Abstract dc block prediction code to own function
Change-Id: Id068a30761fe6fd1be4f3013ff3dfbd50ba74129
diff --git a/av1/encoder/encodemb.h b/av1/encoder/encodemb.h
index cdf7318..fcd34a3 100644
--- a/av1/encoder/encodemb.h
+++ b/av1/encoder/encodemb.h
@@ -157,8 +157,13 @@
return true;
}
-// Scaling terms (precision of 12 bits) to obtain DC coefficient from block
-// residual mean
+// Scaling terms (precision of 12 bits) to perform tx-size specific
+// normalization that is used in DCT_DCT forward transform.
+// For transform blocks of 1:2 and 2:1 - sqrt(2) normalization is used
+// For transform blocks of 1:4 and 4:1 - factor of 2 is used
+// For transform blocks TX_8x8 and below - an additional factor of 2 is used
+// For transform blocks max(width,height)=64 - currently not supported
+
static const uint16_t dc_coeff_scale[TX_SIZES_ALL] = {
1024, 2048, 4096, 4096, 0, 1448, 1448, 2896, 2896, 2896,
2896, 0, 0, 2048, 2048, 4096, 4096, 0, 0
diff --git a/av1/encoder/tx_search.c b/av1/encoder/tx_search.c
index 258b44c..82100d1 100644
--- a/av1/encoder/tx_search.c
+++ b/av1/encoder/tx_search.c
@@ -2161,6 +2161,67 @@
return skip_block_trellis;
}
+// Predict DC only blocks if the residual variance is below a qstep based
+// threshold.For such blocks, transform type search is bypassed.
+static INLINE void predict_dc_only_block(
+ MACROBLOCK *x, int plane, BLOCK_SIZE plane_bsize, TX_SIZE tx_size,
+ int block, int blk_row, int blk_col, RD_STATS *best_rd_stats,
+ int64_t *block_sse, unsigned int *block_mse_q8, int64_t *per_px_mean,
+ int *dc_only_blk) {
+ MACROBLOCKD *xd = &x->e_mbd;
+ MB_MODE_INFO *mbmi = xd->mi[0];
+ const int dequant_shift = (is_cur_buf_hbd(xd)) ? xd->bd - 5 : 3;
+ const int qstep = x->plane[plane].dequant_QTX[1] >> dequant_shift;
+ uint64_t block_var = UINT64_MAX;
+ const int dc_qstep = x->plane[plane].dequant_QTX[0] >> 3;
+ *block_sse = pixel_diff_stats(x, plane, blk_row, blk_col, plane_bsize,
+ txsize_to_bsize[tx_size], block_mse_q8,
+ per_px_mean, &block_var);
+ assert((*block_mse_q8) != UINT_MAX);
+ uint64_t var_threshold = (uint64_t)(1.8 * qstep * qstep);
+ if (is_cur_buf_hbd(xd))
+ block_var = ROUND_POWER_OF_TWO(block_var, (xd->bd - 8) * 2);
+ // Early prediction of skip block if residual mean and variance are less
+ // than qstep based threshold
+ if (((llabs(*per_px_mean) * dc_coeff_scale[tx_size]) < (dc_qstep << 12)) &&
+ (block_var < var_threshold)) {
+ // If the normalized mean of residual block is less than the dc qstep and
+ // the normalized block variance is less than ac qstep, then the block is
+ // assumed to be a skip block and its rdcost is updated accordingly.
+ best_rd_stats->skip_txfm = 1;
+
+ x->plane[plane].eobs[block] = 0;
+
+ best_rd_stats->dist = (*block_sse) << 4;
+ best_rd_stats->sse = best_rd_stats->dist;
+
+ ENTROPY_CONTEXT ctxa[MAX_MIB_SIZE];
+ ENTROPY_CONTEXT ctxl[MAX_MIB_SIZE];
+ av1_get_entropy_contexts(plane_bsize, &xd->plane[plane], ctxa, ctxl);
+ ENTROPY_CONTEXT *ta = ctxa;
+ ENTROPY_CONTEXT *tl = ctxl;
+ const TX_SIZE txs_ctx = get_txsize_entropy_ctx(tx_size);
+ TXB_CTX txb_ctx_tmp;
+ const PLANE_TYPE plane_type = get_plane_type(plane);
+ get_txb_ctx(plane_bsize, tx_size, plane, ta, tl, &txb_ctx_tmp);
+ const int zero_blk_rate = x->coeff_costs.coeff_costs[txs_ctx][plane_type]
+ .txb_skip_cost[txb_ctx_tmp.txb_skip_ctx][1];
+ best_rd_stats->rate =
+ zero_blk_rate *
+ (block_size_wide[plane_bsize] >> tx_size_wide_log2[tx_size]) *
+ (block_size_high[plane_bsize] >> tx_size_high_log2[tx_size]);
+
+ best_rd_stats->rdcost =
+ RDCOST(x->rdmult, best_rd_stats->rate, best_rd_stats->sse);
+
+ x->plane[plane].txb_entropy_ctx[block] = 0;
+ } else if (block_var < var_threshold) {
+ // Predict DC only blocks based on residual variance.
