diff options
| author | Henrik Gramner <gramner@twoorioles.com> | 2021-01-30 01:46:00 +0300 |
|---|---|---|
| committer | Henrik Gramner <henrik@gramner.com> | 2021-02-15 17:10:36 +0300 |
| commit | 989057fb39f16dd2302fd6d55d86c4c5369475f1 (patch) | |
| tree | b79f0b570b38096def340082464bcbb80bdfb82c /src/decode.c | |
| parent | a92e307f17228d9bb3a98cfd3b025cefe469acb1 (diff) | |
Optimize non-qmatrix coefficient decoding
Not having a quantizer matrix is the most common case, so it's
worth having a separate code path for it that eliminates some
calculations and table lookups.
Without a qm, not only can we skip calculating dq * qm, but only
Exp-Golomb-coded coefficients will have the potential to overflow,
so we can also skip clipping for the vast majority of coefficients.
Diffstat (limited to 'src/decode.c')
| -rw-r--r-- | src/decode.c | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/src/decode.c b/src/decode.c index 1314ce2..a308300 100644 --- a/src/decode.c +++ b/src/decode.c @@ -2966,15 +2966,13 @@ int dav1d_decode_frame(Dav1dFrameContext *const f) { // setup dequant tables init_quant_tables(f->seq_hdr, f->frame_hdr, f->frame_hdr->quant.yac, f->dq); if (f->frame_hdr->quant.qm) - for (int j = 0; j < N_RECT_TX_SIZES; j++) { - f->qm[0][j][0] = dav1d_qm_tbl[f->frame_hdr->quant.qm_y][0][j]; - f->qm[0][j][1] = dav1d_qm_tbl[f->frame_hdr->quant.qm_u][1][j]; - f->qm[0][j][2] = dav1d_qm_tbl[f->frame_hdr->quant.qm_v][1][j]; - } - for (int i = f->frame_hdr->quant.qm; i < 2; i++) - for (int tx = 0; tx < N_RECT_TX_SIZES; tx++) - for (int pl = 0; pl < 3; pl++) - f->qm[i][tx][pl] = dav1d_qm_tbl[15][!!pl][tx]; + for (int i = 0; i < N_RECT_TX_SIZES; i++) { + f->qm[i][0] = dav1d_qm_tbl[f->frame_hdr->quant.qm_y][0][i]; + f->qm[i][1] = dav1d_qm_tbl[f->frame_hdr->quant.qm_u][1][i]; + f->qm[i][2] = dav1d_qm_tbl[f->frame_hdr->quant.qm_v][1][i]; + } + else + memset(f->qm, 0, sizeof(f->qm)); // setup jnt_comp weights if (f->frame_hdr->switchable_comp_refs) { |