/* * 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 #include #include #include "./vpx_dsp_rtcd.h" #include "./vpx_scale_rtcd.h" #include "vpx_mem/vpx_mem.h" #include "vpx_ports/mem.h" #include "vpx_scale/vpx_scale.h" #include "vpx_scale/yv12config.h" #include "vp9/common/vp9_entropymv.h" #include "vp9/common/vp9_quant_common.h" #include "vp9/common/vp9_reconinter.h" // vp9_setup_dst_planes() #include "vp9/common/vp9_systemdependent.h" #include "vp9/encoder/vp9_aq_variance.h" #include "vp9/encoder/vp9_block.h" #include "vp9/encoder/vp9_encodeframe.h" #include "vp9/encoder/vp9_encodemb.h" #include "vp9/encoder/vp9_encodemv.h" #include "vp9/encoder/vp9_encoder.h" #include "vp9/encoder/vp9_extend.h" #include "vp9/encoder/vp9_firstpass.h" #include "vp9/encoder/vp9_mcomp.h" #include "vp9/encoder/vp9_quantize.h" #include "vp9/encoder/vp9_rd.h" #include "vp9/encoder/vp9_variance.h" #define OUTPUT_FPF 0 #define ARF_STATS_OUTPUT 0 #define GROUP_ADAPTIVE_MAXQ 1 #define BOOST_BREAKOUT 12.5 #define BOOST_FACTOR 12.5 #define ERR_DIVISOR 128.0 #define FACTOR_PT_LOW 0.70 #define FACTOR_PT_HIGH 0.90 #define FIRST_PASS_Q 10.0 #define GF_MAX_BOOST 96.0 #define INTRA_MODE_PENALTY 1024 #define KF_MAX_BOOST 128.0 #define MIN_ARF_GF_BOOST 240 #define MIN_DECAY_FACTOR 0.01 #define MIN_KF_BOOST 300 #define NEW_MV_MODE_PENALTY 32 #define SVC_FACTOR_PT_LOW 0.45 #define DARK_THRESH 64 #define DEFAULT_GRP_WEIGHT 1.0 #define RC_FACTOR_MIN 0.75 #define RC_FACTOR_MAX 1.75 #define NCOUNT_INTRA_THRESH 8192 #define NCOUNT_INTRA_FACTOR 3 #define NCOUNT_FRAME_II_THRESH 5.0 #define DOUBLE_DIVIDE_CHECK(x) ((x) < 0 ? (x) - 0.000001 : (x) + 0.000001) #if ARF_STATS_OUTPUT unsigned int arf_count = 0; #endif // Resets the first pass file to the given position using a relative seek from // the current position. static void reset_fpf_position(TWO_PASS *p, const FIRSTPASS_STATS *position) { p->stats_in = position; } // Read frame stats at an offset from the current position. static const FIRSTPASS_STATS *read_frame_stats(const TWO_PASS *p, int offset) { if ((offset >= 0 && p->stats_in + offset >= p->stats_in_end) || (offset < 0 && p->stats_in + offset < p->stats_in_start)) { return NULL; } return &p->stats_in[offset]; } static int input_stats(TWO_PASS *p, FIRSTPASS_STATS *fps) { if (p->stats_in >= p->stats_in_end) return EOF; *fps = *p->stats_in; ++p->stats_in; return 1; } static void output_stats(FIRSTPASS_STATS *stats, struct vpx_codec_pkt_list *pktlist) { struct vpx_codec_cx_pkt pkt; pkt.kind = VPX_CODEC_STATS_PKT; pkt.data.twopass_stats.buf = stats; pkt.data.twopass_stats.sz = sizeof(FIRSTPASS_STATS); vpx_codec_pkt_list_add(pktlist, &pkt); // TEMP debug code #if OUTPUT_FPF { FILE *fpfile; fpfile = fopen("firstpass.stt", "a"); fprintf(fpfile, "%12.0lf %12.4lf %12.0lf %12.0lf %12.0lf %12.4lf %12.4lf" "%12.4lf %12.4lf %12.4lf %12.4lf %12.4lf %12.4lf %12.4lf %12.4lf" "%12.4lf %12.4lf %12.0lf %12.0lf %12.0lf %12.4lf\n", stats->frame, stats->weight, stats->intra_error, stats->coded_error, stats->sr_coded_error, stats->pcnt_inter, stats->pcnt_motion, stats->pcnt_second_ref, stats->pcnt_neutral, stats->ul_intra_pct, stats->image_start_row, stats->MVr, stats->mvr_abs, stats->MVc, stats->mvc_abs, stats->MVrv, stats->MVcv, stats->mv_in_out_count, stats->new_mv_count, stats->count, stats->duration); fclose(fpfile); } #endif } #if CONFIG_FP_MB_STATS static void output_fpmb_stats(uint8_t *this_frame_mb_stats, VP9_COMMON *cm, struct vpx_codec_pkt_list *pktlist) { struct vpx_codec_cx_pkt pkt; pkt.kind = VPX_CODEC_FPMB_STATS_PKT; pkt.data.firstpass_mb_stats.buf = this_frame_mb_stats; pkt.data.firstpass_mb_stats.sz = cm->initial_mbs * sizeof(uint8_t); vpx_codec_pkt_list_add(pktlist, &pkt); } #endif static void zero_stats(FIRSTPASS_STATS *section) { section->frame = 0.0; section->weight = 0.0; section->intra_error = 0.0; section->coded_error = 0.0; section->sr_coded_error = 0.0; section->pcnt_inter = 0.0; section->pcnt_motion = 0.0; section->pcnt_second_ref = 0.0; section->pcnt_neutral = 0.0; section->ul_intra_pct = 0.0; section->image_start_row = 0.0; section->MVr = 0.0; section->mvr_abs = 0.0; section->MVc = 0.0; section->mvc_abs = 0.0; section->MVrv = 0.0; section->MVcv = 0.0; section->mv_in_out_count = 0.0; section->new_mv_count = 0.0; section->count = 0.0; section->duration = 1.0; section->spatial_layer_id = 0; } static void accumulate_stats(FIRSTPASS_STATS *section, const FIRSTPASS_STATS *frame) { section->frame += frame->frame; section->weight += frame->weight; section->spatial_layer_id = frame->spatial_layer_id; section->intra_error += frame->intra_error; section->coded_error += frame->coded_error; section->sr_coded_error += frame->sr_coded_error; section->pcnt_inter += frame->pcnt_inter; section->pcnt_motion += frame->pcnt_motion; section->pcnt_second_ref += frame->pcnt_second_ref; section->pcnt_neutral += frame->pcnt_neutral; section->ul_intra_pct += frame->ul_intra_pct; section->image_start_row += frame->image_start_row; section->MVr += frame->MVr; section->mvr_abs += frame->mvr_abs; section->MVc += frame->MVc; section->mvc_abs += frame->mvc_abs; section->MVrv += frame->MVrv; section->MVcv += frame->MVcv; section->mv_in_out_count += frame->mv_in_out_count; section->new_mv_count += frame->new_mv_count; section->count += frame->count; section->duration += frame->duration; } static void subtract_stats(FIRSTPASS_STATS *section, const FIRSTPASS_STATS *frame) { section->frame -= frame->frame; section->weight -= frame->weight; section->intra_error -= frame->intra_error; section->coded_error -= frame->coded_error; section->sr_coded_error -= frame->sr_coded_error; section->pcnt_inter -= frame->pcnt_inter; section->pcnt_motion -= frame->pcnt_motion; section->pcnt_second_ref -= frame->pcnt_second_ref; section->pcnt_neutral -= frame->pcnt_neutral; section->ul_intra_pct -= frame->ul_intra_pct; section->image_start_row -= frame->image_start_row; section->MVr -= frame->MVr; section->mvr_abs -= frame->mvr_abs; section->MVc -= frame->MVc; section->mvc_abs -= frame->mvc_abs; section->MVrv -= frame->MVrv; section->MVcv -= frame->MVcv; section->mv_in_out_count -= frame->mv_in_out_count; section->new_mv_count -= frame->new_mv_count; section->count -= frame->count; section->duration -= frame->duration; } // Calculate a modified Error used in distributing bits between easier and // harder frames. static double calculate_modified_err(const TWO_PASS *twopass, const VP9EncoderConfig *oxcf, const FIRSTPASS_STATS *this_frame) { const FIRSTPASS_STATS *const stats = &twopass->total_stats; const double av_weight = stats->weight / stats->count; const double av_err = (stats->coded_error * av_weight) / stats->count; const double modified_error = av_err * pow(this_frame->coded_error * this_frame->weight / DOUBLE_DIVIDE_CHECK(av_err), oxcf->two_pass_vbrbias / 100.0); return fclamp(modified_error, twopass->modified_error_min, twopass->modified_error_max); } // This function returns the maximum target rate per frame. static int frame_max_bits(const RATE_CONTROL *rc, const VP9EncoderConfig *oxcf) { int64_t max_bits = ((int64_t)rc->avg_frame_bandwidth * (int64_t)oxcf->two_pass_vbrmax_section) / 100; if (max_bits < 0) max_bits = 0; else if (max_bits > rc->max_frame_bandwidth) max_bits = rc->max_frame_bandwidth; return (int)max_bits; } void vp9_init_first_pass(VP9_COMP *cpi) { zero_stats(&cpi->twopass.total_stats); } void vp9_end_first_pass(VP9_COMP *cpi) { if (is_two_pass_svc(cpi)) { int i; for (i = 0; i < cpi->svc.number_spatial_layers; ++i) { output_stats(&cpi->svc.layer_context[i].twopass.total_stats, cpi->output_pkt_list); } } else { output_stats(&cpi->twopass.total_stats, cpi->output_pkt_list); } } static vp9_variance_fn_t get_block_variance_fn(BLOCK_SIZE bsize) { switch (bsize) { case BLOCK_8X8: return vpx_mse8x8; case BLOCK_16X8: return vpx_mse16x8; case BLOCK_8X16: return vpx_mse8x16; default: return vpx_mse16x16; } } static unsigned int get_prediction_error(BLOCK_SIZE bsize, const struct buf_2d *src, const struct buf_2d *ref) { unsigned int sse; const vp9_variance_fn_t fn = get_block_variance_fn(bsize); fn(src->buf, src->stride, ref->buf, ref->stride, &sse); return sse; } #if CONFIG_VP9_HIGHBITDEPTH static vp9_variance_fn_t highbd_get_block_variance_fn(BLOCK_SIZE bsize, int bd) { switch (bd) { default: switch (bsize) { case BLOCK_8X8: return vpx_highbd_8_mse8x8; case BLOCK_16X8: return vpx_highbd_8_mse16x8; case BLOCK_8X16: return vpx_highbd_8_mse8x16; default: return vpx_highbd_8_mse16x16; } break; case 10: switch (bsize) { case BLOCK_8X8: return vpx_highbd_10_mse8x8; case BLOCK_16X8: return vpx_highbd_10_mse16x8; case BLOCK_8X16: return vpx_highbd_10_mse8x16; default: return vpx_highbd_10_mse16x16; } break; case 12: switch (bsize) { case BLOCK_8X8: return vpx_highbd_12_mse8x8; case BLOCK_16X8: return vpx_highbd_12_mse16x8; case BLOCK_8X16: return vpx_highbd_12_mse8x16; default: return vpx_highbd_12_mse16x16; } break; } } static unsigned int highbd_get_prediction_error(BLOCK_SIZE bsize, const struct buf_2d *src, const struct buf_2d *ref, int bd) { unsigned int sse; const vp9_variance_fn_t fn = highbd_get_block_variance_fn(bsize, bd); fn(src->buf, src->stride, ref->buf, ref->stride, &sse); return sse; } #endif // CONFIG_VP9_HIGHBITDEPTH // Refine the motion search range according to the frame dimension // for first pass test. static int get_search_range(const VP9_COMP *cpi) { int sr = 0; const int dim = MIN(cpi->initial_width, cpi->initial_height); while ((dim << sr) < MAX_FULL_PEL_VAL) ++sr; return sr; } static void first_pass_motion_search(VP9_COMP *cpi, MACROBLOCK *x, const MV *ref_mv, MV *best_mv, int *best_motion_err) { MACROBLOCKD *const xd = &x->e_mbd; MV tmp_mv = {0, 0}; MV ref_mv_full = {ref_mv->row >> 3, ref_mv->col >> 3}; int num00, tmp_err, n; const BLOCK_SIZE bsize = xd->mi[0]->mbmi.sb_type; vp9_variance_fn_ptr_t v_fn_ptr = cpi->fn_ptr[bsize]; const int new_mv_mode_penalty = NEW_MV_MODE_PENALTY; int step_param = 3; int further_steps = (MAX_MVSEARCH_STEPS - 1) - step_param; const int sr = get_search_range(cpi); step_param += sr; further_steps -= sr; // Override the default variance function to use MSE. v_fn_ptr.vf = get_block_variance_fn(bsize); #if CONFIG_VP9_HIGHBITDEPTH if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) { v_fn_ptr.vf = highbd_get_block_variance_fn(bsize, xd->bd); } #endif // CONFIG_VP9_HIGHBITDEPTH // Center the initial step/diamond search on best mv. tmp_err = cpi->diamond_search_sad(x, &cpi->ss_cfg, &ref_mv_full, &tmp_mv, step_param, x->sadperbit16, &num00, &v_fn_ptr, ref_mv); if (tmp_err < INT_MAX) tmp_err = vp9_get_mvpred_var(x, &tmp_mv, ref_mv, &v_fn_ptr, 1); if (tmp_err < INT_MAX - new_mv_mode_penalty) tmp_err += new_mv_mode_penalty; if (tmp_err < *best_motion_err) { *best_motion_err = tmp_err; *best_mv = tmp_mv; } // Carry out further step/diamond searches as necessary. n = num00; num00 = 0; while (n < further_steps) { ++n; if (num00) { --num00; } else { tmp_err = cpi->diamond_search_sad(x, &cpi->ss_cfg, &ref_mv_full, &tmp_mv, step_param + n, x->sadperbit16, &num00, &v_fn_ptr, ref_mv); if (tmp_err < INT_MAX) tmp_err = vp9_get_mvpred_var(x, &tmp_mv, ref_mv, &v_fn_ptr, 1); if (tmp_err < INT_MAX - new_mv_mode_penalty) tmp_err += new_mv_mode_penalty; if (tmp_err < *best_motion_err) { *best_motion_err = tmp_err; *best_mv = tmp_mv; } } } } static BLOCK_SIZE get_bsize(const VP9_COMMON *cm, int mb_row, int mb_col) { if (2 * mb_col + 1 < cm->mi_cols) { return 2 * mb_row + 1 < cm->mi_rows ? BLOCK_16X16 : BLOCK_16X8; } else { return 2 * mb_row + 1 < cm->mi_rows ? BLOCK_8X16 : BLOCK_8X8; } } static int find_fp_qindex(vpx_bit_depth_t bit_depth) { int i; for (i = 0; i < QINDEX_RANGE; ++i) if (vp9_convert_qindex_to_q(i, bit_depth) >= FIRST_PASS_Q) break; if (i == QINDEX_RANGE) i--; return i; } static void set_first_pass_params(VP9_COMP *cpi) { VP9_COMMON *const cm = &cpi->common; if (!cpi->refresh_alt_ref_frame && (cm->current_video_frame == 0 || (cpi->frame_flags & FRAMEFLAGS_KEY))) { cm->frame_type = KEY_FRAME; } else { cm->frame_type = INTER_FRAME; } // Do not use periodic key frames. cpi->rc.frames_to_key = INT_MAX; } #define UL_INTRA_THRESH 50 #define INVALID_ROW -1 void vp9_first_pass(VP9_COMP *cpi, const struct lookahead_entry *source) { int mb_row, mb_col; MACROBLOCK *const x = &cpi->td.mb; VP9_COMMON *const cm = &cpi->common; MACROBLOCKD *const xd = &x->e_mbd; TileInfo tile; struct macroblock_plane *const p = x->plane; struct macroblockd_plane *const pd = xd->plane; const PICK_MODE_CONTEXT *ctx = &cpi->td.pc_root->none; int i; int recon_yoffset, recon_uvoffset; int64_t intra_error = 0; int64_t coded_error = 0; int64_t sr_coded_error = 0; int sum_mvr = 0, sum_mvc = 0; int sum_mvr_abs = 0, sum_mvc_abs = 0; int64_t sum_mvrs = 0, sum_mvcs = 0; int mvcount = 0; int intercount = 0; int second_ref_count = 0; const int intrapenalty = INTRA_MODE_PENALTY; double neutral_count; int ul_intra_count = 0; int image_data_start_row = INVALID_ROW; int new_mv_count = 0; int sum_in_vectors = 0; MV lastmv = {0, 0}; TWO_PASS *twopass = &cpi->twopass; const MV zero_mv = {0, 0}; int recon_y_stride, recon_uv_stride, uv_mb_height; YV12_BUFFER_CONFIG *const lst_yv12 = get_ref_frame_buffer(cpi, LAST_FRAME); YV12_BUFFER_CONFIG *gld_yv12 = get_ref_frame_buffer(cpi, GOLDEN_FRAME); YV12_BUFFER_CONFIG *const new_yv12 = get_frame_new_buffer(cm); const YV12_BUFFER_CONFIG *first_ref_buf = lst_yv12; LAYER_CONTEXT *const lc = is_two_pass_svc(cpi) ? &cpi->svc.layer_context[cpi->svc.spatial_layer_id] : NULL; double intra_factor; double brightness_factor; BufferPool *const pool = cm->buffer_pool; // First pass code requires valid last and new frame buffers. assert(new_yv12 != NULL); assert((lc != NULL) || frame_is_intra_only(cm) || (lst_yv12 != NULL)); #if CONFIG_FP_MB_STATS if (cpi->use_fp_mb_stats) { vp9_zero_array(cpi->twopass.frame_mb_stats_buf, cm->initial_mbs); } #endif vp9_clear_system_state(); intra_factor = 0.0; brightness_factor = 0.0; neutral_count = 0.0; set_first_pass_params(cpi); vp9_set_quantizer(cm, find_fp_qindex(cm->bit_depth)); if (lc != NULL) { twopass = &lc->twopass; cpi->lst_fb_idx = cpi->svc.spatial_layer_id; cpi->ref_frame_flags = VP9_LAST_FLAG; if (cpi->svc.number_spatial_layers + cpi->svc.spatial_layer_id < REF_FRAMES) { cpi->gld_fb_idx = cpi->svc.number_spatial_layers + cpi->svc.spatial_layer_id; cpi->ref_frame_flags |= VP9_GOLD_FLAG; cpi->refresh_golden_frame = (lc->current_video_frame_in_layer == 0); } else { cpi->refresh_golden_frame = 0; } if (lc->current_video_frame_in_layer == 0) cpi->ref_frame_flags = 0; vp9_scale_references(cpi); // Use either last frame or alt frame for motion search. if (cpi->ref_frame_flags & VP9_LAST_FLAG) { first_ref_buf = vp9_get_scaled_ref_frame(cpi, LAST_FRAME); if (first_ref_buf == NULL) first_ref_buf = get_ref_frame_buffer(cpi, LAST_FRAME); } if (cpi->ref_frame_flags & VP9_GOLD_FLAG) { gld_yv12 = vp9_get_scaled_ref_frame(cpi, GOLDEN_FRAME); if (gld_yv12 == NULL) { gld_yv12 = get_ref_frame_buffer(cpi, GOLDEN_FRAME); } } else { gld_yv12 = NULL; } set_ref_ptrs(cm, xd, (cpi->ref_frame_flags & VP9_LAST_FLAG) ? LAST_FRAME: NONE, (cpi->ref_frame_flags & VP9_GOLD_FLAG) ? GOLDEN_FRAME : NONE); cpi->Source = vp9_scale_if_required(cm, cpi->un_scaled_source, &cpi->scaled_source); } vp9_setup_block_planes(&x->e_mbd, cm->subsampling_x, cm->subsampling_y); vp9_setup_src_planes(x, cpi->Source, 0, 0); vp9_setup_dst_planes(xd->plane, new_yv12, 0, 0); if (!frame_is_intra_only(cm)) { vp9_setup_pre_planes(xd, 0, first_ref_buf, 0, 0, NULL); } xd->mi = cm->mi_grid_visible; xd->mi[0] = cm->mi; vp9_frame_init_quantizer(cpi); for (i = 0; i < MAX_MB_PLANE; ++i) { p[i].coeff = ctx->coeff_pbuf[i][1]; p[i].qcoeff = ctx->qcoeff_pbuf[i][1]; pd[i].dqcoeff = ctx->dqcoeff_pbuf[i][1]; p[i].eobs = ctx->eobs_pbuf[i][1]; } x->skip_recode = 0; vp9_init_mv_probs(cm); vp9_initialize_rd_consts(cpi); // Tiling is ignored in the first pass. vp9_tile_init(&tile, cm, 0, 0); recon_y_stride = new_yv12->y_stride; recon_uv_stride = new_yv12->uv_stride; uv_mb_height = 16 >> (new_yv12->y_height > new_yv12->uv_height); for (mb_row = 0; mb_row < cm->mb_rows; ++mb_row) { MV best_ref_mv = {0, 0}; // Reset above block coeffs. xd->up_available = (mb_row != 0); recon_yoffset = (mb_row * recon_y_stride * 16); recon_uvoffset = (mb_row * recon_uv_stride * uv_mb_height); // Set up limit values for motion vectors to prevent them extending // outside the UMV borders. x->mv_row_min = -((mb_row * 16) + BORDER_MV_PIXELS_B16); x->mv_row_max = ((cm->mb_rows - 1 - mb_row) * 16) + BORDER_MV_PIXELS_B16; for (mb_col = 0; mb_col < cm->mb_cols; ++mb_col) { int this_error; const int use_dc_pred = (mb_col || mb_row) && (!mb_col || !mb_row); const BLOCK_SIZE bsize = get_bsize(cm, mb_row, mb_col); double log_intra; int level_sample; #if CONFIG_FP_MB_STATS const int mb_index = mb_row * cm->mb_cols + mb_col; #endif vp9_clear_system_state(); xd->plane[0].dst.buf = new_yv12->y_buffer + recon_yoffset; xd->plane[1].dst.buf = new_yv12->u_buffer + recon_uvoffset; xd->plane[2].dst.buf = new_yv12->v_buffer + recon_uvoffset; xd->left_available = (mb_col != 0); xd->mi[0]->mbmi.sb_type = bsize; xd->mi[0]->mbmi.ref_frame[0] = INTRA_FRAME; set_mi_row_col(xd, &tile, mb_row << 1, num_8x8_blocks_high_lookup[bsize], mb_col << 1, num_8x8_blocks_wide_lookup[bsize], cm->mi_rows, cm->mi_cols); // Do intra 16x16 prediction. x->skip_encode = 0; xd->mi[0]->mbmi.mode = DC_PRED; xd->mi[0]->mbmi.tx_size = use_dc_pred ? (bsize >= BLOCK_16X16 ? TX_16X16 : TX_8X8) : TX_4X4; vp9_encode_intra_block_plane(x, bsize, 0); this_error = vpx_get_mb_ss(x->plane[0].src_diff); // Keep a record of blocks that have almost no intra error residual // (i.e. are in effect completely flat and untextured in the intra // domain). In natural videos this is uncommon, but it is much more // common in animations, graphics and screen content, so may be used // as a signal to detect these types of content. if (this_error < UL_INTRA_THRESH) { ++ul_intra_count; } else if ((mb_col > 0) && (image_data_start_row == INVALID_ROW)) { image_data_start_row = mb_row; } #if CONFIG_VP9_HIGHBITDEPTH if (cm->use_highbitdepth) { switch (cm->bit_depth) { case VPX_BITS_8: break; case VPX_BITS_10: this_error >>= 4; break; case VPX_BITS_12: this_error >>= 8; break; default: assert(0 && "cm->bit_depth should be VPX_BITS_8, " "VPX_BITS_10 or VPX_BITS_12"); return; } } #endif // CONFIG_VP9_HIGHBITDEPTH vp9_clear_system_state(); log_intra = log(this_error + 1.0); if (log_intra < 10.0) intra_factor += 1.0 + ((10.0 - log_intra) * 0.05); else intra_factor += 1.0; #if CONFIG_VP9_HIGHBITDEPTH if (cm->use_highbitdepth) level_sample = CONVERT_TO_SHORTPTR(x->plane[0].src.buf)[0]; else level_sample = x->plane[0].src.buf[0]; #else level_sample = x->plane[0].src.buf[0]; #endif if ((level_sample < DARK_THRESH) && (log_intra < 9.0)) brightness_factor += 1.0 + (0.01 * (DARK_THRESH - level_sample)); else brightness_factor += 1.0; // Intrapenalty below deals with situations where the intra and inter // error scores are very low (e.g. a plain black frame). // We do not have special cases in first pass for 0,0 and nearest etc so // all inter modes carry an overhead cost estimate for the mv. // When the error score is very low this causes us to pick all or lots of // INTRA modes and throw lots of key frames. // This penalty adds a cost matching that of a 0,0 mv to the intra case. this_error += intrapenalty; // Accumulate the intra error. intra_error += (int64_t)this_error; #if CONFIG_FP_MB_STATS if (cpi->use_fp_mb_stats) { // initialization cpi->twopass.frame_mb_stats_buf[mb_index] = 0; } #endif // Set up limit values for motion vectors to prevent them extending // outside the UMV borders. x->mv_col_min = -((mb_col * 16) + BORDER_MV_PIXELS_B16); x->mv_col_max = ((cm->mb_cols - 1 - mb_col) * 16) + BORDER_MV_PIXELS_B16; // Other than for the first frame do a motion search. if ((lc == NULL && cm->current_video_frame > 0) || (lc != NULL && lc->current_video_frame_in_layer > 0)) { int tmp_err, motion_error, raw_motion_error; // Assume 0,0 motion with no mv overhead. MV mv = {0, 0} , tmp_mv = {0, 0}; struct buf_2d unscaled_last_source_buf_2d; xd->plane[0].pre[0].buf = first_ref_buf->y_buffer + recon_yoffset; #if CONFIG_VP9_HIGHBITDEPTH if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) { motion_error = highbd_get_prediction_error( bsize, &x->plane[0].src, &xd->plane[0].pre[0], xd->bd); } else { motion_error = get_prediction_error( bsize, &x->plane[0].src, &xd->plane[0].pre[0]); } #else motion_error = get_prediction_error( bsize, &x->plane[0].src, &xd->plane[0].pre[0]); #endif // CONFIG_VP9_HIGHBITDEPTH // Compute the motion error of the 0,0 motion using the last source // frame as the reference. Skip the further motion search on // reconstructed frame if this error is small. unscaled_last_source_buf_2d.buf = cpi->unscaled_last_source->y_buffer + recon_yoffset; unscaled_last_source_buf_2d.stride = cpi->unscaled_last_source->y_stride; #if CONFIG_VP9_HIGHBITDEPTH if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) { raw_motion_error = highbd_get_prediction_error( bsize, &x->plane[0].src, &unscaled_last_source_buf_2d, xd->bd); } else { raw_motion_error = get_prediction_error( bsize, &x->plane[0].src, &unscaled_last_source_buf_2d); } #else raw_motion_error = get_prediction_error( bsize, &x->plane[0].src, &unscaled_last_source_buf_2d); #endif // CONFIG_VP9_HIGHBITDEPTH // TODO(pengchong): Replace the hard-coded threshold if (raw_motion_error > 25 || lc != NULL) { // Test last reference frame using the previous best mv as the // starting point (best reference) for the search. first_pass_motion_search(cpi, x, &best_ref_mv, &mv, &motion_error); // If the current best reference mv is not centered on 0,0 then do a // 0,0 based search as well. if (!is_zero_mv(&best_ref_mv)) { tmp_err = INT_MAX; first_pass_motion_search(cpi, x, &zero_mv, &tmp_mv, &tmp_err); if (tmp_err < motion_error) { motion_error = tmp_err; mv = tmp_mv; } } // Search in an older reference frame. if (((lc == NULL && cm->current_video_frame > 1) || (lc != NULL && lc->current_video_frame_in_layer > 1)) && gld_yv12 != NULL) { // Assume 0,0 motion with no mv overhead. int gf_motion_error; xd->plane[0].pre[0].buf = gld_yv12->y_buffer + recon_yoffset; #if CONFIG_VP9_HIGHBITDEPTH if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) { gf_motion_error = highbd_get_prediction_error( bsize, &x->plane[0].src, &xd->plane[0].pre[0], xd->bd); } else { gf_motion_error = get_prediction_error( bsize, &x->plane[0].src, &xd->plane[0].pre[0]); } #else gf_motion_error = get_prediction_error( bsize, &x->plane[0].src, &xd->plane[0].pre[0]); #endif // CONFIG_VP9_HIGHBITDEPTH first_pass_motion_search(cpi, x, &zero_mv, &tmp_mv, &gf_motion_error); if (gf_motion_error < motion_error && gf_motion_error < this_error) ++second_ref_count; // Reset to last frame as reference buffer. xd->plane[0].pre[0].buf = first_ref_buf->y_buffer + recon_yoffset; xd->plane[1].pre[0].buf = first_ref_buf->u_buffer + recon_uvoffset; xd->plane[2].pre[0].buf = first_ref_buf->v_buffer + recon_uvoffset; // In accumulating a score for the older reference frame take the // best of the motion predicted score and the intra coded error // (just as will be done for) accumulation of "coded_error" for // the last frame. if (gf_motion_error < this_error) sr_coded_error += gf_motion_error; else sr_coded_error += this_error; } else { sr_coded_error += motion_error; } } else { sr_coded_error += motion_error; } // Start by assuming that intra mode is best. best_ref_mv.row = 0; best_ref_mv.col = 0; #if CONFIG_FP_MB_STATS if (cpi->use_fp_mb_stats) { // intra predication statistics cpi->twopass.frame_mb_stats_buf[mb_index] = 0; cpi->twopass.frame_mb_stats_buf[mb_index] |= FPMB_DCINTRA_MASK; cpi->twopass.frame_mb_stats_buf[mb_index] |= FPMB_MOTION_ZERO_MASK; if (this_error > FPMB_ERROR_LARGE_TH) { cpi->twopass.frame_mb_stats_buf[mb_index] |= FPMB_ERROR_LARGE_MASK; } else if (this_error < FPMB_ERROR_SMALL_TH) { cpi->twopass.frame_mb_stats_buf[mb_index] |= FPMB_ERROR_SMALL_MASK; } } #endif if (motion_error <= this_error) { vp9_clear_system_state(); // Keep a count of cases where the inter and intra were very close // and very low. This helps with scene cut detection for example in // cropped clips with black bars at the sides or top and bottom. if (((this_error - intrapenalty) * 9 <= motion_error * 10) && (this_error < (2 * intrapenalty))) { neutral_count += 1.0; // Also track cases where the intra is not much worse than the inter // and use this in limiting the GF/arf group length. } else if ((this_error > NCOUNT_INTRA_THRESH) && (this_error < (NCOUNT_INTRA_FACTOR * motion_error))) { neutral_count += (double)motion_error / DOUBLE_DIVIDE_CHECK((double)this_error); } mv.row *= 8; mv.col *= 8; this_error = motion_error; xd->mi[0]->mbmi.mode = NEWMV; xd->mi[0]->mbmi.mv[0].as_mv = mv; xd->mi[0]->mbmi.tx_size = TX_4X4; xd->mi[0]->mbmi.ref_frame[0] = LAST_FRAME; xd->mi[0]->mbmi.ref_frame[1] = NONE; vp9_build_inter_predictors_sby(xd, mb_row << 1, mb_col << 1, bsize); vp9_encode_sby_pass1(x, bsize); sum_mvr += mv.row; sum_mvr_abs += abs(mv.row); sum_mvc += mv.col; sum_mvc_abs += abs(mv.col); sum_mvrs += mv.row * mv.row; sum_mvcs += mv.col * mv.col; ++intercount; best_ref_mv = mv; #if CONFIG_FP_MB_STATS if (cpi->use_fp_mb_stats) { // inter predication statistics cpi->twopass.frame_mb_stats_buf[mb_index] = 0; cpi->twopass.frame_mb_stats_buf[mb_index] &= ~FPMB_DCINTRA_MASK; cpi->twopass.frame_mb_stats_buf[mb_index] |= FPMB_MOTION_ZERO_MASK; if (this_error > FPMB_ERROR_LARGE_TH) { cpi->twopass.frame_mb_stats_buf[mb_index] |= FPMB_ERROR_LARGE_MASK; } else if (this_error < FPMB_ERROR_SMALL_TH) { cpi->twopass.frame_mb_stats_buf[mb_index] |= FPMB_ERROR_SMALL_MASK; } } #endif if (!is_zero_mv(&mv)) { ++mvcount; #if CONFIG_FP_MB_STATS if (cpi->use_fp_mb_stats) { cpi->twopass.frame_mb_stats_buf[mb_index] &= ~FPMB_MOTION_ZERO_MASK; // check estimated motion direction if (mv.as_mv.col > 0 && mv.as_mv.col >= abs(mv.as_mv.row)) { // right direction cpi->twopass.frame_mb_stats_buf[mb_index] |= FPMB_MOTION_RIGHT_MASK; } else if (mv.as_mv.row < 0 && abs(mv.as_mv.row) >= abs(mv.as_mv.col)) { // up direction cpi->twopass.frame_mb_stats_buf[mb_index] |= FPMB_MOTION_UP_MASK; } else if (mv.as_mv.col < 0 && abs(mv.as_mv.col) >= abs(mv.as_mv.row)) { // left direction cpi->twopass.frame_mb_stats_buf[mb_index] |= FPMB_MOTION_LEFT_MASK; } else { // down direction cpi->twopass.frame_mb_stats_buf[mb_index] |= FPMB_MOTION_DOWN_MASK; } } #endif // Non-zero vector, was it different from the last non zero vector? if (!is_equal_mv(&mv, &lastmv)) ++new_mv_count; lastmv = mv; // Does the row vector point inwards or outwards? if (mb_row < cm->mb_rows / 2) { if (mv.row > 0) --sum_in_vectors; else if (mv.row < 0) ++sum_in_vectors; } else if (mb_row > cm->mb_rows / 2) { if (mv.row > 0) ++sum_in_vectors; else if (mv.row < 0) --sum_in_vectors; } // Does the col vector point inwards or outwards? if (mb_col < cm->mb_cols / 2) { if (mv.col > 0) --sum_in_vectors; else if (mv.col < 0) ++sum_in_vectors; } else if (mb_col > cm->mb_cols / 2) { if (mv.col > 0) ++sum_in_vectors; else if (mv.col < 0) --sum_in_vectors; } } } } else { sr_coded_error += (int64_t)this_error; } coded_error += (int64_t)this_error; // Adjust to the next column of MBs. x->plane[0].src.buf += 16; x->plane[1].src.buf += uv_mb_height; x->plane[2].src.buf += uv_mb_height; recon_yoffset += 16; recon_uvoffset += uv_mb_height; } // Adjust to the next row of MBs. x->plane[0].src.buf += 16 * x->plane[0].src.stride - 16 * cm->mb_cols; x->plane[1].src.buf += uv_mb_height * x->plane[1].src.stride - uv_mb_height * cm->mb_cols; x->plane[2].src.buf += uv_mb_height * x->plane[1].src.stride - uv_mb_height * cm->mb_cols; vp9_clear_system_state(); } // Clamp the image start to rows/2. This number of rows is discarded top // and bottom as dead data so rows / 2 means the frame is blank. if ((image_data_start_row > cm->mb_rows / 2) || (image_data_start_row == INVALID_ROW)) { image_data_start_row = cm->mb_rows / 2; } // Exclude any image dead zone if (image_data_start_row > 0) { ul_intra_count = MAX(0, ul_intra_count - (image_data_start_row * cm->mb_cols * 2)); } { FIRSTPASS_STATS fps; // The minimum error here insures some bit allocation to frames even // in static regions. The allocation per MB declines for larger formats // where the typical "real" energy per MB also falls. // Initial estimate here uses sqrt(mbs) to define the min_err, where the // number of mbs is proportional to the image area. const int num_mbs = (cpi->oxcf.resize_mode != RESIZE_NONE) ? cpi->initial_mbs : cpi->common.MBs; const double min_err = 200 * sqrt(num_mbs); intra_factor = intra_factor / (double)num_mbs; brightness_factor = brightness_factor / (double)num_mbs; fps.weight = intra_factor * brightness_factor; fps.frame = cm->current_video_frame; fps.spatial_layer_id = cpi->svc.spatial_layer_id; fps.coded_error = (double)(coded_error >> 8) + min_err; fps.sr_coded_error = (double)(sr_coded_error >> 8) + min_err; fps.intra_error = (double)(intra_error >> 8) + min_err; fps.count = 1.0; fps.pcnt_inter = (double)intercount / num_mbs; fps.pcnt_second_ref = (double)second_ref_count / num_mbs; fps.pcnt_neutral = (double)neutral_count / num_mbs; fps.ul_intra_pct = (double)ul_intra_count / num_mbs; fps.image_start_row = (double)image_data_start_row; if (mvcount > 0) { fps.MVr = (double)sum_mvr / mvcount; fps.mvr_abs = (double)sum_mvr_abs / mvcount; fps.MVc = (double)sum_mvc / mvcount; fps.mvc_abs = (double)sum_mvc_abs / mvcount; fps.MVrv = ((double)sum_mvrs - (fps.MVr * fps.MVr / mvcount)) / mvcount; fps.MVcv = ((double)sum_mvcs - (fps.MVc * fps.MVc / mvcount)) / mvcount; fps.mv_in_out_count = (double)sum_in_vectors / (mvcount * 2); fps.new_mv_count = new_mv_count; fps.pcnt_motion = (double)mvcount / num_mbs; } else { fps.MVr = 0.0; fps.mvr_abs = 0.0; fps.MVc = 0.0; fps.mvc_abs = 0.0; fps.MVrv = 0.0; fps.MVcv = 0.0; fps.mv_in_out_count = 0.0; fps.new_mv_count = 0.0; fps.pcnt_motion = 0.0; } // TODO(paulwilkins): Handle the case when duration is set to 0, or // something less than the full time between subsequent values of // cpi->source_time_stamp. fps.duration = (double)(source->ts_end - source->ts_start); // Don't want to do output stats with a stack variable! twopass->this_frame_stats = fps; output_stats(&twopass->this_frame_stats, cpi->output_pkt_list); accumulate_stats(&twopass->total_stats, &fps); #if CONFIG_FP_MB_STATS if (cpi->use_fp_mb_stats) { output_fpmb_stats(twopass->frame_mb_stats_buf, cm, cpi->output_pkt_list); } #endif } // Copy the previous Last Frame back into gf and and arf buffers if // the prediction is good enough... but also don't allow it to lag too far. if ((twopass->sr_update_lag > 3) || ((cm->current_video_frame > 0) && (twopass->this_frame_stats.pcnt_inter > 0.20) && ((twopass->this_frame_stats.intra_error / DOUBLE_DIVIDE_CHECK(twopass->this_frame_stats.coded_error)) > 2.0))) { if (gld_yv12 != NULL) { ref_cnt_fb(pool->frame_bufs, &cm->ref_frame_map[cpi->gld_fb_idx], cm->ref_frame_map[cpi->lst_fb_idx]); } twopass->sr_update_lag = 1; } else { ++twopass->sr_update_lag; } vp9_extend_frame_borders(new_yv12); if (lc != NULL) { vp9_update_reference_frames(cpi); } else { // The frame we just compressed now becomes the last frame. ref_cnt_fb(pool->frame_bufs, &cm->ref_frame_map[cpi->lst_fb_idx], cm->new_fb_idx); } // Special case for the first frame. Copy into the GF buffer as a second // reference. if (cm->current_video_frame == 0 && cpi->gld_fb_idx != INVALID_IDX && lc == NULL) { ref_cnt_fb(pool->frame_bufs, &cm->ref_frame_map[cpi->gld_fb_idx], cm->ref_frame_map[cpi->lst_fb_idx]); } // Use this to see what the first pass reconstruction looks like. if (0) { char filename[512]; FILE *recon_file; snprintf(filename, sizeof(filename), "enc%04d.yuv", (int)cm->current_video_frame); if (cm->current_video_frame == 0) recon_file = fopen(filename, "wb"); else recon_file = fopen(filename, "ab"); (void)fwrite(lst_yv12->buffer_alloc, lst_yv12->frame_size, 1, recon_file); fclose(recon_file); } ++cm->current_video_frame; if (cpi->use_svc) vp9_inc_frame_in_layer(cpi); } static double calc_correction_factor(double err_per_mb, double err_divisor, double pt_low, double pt_high, int q, vpx_bit_depth_t bit_depth) { const double error_term = err_per_mb / err_divisor; // Adjustment based on actual quantizer to power term. const double power_term = MIN(vp9_convert_qindex_to_q(q, bit_depth) * 0.01 + pt_low, pt_high); // Calculate correction factor. if (power_term < 1.0) assert(error_term >= 0.0); return fclamp(pow(error_term, power_term), 0.05, 5.0); } // Larger image formats are expected to be a little harder to code relatively // given the same prediction error score. This in part at least relates to the // increased size and hence coding cost of motion vectors. #define EDIV_SIZE_FACTOR 800 static int get_twopass_worst_quality(const VP9_COMP *cpi, const double section_err, int section_target_bandwidth, double group_weight_factor) { const RATE_CONTROL *const rc = &cpi->rc; const VP9EncoderConfig *const oxcf = &cpi->oxcf; if (section_target_bandwidth <= 0) { return rc->worst_quality; // Highest value allowed } else { const int num_mbs = (cpi->oxcf.resize_mode != RESIZE_NONE) ? cpi->initial_mbs : cpi->common.MBs; const double err_per_mb = section_err / num_mbs; const double speed_term = 1.0 + 0.04 * oxcf->speed; const double ediv_size_correction = num_mbs / EDIV_SIZE_FACTOR; const int target_norm_bits_per_mb = ((uint64_t)section_target_bandwidth << BPER_MB_NORMBITS) / num_mbs; int q; int is_svc_upper_layer = 0; if (is_two_pass_svc(cpi) && cpi->svc.spatial_layer_id > 0) is_svc_upper_layer = 1; // Try and pick a max Q that will be high enough to encode the // content at the given rate. for (q = rc->best_quality; q < rc->worst_quality; ++q) { const double factor = calc_correction_factor(err_per_mb, ERR_DIVISOR - ediv_size_correction, is_svc_upper_layer ? SVC_FACTOR_PT_LOW : FACTOR_PT_LOW, FACTOR_PT_HIGH, q, cpi->common.bit_depth); const int bits_per_mb = vp9_rc_bits_per_mb(INTER_FRAME, q, factor * speed_term * group_weight_factor, cpi->common.bit_depth); if (bits_per_mb <= target_norm_bits_per_mb) break; } // Restriction on active max q for constrained quality mode. if (cpi->oxcf.rc_mode == VPX_CQ) q = MAX(q, oxcf->cq_level); return q; } } static void setup_rf_level_maxq(VP9_COMP *cpi) { int i; RATE_CONTROL *const rc = &cpi->rc; for (i = INTER_NORMAL; i < RATE_FACTOR_LEVELS; ++i) { int qdelta = vp9_frame_type_qdelta(cpi, i, rc->worst_quality); rc->rf_level_maxq[i] = MAX(rc->worst_quality + qdelta, rc->best_quality); } } void vp9_init_subsampling(VP9_COMP *cpi) { const VP9_COMMON *const cm = &cpi->common; RATE_CONTROL *const rc = &cpi->rc; const int w = cm->width; const int h = cm->height; int i; for (i = 0; i < FRAME_SCALE_STEPS; ++i) { // Note: Frames with odd-sized dimensions may result from this scaling. rc->frame_width[i] = (w * 16) / frame_scale_factor[i]; rc->frame_height[i] = (h * 16) / frame_scale_factor[i]; } setup_rf_level_maxq(cpi); } void calculate_coded_size(VP9_COMP *cpi, int *scaled_frame_width, int *scaled_frame_height) { RATE_CONTROL *const rc = &cpi->rc; *scaled_frame_width = rc->frame_width[rc->frame_size_selector]; *scaled_frame_height = rc->frame_height[rc->frame_size_selector]; } void vp9_init_second_pass(VP9_COMP *cpi) { SVC *const svc = &cpi->svc; const VP9EncoderConfig *const oxcf = &cpi->oxcf; const int is_two_pass_svc = (svc->number_spatial_layers > 1) || (svc->number_temporal_layers > 1); TWO_PASS *const twopass = is_two_pass_svc ? &svc->layer_context[svc->spatial_layer_id].twopass : &cpi->twopass; double frame_rate; FIRSTPASS_STATS *stats; zero_stats(&twopass->total_stats); zero_stats(&twopass->total_left_stats); if (!twopass->stats_in_end) return; stats = &twopass->total_stats; *stats = *twopass->stats_in_end; twopass->total_left_stats = *stats; frame_rate = 10000000.0 * stats->count / stats->duration; // Each frame can have a different duration, as the frame rate in the source // isn't guaranteed to be constant. The frame rate prior to the first frame // encoded in the second pass is a guess. However, the sum duration is not. // It is calculated based on the actual durations of all frames from the // first pass. if (is_two_pass_svc) { vp9_update_spatial_layer_framerate(cpi, frame_rate); twopass->bits_left = (int64_t)(stats->duration * svc->layer_context[svc->spatial_layer_id].target_bandwidth / 10000000.0); } else { vp9_new_framerate(cpi, frame_rate); twopass->bits_left = (int64_t)(stats->duration * oxcf->target_bandwidth / 10000000.0); } // This variable monitors how far behind the second ref update is lagging. twopass->sr_update_lag = 1; // Scan the first pass file and calculate a modified total error based upon // the bias/power function used to allocate bits. { const double avg_error = stats->coded_error / DOUBLE_DIVIDE_CHECK(stats->count); const FIRSTPASS_STATS *s = twopass->stats_in; double modified_error_total = 0.0; twopass->modified_error_min = (avg_error * oxcf->two_pass_vbrmin_section) / 100; twopass->modified_error_max = (avg_error * oxcf->two_pass_vbrmax_section) / 100; while (s < twopass->stats_in_end) { modified_error_total += calculate_modified_err(twopass, oxcf, s); ++s; } twopass->modified_error_left = modified_error_total; } // Reset the vbr bits off target counters cpi->rc.vbr_bits_off_target = 0; cpi->rc.vbr_bits_off_target_fast = 0; cpi->rc.rate_error_estimate = 0; // Static sequence monitor variables. twopass->kf_zeromotion_pct = 100; twopass->last_kfgroup_zeromotion_pct = 100; if (oxcf->resize_mode != RESIZE_NONE) { vp9_init_subsampling(cpi); } } #define SR_DIFF_PART 0.0015 #define MOTION_AMP_PART 0.003 #define INTRA_PART 0.005 #define DEFAULT_DECAY_LIMIT 0.75 #define LOW_SR_DIFF_TRHESH 0.1 #define SR_DIFF_MAX 128.0 static double get_sr_decay_rate(const VP9_COMP *cpi, const FIRSTPASS_STATS *frame) { const int num_mbs = (cpi->oxcf.resize_mode != RESIZE_NONE) ? cpi->initial_mbs : cpi->common.MBs; double sr_diff = (frame->sr_coded_error - frame->coded_error) / num_mbs; double sr_decay = 1.0; double modified_pct_inter; double modified_pcnt_intra; const double motion_amplitude_factor = frame->pcnt_motion * ((frame->mvc_abs + frame->mvr_abs) / 2); modified_pct_inter = frame->pcnt_inter; if ((frame->intra_error / DOUBLE_DIVIDE_CHECK(frame->coded_error)) < (double)NCOUNT_FRAME_II_THRESH) { modified_pct_inter = frame->pcnt_inter - frame->pcnt_neutral; } modified_pcnt_intra = 100 * (1.0 - modified_pct_inter); if ((sr_diff > LOW_SR_DIFF_TRHESH)) { sr_diff = MIN(sr_diff, SR_DIFF_MAX); sr_decay = 1.0 - (SR_DIFF_PART * sr_diff) - (MOTION_AMP_PART * motion_amplitude_factor) - (INTRA_PART * modified_pcnt_intra); } return MAX(sr_decay, MIN(DEFAULT_DECAY_LIMIT, modified_pct_inter)); } // This function gives an estimate of how badly we believe the prediction // quality is decaying from frame to frame. static double get_zero_motion_factor(const VP9_COMP *cpi, const FIRSTPASS_STATS *frame) { const double zero_motion_pct = frame->pcnt_inter - frame->pcnt_motion; double sr_decay = get_sr_decay_rate(cpi, frame); return MIN(sr_decay, zero_motion_pct); } #define ZM_POWER_FACTOR 0.75 static double get_prediction_decay_rate(const VP9_COMP *cpi, const FIRSTPASS_STATS *next_frame) { const double sr_decay_rate = get_sr_decay_rate(cpi, next_frame); const double zero_motion_factor = (0.95 * pow((next_frame->pcnt_inter - next_frame->pcnt_motion), ZM_POWER_FACTOR)); return MAX(zero_motion_factor, (sr_decay_rate + ((1.0 - sr_decay_rate) * zero_motion_factor))); } // Function to test for a condition where a complex transition is followed // by a static section. For example in slide shows where there is a fade // between slides. This is to help with more optimal kf and gf positioning. static int detect_transition_to_still(VP9_COMP *cpi, int frame_interval, int still_interval, double loop_decay_rate, double last_decay_rate) { TWO_PASS *const twopass = &cpi->twopass; RATE_CONTROL *const rc = &cpi->rc; // Break clause to detect very still sections after motion // For example a static image after a fade or other transition // instead of a clean scene cut. if (frame_interval > rc->min_gf_interval && loop_decay_rate >= 0.999 && last_decay_rate < 0.9) { int j; // Look ahead a few frames to see if static condition persists... for (j = 0; j < still_interval; ++j) { const FIRSTPASS_STATS *stats = &twopass->stats_in[j]; if (stats >= twopass->stats_in_end) break; if (stats->pcnt_inter - stats->pcnt_motion < 0.999) break; } // Only if it does do we signal a transition to still. return j == still_interval; } return 0; } // This function detects a flash through the high relative pcnt_second_ref // score in the frame following a flash frame. The offset passed in should // reflect this. static int detect_flash(const TWO_PASS *twopass, int offset) { const FIRSTPASS_STATS *const next_frame = read_frame_stats(twopass, offset); // What we are looking for here is a situation where there is a // brief break in prediction (such as a flash) but subsequent frames // are reasonably well predicted by an earlier (pre flash) frame. // The recovery after a flash is indicated by a high pcnt_second_ref // compared to pcnt_inter. return next_frame != NULL && next_frame->pcnt_second_ref > next_frame->pcnt_inter && next_frame->pcnt_second_ref >= 0.5; } // Update the motion related elements to the GF arf boost calculation. static void accumulate_frame_motion_stats(const FIRSTPASS_STATS *stats, double *mv_in_out, double *mv_in_out_accumulator, double *abs_mv_in_out_accumulator, double *mv_ratio_accumulator) { const double pct = stats->pcnt_motion; // Accumulate Motion In/Out of frame stats. *mv_in_out = stats->mv_in_out_count * pct; *mv_in_out_accumulator += *mv_in_out; *abs_mv_in_out_accumulator += fabs(*mv_in_out); // Accumulate a measure of how uniform (or conversely how random) the motion // field is (a ratio of abs(mv) / mv). if (pct > 0.05) { const double mvr_ratio = fabs(stats->mvr_abs) / DOUBLE_DIVIDE_CHECK(fabs(stats->MVr)); const double mvc_ratio = fabs(stats->mvc_abs) / DOUBLE_DIVIDE_CHECK(fabs(stats->MVc)); *mv_ratio_accumulator += pct * (mvr_ratio < stats->mvr_abs ? mvr_ratio : stats->mvr_abs); *mv_ratio_accumulator += pct * (mvc_ratio < stats->mvc_abs ? mvc_ratio : stats->mvc_abs); } } #define BASELINE_ERR_PER_MB 1000.0 static double calc_frame_boost(VP9_COMP *cpi, const FIRSTPASS_STATS *this_frame, double this_frame_mv_in_out, double max_boost) { double frame_boost; const double lq = vp9_convert_qindex_to_q(cpi->rc.avg_frame_qindex[INTER_FRAME], cpi->common.bit_depth); const double boost_q_correction = MIN((0.5 + (lq * 0.015)), 1.5); const int num_mbs = (cpi->oxcf.resize_mode != RESIZE_NONE) ? cpi->initial_mbs : cpi->common.MBs; // Underlying boost factor is based on inter error ratio. frame_boost = (BASELINE_ERR_PER_MB * num_mbs) / DOUBLE_DIVIDE_CHECK(this_frame->coded_error); frame_boost = frame_boost * BOOST_FACTOR * boost_q_correction; // Increase boost for frames where new data coming into frame (e.g. zoom