UPDATE_PICTURE(last_picture);
UPDATE_PICTURE(next_picture);
+#define REBASE_PICTURE(pic, new_ctx, old_ctx) \
+ ((pic && pic >= old_ctx->picture && \
+ pic < old_ctx->picture + MAX_PICTURE_COUNT) ? \
+ &new_ctx->picture[pic - old_ctx->picture] : NULL)
+
s->last_picture_ptr = REBASE_PICTURE(s1->last_picture_ptr, s, s1);
s->current_picture_ptr = REBASE_PICTURE(s1->current_picture_ptr, s, s1);
s->next_picture_ptr = REBASE_PICTURE(s1->next_picture_ptr, s, s1);