A hybrid codec scalable video bitstream comprises first encapsulation units carrying video data of a base layer and encoded according to a first video coding standard and second encapsulation units carrying video data of at least one enhancement layer and encoded according to a second video coding standard. A prefix syntax element is added to each second encapsulation unit. The prefix syntax element has a value triggering a legacy decoder to discard or ignore the second encapsulation units. A non-legacy decoder selects, based on the value of a first portion of each of the first and second encapsulation units, whether to decode the encapsulation unit according to the first video coding standard or remove the first portion from the encapsulation unit and decode the remaining portion of the encapsulation unit according to the second video coding standard.