+ // For chroma plane, this early prediction is disabled for intra blocks.
+ if ((plane == 0) || (plane > 0 && is_inter_block(mbmi))) *dc_only_blk = 1;
+ }
+}
+
// Search for the best transform type for a given transform block.
// This function can be used for both inter and intra, both luma and chroma.
static void search_tx_type(const AV1_COMP *cpi, MACROBLOCK *x, int plane,
@@ -2247,56 +2308,11 @@
const bool predict_dc_block =
cpi->sf.winner_mode_sf.enable_dc_only_blk_pred && txw != 64 && txh != 64;
int64_t per_px_mean = INT64_MAX;
- uint64_t block_var = UINT64_MAX;
if (predict_dc_block) {
- const int dc_qstep = x->plane[plane].dequant_QTX[0] >> 3;
- block_sse = pixel_diff_stats(x, plane, blk_row, blk_col, plane_bsize,
- txsize_to_bsize[tx_size], &block_mse_q8,
- &per_px_mean, &block_var);
- assert(block_mse_q8 != UINT_MAX);
- uint64_t var_threshold = (uint64_t)(1.8 * qstep * qstep);
- if (is_cur_buf_hbd(xd))
- block_var = ROUND_POWER_OF_TWO(block_var, (xd->bd - 8) * 2);
- // Early prediction of skip block if residual mean and variance are less
- // than qstep based threshold
- if (((llabs(per_px_mean) * dc_coeff_scale[tx_size]) < (dc_qstep << 12)) &&
- (block_var < var_threshold)) {
- // If the normalized mean of residual block is less than the dc qstep and
- // the normalized block variance is less than ac qstep, then the block is
- // assumed to be a skip block and its rdcost is updated accordingly.
- best_rd_stats->skip_txfm = 1;
-
- x->plane[plane].eobs[block] = 0;
-
- best_rd_stats->dist = block_sse << 4;
- best_rd_stats->sse = best_rd_stats->dist;
-
- ENTROPY_CONTEXT ctxa[MAX_MIB_SIZE];
- ENTROPY_CONTEXT ctxl[MAX_MIB_SIZE];
- av1_get_entropy_contexts(plane_bsize, &xd->plane[plane], ctxa, ctxl);
- ENTROPY_CONTEXT *ta = ctxa;
- ENTROPY_CONTEXT *tl = ctxl;
- const TX_SIZE txs_ctx = get_txsize_entropy_ctx(tx_size);
- TXB_CTX txb_ctx_tmp;
- const PLANE_TYPE plane_type = get_plane_type(plane);
- get_txb_ctx(plane_bsize, tx_size, plane, ta, tl, &txb_ctx_tmp);
- const int zero_blk_rate = x->coeff_costs.coeff_costs[txs_ctx][plane_type]
- .txb_skip_cost[txb_ctx_tmp.txb_skip_ctx][1];
- best_rd_stats->rate =
- zero_blk_rate *
- (block_size_wide[plane_bsize] >> tx_size_wide_log2[tx_size]) *
- (block_size_high[plane_bsize] >> tx_size_high_log2[tx_size]);
-
- best_rd_stats->rdcost =
- RDCOST(x->rdmult, best_rd_stats->rate, best_rd_stats->sse);
-
- x->plane[plane].txb_entropy_ctx[block] = 0;
- return;
- } else if (block_var < var_threshold) {
- // Predict DC only blocks based on residual variance.
- // For chroma plane, this early prediction is disabled for intra blocks.
- if ((plane == 0) || (plane > 0 && is_inter_block(mbmi))) dc_only_blk = 1;
- }
+ predict_dc_only_block(x, plane, plane_bsize, tx_size, block, blk_row,
+ blk_col, best_rd_stats, &block_sse, &block_mse_q8,
+ &per_px_mean, &dc_only_blk);
+ if (best_rd_stats->skip_txfm == 1) return;
} else {
block_sse = pixel_diff_dist(x, plane, blk_row, blk_col, plane_bsize,
txsize_to_bsize[tx_size], &block_mse_q8);
