Commit 96d7a686 authored by Frederic Barbier's avatar Frederic Barbier

Cleanup inference of unused variable all_zero

Change-Id: I591badb15e714e23f2c8a2c2df8514fdd75fc880
parent 50098d2f
......@@ -1239,7 +1239,6 @@ void av1_find_mv_refs(const AV1_COMMON *cm, const MACROBLOCKD *xd,
void *const data, int16_t *mode_context) {
int_mv zeromv[2];
BLOCK_SIZE bsize = mi->mbmi.sb_type;
int idx, all_zero = 1;
MV_REFERENCE_FRAME rf[2];
av1_update_mv_context(cm, xd, mi, ref_frame, mv_ref_list, mi_row, mi_col,
......@@ -1280,32 +1279,6 @@ void av1_find_mv_refs(const AV1_COMMON *cm, const MACROBLOCKD *xd,
zeromv,
#endif // USE_CUR_GM_REFMV
mi_row, mi_col, mode_context);
/* Note: If global motion is enabled, then we want to set the ALL_ZERO flag
iff all of the MVs we could generate with NEARMV/NEARESTMV are equivalent
to the global motion vector.
Note: For the following to work properly, the encoder can't throw away
any global motion models after calling this function, even if they are
unused. Instead we rely on the recode loop: If any non-IDENTITY model
is unused, the whole frame will be re-encoded without it.
The problem is that, otherwise, we can end up in the following situation:
* Encoder has a global motion model with nonzero translational part,
and all candidate MVs are zero. So the ALL_ZERO flag is unset.
* Encoder throws away global motion because it is never used.
* Decoder sees that there is no global motion and all candidate MVs are
zero, so sets the ALL_ZERO flag.
* This leads to an encode/decode mismatch.
*/
for (idx = 0; idx < AOMMIN(3, *ref_mv_count); ++idx) {
if (ref_mv_stack[idx].this_mv.as_int != zeromv[0].as_int) all_zero = 0;
if (ref_frame > ALTREF_FRAME)
if (ref_mv_stack[idx].comp_mv.as_int != zeromv[1].as_int) all_zero = 0;
}
if (*ref_mv_count < 2 && ref_frame <= ALTREF_FRAME) {
for (idx = 0; idx < MAX_MV_REF_CANDIDATES; ++idx)
if (mv_ref_list[idx].as_int != zeromv[0].as_int) all_zero = 0;
}
(void)all_zero;
}
void av1_find_best_ref_mvs(int allow_hp, int_mv *mvlist, int_mv *nearest_mv,
......
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