Now in the case of AV-PES playback like VDR does it, there are no TS
packets and thus no PCR. To work around that, the STC is driven by the
video PTS. In practice this works pretty well.
A more "correct" approach would have been to use MPEG-2 PS instead
of AV-PES. The PS have a SCR (system clock reference) in the pack header
to drive the STC.
Another approach would be to let the demux generate e remultiplexed
transport stream which contains all PIDs belonging to the recorded
service (all those listed in the PMT), a modified PAT (pointing to this
PMT only) and maybe some application generation service informations.