out). // Slightly reduce boost if there is a net balance of motion out of the frame // (zoom in). The range for this_frame_mv_in_out is -1.0 to +1.0. if (this_frame_mv_in_out > 0.0) frame_boost += frame_boost * (this_frame_mv_in_out * 2.0); // In the extreme case the boost is halved. else frame_boost += frame_boost * (this_frame_mv_in_out / 2.0); return MIN(frame_boost, max_boost * boost_q_correction); } static int calc_arf_boost(VP9_COMP *cpi, int offset, int f_frames, int b_frames, int *f_boost, int *b_boost) { TWO_PASS *const twopass = &cpi->twopass; int i; double boost_score = 0.0; double mv_ratio_accumulator = 0.0; double decay_accumulator = 1.0; double this_frame_mv_in_out = 0.0; double mv_in_out_accumulator = 0.0; double abs_mv_in_out_accumulator = 0.0; int arf_boost; int flash_detected = 0; // Search forward from the proposed arf/next gf position. for (i = 0; i < f_frames; ++i) { const FIRSTPASS_STATS *this_frame = read_frame_stats(twopass, i + offset); if (this_frame == NULL) break; // Update the motion related elements to the boost calculation. accumulate_frame_motion_stats(this_frame, &this_frame_mv_in_out, &mv_in_out_accumulator, &abs_mv_in_out_accumulator, &mv_ratio_accumulator); // We want to discount the flash frame itself and the recovery // frame that follows as both will have poor scores. flash_detected = detect_flash(twopass, i + offset) || detect_flash(twopass, i + offset + 1); // Accumulate the effect of prediction quality decay. if (!flash_detected) { decay_accumulator *= get_prediction_decay_rate(cpi, this_frame); decay_accumulator = decay_accumulator < MIN_DECAY_FACTOR ? MIN_DECAY_FACTOR : decay_accumulator; } boost_score += decay_accumulator * calc_frame_boost(cpi, this_frame, this_frame_mv_in_out, GF_MAX_BOOST); } *f_boost = (int)boost_score; // Reset for backward looking loop. boost_score = 0.0; mv_ratio_accumulator = 0.0; decay_accumulator = 1.0; this_frame_mv_in_out = 0.0; mv_in_out_accumulator = 0.0; abs_mv_in_out_accumulator = 0.0; // Search backward towards last gf position. for (i = -1; i >= -b_frames; --i) { const FIRSTPASS_STATS *this_frame = read_frame_stats(twopass, i + offset); if (this_frame == NULL) break; // Update the motion related elements to the boost calculation. accumulate_frame_motion_stats(this_frame, &this_frame_mv_in_out, &mv_in_out_accumulator, &abs_mv_in_out_accumulator, &mv_ratio_accumulator); // We want to discount the the flash frame itself and the recovery // frame that follows as both will have poor scores. flash_detected = detect_flash(twopass, i + offset) || detect_flash(twopass, i + offset + 1); // Cumulative effect of prediction quality decay. if (!flash_detected) { decay_accumulator *= get_prediction_decay_rate(cpi, this_frame); decay_accumulator = decay_accumulator < MIN_DECAY_FACTOR ? MIN_DECAY_FACTOR : decay_accumulator; } boost_score += decay_accumulator * calc_frame_boost(cpi, this_frame, this_frame_mv_in_out, GF_MAX_BOOST); } *b_boost = (int)boost_score; arf_boost = (*f_boost + *b_boost); if (arf_boost < ((b_frames + f_frames) * 20)) arf_boost = ((b_frames + f_frames) * 20); arf_boost = MAX(arf_boost, MIN_ARF_GF_BOOST); return arf_boost; } // Calculate a section intra ratio used in setting max loop filter. static int calculate_section_intra_ratio(const FIRSTPASS_STATS *begin, const FIRSTPASS_STATS *end, int section_length) { const FIRSTPASS_STATS *s = begin; double intra_error = 0.0; double coded_error = 0.0; int i = 0; while (s < end && i < section_length) { intra_error += s->intra_error; coded_error += s->coded_error; ++s; ++i; } return (int)(intra_error / DOUBLE_DIVIDE_CHECK(coded_error)); } // Calculate the total bits to allocate in this GF/ARF group. static int64_t calculate_total_gf_group_bits(VP9_COMP *cpi, double gf_group_err) { const RATE_CONTROL *const rc = &cpi->rc; const TWO_PASS *const twopass = &cpi->twopass; const int max_bits = frame_max_bits(rc, &cpi->oxcf); int64_t total_group_bits; // Calculate the bits to be allocated to the group as a whole. if ((twopass->kf_group_bits > 0) && (twopass->kf_group_error_left > 0)) { total_group_bits = (int64_t)(twopass->kf_group_bits * (gf_group_err / twopass->kf_group_error_left)); } else { total_group_bits = 0; } // Clamp odd edge cases. total_group_bits = (total_group_bits < 0) ? 0 : (total_group_bits > twopass->kf_group_bits) ? twopass->kf_group_bits : total_group_bits; // Clip based on user supplied data rate variability limit. if (total_group_bits > (int64_t)max_bits * rc->baseline_gf_interval) total_group_bits = (int64_t)max_bits * rc->baseline_gf_interval; return total_group_bits; } // Calculate the number bits extra to assign to boosted frames in a group. static int calculate_boost_bits(int frame_count, int boost, int64_t total_group_bits) { int allocation_chunks; // return 0 for invalid inputs (could arise e.g. through rounding errors) if (!boost || (total_group_bits <= 0) || (frame_count <= 0) ) return 0; allocation_chunks = (frame_count * 100) + boost; // Prevent overflow. if (boost > 1023) { int divisor = boost >> 10; boost /= divisor; allocation_chunks /= divisor; } // Calculate the number of extra bits for use in the boosted frame or frames. return MAX((int)(((int64_t)boost * total_group_bits) / allocation_chunks), 0); } // Current limit on maximum number of active arfs in a GF/ARF group. #define MAX_ACTIVE_ARFS 2 #define ARF_SLOT1 2 #define ARF_SLOT2 3 // This function indirects the choice of buffers for arfs. // At the moment the values are fixed but this may change as part of // the integration process with other codec features that swap buffers around. static void get_arf_buffer_indices(unsigned char *arf_buffer_indices) { arf_buffer_indices[0] = ARF_SLOT1; arf_buffer_indices[1] = ARF_SLOT2; } static void allocate_gf_group_bits(VP9_COMP *cpi, int64_t gf_group_bits, double group_error, int gf_arf_bits) { RATE_CONTROL *const rc = &cpi->rc; const VP9EncoderConfig *const oxcf = &cpi->oxcf; TWO_PASS *const twopass = &cpi->twopass; GF_GROUP *const gf_group = &twopass->gf_group; FIRSTPASS_STATS frame_stats; int i; int frame_index = 1; int target_frame_size; int key_frame; const int max_bits = frame_max_bits(&cpi->rc, &cpi->oxcf); int64_t total_group_bits = gf_group_bits; double modified_err = 0.0; double err_fraction; int mid_boost_bits = 0; int mid_frame_idx; unsigned char arf_buffer_indices[MAX_ACTIVE_ARFS]; int alt_frame_index = frame_index; int has_temporal_layers = is_two_pass_svc(cpi) && cpi->svc.number_temporal_layers > 1; // Only encode alt reference frame in temporal base layer. if (has_temporal_layers) alt_frame_index = cpi->svc.number_temporal_layers; key_frame = cpi->common.frame_type == KEY_FRAME || vp9_is_upper_layer_key_frame(cpi); get_arf_buffer_indices(arf_buffer_indices); // For key frames the frame target rate is already set and it // is also the golden frame. if (!key_frame) { if (rc->source_alt_ref_active) { gf_group->update_type[0] = OVERLAY_UPDATE; gf_group->rf_level[0] = INTER_NORMAL; gf_group->bit_allocation[0] = 0; gf_group->arf_update_idx[0] = arf_buffer_indices[0]; gf_group->arf_ref_idx[0] = arf_buffer_indices[0]; } else { gf_group->update_type[0] = GF_UPDATE; gf_group->rf_level[0] = GF_ARF_STD; gf_group->bit_allocation[0] = gf_arf_bits; gf_group->arf_update_idx[0] = arf_buffer_indices[0]; gf_group->arf_ref_idx[0] = arf_buffer_indices[0]; } // Step over the golden frame / overlay frame if (EOF == input_stats(twopass, &frame_stats)) return; } // Deduct the boost bits for arf (or gf if it is not a key frame) // from the group total. if (rc->source_alt_ref_pending || !key_frame) total_group_bits -= gf_arf_bits; // Store the bits to spend on the ARF if there is one. if (rc->source_alt_ref_pending) { gf_group->update_type[alt_frame_index] = ARF_UPDATE; gf_group->rf_level[alt_frame_index] = GF_ARF_STD; gf_group->bit_allocation[alt_frame_index] = gf_arf_bits; if (has_temporal_layers) gf_group->arf_src_offset[alt_frame_index] = (unsigned char)(rc->baseline_gf_interval - cpi->svc.number_temporal_layers); else gf_group->arf_src_offset[alt_frame_index] = (unsigned char)(rc->baseline_gf_interval - 1); gf_group->arf_update_idx[alt_frame_index] = arf_buffer_indices[0]; gf_group->arf_ref_idx[alt_frame_index] = arf_buffer_indices[cpi->multi_arf_last_grp_enabled && rc->source_alt_ref_active]; if (!has_temporal_layers) ++frame_index; if (cpi->multi_arf_enabled) { // Set aside a slot for a level 1 arf. gf_group->update_type[frame_index] = ARF_UPDATE; gf_group->rf_level[frame_index] = GF_ARF_LOW; gf_group->arf_src_offset[frame_index] = (unsigned char)((rc->baseline_gf_interval >> 1) - 1); gf_group->arf_update_idx[frame_index] = arf_buffer_indices[1]; gf_group->arf_ref_idx[frame_index] = arf_buffer_indices[0]; ++frame_index; } } // Define middle frame mid_frame_idx = frame_index + (rc->baseline_gf_interval >> 1) - 1; // Allocate bits to the other frames in the group. for (i = 0; i < rc->baseline_gf_interval - rc->source_alt_ref_pending; ++i) { int arf_idx = 0; if (EOF == input_stats(twopass, &frame_stats)) break; if (has_temporal_layers && frame_index == alt_frame_index) { ++frame_index; } modified_err = calculate_modified_err(twopass, oxcf, &frame_stats); if (group_error > 0) err_fraction = modified_err / DOUBLE_DIVIDE_CHECK(group_error); else err_fraction = 0.0; target_frame_size = (int)((double)total_group_bits * err_fraction); if (rc->source_alt_ref_pending && cpi->multi_arf_enabled) { mid_boost_bits += (target_frame_size >> 4); target_frame_size -= (target_frame_size >> 4); if (frame_index <= mid_frame_idx) arf_idx = 1; } gf_group->arf_update_idx[frame_index] = arf_buffer_indices[arf_idx]; gf_group->arf_ref_idx[frame_index] = arf_buffer_indices[arf_idx]; target_frame_size = clamp(target_frame_size, 0, MIN(max_bits, (int)total_group_bits)); gf_group->update_type[frame_index] = LF_UPDATE; gf_group->rf_level[frame_index] = INTER_NORMAL; gf_group->bit_allocation[frame_index] = target_frame_size; ++frame_index; } // Note: // We need to configure the frame at the end of the sequence + 1 that will be // the start frame for the next group. Otherwise prior to the call to // vp9_rc_get_second_pass_params() the data will be undefined. gf_group->arf_update_idx[frame_index] = arf_buffer_indices[0]; gf_group->arf_ref_idx[frame_index] = arf_buffer_indices[0]; if (rc->source_alt_ref_pending) { gf_group->update_type[frame_index] = OVERLAY_UPDATE; gf_group->rf_level[frame_index] = INTER_NORMAL; // Final setup for second arf and its overlay. if (cpi->multi_arf_enabled) { gf_group->bit_allocation[2] = gf_group->bit_allocation[mid_frame_idx] + mid_boost_bits; gf_group->update_type[mid_frame_idx] = OVERLAY_UPDATE; gf_group->bit_allocation[mid_frame_idx] = 0; } } else { gf_group->update_type[frame_index] = GF_UPDATE; gf_group->rf_level[frame_index] = GF_ARF_STD; } // Note