Windows Explorer Doesn't Display Certain AVI & FLV Thumbnails

[ezehelm]

I’m using Windows 7 Starter 32-bit. My Windows Explorer can display thumbnails perfectly fine, EXCEPT for a few files. Some FLVs and AVIs have thumbnails, while some others don’t.

It’s not an issue of a slow CPU or bloated RAM, cause I’ve waited and waited, but some thumbnails are still missing. I don't think it's an issue of missing codecs, either, cause they can be played fine (I’m using K-Lite Mega 7.8.0 - 4th October 2011). So I decided to check these oddballs using MediaInfo, one by one.

For FLVs, all of my files come in two formats:

1) Format: AVC, Codec ID: 7
2) Format: Sorenson Spark, Codec ID: 2

Some have thumbnails, some don’t. All were downloaded from YouTube via KeepVid.com. The only pattern I see is that all videos from before January 2009 had thumbnails, while almost all videos downloaded from then till the present (October 2011) didn’t.

As for AVIs, the problematic ones are:

1) Format: MPEG-4 Visual, Codec ID: XVid
2) Format AVC, Codec ID: AVC1

Again, it seems random. There are other AVIs encoded with AVC1 which had thumbnails. So... What might be the solution for this? I’m stumped.

I found another post with the same problem as me, but nobody replied to that:

Windows 7 64-bit not displaying thumbnails for certain AVI files

[no12]

This may be down to the specific structure of each video file.
Without seeing the data, I can only speculate.