TMPGEnc and Motion Search Accuracy (need opinions)

[vivisimonvi]

As painful as it is to wait a long time to encode, this actually may be helpful to some.


First off I have an ATI capture card. I don't capture AVI since the files are way to big for my harddrive. I capture MPEG directly with a really high bitrate (for me, direct VCD capture sucks!). After that I re-encode to a lower bitrate that's big enough to fit on a disc as a VCD or XVCD. Now my problem was this... I assume setting the Search Motion Accuracy to "High Quality" or "Highest Quality" I would get the best video quality overall. I conducted a little test, I re-encoded an "uncompressed" MPEG file using the "Lowest Quality" setting (which is a LOT faster than "Highest Quality" obviously).

After viewing the two separate Highest and Lowest Quality files about 30 times, I COULD NOT tell the difference between the two. The pixelation, fast motion scenes, and small objects, all appeared exactly alike from both MPEG files! (I was recording a football game segment for this test)

Could I have been wasting all this time using a setting that doesn't matter if you're using an "uncompressed" MPEG file? I assume Motion Search Accuracy is only good when using uncompressed AVI files. Anyone have any experience or opinion on this matter??

[kinneera]

It would seem to make sense that if you are re-encoding video that is already in MPEG format, the motion search part of encoding has already been taken care of. All you are doing is stripping out bits. I don't really know if that's an accurate assessment of the situation, though.

[vivisimonvi]

I had that thought in mind as well. To my suprise actually, I played the two files at random, I guessed which one would be the better quality one (I picked the Highest Quality encoded one). Probably 90% of my assumption was based on luck, lol.

I'm glad I discovered this now, I haven't encoded much stuff I have on VHS. Now it'll take 10 times faster to complete than what I used to do.

[vivisimonvi]

Another thing I noticed using "uncompressed" MPEG, under Rate Control Mode, that Variable Bitrate (VBR) didn't seem to work out the way it was supposed to. The bitrate seemed always maxed out at every frame sequence (you can tell looking at the encoding log), even on "still" scenes from the video source the bitrate was maxed out.