MPEG vs. WMV

Can someone tell the difference between the same video stream encoded in MPEGII versus a WMV file half the size?

 

Not sure what you mean, but the easiest way to tell would be to use your eyes.

I'm pretty sure WMV is based off MPEG4, which has better compression than MPEG2.

 

I've been viewing a few video clips...but maybe I don't know what to look for.

I have a few files stored complements of Vista MCE, in MS-DVR format. I converted all three to MPEGII and then to WMV. The WMV files took half the space for the same length. I'm pretty much looking for a way to convert stored/DVR'ed video into a more compressed format...because MS-DVR takes up a lot of space.

 

The looks depend on the compression rate you set. But WMV gives you better compression as MPEG is not compressed.

So if space matters, convert your clips to WMV but keeping a high mb/s ratio to maintain the quality

 

MS-DVR is already MPEGII. Rather than re-encoding it I would suggest changing your capture settings to use lower resolution or lower quality from the beginning. Converting media between compressed formats is usually not desirable since it introduces lots of artifacts.

There are capture cards out there now that output MPEG4 instead of MPEGII, one of those would be the best of all worlds. I think Conexant is the brand I'm thinking of, I saw one at Circuit City a few weeks ago for under $100.

 

I already have a TV tuner, which plugs into Vista MCE. It takes beautiful recordings, but I want to compress them a little more without loosing too much.

AFAIK, Vista MCE decides how big the final files are...not the tuner.

 

That kinda sucks that MCE won't let you change settings. I run SageTV and you can change the settings to whatever the board supports, I capture at 480x480, about 1.6 GB/hr, but then I don't have an HD set either. In your case recompressing probably makes sense if MCE is capturing at DVD quality (which is probably the default), and go with the MPEG4-derived one (WMV) as suggested by Lithus above.

 

Take some snapshots and compare, cos you may not be able to see any difference while the video is playing. Look for evidence of blocky video or sometimes a shadow/ residue left behind by a fast moving object.

I think MPEG4/H.264 or DivX/XViD is better than WMV.

Here are some samples







(Source)