Change mv scaling behaviour
This patch changes the motion vector scaling and clamping to be
slightly more accurate (removing an occasional 1px offset due to
multiple roundings) and fixes the border clamping when scaling
frames.
Change-Id: I032dc0b87854eebafa58f1f803981e23c8cc2d9b
diff --git a/av1/common/reconinter.c b/av1/common/reconinter.c
index 00fc282..a469370 100644
--- a/av1/common/reconinter.c
+++ b/av1/common/reconinter.c
@@ -1008,10 +1008,7 @@
const MV mv = this_mbmi->mv[ref].as_mv;
- const MV mv_q4 = clamp_mv_to_umv_border_sb(
- xd, &mv, bw, bh, pd->subsampling_x, pd->subsampling_y);
uint8_t *pre;
- MV32 scaled_mv;
int xs, ys, subpel_x, subpel_y;
const int is_scaled = av1_is_scaled(sf);
ConvolveParams conv_params = get_conv_params(ref, ref, plane);
@@ -1032,23 +1029,41 @@
dst += dst_buf->stride * y + x;
if (is_scaled) {
- pre =
- pre_buf->buf + scaled_buffer_offset(x, y, pre_buf->stride, sf);
- scaled_mv = av1_scale_mv(&mv_q4, mi_x + x, mi_y + y, sf);
+ int ssx = pd->subsampling_x;
+ int ssy = pd->subsampling_y;
+ int orig_pos_y = (mi_y << (SUBPEL_BITS - ssy)) + (y << SUBPEL_BITS);
+ orig_pos_y += mv.row * (1 << (1 - ssy));
+ int orig_pos_x = (mi_x << (SUBPEL_BITS - ssx)) + (x << SUBPEL_BITS);
+ orig_pos_x += mv.col * (1 << (1 - ssx));
+ int pos_y = sf->scale_value_y(orig_pos_y, sf);
+ int pos_x = sf->scale_value_x(orig_pos_x, sf);
+
+ const int top = -((AOM_INTERP_EXTEND + bh) << SUBPEL_BITS);
+ const int bottom = (pre_buf->height + AOM_INTERP_EXTEND)
+ << SUBPEL_BITS;
+ const int left = -((AOM_INTERP_EXTEND + bw) << SUBPEL_BITS);
+ const int right = (pre_buf->width + AOM_INTERP_EXTEND)
+ << SUBPEL_BITS;
+ pos_y = clamp(pos_y, top, bottom);
+ pos_x = clamp(pos_x, left, right);
+
+ pre = pre_buf->buf0 + (pos_y >> SUBPEL_BITS) * pre_buf->stride +
+ (pos_x >> SUBPEL_BITS);
+ subpel_x = pos_x & SUBPEL_MASK;
+ subpel_y = pos_y & SUBPEL_MASK;
xs = sf->x_step_q4;
ys = sf->y_step_q4;
} else {
- pre = pre_buf->buf + y * pre_buf->stride + x;
- scaled_mv.row = mv_q4.row;
- scaled_mv.col = mv_q4.col;
+ const MV mv_q4 = clamp_mv_to_umv_border_sb(
+ xd, &mv, bw, bh, pd->subsampling_x, pd->subsampling_y);
xs = ys = SCALE_DENOMINATOR;
+ subpel_x = mv_q4.col & SUBPEL_MASK;
+ subpel_y = mv_q4.row & SUBPEL_MASK;
+ pre = pre_buf->buf +
+ (y + (mv_q4.row >> SUBPEL_BITS)) * pre_buf->stride +
+ (x + (mv_q4.col >> SUBPEL_BITS));
}
- subpel_x = scaled_mv.col & SUBPEL_MASK;
- subpel_y = scaled_mv.row & SUBPEL_MASK;
- pre += (scaled_mv.row >> SUBPEL_BITS) * pre_buf->stride +
- (scaled_mv.col >> SUBPEL_BITS);
-
#if CONFIG_EXT_INTER
if (ref && is_masked_compound_type(mi->mbmi.interinter_compound_type))
av1_make_masked_inter_predictor(
@@ -1093,7 +1108,6 @@
struct buf_2d *const dst_buf = &pd->dst;
uint8_t *const dst = dst_buf->buf + dst_buf->stride * y + x;
uint8_t *pre[2];
- MV32 scaled_mv[2];
SubpelParams subpel_params[2];
#if CONFIG_CONVOLVE_ROUND
DECLARE_ALIGNED(16, int32_t, tmp_dst[MAX_SB_SIZE * MAX_SB_SIZE]);
@@ -1127,33 +1141,49 @@
: mi->mbmi.mv[ref].as_mv;
#endif
- // TODO(jkoleszar): This clamping is done in the incorrect place for the
- // scaling case. It needs to be done on the scaled MV, not the pre-scaling
- // MV. Note however that it performs the subsampling aware scaling so
- // that the result is always q4.
