By warren on Dec 29, 2008
I recently captured some old 8mm video tape of the family to iMovie. My strategy for archiving is to copy the material to a new medium every few years. We will see how that works out.
In any event, I want to throw all the videos on a hard drive and store it offsite in our safety deposit box. However, the raw .DV footage is too large and won't fit (and I am too cheap to buy more hard drives or a larger safety deposit box).
Necessity being the mother of invention, I needed a script to encode and compress all my .DV footage. MP4 seems to be a good choice for a format that is widely supported and offers good compression quality. I wanted to preserve the folder event structure in iMovie - so a simple find command was not going to cut it.
I started off with bash - but quickly became frustrated with the quirky syntax. One of the problems with shell scripts is that file and path names are strings - not objects. You often run into escaping issues when presented with long file names and special characters. You can work around these issues - but it is much more painful than it ought to be.
I elected to give python a go and see if it was any easier. This is my first python script - and I don't claim this is a particullarily good example. However - if you are facing the same issue - please feel free to use this as a starting point.
You will need a copy of the Handbrake CLI to perform the mp4 encoding. Handbrake uses the x264 encoder.
Without further ado, here is the script:
1 #!/usr/bin/env python 2 # Script to encode DV files to MP4 using HandBrakeCLI 3 # Preserves the folder structure of the iMove events 4 __author__="warrenstrange" 5 __date__ ="$Dec 28, 2008 6:28:09 PM$" 6 7 import os 8 import subprocess 9 import os.path 10 11 # Source for .dv files 12 root = "/Volumes/Velocity1/iMovie Events.localized" 13 # Destination for encoded MP4 files 14 dest = "/Volumes/WSTCD/mp4.bak" 15 #dest = "/var/tmp/xx" 16 17 def encode(path, dest): 18 for root, dirs, files in os.walk(path, topdown=False): 19 for name in files: 20 # Get the extension 21 (base, ext)=os.path.splitext(name) 22 # If it is a .dv file 23 if ext.lower() == ".dv": 24 # Get the directory folder where the .dv file is stored 25 (h,tail) = os.path.split(root) 26 # Form the destination directory folder name 27 destdir = os.path.join(dest,tail) 28 # Create the destination directory if required 29 if not os.path.exists(destdir): 30 os.mkdir(destdir) 31 # Form the output file name (.MP4 extenstion) 32 newfile = os.path.join(destdir, base + ".MP4") 33 infile = os.path.join(root,name) 34 # If it already exists don't overwrite it - skip it 35 if os.path.exists(newfile): 36 print "skipping " + infile 37 else: 38 subprocess.call( ["HandBrakeCLI", "--preset=Universal", "-i" ,infile, "-o", newfile]) 39 40 41 if __name__ == "__main__": 42 encode(root, dest) 43 44