Mr Lazy

August 27, 2009

Producing thumbnails on the WD TV for AVCHD clips

Filed under: WD TV — Mr Lazy @ 11:26
Tags: , ,

The WD TV plays back the AVCHD produced by my camcorder beautifully.  But I haven’t had much time to do any editing yet, so I currently have over a thousand clips.  Windows 7 can automatically produce thumbnails from AVCHD clips and so can Vista with a little tweaking, so it’s a pity that WD didn’t focus a little more on this aspect.

The tricky part is generating the thumbnails – obviously when you have thousands you don’t want to do this by hand 🙂  Because I have a Canon HF100 camcorder I used Pixela ImageMixer 3 SE – I don’t know if this will work with other camcorders – or the application that came bunded with your camcorder may also produce thumbnails.  Note that ImageMixer does not output thumbnails as a feature – I had to dig around various directories to see if the thumbnails it produced for display purposes were saved somewhere as files.

If you don’t have an application that can generate thumbnails and would rather not go down the manual route (ie. generating JPEGs from Windows Movie Maker, MPC-HC, VLC etc.) then you could try this program which I started to use before I realised that ImageMixer could generate thumbnails:
http://cfed-ttf.blogspot.com/2008/07/thumbcache-version-2.html.  It provides a means to extract the thumbnails that Explorer uses in Vista (you will need to have enabled AVCHD thumbnail generation in Vista first of course with the appropriate codecs etc).  Be warned though that this method will be VERY convoluted with a lot of manual tasks – I was going through 21 steps.

Tools I used:
– ReNamer available from: http://www.den4b.com/
– IrfanView available from: http://www.irfanview.com/
– Pixela ImageMixer 3 SE available from: http://www.pixela.co.jp/oem/canon/e/

I’m not going to give you a tutorial on each of those programs, but it should be possible to easily work out each step by reading the built-in help or documentation for each program.

If you already use ImageMixer to import video directly from the camcorder or via a card reader you will know that internally it uses filenames based on a date-time format ie. YYYYMMDDHHSS.  Although I don’t use ImageMixer for this purpose (I just copy straight from SDHC card via card reader) I chose to rename my clips using that format because that way I would be able to tell from the WD TV when a particular video clip was shot (by default, the HF100 generates filenames such as “00001.MTS” etc).  It also meant I could store all the clips in the same directory without fear of overwriting any with the same name.  To do this I used ReNamer with a rule that used the :File_DateModified: meta tag.  Unless the file has been altered in some way the Date Modified value should reflect when the video was taken (note that the act of renaming does not change this value).  FYI, it actually represents when recording stopped, rather than when recording started.

1) ensure that the ImageMixer thumbnail directory is empty – thumbnails are stored in C:\ProgramData\PIXELA\ImageMixer 3 SE\IMxLibrary\_Data\Thumbnails.  By default Vista hides the ProgramData directory, so you will need to show hidden files.  Just delete any files in here.
2) start ImageMixer 3
3) use File->Add folder to library.  This generates the thumbnails – note that they are in TIFF format
4) use ReNamer to remove the suffix (ie. “_12”) at the end of the thumbnail’s filename
5) use IrfanView Batch conversion to convert the TIFFs to JPEGs
6) copy the JPEGs to the same folder as your videos

UPDATE Jun10: I’m now using ffmpeg to produce my thumbnails using one of the following commands:

for %i in ("<pathname>\*.m2ts") do ffmpeg -i "%i" -f image2 -ss 30 -t 0.001 -s 320x180 -deinterlace -y "<pathname>\%~ni.jpg"
ffmpeg -i "<pathname>\video.m2ts" -f image2 -r 0.25 -s 320x180 -deinterlace -y "<pathname>\thumb%d.jpg"

The first command will go through all the .m2ts files in the folder and produce one 320×180 size (I’m using the wide view of MSheet) thumbnail for each video based on the frame at 30 seconds in.  The second command, when given a single input file, will generate a thumbnail for every 2 seconds of video so you can review them and choose the best one, which is ideal for home videos.  If it seems odd that I’ve used a framerate (-r) of 0.25 it’s because the HF100 stores video in interlaced format.  If your camera stores video in the more common progressive format then you will need to change this parameter accordingly (ie. 0.5 for every 2 seconds) and remove the deinterlace flag.

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