}
mb->mv_x = mb->mv_y = 0; /* no motion vector coded */
- if (band->inherit_mv){
+ if (band->inherit_mv && ref_mb){
/* motion vector inheritance */
if (mv_scale) {
mb->mv_x = ivi_scale_mv(ref_mb->mv_x, mv_scale);
}
}
} else {
- if (band->inherit_mv) {
+ if (band->inherit_mv && ref_mb) {
mb->type = ref_mb->type; /* copy mb_type from corresponding reference mb */
} else if (ctx->frame_type == FRAMETYPE_INTRA) {
mb->type = 0; /* mb_type is always INTRA for intra-frames */
if (!mb->type) {
mb->mv_x = mb->mv_y = 0; /* there is no motion vector in intra-macroblocks */
} else {
- if (band->inherit_mv){
+ if (band->inherit_mv && ref_mb){
/* motion vector inheritance */
if (mv_scale) {
mb->mv_x = ivi_scale_mv(ref_mb->mv_x, mv_scale);