(cpi, filt_high);
369	356k	vp8_loop_filter_frame_yonly(cm, &cpi->mb.e_mbd, filt_high);
370
371	356k	filt_err = vp8_calc_ss_err(sd, cm->frame_to_show);
372	356k	ss_err[filt_high] = filt_err;
373	356k	} else {
374	23.2k	filt_err = ss_err[filt_high];
375	23.2k	}
376
377		/* Was it better than the previous best? */
378	380k	if (filt_err < (best_err - Bias)) {
379	46.6k	best_err = filt_err;
380	46.6k	filt_best = filt_high;
381	46.6k	}
382	380k	}
383
384		/* Half the step distance if the best filter value was the same
385		* as last time
386		*/
387	433k	if (filt_best == filt_mid) {
388	362k	filter_step = filter_step / 2;
389	362k	filt_direction = 0;
390	362k	} else {
391	71.3k	filt_direction = (filt_best < filt_mid) ? -1 : 1;
392	71.3k	filt_mid = filt_best;
393	71.3k	}
394	433k	}
395
396	110k	cm->filter_level = filt_best;
397
398		/* restore unfiltered frame pointer */
399	110k	cm->frame_to_show = saved_frame;
400	110k	}