GMC effects

[ChannelK]

I have just completed two identicle Divx5s exept one with GMC and one without. The film is starwars 1, phantom menace and im am trying to verfy the effects/talked about bugs of GMC, but fail to see either. Any tips of what to look for and in what typs of scenes most affected, eg. the fast motion podrace scene (bright), the fast motion space battles (dark) etc.

130min 16:9 anamorphic > 128kbps mp3, 750kbps video at 488*156 (something like that res). Compressibility returned 69% at 0.31 pixels/ frame and a 800Mb cd (90 min.) B-frames, neutral bicub, no deint, 1 with 1 without GMC (no other filters).

Any feedback apprecated.....

[Petzku]

What a horribly small resolution you got there. It might at least partially be the reason for you not to detect any differencies.

[grug2k]

488*156??? Not only is that ridiculously small for a 2.35:1 movie and a 800mb CD, its also an aspect ratio of something like 3:1...

[ChannelK]

Soemthing like that res, the aspect ratio was maintained. I choose the res simply from comporessibility tests, I did a test at each res until the result was in the 60-70% range, it turned out to be exactly half of the original res, which also allowed me to achive a higher compresibility result by not using any deinterlacing, as reducing a PAL interlaced streams to half res. effectively deinterlaces. There is absolutely nothing wrong with the resulting picture on my 17inch or crt TV, however I do relise that i might pay for it in the future with HDTVs.

But, back to the origanl question, had i encoded with a much higher es. what types of things should I be looking for with / without GMC?

[ChannelK]

Oh i should probably also add that this was experimentation and my usual res's are generally much bigger with a field deinterlace. Just trying reducing res. instead of deinting.

[UGAthecat]

I would encode at a higher resolution to help the differences stand out, but since you already have some files to work with, you could try taking a couple of frames and save them as bmps, load them into photoshop or PSP, and run them through a filter or layer them to view only the differences between the frames.
Another way to do it would be to make an avisynth script that would load the 2 videos and show the differences (search the forums for help with that, i'm at work and can't get to a script i used to do this before)
if you go with the save frames as bmp method, make sure to get frames from scenes that do things that would cause GMC to kick in, like full camera pans, and a few frames from other scenes as well.

[theReal]

ChannelK, ever heard of Inverse Telecining? You don't have to deinterlace 99% of all NTSC DVD's, most of them can be decimated to the original (progressive) frames with DVD2AVI with no trouble at all!

If you want to do a 1 CD rip, the compress test does not have to be around 70% - rather use a decent resolution with something like 50-60% and/or use a good filter like convolution3d to improve compressibility.

[ChannelK]

@ theReal, this thread is originally concerning a PAL dvd, however, in this thread

http://forum.doom9.org/showthread.php?s=&threadid=32723

you did suggest convelution3d however i was unable to implemet it (please see my last question there converning this). I now am also aware of inversetelecining, but editing the .avs script (via GKnot) i simply enabled telecide() and decomb() (with great success!) Should I have used the actual inversetelecine() option instead?

[theReal]

The film is starwars 1, phantom menace An interlaced PAL DVD??? I've never seen an interlaced PAL DVD from a recent movie, are you sure it's interlaced?? DVD2AVI always says "PAL interlaced", but usually it's not (99% are not interlaced).

The inversetelecine() filter is just one option, Decomb (telecide and decimate) is another - the process is always called inverse telecining, no matter which of the plugins you use.

Convolution3d is a plugin, you have to load the dll in the avisynth script first. You can download it here: http://hellninjacommando.com/con3d/

[ChannelK]

@theReal, i never metioned anything about interlacing in this thread, the other thread what i have already refered to was about interlacing, which concerns another dvd that was a tv series put on dvd, thus interlaced. here I am just trying to figure out the effects of GMC.

But thanks for the help (re. con3d)

Ps. Teleciding (without decomb) the PAL dvd that was interlaced as suggested in the other thread worked very well.

[theReal]

it turned out to be exactly half of the original res, which also allowed me to achive a higher compresibility result by not using any deinterlacingI didn't see that you were referring to another thread with this.

[ChannelK]

HAHAHAHA, Oh i see the post you were reffering to, yes it seems that entry perhaps should have been on the other post, i think perhaps it was meant to be, but not written the way it was. The results of a clutter taskbar i expectand trying to do to many things at once. Perhaps this thread should be closed before.....lol