whether multi-arf was enabled this group for next time. cpi->multi_arf_last_grp_enabled = cpi->multi_arf_enabled; } // Analyse and define a gf/arf group. static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) { VP9_COMMON *const cm = &cpi->common; RATE_CONTROL *const rc = &cpi->rc; VP9EncoderConfig *const oxcf = &cpi->oxcf; TWO_PASS *const twopass = &cpi->twopass; FIRSTPASS_STATS next_frame; const FIRSTPASS_STATS *const start_pos = twopass->stats_in; int i; double boost_score = 0.0; double old_boost_score = 0.0; double gf_group_err = 0.0; #if GROUP_ADAPTIVE_MAXQ double gf_group_raw_error = 0.0; #endif double gf_first_frame_err = 0.0; double mod_frame_err = 0.0; double mv_ratio_accumulator = 0.0; double decay_accumulator = 1.0; double zero_motion_accumulator = 1.0; double loop_decay_rate = 1.00; double last_loop_decay_rate = 1.00; double this_frame_mv_in_out = 0.0; double mv_in_out_accumulator = 0.0; double abs_mv_in_out_accumulator = 0.0; double mv_ratio_accumulator_thresh; unsigned int allow_alt_ref = is_altref_enabled(cpi); int f_boost = 0; int b_boost = 0; int flash_detected; int active_max_gf_interval; int active_min_gf_interval; int64_t gf_group_bits; double gf_group_error_left; int gf_arf_bits; int is_key_frame = frame_is_intra_only(cm); // Reset the GF group data structures unless this is a key // frame in which case it will already have been done. if (is_key_frame == 0) { vp9_zero(twopass->gf_group); } vp9_clear_system_state(); vp9_zero(next_frame); // Load stats for the current frame. mod_frame_err = calculate_modified_err(twopass, oxcf, this_frame); // Note the error of the frame at the start of the group. This will be // the GF frame error if we code a normal gf. gf_first_frame_err = mod_frame_err; // If this is a key frame or the overlay from a previous arf then // the error score / cost of this frame has already been accounted for. if (is_key_frame || rc->source_alt_ref_active) { gf_group_err -= gf_first_frame_err; #if GROUP_ADAPTIVE_MAXQ gf_group_raw_error -= this_frame->coded_error; #endif } // Motion breakout threshold for loop below depends on image size. mv_ratio_accumulator_thresh = (cpi->initial_height + cpi->initial_width) / 4.0; // Set a maximum and minimum interval for the GF group. // If the image appears almost completely static we can extend beyond this. { int int_max_q = (int)(vp9_convert_qindex_to_q(twopass->active_worst_quality, cpi->common.bit_depth)); int int_lbq = (int)(vp9_convert_qindex_to_q(rc->last_boosted_qindex, cpi->common.bit_depth)); active_min_gf_interval = rc->min_gf_interval + MIN(2, int_max_q / 200); if (active_min_gf_interval > rc->max_gf_interval) active_min_gf_interval = rc->max_gf_interval; if (cpi->multi_arf_allowed) { active_max_gf_interval = rc->max_gf_interval; } else { // The value chosen depends on the active Q range. At low Q we have // bits to spare and are better with a smaller interval and smaller boost. // At high Q when there are few bits to spare we are better with a longer // interval to spread the cost of the GF. active_max_gf_interval = 12 + MIN(4, (int_lbq / 6)); if (active_max_gf_interval > rc->max_gf_interval) active_max_gf_interval = rc->max_gf_interval; if (active_max_gf_interval < active_min_gf_interval) active_max_gf_interval = active_min_gf_interval; } } i = 0; while (i < rc->static_scene_max_gf_interval && i < rc->frames_to_key) { ++i; // Accumulate error score of frames in this gf group. mod_frame_err = calculate_modified_err(twopass, oxcf, this_frame); gf_group_err += mod_frame_err; #if GROUP_ADAPTIVE_MAXQ gf_group_raw_error += this_frame->coded_error; #endif if (EOF == input_stats(twopass, &next_frame)) break; // Test for the case where there is a brief flash but the prediction // quality back to an earlier frame is then restored. flash_detected = detect_flash(twopass, 0); // Update the motion related elements to the boost calculation. accumulate_frame_motion_stats(&next_frame, &this_frame_mv_in_out, &mv_in_out_accumulator, &abs_mv_in_out_accumulator, &mv_ratio_accumulator); // Accumulate the effect of prediction quality decay. if (!flash_detected) { last_loop_decay_rate = loop_decay_rate; loop_decay_rate = get_prediction_decay_rate(cpi, &next_frame); decay_accumulator = decay_accumulator * loop_decay_rate; // Monitor for static sections. zero_motion_accumulator = MIN(zero_motion_accumulator, get_zero_motion_factor(cpi, &next_frame)); // Break clause to detect very still sections after motion. For example, // a static image after a fade or other transition. if (detect_transition_to_still(cpi, i, 5, loop_decay_rate, last_loop_decay_rate)) { allow_alt_ref = 0; break; } } // Calculate a boost number for this frame. boost_score += decay_accumulator * calc_frame_boost(cpi, &next_frame, this_frame_mv_in_out, GF_MAX_BOOST); // Break out conditions. if ( // Break at active_max_gf_interval unless almost totally static. (i >= active_max_gf_interval && (zero_motion_accumulator < 0.995)) || ( // Don't break out with a very short interval. (i > active_min_gf_interval) && (!flash_detected) && ((mv_ratio_accumulator > mv_ratio_accumulator_thresh) || (abs_mv_in_out_accumulator > 3.0) || (mv_in_out_accumulator < -2.0) || ((boost_score - old_boost_score) < BOOST_BREAKOUT)))) { boost_score = old_boost_score; break; } *this_frame = next_frame; old_boost_score = boost_score; } twopass->gf_zeromotion_pct = (int)(zero_motion_accumulator * 1000.0); // Was the group length constrained by the requirement for a new KF? rc->constrained_gf_group = (i >= rc->frames_to_key) ? 1 : 0; // Should we use the alternate reference frame. if (allow_alt_ref && (i < cpi->oxcf.lag_in_frames) && (i >= rc->min_gf_interval)) { // Calculate the boost for alt ref. rc->gfu_boost = calc_arf_boost(cpi, 0, (i - 1), (i - 1), &f_boost, &b_boost); rc->source_alt_ref_pending = 1; // Test to see if multi arf is appropriate. cpi->multi_arf_enabled = (cpi->multi_arf_allowed && (rc->baseline_gf_interval >= 6) && (zero_motion_accumulator < 0.995)) ? 1 : 0; } else { rc->gfu_boost = MAX((int)boost_score, MIN_ARF_GF_BOOST); rc->source_alt_ref_pending = 0; } // Set the interval until the next gf. if (is_key_frame || rc->source_alt_ref_pending) rc->baseline_gf_interval = i - 1; else rc->baseline_gf_interval = i; // Only encode alt reference frame in temporal base layer. So // baseline_gf_interval should be multiple of a temporal layer group // (typically the frame distance between two base layer frames) if (is_two_pass_svc(cpi) && cpi->svc.number_temporal_layers > 1) { int count = (1 << (cpi->svc.number_temporal_layers - 1)) - 1; int new_gf_interval = (rc->baseline_gf_interval + count) & (~count); int j; for (j = 0; j < new_gf_interval - rc->baseline_gf_interval; ++j) { if (EOF == input_stats(twopass, this_frame)) break; gf_group_err += calculate_modified_err(twopass, oxcf, this_frame); #if GROUP_ADAPTIVE_MAXQ gf_group_raw_error += this_frame->coded_error; #endif } rc->baseline_gf_interval = new_gf_interval; } rc->frames_till_gf_update_due = rc->baseline_gf_interval; // Reset the file position. reset_fpf_position(twopass, start_pos); // Calculate the bits to be allocated to the gf/arf group as a whole gf_group_bits = calculate_total_gf_group_bits(cpi, gf_group_err); #if GROUP_ADAPTIVE_MAXQ // Calculate an estimate of the maxq needed for the group. // We are more agressive about correcting for sections // where there could be significant overshoot than for easier // sections where we do not wish to risk creating an overshoot // of the allocated bit budget. if ((cpi->oxcf.rc_mode != VPX_Q) && (rc->baseline_gf_interval > 1)) { const int vbr_group_bits_per_frame = (int)(gf_group_bits / rc->baseline_gf_interval); const double group_av_err = gf_group_raw_error / rc->baseline_gf_interval; int tmp_q; // rc factor is a weight factor that corrects for local rate control drift. double rc_factor = 1.0; if (rc->rate_error_estimate > 0) { rc_factor = MAX(RC_FACTOR_MIN, (double)(100 - rc->rate_error_estimate) / 100.0); } else { rc_factor = MIN(RC_FACTOR_MAX, (double)(100 - rc->rate_error_estimate) / 100.0); } tmp_q = get_twopass_worst_quality(cpi, group_av_err, vbr_group_bits_per_frame, twopass->kfgroup_inter_fraction * rc_factor); twopass->active_worst_quality = MAX(tmp_q, twopass->active_worst_quality >> 1); } #endif // Calculate the extra bits to be used for boosted frame(s) gf_arf_bits = calculate_boost_bits(rc->baseline_gf_interval, rc->gfu_boost, gf_group_bits); // Adjust KF group bits and error remaining. twopass->kf_group_error_left -= (int64_t)gf_group_err; // If this is an arf update we want to remove the score for the overlay // frame at the end which will usually be very cheap to code. // The overlay frame has already, in effect, been coded so we want to spread // the remaining bits among the other frames. // For normal GFs remove the score for the GF itself unless this is // also a key frame in which case it has already been accounted for. if (rc->source_alt_ref_pending) { gf_group_error_left = gf_group_err - mod_frame_err; } else if (is_key_frame == 0) { gf_group_error_left = gf_group_err - gf_first_frame_err; } else { gf_group_error_left = gf_group_err; } // Allocate bits to each of the frames in the GF group. allocate_gf_group_bits(cpi, gf_group_bits, gf_group_error_left, gf_arf_bits); // Reset the file position. reset_fpf_position(twopass, start_pos); // Calculate a section intra ratio used in setting max loop filter. if (cpi->common.frame_type != KEY_FRAME) { twopass->section_intra_rating = calculate_section_intra_ratio(start_pos, twopass->stats_in_end, rc->baseline_gf_interval); } if (oxcf->resize_mode == RESIZE_DYNAMIC) { // Default to starting GF groups at normal frame size. cpi->rc.next_frame_size_selector = UNSCALED; } } // Threshold for use of the lagging second reference frame. High second ref // usage may point to a transient event like a flash or occlusion rather than // a real scene cut. #define SECOND_REF_USEAGE_THRESH 0.1 // Minimum % intra coding observed in first pass (1.0 = 100%) #define MIN_INTRA_LEVEL 0.25 // Minimum ratio between the % of intra coding and inter coding in the first // pass after discounting neutral blocks (discounting neutral blocks in this // way helps catch scene cuts in clips with very flat areas or letter box // format clips with image padding. #define INTRA_VS_INTER_THRESH 2.0 // Hard threshold where the first pass chooses intra for almost all blocks. // In such a case even if the frame is not a scene cut coding a key frame // may be a good option. #define VERY_LOW_INTER_THRESH 0.05 // Maximum threshold for the relative ratio of intra error score vs best // inter error score. #define KF_II_ERR_THRESHOLD 2.5 // In real scene cuts there is almost always a sharp change in the intra // or inter