Patrick O'Callaghan wrote: > On Thu, 2009-03-05 at 15:32 +0000, John Pilkington wrote: >> Hi: I'm asking here because this is the most fc10-oriented list that I >> use and I thought someone might know the answer. I'd be happy to ask >> elsewhere but don't know where might be the best place. >> >> I'm trying to do shrink-to-fit with video files on fc10 after tcrequant >> was deprecated. vamps looks as if it will do the job but I think I need >> to chop off a few kb from the end of the input file first to avoid a >> failure exit. I can do this with dd but that's slow and file truncation >> would be better. I can't see a command-line truncate but since I am >> hacking the mythburn.py script I thought I had found the answer here, in >> truncate([size]) : >> >> http://www.python.org/doc/2.5.2/lib/bltin-file-objects.html >> >> I've tried that. The file size shrinks as required but the result is >> zero-filled. Here's some stripped-down test code: >> >> vobsize = os.path.getsize(source) >> write("Initial vobsize is %s bytes" % vobsize) >> >> vobsize -= 2048 >> f=open(source,'wb') >> f.truncate( vobsize ) >> f.close() >> >> vobsize = os.path.getsize(source) >> write("vobsize after truncation is %s bytes" % vobsize) >> >> Is this a known problem with python, or in its fc10 implementation? >> Where would be the best place to ask how to do this job? > > I've no idea, but I suspect you could probably write a tiny C program to > do the truncation is less time than it would take to get an answer. > > poc > For the record - ie in case someone comes to this by Google - the problem was solved by using f=open(source,'ab'), which opens the binary file in append mode. John P
