I just discovered a somewhat obscure solution to a strange issue I had with reading DV AVI files in LabVIEW (note
that I only had this problem on XP Pro Tablet Edition SP2, not on
desktop machines running XP Pro SP2).
Problem:
I have a 720 x 480 DV AVI file, but when I read this file into LabVIEW
using the "Read AVI Example.vi" it is displayed with a resolution of
360 x 240, which is half the correct value. I noticed that this
is the resolution reported by the IMAQ AVI Get Info.vi. Note that
the Microsoft "DV Video Decoder" is used to play this video. All
other video players on my computer (Windows Media Player, Quicktime,
Win DVD...) display the video in the proper full resolution (720 x
480), also using the DV Video Decoder. To add to my confusion, I
opened the video on a desktop XP computer with LabVIEW and Vision and
it displayed the video at 720 x 480, so the issue was restricted to my
laptop.
Solution:
I found this on the DivX forum at: http://forums.divx.com/groupee/forums/a/tpc/f/441101651/m/759106591
In case the link dies, here are the instructions:
- Install Microsoft DirectX 9 or later (I already had this installed).
- Run an ancient version of Media Player (6.4) by selecting Run from the Start menu and entering:
"C:\\Program Files\\Windows Media Player\\mplayer2.exe"
then click OK to launch Media Player 6.4.
- Drag and drop a DV AVI file onto Media Player 6.4 so that it begins to play. From the File menu choose Properties, then click the Advanced tab of the Properties window. Select the DV Video decoder and click the Properties button.
- From the DV Video decoder properties window set full decoding resolution and enable Save as default, then click OK.
So far as I can tell, you can only access this property from within
Media Player 6.4 and for some reason my tablet PC was set to play DV
videos at half resolution (which only LabVIEW seemed to be affected
by). Anyhow, this actually worked for me and I wasn't able to
find this anywhere on the NI forums so I thought it might help the next
person who runs into this strange little DV-AVI quirk.
Michelle
LabVIEW 7.1.1 with Vision 7.1.1 on Windows XP Pro Tablet Edition (Toshiba M200)