C++ (Cpp) vp10_compute_qdelta_by_rate示例

示例#1

文件： aq_complexity.c 项目： jmvalin/aom

void vp10_setup_in_frame_q_adj(VP10_COMP *cpi) {
  VP10_COMMON *const cm = &cpi->common;
  struct segmentation *const seg = &cm->seg;

  // Make SURE use of floating point in this function is safe.
  vpx_clear_system_state();

  if (frame_is_intra_only(cm) || cm->error_resilient_mode ||
      cpi->refresh_alt_ref_frame ||
      (cpi->refresh_golden_frame && !cpi->rc.is_src_frame_alt_ref)) {
    int segment;
    const int aq_strength = get_aq_c_strength(cm->base_qindex, cm->bit_depth);

    // Clear down the segment map.
    memset(cpi->segmentation_map, DEFAULT_AQ2_SEG, cm->mi_rows * cm->mi_cols);

    vp10_clearall_segfeatures(seg);

    // Segmentation only makes sense if the target bits per SB is above a
    // threshold. Below this the overheads will usually outweigh any benefit.
    if (cpi->rc.sb64_target_rate < 256) {
      vp10_disable_segmentation(seg);
      return;
    }

    vp10_enable_segmentation(seg);

    // Select delta coding method.
    seg->abs_delta = SEGMENT_DELTADATA;

    // Default segment "Q" feature is disabled so it defaults to the baseline Q.
    vp10_disable_segfeature(seg, DEFAULT_AQ2_SEG, SEG_LVL_ALT_Q);

    // Use some of the segments for in frame Q adjustment.
    for (segment = 0; segment < AQ_C_SEGMENTS; ++segment) {
      int qindex_delta;

      if (segment == DEFAULT_AQ2_SEG) continue;

      qindex_delta = vp10_compute_qdelta_by_rate(
          &cpi->rc, cm->frame_type, cm->base_qindex,
          aq_c_q_adj_factor[aq_strength][segment], cm->bit_depth);

      // For AQ complexity mode, we dont allow Q0 in a segment if the base
      // Q is not 0. Q0 (lossless) implies 4x4 only and in AQ mode 2 a segment
      // Q delta is sometimes applied without going back around the rd loop.
      // This could lead to an illegal combination of partition size and q.
      if ((cm->base_qindex != 0) && ((cm->base_qindex + qindex_delta) == 0)) {
        qindex_delta = -cm->base_qindex + 1;
      }
      if ((cm->base_qindex + qindex_delta) > 0) {
        vp10_enable_segfeature(seg, segment, SEG_LVL_ALT_Q);
        vp10_set_segdata(seg, segment, SEG_LVL_ALT_Q, qindex_delta);
      }
    }
  }
}

示例#2

文件： aq_cyclicrefresh.c 项目： Crawping/chromium_extract

// Compute delta-q for the segment.
static int compute_deltaq(const VP10_COMP *cpi, int q, double rate_factor) {
  const CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
  const RATE_CONTROL *const rc = &cpi->rc;
  int deltaq = vp10_compute_qdelta_by_rate(rc, cpi->common.frame_type,
                                          q, rate_factor,
                                          cpi->common.bit_depth);
  if ((-deltaq) > cr->max_qdelta_perc * q / 100) {
    deltaq = -cr->max_qdelta_perc * q / 100;
  }
  return deltaq;
}