Replacing BWDREFs with ARFs (for GF=4 only) The two types of backward reference frames (BWDREF and ARF) have different reference buffer update rules. This patch trys to unify the update rules by replacing BWDREFs with ARFs in the most simple case i.e. GF=4. Change-Id: I65dd4a5be8709ba4b60b43495674a7455ac72f95
diff --git a/av1/encoder/firstpass.c b/av1/encoder/firstpass.c index e569df3..4e303dc 100644 --- a/av1/encoder/firstpass.c +++ b/av1/encoder/firstpass.c
@@ -2130,6 +2130,161 @@ } #endif // USE_GF16_MULTI_LAYER +#if USE_SYMM_MULTI_LAYER +#define GF_INTERVAL_4 4 +#define GF_FRAME_PARAMS 4 + +static const unsigned char gf4_multi_layer_params[][GF_FRAME_PARAMS] = { + { + // gf_group->index == 0 (Frame 0) + // It can also be KEY frame. Will assign the proper value + // in define_gf_group_structure + OVERLAY_UPDATE, // update_type (default value) + 0, // arf_src_offset + 0, // brf_src_offset + 0 // arf_update_idx + }, + { + // gf_group->index == 1 (Frame 4) + ARF_UPDATE, // update_type + GF_INTERVAL_4 - 1, // arf_src_offset + 0, // brf_src_offset + 0 // arf_update_idx + }, + { + // gf_group->index == 2 (Frame 2) + INTNL_ARF_UPDATE, // update_type + (GF_INTERVAL_4 >> 1) - 1, // arf_src_offset + 0, // brf_src_offset + 0 // arf_update_idx + }, + { + // gf_group->index == 3 (Frame 1) + LF_UPDATE, // update_type + 0, // arf_src_offset + 0, // brf_src_offset + 0 // arf_update_idx + }, + + { + // gf_group->index == 4 (Frame 2 - OVERLAY) + INTNL_OVERLAY_UPDATE, // update_type + 0, // arf_src_offset + 0, // brf_src_offset + 0 // arf_update_idx + }, + { + // gf_group->index == 5 (Frame 3) + LF_UPDATE, // update_type + 0, // arf_src_offset + 0, // brf_src_offset + 1 // arf_update_idx + } +}; + +static int update_type_2_rf_level(FRAME_UPDATE_TYPE update_type) { + // Derive rf_level from update_type + switch (update_type) { + case LF_UPDATE: return INTER_NORMAL; + case ARF_UPDATE: return GF_ARF_STD; + case OVERLAY_UPDATE: return INTER_NORMAL; + case BRF_UPDATE: return GF_ARF_LOW; + case LAST_BIPRED_UPDATE: return INTER_NORMAL; + case BIPRED_UPDATE: return INTER_NORMAL; + case INTNL_ARF_UPDATE: return GF_ARF_LOW; + case INTNL_OVERLAY_UPDATE: return INTER_NORMAL; + default: return INTER_NORMAL; + } +} + +static void gf4_arf_position_handling(AV1_COMP *cpi) { + cpi->arf_pos_for_ovrly[0] = 6; + cpi->arf_pos_for_ovrly[1] = 4; + + cpi->arf_pos_in_gf[0] = 1; + cpi->arf_pos_in_gf[1] = 2; +} + +static int define_gf_group_structure_4(AV1_COMP *cpi) { + RATE_CONTROL *const rc = &cpi->rc; + TWO_PASS *const twopass = &cpi->twopass; + GF_GROUP *const gf_group = &twopass->gf_group; + const int key_frame = cpi->common.frame_type == KEY_FRAME; + + assert(rc->baseline_gf_interval == GF_INTERVAL_4); + + const int gf_update_frames = rc->baseline_gf_interval + 2; + int frame_index; + + for (frame_index = 0; frame_index < gf_update_frames; ++frame_index) { + int param_idx = 0; + + gf_group->bidir_pred_enabled[frame_index] = 0; + + if (frame_index == 0) { + // gf_group->arf_src_offset[frame_index] = 0; + gf_group->brf_src_offset[frame_index] = 