ffmpeg | branch: master | Frank Plowman <p...@frankplowman.com> | Mon Dec 30 17:57:52 2024 +0000| [539cea31830e71f1ce290c56ff2d639b209c2ac2] | committer: Nuo Mi
lavc/vvc: Fix race condition for MVs cropped to subpic When the current subpicture has sps_subpic_treated_as_pic_flag equal to 1, motion vectors are cropped such that they cannot point to other subpictures. This was accounted for in the prediction logic, but not in pred_get_y, which is used by the scheduling logic to determine which parts of the reference pictures must have been reconstructed before inter prediction of a subsequent frame may begin. Consequently, where a motion vector pointed to a location significantly above the current subpicture, there was the possibility of a race condition. Patch fixes this by cropping the motion vector to the current subpicture in pred_get_y. Signed-off-by: Frank Plowman <p...@frankplowman.com> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=539cea31830e71f1ce290c56ff2d639b209c2ac2 --- libavcodec/vvc/ctu.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/libavcodec/vvc/ctu.c b/libavcodec/vvc/ctu.c index 83864c5d98..080b740cc6 100644 --- a/libavcodec/vvc/ctu.c +++ b/libavcodec/vvc/ctu.c @@ -2393,13 +2393,19 @@ static int has_inter_luma(const CodingUnit *cu) return cu->pred_mode != MODE_INTRA && cu->pred_mode != MODE_PLT && cu->tree_type != DUAL_TREE_CHROMA; } -static int pred_get_y(const int y0, const Mv *mv, const int height) +static int pred_get_y(const VVCLocalContext *lc, const int y0, const Mv *mv, const int height) { - return FFMAX(0, y0 + (mv->y >> 4) + height); + const VVCPPS *pps = lc->fc->ps.pps; + const int idx = lc->sc->sh.r->curr_subpic_idx; + const int top = pps->subpic_y[idx]; + const int bottom = top + pps->subpic_height[idx]; + + return av_clip(y0 + (mv->y >> 4) + height, top, bottom); } -static void cu_get_max_y(const CodingUnit *cu, int max_y[2][VVC_MAX_REF_ENTRIES], const VVCFrameContext *fc) +static void cu_get_max_y(const CodingUnit *cu, int max_y[2][VVC_MAX_REF_ENTRIES], const VVCLocalContext *lc) { + const VVCFrameContext *fc = lc->fc; const PredictionUnit *pu = &cu->pu; if (pu->merge_gpm_flag) { @@ -2407,7 +2413,7 @@ static void cu_get_max_y(const CodingUnit *cu, int max_y[2][VVC_MAX_REF_ENTRIES] const MvField *mvf = pu->gpm_mv + i; const int lx = mvf->pred_flag - PF_L0; const int idx = mvf->ref_idx[lx]; - const int y = pred_get_y(cu->y0, mvf->mv + lx, cu->cb_height); + const int y = pred_get_y(lc, cu->y0, mvf->mv + lx, cu->cb_height); max_y[lx][idx] = FFMAX(max_y[lx][idx], y); } @@ -2425,7 +2431,7 @@ static void cu_get_max_y(const CodingUnit *cu, int max_y[2][VVC_MAX_REF_ENTRIES] const PredFlag mask = 1 << lx; if (mvf->pred_flag & mask) { const int idx = mvf->ref_idx[lx]; - const int y = pred_get_y(y0, mvf->mv + lx, sbh); + const int y = pred_get_y(lc, y0, mvf->mv + lx, sbh); max_y[lx][idx] = FFMAX(max_y[lx][idx], y + max_dmvr_off); } @@ -2452,7 +2458,7 @@ static void ctu_get_pred(VVCLocalContext *lc, const int rs) while (cu) { if (has_inter_luma(cu)) { - cu_get_max_y(cu, ctu->max_y, fc); + cu_get_max_y(cu, ctu->max_y, lc); ctu->has_dmvr |= cu->pu.dmvr_flag; } cu = cu->next; _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