error score. #define ERR_CHANGE_THRESHOLD 0.4 // For real scene cuts we expect an improvment in the intra inter error // ratio in the next frame. #define II_IMPROVEMENT_THRESHOLD 3.5 #define KF_II_MAX 128.0 static int test_candidate_kf(TWO_PASS *twopass, const FIRSTPASS_STATS *last_frame, const FIRSTPASS_STATS *this_frame, const FIRSTPASS_STATS *next_frame) { int is_viable_kf = 0; double pcnt_intra = 1.0 - this_frame->pcnt_inter; double modified_pcnt_inter = this_frame->pcnt_inter - this_frame->pcnt_neutral; // Does the frame satisfy the primary criteria of a key frame? // See above for an explanation of the test criteria. // If so, then examine how well it predicts subsequent frames. if ((this_frame->pcnt_second_ref < SECOND_REF_USEAGE_THRESH) && (next_frame->pcnt_second_ref < SECOND_REF_USEAGE_THRESH) && ((this_frame->pcnt_inter < VERY_LOW_INTER_THRESH) || ((pcnt_intra > MIN_INTRA_LEVEL) && (pcnt_intra > (INTRA_VS_INTER_THRESH * modified_pcnt_inter)) && ((this_frame->intra_error / DOUBLE_DIVIDE_CHECK(this_frame->coded_error)) < KF_II_ERR_THRESHOLD) && ((fabs(last_frame->coded_error - this_frame->coded_error) / DOUBLE_DIVIDE_CHECK(this_frame->coded_error) > ERR_CHANGE_THRESHOLD) || (fabs(last_frame->intra_error - this_frame->intra_error) / DOUBLE_DIVIDE_CHECK(this_frame->intra_error) > ERR_CHANGE_THRESHOLD) || ((next_frame->intra_error / DOUBLE_DIVIDE_CHECK(next_frame->coded_error)) > II_IMPROVEMENT_THRESHOLD))))) { int i; const FIRSTPASS_STATS *start_pos = twopass->stats_in; FIRSTPASS_STATS local_next_frame = *next_frame; double boost_score = 0.0; double old_boost_score = 0.0; double decay_accumulator = 1.0; // Examine how well the key frame predicts subsequent frames. for (i = 0; i < 16; ++i) { double next_iiratio = (BOOST_FACTOR * local_next_frame.intra_error / DOUBLE_DIVIDE_CHECK(local_next_frame.coded_error)); if (next_iiratio > KF_II_MAX) next_iiratio = KF_II_MAX; // Cumulative effect of decay in prediction quality. if (local_next_frame.pcnt_inter > 0.85) decay_accumulator *= local_next_frame.pcnt_inter; else decay_accumulator *= (0.85 + local_next_frame.pcnt_inter) / 2.0; // Keep a running total. boost_score += (decay_accumulator * next_iiratio); // Test various breakout clauses. if ((local_next_frame.pcnt_inter < 0.05) || (next_iiratio < 1.5) || (((local_next_frame.pcnt_inter - local_next_frame.pcnt_neutral) < 0.20) && (next_iiratio < 3.0)) || ((boost_score - old_boost_score) < 3.0) || (local_next_frame.intra_error < 200)) { break; } old_boost_score = boost_score; // Get the next frame details if (EOF == input_stats(twopass, &local_next_frame)) break; } // If there is tolerable prediction for at least the next 3 frames then // break out else discard this potential key frame and move on if (boost_score > 30.0 && (i > 3)) { is_viable_kf = 1; } else { // Reset the file position reset_fpf_position(twopass, start_pos); is_viable_kf = 0; } } return is_viable_kf; } static void find_next_key_frame(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) { int i, j; RATE_CONTROL *const rc = &cpi->rc; TWO_PASS *const twopass = &cpi->twopass; GF_GROUP *const gf_group = &twopass->gf_group; const VP9EncoderConfig *const oxcf = &cpi->oxcf; const FIRSTPASS_STATS first_frame = *this_frame; const FIRSTPASS_STATS *const start_position = twopass->stats_in; FIRSTPASS_STATS next_frame; FIRSTPASS_STATS last_frame; int kf_bits = 0; int loop_decay_counter = 0; double decay_accumulator = 1.0; double av_decay_accumulator = 0.0; double zero_motion_accumulator = 1.0; double boost_score = 0.0; double kf_mod_err = 0.0; double kf_group_err = 0.0; double recent_loop_decay[8] = {1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0}; vp9_zero(next_frame); cpi->common.frame_type = KEY_FRAME; // Reset the GF group data structures. vp9_zero(*gf_group); // Is this a forced key frame by interval. rc->this_key_frame_forced = rc->next_key_frame_forced; // Clear the alt ref active flag and last group multi arf flags as they // can never be set for a key frame. rc->source_alt_ref_active = 0; cpi->multi_arf_last_grp_enabled = 0; // KF is always a GF so clear frames till next gf counter. rc->frames_till_gf_update_due = 0; rc->frames_to_key = 1; twopass->kf_group_bits = 0; // Total bits available to kf group twopass->kf_group_error_left = 0; // Group modified error score. kf_mod_err = calculate_modified_err(twopass, oxcf, this_frame); // Find the next keyframe. i = 0; while (twopass->stats_in < twopass->stats_in_end && rc->frames_to_key < cpi->oxcf.key_freq) { // Accumulate kf group error. kf_group_err += calculate_modified_err(twopass, oxcf, this_frame); // Load the next frame's stats. last_frame = *this_frame; input_stats(twopass, this_frame); // Provided that we are not at the end of the file... if (cpi->oxcf.auto_key && twopass->stats_in < twopass->stats_in_end) { double loop_decay_rate; // Check for a scene cut. if (test_candidate_kf(twopass, &last_frame, this_frame, twopass->stats_in)) break; // How fast is the prediction quality decaying? loop_decay_rate = get_prediction_decay_rate(cpi, twopass->stats_in); // We want to know something about the recent past... rather than // as used elsewhere where we are concerned with decay in prediction // quality since the last GF or KF. recent_loop_decay[i % 8] = loop_decay_rate; decay_accumulator = 1.0; for (j = 0; j < 8; ++j) decay_accumulator *= recent_loop_decay[j]; // Special check for transition or high motion followed by a // static scene. if (detect_transition_to_still(cpi, i, cpi->oxcf.key_freq - i, loop_decay_rate, decay_accumulator)) break; // Step on to the next frame. ++rc->frames_to_key; // If we don't have a real key frame within the next two // key_freq intervals then break out of the loop. if (rc->frames_to_key >= 2 * cpi->oxcf.key_freq) break; } else { ++rc->frames_to_key; } ++i; } // If there is a max kf interval set by the user we must obey it. // We already breakout of the loop above at 2x max. // This code centers the extra kf if the actual natural interval // is between 1x and 2x. if (cpi->oxcf.auto_key && rc->frames_to_key > cpi->oxcf.key_freq) { FIRSTPASS_STATS tmp_frame = first_frame; rc->frames_to_key /= 2; // Reset to the start of the group. reset_fpf_position(twopass, start_position); kf_group_err = 0.0; // Rescan to get the correct error data for the forced kf group. for (i = 0; i < rc->frames_to_key; ++i) { kf_group_err += calculate_modified_err(twopass, oxcf, &tmp_frame); input_stats(twopass, &tmp_frame); } rc->next_key_frame_forced = 1; } else if (twopass->stats_in == twopass->stats_in_end || rc->frames_to_key >= cpi->oxcf.key_freq) { rc->next_key_frame_forced = 1; } else { rc->next_key_frame_forced = 0; } if (is_two_pass_svc(cpi) && cpi->svc.number_temporal_layers > 1) { int count = (1 << (cpi->svc.number_temporal_layers - 1)) - 1; int new_frame_to_key = (rc->frames_to_key + count) & (~count); int j; for (j = 0; j < new_frame_to_key - rc->frames_to_key; ++j) { if (EOF == input_stats(twopass, this_frame)) break; kf_group_err += calculate_modified_err(twopass, oxcf, this_frame); } rc->frames_to_key = new_frame_to_key; } // Special case for the last key frame of the file. if (twopass->stats_in >= twopass->stats_in_end) { // Accumulate kf group error. kf_group_err += calculate_modified_err(twopass, oxcf, this_frame); } // Calculate the number of bits that should be assigned to the kf group. if (twopass->bits_left > 0 && twopass->modified_error_left > 0.0) { // Maximum number of bits for a single normal frame (not key frame). const int max_bits = frame_max_bits(rc, &cpi->oxcf); // Maximum number of bits allocated to the key frame group. int64_t max_grp_bits; // Default allocation based on bits left and relative // complexity of the section. twopass->kf_group_bits = (int64_t)(twopass->bits_left * (kf_group_err / twopass->modified_error_left)); // Clip based on maximum per frame rate defined by the user. max_grp_bits = (int64_t)max_bits * (int64_t)rc->frames_to_key; if (twopass->kf_group_bits > max_grp_bits) twopass->kf_group_bits = max_grp_bits; } else { twopass->kf_group_bits = 0; } twopass->kf_group_bits = MAX(0, twopass->kf_group_bits); // Reset the first pass file position. reset_fpf_position(twopass, start_position); // Scan through the kf group collating various stats used to determine // how many bits to spend on it. decay_accumulator = 1.0; boost_score = 0.0; for (i = 0; i < (rc->frames_to_key - 1); ++i) { if (EOF == input_stats(twopass, &next_frame)) break; // Monitor for static sections. zero_motion_accumulator = MIN(zero_motion_accumulator, get_zero_motion_factor(cpi, &next_frame)); // Not all frames in the group are necessarily used in calculating boost. if ((i <= rc->max_gf_interval) || ((i <= (rc->max_gf_interval * 4)) && (decay_accumulator > 0.5))) { const double frame_boost = calc_frame_boost(cpi, this_frame, 0, KF_MAX_BOOST); // How fast is prediction quality decaying. if (!detect_flash(twopass, 0)) { const double loop_decay_rate = get_prediction_decay_rate(cpi, &next_frame); decay_accumulator *= loop_decay_rate; decay_accumulator = MAX(decay_accumulator, MIN_DECAY_FACTOR); av_decay_accumulator += decay_accumulator; ++loop_decay_counter; } boost_score += (decay_accumulator * frame_boost); } } av_decay_accumulator /= (double)loop_decay_counter; reset_fpf_position(twopass, start_position); // Store the zero motion percentage twopass->kf_zeromotion_pct = (int)(zero_motion_accumulator * 100.0); // Calculate a section intra ratio used in setting max loop filter. twopass->section_intra_rating = calculate_section_intra_ratio(start_position, twopass->stats_in_end, rc->frames_to_key); // Apply various clamps for min and max boost rc->kf_boost = (int)(av_decay_accumulator * boost_score); rc->kf_boost = MAX(rc->kf_boost, (rc->frames_to_key * 3)); rc->kf_boost = MAX(rc->kf_boost, MIN_KF_BOOST); // Work out how many bits to allocate for the key frame itself. kf_bits = calculate_boost_bits((rc->frames_to_key - 1), rc->kf_boost, twopass->kf_group_bits); // Work out the fraction of the kf group bits reserved for the inter frames // within the group after discounting the bits for the kf itself. if (twopass->kf_group_bits) { twopass->kfgroup_inter_fraction = (double)(twopass->kf_group_bits - kf_bits) / (double)twopass->kf_group_bits; } else { twopass->kfgroup_inter_fraction = 1.0; } twopass->kf_group_bits -= kf_bits; // Save the bits to spend on the key frame. gf_group->bit_allocation[0] = kf_bits; gf_group->update_type[0] = KF_UPDATE; gf_group->rf_level[0] = KF_STD; // Note the total error score of the kf group minus the key frame itself. twopass->kf_group_error_left = (int)(kf_group_err - kf_mod_err); // Adjust the count of total modified error left. // The count of bits left is adjusted elsewhere based on real coded frame // sizes. twopass->modified_error_left -= kf_group_err; if (oxcf->resize_mode == RESIZE_DYNAMIC) { // Default to normal-sized frame on keyframes. cpi->rc.next_frame_size_selector = UNSCALED; } } // Define the reference buffers that will be updated post encode. static void configure_buffer_updates(VP9_COMP *cpi) { TWO_PASS *const twopass = &cpi->twopass; cpi->rc.is_src_frame_alt_ref = 0; switch (twopass->gf_group.update_type[twopass->gf_group.index]) { case KF_UPDATE: cpi->refresh_last_frame = 1; cpi->refresh_golden_frame = 1; cpi->refresh_alt_ref_frame = 1; break; case LF_UPDATE: cpi->refresh_last_frame = 1; cpi->refresh_golden_frame = 0; cpi->refresh_alt_ref_frame = 0; break; case GF_UPDATE: cpi->refresh_last_frame = 1; cpi->refresh_golden_frame = 1; cpi->refresh_alt_ref_frame = 0; break; case OVERLAY_UPDATE: cpi->refresh_last_frame = 0; cpi->refresh_golden_frame = 1; cpi->refresh_alt_ref_frame = 0; cpi->rc.is_src_frame_alt_ref = 1; break; case ARF_UPDATE: cpi->refresh_last_frame = 0; cpi->refresh_golden_frame = 0; cpi->refresh_alt_ref_frame = 1; break; default: assert(0); break; } if (is_two_pass_svc(cpi)) { if (cpi->svc.temporal_layer_id > 0) { cpi->refresh_last_frame = 0; cpi->refresh_golden_frame = 0; } if (cpi->svc.layer_context[cpi->svc.spatial_layer_id].gold_ref_idx < 0) cpi->refresh_golden_frame = 0; if (cpi->alt_ref_source == NULL) cpi->refresh_alt_ref_frame = 0; } } static int is_skippable_frame(const VP9_COMP *cpi) { // If the current frame does not have non-zero motion vector detected in the // first pass, and so do its previous and forward frames, then this frame // can be skipped for partition check, and the partition size is assigned // according to the variance const SVC *const svc = &cpi->svc; const TWO_PASS *const twopass = is_two_pass_svc(cpi) ? &svc->layer_context[svc->spatial_layer_id].twopass : &cpi->twopass; return (!frame_is_intra_only(&cpi->common) && twopass->stats_in - 2 > twopass->stats_in_start && twopass->stats_in < twopass->stats_in_end && (twopass->stats_in - 1)->pcnt_inter - (twopass->stats_in - 1)->pcnt_motion == 1 && (twopass->stats_in - 2)->pcnt_inter - (twopass->stats_in - 2)->pcnt_motion == 1 && twopass->stats_in->pcnt_inter - twopass->stats_in->pcnt_motion == 1); } void vp9_rc_get_second_pass_params(VP9_COMP *cpi) { VP9_COMMON *const cm = &cpi->common; RATE_CONTROL *const rc = &cpi->rc; TWO_PASS *const twopass = &cpi->twopass; GF_GROUP *const gf_group = &twopass->gf_group; int frames_left; FIRSTPASS_STATS this_frame; int target_rate; LAYER_CONTEXT *const lc = is_two_pass_svc(cpi) ? &cpi->svc.layer_context[cpi->svc.spatial_layer_id] : 0; if (lc != NULL) { frames_left = (int)(twopass->total_stats.count - lc->current_video_frame_in_layer); } else { frames_left = (int)(twopass->total_stats.count - cm->current_video_frame); } if (!twopass->stats_in) return; // If this is an arf frame then we dont want to read the stats file or // advance the input pointer as we already have what we need. if (gf_group->update_type[gf_group->index] == ARF_UPDATE) { int target_rate; configure_buffer_updates(cpi); target_rate = gf_group->bit_allocation[gf_group->index]; target_rate = vp9_rc_clamp_pframe_target_size(cpi, target_rate); rc->base_frame_target = target_rate; cm->frame_type = INTER_FRAME; if (lc != NULL) { if (cpi->svc.spatial_layer_id == 0) { lc->is_key_frame = 0; } else { lc->is_key_frame = cpi->svc.layer_context[0].is_key_frame; if (lc->is_key_frame) cpi->ref_frame_flags &= (~VP9_LAST_FLAG); } } // Do the firstpass stats indicate that this frame is skippable for the // partition search? if (cpi->sf.allow_partition_search_skip && cpi->oxcf.pass == 2 && (!cpi->use_svc || is_two_pass_svc(cpi))) { cpi->partition_search_skippable_frame = is_skippable_frame(cpi); } return; } vp9_clear_system_state(); if (cpi->oxcf.rc_mode == VPX_Q) { twopass->active_worst_quality = cpi->oxcf.cq_level; } else if (cm->current_video_frame == 0 || (lc != NULL && lc->current_video_frame_in_layer == 0)) { // Special case code for first frame. const int section_target_bandwidth = (int)(twopass->bits_left / frames_left); const double section_error = twopass->total_left_stats.coded_error / twopass->total_left_stats.count; const int tmp_q = get_twopass_worst_quality(cpi, section_error, section_target_bandwidth, DEFAULT_GRP_WEIGHT); twopass->active_worst_quality = tmp_q; twopass->baseline_active_worst_quality = tmp_q; rc->ni_av_qi = tmp_q; rc->last_q[INTER_FRAME] = tmp_q; rc->avg_q = vp9_convert_qindex_to_q(tmp_q, cm->bit_depth); rc->avg_frame_qindex[INTER_FRAME] = tmp_q; rc->last_q[KEY_FRAME] = (tmp_q + cpi->oxcf.best_allowed_q) / 2; rc->avg_frame_qindex[KEY_FRAME] = rc->last_q[KEY_FRAME]; } vp9_zero(this_frame); if (EOF == input_stats(twopass, &this_frame)) return; // Keyframe and section processing. if (rc->frames_to_key == 0 || (cpi->frame_flags & FRAMEFLAGS_KEY)) { FIRSTPASS_STATS this_frame_copy; this_frame_copy = this_frame; // Define next KF group and assign bits to it. find_next_key_frame(cpi, &this_frame); this_frame = this_frame_copy; } else { cm->frame_type = INTER_FRAME; } if (lc != NULL) { if (cpi->svc.spatial_layer_id == 0) { lc->is_key_frame = (cm->frame_type == KEY_FRAME); if (lc->is_key_frame) { cpi->ref_frame_flags &= (~VP9_LAST_FLAG & ~VP9_GOLD_FLAG & ~VP9_ALT_FLAG); lc->frames_from_key_frame = 0; // Encode an intra only empty frame since we have a key frame. cpi->svc.encode_intra_empty_frame = 1; } } else { cm->frame_type = INTER_FRAME; lc->is_key_frame = cpi->svc.layer_context[0].is_key_frame; if (lc->is_key_frame) { cpi->ref_frame_flags &= (~VP9_LAST_FLAG); lc->frames_from_key_frame = 0; } } } // Define a new GF/ARF group. (Should always enter here for key frames). if (rc->frames_till_gf_update_due == 0) { define_gf_group(cpi, &this_frame); rc->frames_till_gf_update_due = rc->baseline_gf_interval; if (lc != NULL) cpi->refresh_golden_frame = 1; #if ARF_STATS_OUTPUT { FILE *fpfile; fpfile = fopen("arf.stt", "a"); ++arf_count; fprintf(fpfile, "%10d %10ld %10d %10d %10ld\n", cm->current_video_frame, rc->frames_till_gf_update_due, rc->kf_boost, arf_count, rc->gfu_boost); fclose(fpfile); } #endif } configure_buffer_updates(cpi); // Do the firstpass stats indicate that this frame is skippable for the // partition search? if (cpi->sf.allow_partition_search_skip && cpi->oxcf.pass == 2 && (!cpi->use_svc || is_two_pass_svc(cpi))) { cpi->partition_search_skippable_frame = is_skippable_frame(cpi); } target_rate = gf_group->bit_allocation[gf_group->index]; if (cpi->common.frame_type == KEY_FRAME) target_rate = vp9_rc_clamp_iframe_target_size(cpi, target_rate); else target_rate = vp9_rc_clamp_pframe_target_size(cpi, target_rate); rc->base_frame_target = target_rate; { const int num_mbs = (cpi->oxcf.resize_mode != RESIZE_NONE) ? cpi->initial_mbs : cpi->common.MBs; // The multiplication by 256 reverses a scaling factor of (>> 8) // applied when combining MB error values for the frame. twopass->mb_av_energy = log(((this_frame.intra_error * 256.0) / num_mbs) + 1.0); } // Update the total stats remaining structure. subtract_stats(&twopass->total_left_stats, &this_frame); } #define MINQ_ADJ_LIMIT 48 #define MINQ_ADJ_LIMIT_CQ 20 #define HIGH_UNDERSHOOT_RATIO 2 void vp9_twopass_postencode_update(VP9_COMP *cpi) { TWO_PASS *const twopass = &cpi->twopass; RATE_CONTROL *const rc = &cpi->rc; const int bits_used = rc->base_frame_target; // VBR correction is done through rc->vbr_bits_off_target. Based on the // sign of this value, a limited % adjustment is made to the target rate // of subsequent frames, to try and push it back towards 0. This method // is designed to prevent extreme behaviour at the end of a clip // or group of frames. rc->vbr_bits_off_target += rc->base_frame_target - rc->projected_frame_size; twopass->bits_left = MAX(twopass->bits_left - bits_used, 0); // Calculate the pct rc error. if (rc->total_actual_bits) { rc->rate_error_estimate = (int)((rc->vbr_bits_off_target * 100) / rc->total_actual_bits); rc->rate_error_estimate = clamp(rc->rate_error_estimate, -100, 100); } else { rc->rate_error_estimate = 0; } if (cpi->common.frame_type != KEY_FRAME && !vp9_is_upper_layer_key_frame(cpi)) { twopass->kf_group_bits -= bits_used; twopass->last_kfgroup_zeromotion_pct = twopass->kf_zeromotion_pct; } twopass->kf_group_bits = MAX(twopass->kf_group_bits, 0); // Increment the gf group index ready for the next frame. ++twopass->gf_group.index; // If the rate control is drifting consider adjustment to min or maxq. if ((cpi->oxcf.rc_mode != VPX_Q) && (cpi->twopass.gf_zeromotion_pct < VLOW_MOTION_THRESHOLD) && !cpi->rc.is_src_frame_alt_ref) { const int maxq_adj_limit = rc->worst_quality - twopass->active_worst_quality; const int minq_adj_limit = (cpi->oxcf.rc_mode == VPX_CQ ? MINQ_ADJ_LIMIT_CQ : MINQ_ADJ_LIMIT); // Undershoot. if (rc->rate_error_estimate > cpi->oxcf.under_shoot_pct) { --twopass->extend_maxq; if (rc->rolling_target_bits >= rc->rolling_actual_bits) ++twopass->extend_minq; // Overshoot. } else if (rc->rate_error_estimate < -cpi->oxcf.over_shoot_pct) { --twopass->extend_minq; if (rc->rolling_target_bits < rc->rolling_actual_bits) ++twopass->extend_maxq; } else { // Adjustment for extreme local overshoot. if (rc->projected_frame_size > (2 * rc->base_frame_target) && rc->projected_frame_size > (2 * rc->avg_frame_bandwidth)) ++twopass->extend_maxq; // Unwind undershoot or overshoot adjustment. if (rc->rolling_target_bits < rc->rolling_actual_bits) --twopass->extend_minq; else if (rc->rolling_target_bits > rc->rolling_actual_bits) --twopass->extend_maxq; } twopass->extend_minq = clamp(twopass->extend_minq, 0, minq_adj_limit); twopass->extend_maxq = clamp(twopass->extend_maxq, 0, maxq_adj_limit); // If there is a big and undexpected undershoot then feed the extra // bits back in quickly. One situation where this may happen is if a // frame is unexpectedly almost perfectly predicted by the ARF or GF // but not very well predcited by the previous frame. if (!frame_is_kf_gf_arf(cpi) && !cpi->rc.is_src_frame_alt_ref) { int fast_extra_thresh = rc->base_frame_target / HIGH_UNDERSHOOT_RATIO; if (rc->projected_frame_size < fast_extra_thresh) { rc->vbr_bits_off_target_fast += fast_extra_thresh - rc->projected_frame_size; rc->vbr_bits_off_target_fast = MIN(rc->vbr_bits_off_target_fast, (4 * rc->avg_frame_bandwidth)); // Fast adaptation of minQ if necessary to use up the extra bits. if (rc->avg_frame_bandwidth) { twopass->extend_minq_fast = (int)(rc->vbr_bits_off_target_fast * 8 / rc->avg_frame_bandwidth); } twopass->extend_minq_fast = MIN(twopass->extend_minq_fast, minq_adj_limit - twopass->extend_minq); } else if (rc->vbr_bits_off_target_fast) { twopass->extend_minq_fast = MIN(twopass->extend_minq_fast, minq_adj_limit - twopass->extend_minq); } else { twopass->extend_minq_fast = 0; } } } }