How to fix bad multibyte data?

Hi All,

I have a v7.1 database whose encoding is EUC_JP and I'm trying to get it
into a v7.4 database whose encoding is also EUC_JP. Unfortunately it seems
that 7.4 is much stricter about it's multibyte data then 7.1 was because
attempts to restore into the 7.4 db result in "Invalid byte sequence for
encoding"EUC_JP":  0x8e' errors.

There is no doubt that the data in the 7.1 database is bad, though I'm not
sure exactly how it got that way (the data was loaded by a C program from
CSV file). Anyway, I can dump/restore on 7.1 ok. and I can restore into a
7.4 DB with the encoding set to SQL_ASCII but that isn't really what we
want.

I'm thinking that I may have to put the dump file through some kind of
filter that will at least ensure that the data is valid EUC_JP, even if it
mangles the data a little by dropping the invalid bytes.

The question is, how would one go about this? I think a perl script might do
the job (I'm not familiar with perl at all though), but there might be other
ways... so before I go off down that path, I'm wondering if anyone has any
suggestions.

Regards
Iain