When will a defendant's failure to object to a motion of appeal be considered in a separate habeas corpus proceeding?

Defendant attempts to rely on the affidavit of his trial counsel to excuse the failure to object. However, the affidavit is no part of the record on appeal and it is well settled in California that on direct appeal from a judgment, a reviewing court will not consider matters outside the record. Accordingly, the issue is not properly before us on this direct appeal (People v. Gardner, 71 Cal.2d 843, 79 Cal.Rptr. 743, 457 P.2d 575), but to be considered in a separate habeas corpus proceeding (In re Rinegold, Cal.App., 92 Cal.Rptr. 18). ³