I usually expect 3 fields to be populated during import (or during an Update Library from tags), for video files: Duration, Bitrate, Dimensions.
My thoughts on this, from personal experience and various bits and pieces around the forum, go like:
- using ffdshow as video decoder for almost everything doesn't work well. Almost none of those 3 fields get populated, or, in let's say 10% of the cases, bitrate and duration gets filed with astronomic values. Using bleeding edge ffdshow version.
- it seems that if the analyzing background thread fails on one file, it will fail on all the subsequent ones (this might need to be better documented)
- if I ditch ffdshow and use other combination of filters, Duration and Bitrate gets filled right, in a much faster manner. Dimensions however will never, ever be right. I have a zillion of 1080p files ripped from Blu-Rays and the likes. NONE shows up as 1920x1080. This brings me back to some old topic I was reading about on Doom9 at some point that for the life of me I can't find it now. Talking about when the dimensions of a video are retrieved for a DirectShow player. I believe the analysis takes aspect ratio (or some combination of actual Dimensions and SAR/PAR/DAR/whatever) into consideration and it returns incorrect numbers. I still have no idea why most 1080p videos are shown as having a 2048x1080 resolution, while for music video clips it's clear that the aspect ratio flag plays a role (so Dimensions appear 768x576, 1024x576, etc).
That is however NOT what I expected. I'd like the actual Dimensions of the files. This may or may not be possible using the method of rendering the file through the DirectShow chain, since I believe you can only return the values after the process is complete. The other option I was thinking is to read the specs from the files headers/tags (MediaInfo style), and not render the files. Would that be possible?