[mdlug] Why I like Linux - bulk DV encoding

[Ingles, Raymond]

 We have a bunch of Digital8 tapes from our old camcorder - basically DV
video on Hi8 tapes. Over the holidays I finally got the gumption to
extract and convert them to something more modern. Fortunately, Linux is
ideal for this sort of thing.

 Using 'dvgrab', I can just hook the camcorder up via Firewire. I don't
even need to manually rewind the tapes before capturing; dvgrab has a
"-rewind" command that takes care of that. The command I've settled on
is:

 dvgrab -rewind -autosplit=28800 -timestamp dv-

 The 'autosplit' generates a new file if there's a gap of 8 hours or
longer between clips, and the 'timestamp' flag incorporates the time and
date into the filename. I just swap tapes every so often and it grabs
the video and saves it for me.

 Then, I used the 'h264enc' script to experiment with the best way to
convert the video to H264. I decided to deinterlace the video, and used
the 'ps3hq' (Playstation 3 High Quality) preset otherwise, so I could
play the files easily on our big TV via the PS3. Happily, the h264enc
has an option to write out its mencoder commands to a file, so I could
incorporate them into my own script with only slight editing of the
input and output filenames.

 Once I had a script that would encode a single file properly, I wrote a
second, wrapper script that would call the encoding script repeatedly
for all DV files in a given directory. (BTW, DV is not a well-compressed
codec - the H264 files are about 1/13th the size of the DV versions, and
nearly indistinguishable in quality.) Encoding the video takes a while -
even on an Athlon 64 X2 Windsor 5600+ (dual-core, 2.8GHz), it processes
at around 10fps - but is also 'fire and forget'.

 I plan on giving the old tapes to my parents to store at their house
for an offsite back-up. I'll keep the H264 files on my hard drive here,
and also back them up to DVD. Burned DVDs are hardly a reliable backup
mechanism, of course, but there's the 'par2' utility, which generates
redundant parity information for files. I plan on burning the DVDs with
~15% redundancy, so that they'll need to be fairly damaged/aged before
recovery is impossible.

 Sincerely,

 Ray Ingles                                                (313)
227-2317

 "Deism has always struck me as rather pointless. A kind of religion
lite
  for people who want to try and be rational but are unable to let go of
       superstition entirely. It is a nicotine patch for the soul."
                            - Matt Penfold

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