0; + gf_group->bidir_pred_enabled[frame_index] = 0; + + // For key frames the frame target rate is already set and it + // is also the golden frame. + if (key_frame) continue; + + gf_group->update_type[frame_index] = + gf4_multi_layer_params[frame_index][param_idx++]; + + if (rc->source_alt_ref_active) { + gf_group->update_type[frame_index] = OVERLAY_UPDATE; + } else { + gf_group->update_type[frame_index] = GF_UPDATE; + } + param_idx++; + } else { + gf_group->update_type[frame_index] = + gf4_multi_layer_params[frame_index][param_idx++]; + } + + // setup other parameters + gf_group->rf_level[frame_index] = + update_type_2_rf_level(gf_group->update_type[frame_index]); + + // == arf_src_offset == + gf_group->arf_src_offset[frame_index] = + gf4_multi_layer_params[frame_index][param_idx++]; + + // == brf_src_offset == + gf_group->brf_src_offset[frame_index] = + gf4_multi_layer_params[frame_index][param_idx++]; + + // == arf_update_idx == + gf_group->brf_src_offset[frame_index] = + gf4_multi_layer_params[frame_index][param_idx]; + } + + // 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 av1_rc_get_second_pass_params() the data will be undefined. + gf_group->arf_update_idx[frame_index] = 0; + gf_group->arf_ref_idx[frame_index] = 0; + + if (rc->source_alt_ref_pending) { + gf_group->update_type[frame_index] = OVERLAY_UPDATE; + gf_group->rf_level[frame_index] = INTER_NORMAL; + + } else { + gf_group->update_type[frame_index] = GF_UPDATE; + gf_group->rf_level[frame_index] = GF_ARF_STD; + } + + gf_group->bidir_pred_enabled[frame_index] = 0; + gf_group->brf_src_offset[frame_index] = 0; + + gf4_arf_position_handling(cpi); + + return gf_update_frames; +} +#endif // USE_SYMM_MULTI_LAYER + static void define_gf_group_structure(AV1_COMP *cpi) { RATE_CONTROL *const rc = &cpi->rc; @@ -2139,6 +2294,14 @@ return; } #endif // USE_GF16_MULTI_LAYER +#if USE_SYMM_MULTI_LAYER + if (rc->baseline_gf_interval == 4 && rc->source_alt_ref_pending && + cpi->extra_arf_allowed > 0) { + // used only if arf is allowed + define_gf_group_structure_4(cpi); + return; + } +#endif TWO_PASS *const twopass = &cpi->twopass; GF_GROUP *const gf_group = &twopass->gf_group; @@ -2728,9 +2891,17 @@ if (!cpi->extra_arf_allowed) { cpi->num_extra_arfs = 0; } else { +#if USE_SYMM_MULTI_LAYER + if (rc->baseline_gf_interval == 4 && rc->source_alt_ref_pending) + cpi->num_extra_arfs = 1; + else + cpi->num_extra_arfs = get_number_of_extra_arfs( + rc->baseline_gf_interval, rc->source_alt_ref_pending); +#else // Compute how many extra alt_refs we can have cpi->num_extra_arfs = get_number_of_extra_arfs(rc->baseline_gf_interval, rc->source_alt_ref_pending); +#endif // USE_SYMM_MULTI_LAYER } // Currently at maximum two extra ARFs' are allowed assert(cpi->num_extra_arfs <= MAX_EXT_ARFS);
diff --git a/av1/encoder/ratectrl.h b/av1/encoder/ratectrl.h index 14bac07..604f5cb 100644 --- a/av1/encoder/ratectrl.h +++ b/av1/encoder/ratectrl.h
@@ -29,6 +29,9 @@ #if FIX_GF_INTERVAL_LENGTH #define FIXED_GF_LENGTH 4 +#define USE_SYMM_MULTI_LAYER 1 +#else +#define USE_SYMM_MULTI_LAYER 0 #endif #define MIN_GF_INTERVAL 4