/*

 *  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;

}