[julie_m]

VHS sort-of-works for 405 line signals because the recording is continuous in time, and blanking and sync pulses are represented directly as part of the recording. Whereas, an MPEG stream recorded on a DVD is framed to suit a broadcast standard. Only the active parts of each line are digitised, with the blanking and sync regenerated digitally during playback.

Your DVD recorder will be recording nearly 2/3 of the first 405-line line of the first field into the first 625-line line, ignoring any video signal during the 625-line horizontal flyback period; then recording the rest of the first 405-line line, the first 405-line horizontal flyback period and the beginning of the second 405-line line into the second 625-line line; again ignoring any video signal during the 625-line horizontal flyback period; then recording the end of the second 405-line line into the third 625-line line.

When played back, it will generate 625-line-style sync pulses after each line and field.