- // mv_precision precision is MV_PRECISION_Q4.
- const MV mv_q4 = clamp_mv_to_umv_border_sb(
- xd, &mv, bw, bh, pd->subsampling_x, pd->subsampling_y);
-
const int is_scaled = av1_is_scaled(sf);
if (is_scaled) {
- pre[ref] =
- pre_buf->buf + scaled_buffer_offset(x, y, pre_buf->stride, sf);
- scaled_mv[ref] = av1_scale_mv(&mv_q4, mi_x + x, mi_y + y, sf);
+ // Note: The various inputs here have different units:
+ // * mi_x/mi_y are in units of luma pixels
+ // * mv is in units of 1/8 luma pixels
+ // * x/y are in units of pixels *in the current plane*
+ // Here we unify these into a q4-format position within the current
+ // plane, then project into the reference frame
+ int ssx = pd->subsampling_x;
+ int ssy = pd->subsampling_y;
+ int orig_pos_y = (mi_y << (SUBPEL_BITS - ssy)) + (y << SUBPEL_BITS);
+ orig_pos_y += mv.row * (1 << (1 - ssy));
+ int orig_pos_x = (mi_x << (SUBPEL_BITS - ssx)) + (x << SUBPEL_BITS);
+ orig_pos_x += mv.col * (1 << (1 - ssx));
+ int pos_y = sf->scale_value_y(orig_pos_y, sf);
+ int pos_x = sf->scale_value_x(orig_pos_x, sf);
+
+ // Clamp against the reference frame borders, with enough extension
+ // that we don't force the reference block to be partially onscreen.
+ const int top = -((AOM_INTERP_EXTEND + bh) << SUBPEL_BITS);
+ const int bottom = (pre_buf->height + AOM_INTERP_EXTEND) << SUBPEL_BITS;
+ const int left = -((AOM_INTERP_EXTEND + bw) << SUBPEL_BITS);
+ const int right = (pre_buf->width + AOM_INTERP_EXTEND) << SUBPEL_BITS;
+ pos_y = clamp(pos_y, top, bottom);
+ pos_x = clamp(pos_x, left, right);
+
+ pre[ref] = pre_buf->buf0 + (pos_y >> SUBPEL_BITS) * pre_buf->stride +
+ (pos_x >> SUBPEL_BITS);
+ subpel_params[ref].subpel_x = pos_x & SUBPEL_MASK;
+ subpel_params[ref].subpel_y = pos_y & SUBPEL_MASK;
subpel_params[ref].xs = sf->x_step_q4;
subpel_params[ref].ys = sf->y_step_q4;
} else {
- pre[ref] = pre_buf->buf + (y * pre_buf->stride + x);
- scaled_mv[ref].row = mv_q4.row;
- scaled_mv[ref].col = mv_q4.col;
+ const MV mv_q4 = clamp_mv_to_umv_border_sb(
+ xd, &mv, bw, bh, pd->subsampling_x, pd->subsampling_y);
+ subpel_params[ref].subpel_x = mv_q4.col & SUBPEL_MASK;
+ subpel_params[ref].subpel_y = mv_q4.row & SUBPEL_MASK;
subpel_params[ref].xs = SCALE_DENOMINATOR;
subpel_params[ref].ys = SCALE_DENOMINATOR;
+ pre[ref] = pre_buf->buf +
+ (y + (mv_q4.row >> SUBPEL_BITS)) * pre_buf->stride +
+ (x + (mv_q4.col >> SUBPEL_BITS));
}
-
- subpel_params[ref].subpel_x = scaled_mv[ref].col & SUBPEL_MASK;
- subpel_params[ref].subpel_y = scaled_mv[ref].row & SUBPEL_MASK;
- pre[ref] += (scaled_mv[ref].row >> SUBPEL_BITS) * pre_buf->stride +
- (scaled_mv[ref].col >> SUBPEL_BITS);
}
#if CONFIG_CONVOLVE_ROUND
@@ -2944,16 +2974,7 @@
? average_split_mvs(pd, mi, ref, block)
: mi->mbmi.mv[ref].as_mv;
- // TODO(jkoleszar): This clamping is done in the incorrect place for the
- // scaling case. It needs to be done on the scaled MV, not the pre-scaling
- // MV. Note however that it performs the subsampling aware scaling so
- // that the result is always q4.
