time_div = FFUDIV(s->time, s->avctx->time_base.den);
time_mod = FFUMOD(s->time, s->avctx->time_base.den);
time_incr = time_div - s->last_time_base;
time_div = FFUDIV(s->time, s->avctx->time_base.den);
time_mod = FFUMOD(s->time, s->avctx->time_base.den);
time_incr = time_div - s->last_time_base;