linux systems (OS/X doesn't appear to have the problem):
INFO: [mpeg2enc] Signaling last frame = 499
mpeg2enc: seqencoder.cc:433: void SeqEncoder::EncodeStream(): Assertion `pass1coded.size() == 0' failed.
Abort
So, make the default -M value 0 to disable threading. Actually for buffering
the 'bfr' program can be placed in front of mpeg2enc and obviate the need for
threading in the encoder completely (it doesn't give much of a speed increase
as it turns out).