- // mv_precision precision is MV_PRECISION_Q4.
- const MV mv_q4 = clamp_mv_to_umv_border_sb(xd, &mv, bw, bh, pd->subsampling_x,
- pd->subsampling_y);
-
uint8_t *pre;
- MV32 scaled_mv;
int xs, ys, subpel_x, subpel_y;
const int is_scaled = av1_is_scaled(sf);
ConvolveParams conv_params = get_conv_params(ref, 0, plane);
@@ -2975,22 +2996,38 @@
#endif // CONFIG_GLOBAL_MOTION || CONFIG_WARPED_MOTION
if (is_scaled) {
- pre = pre_buf->buf + scaled_buffer_offset(x, y, pre_buf->stride, sf);
- scaled_mv = av1_scale_mv(&mv_q4, mi_x + x, mi_y + y, sf);
+ int ssx = pd->subsampling_x;
+ int ssy = pd->subsampling_y;
+ int orig_pos_y = (mi_y << (SUBPEL_BITS - ssy)) + (y << SUBPEL_BITS);
+ orig_pos_y += mv.row * (1 << (1 - ssy));
+ int orig_pos_x = (mi_x << (SUBPEL_BITS - ssx)) + (x << SUBPEL_BITS);
+ orig_pos_x += mv.col * (1 << (1 - ssx));
+ int pos_y = sf->scale_value_y(orig_pos_y, sf);
+ int pos_x = sf->scale_value_x(orig_pos_x, sf);
+
+ const int top = -((AOM_INTERP_EXTEND + bh) << SUBPEL_BITS);
+ const int bottom = (pre_buf->height + AOM_INTERP_EXTEND) << SUBPEL_BITS;
+ const int left = -((AOM_INTERP_EXTEND + bw) << SUBPEL_BITS);
+ const int right = (pre_buf->width + AOM_INTERP_EXTEND) << SUBPEL_BITS;
+ pos_y = clamp(pos_y, top, bottom);
+ pos_x = clamp(pos_x, left, right);
+
+ pre = pre_buf->buf0 + (pos_y >> SUBPEL_BITS) * pre_buf->stride +
+ (pos_x >> SUBPEL_BITS);
+ subpel_x = pos_x & SUBPEL_MASK;
+ subpel_y = pos_y & SUBPEL_MASK;
xs = sf->x_step_q4;
ys = sf->y_step_q4;
} else {
- pre = pre_buf->buf + (y * pre_buf->stride + x);
- scaled_mv.row = mv_q4.row;
- scaled_mv.col = mv_q4.col;
+ const MV mv_q4 = clamp_mv_to_umv_border_sb(
+ xd, &mv, bw, bh, pd->subsampling_x, pd->subsampling_y);
xs = ys = SCALE_DENOMINATOR;
+ subpel_x = mv_q4.col & SUBPEL_MASK;
+ subpel_y = mv_q4.row & SUBPEL_MASK;
+ pre = pre_buf->buf + (y + (mv_q4.row >> SUBPEL_BITS)) * pre_buf->stride +
+ (x + (mv_q4.col >> SUBPEL_BITS));
}
- subpel_x = scaled_mv.col & SUBPEL_MASK;
- subpel_y = scaled_mv.row & SUBPEL_MASK;
- pre += (scaled_mv.row >> SUBPEL_BITS) * pre_buf->stride +
- (scaled_mv.col >> SUBPEL_BITS);
-
av1_make_inter_predictor(pre, pre_buf->stride, dst, ext_dst_stride, subpel_x,
subpel_y, sf, w, h, &conv_params,
mi->mbmi.interp_filter,
