Examples of the present invention provide a method of converting a multicast stream into unicast segments. In particular, sequence identifiers are generated based on a clock reference field in the transport stream packets that make up the multicast stream. Every time a new sequence identifier is calculated, a new unicast segment is generated and assigned with the new sequence identifier. Transport stream packets are placed into the new segment until a packet is processed that causes a new sequence identifier to be generated, at which point another new segment is generated and packets placed into that segment. In an improved method, random access indicators in the transports stream packets are used to further constrain when a new segment is generated, to ensure that new segments are coincident with a packet having a random access indicator. This improvement makes random access easier back and forth between and within a stream.