Forum archive - Defining the MB in movies when encoding in GK

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Defining the MB in movies when encoding in GK

Fire Foxer posted 2009 Nov 04 18:46

hello how can i know how much to define the mb in movies that im encoding without doing any compression tests is the square when become's yellow is telling that this is too low? i mean like this one:

manono posted 2009 Nov 04 19:10

You won't know the resulting quality beforehand without doing a compression test. It takes only about 10 minutes to do so why insist on not doing it? It's one of GKnot's best features. The B/P*F is only a guideline and pretty much useless in determining the resolution and file size you should choose. However, the old guideline was 0.200 for 1 CD encodes and 0.270 for 2 CD encodes. But since it all comes down to the compressibility of the movie, those guidelines don't mean a whole lot.

Fire Foxer posted 2009 Nov 04 19:23

hi manono how can i do this compression test in gk? i tought that it can only be done in VD by video analysis pass or something like that

manono posted 2009 Nov 04 20:53

The compression test is explained in the GKnot guides, like this one maybe: http://www.rita.lt/guides/GKnot_DVDtoAVI.htm Near the bottom is the section on the compression test, a section beginning with: : Compressibility Check: You can run a compressibility check to determine more accurately what your resolution should be set at to make the bits/pixel more accurate, although this adds time. Results of 60-80% are most desirable, but good quality can also be attained as low as 40%.

jagabo posted 2009 Nov 04 21:13

Since you don't seem to care so much about file size why don't you just switch to constant quality encoding?

manono posted 2009 Nov 04 23:36

jagabo : Since you don't seem to care so much about file size why don't you just switch to constant quality encoding? If using GKnot then you only do 2-pass encodes. Of course, there's nothing to prevent Fire Foxer from taking the GKnot generated AviSynth script and opening it in VDub(Mod) to do the encoding. Then he can easily do constant quality encodes.

Fire Foxer posted 2009 Nov 05 03:15

ok i did this comression test he encoded a file called LastCompCheck.avs and when he finished the file disappeared where can i see the results of the comp check? and when i started using gk in the begining he did the file size automatically why now he doesn't do it?

manono posted 2009 Nov 05 12:47

Do you see the 2nd picture you uploaded above? Do you see where you circled 0.191? Just below that is the 'Load' button. Press that and load the vdenc.log from the compress test. Then you'll see this: You'll also notice that because the source on which I tested is very hard to compress, I needed a B\P*F figure of 0.615 to get a 65% compress test result. I think you've asked about your file size problem before. Go into VDubMod->Video->Compression and check to see if there are 2 XviDs listed there. If so, try and use the other one for your GKnot encoding and see if that makes a difference. You might have to remove one of them in Add/Remove Programs before testing. I'm just guessing here. I have 2 myself and have both GKnot and AutoGK installed, but didn't have any problem doing that GKnot testing a while ago.

Fire Foxer posted 2009 Nov 05 13:11

ok did it + Compressibility Check: Pressed "Load"-Button. + Compressibility Result: 0.219 Bits per Pixel. + Compressibility Result: 180224 Pixels 704 Blocks. Compressibility Check: 1 what does it mean? how can i know with this information how much mb should be the movie?

manono posted 2009 Nov 05 13:30

What percentage did it give you? That's the important number. You have to have already chosen a resolution, audio bitrate, and final file size. If the resulting percentage is lower than you might like, then you can adjust one or more of the parameters, or add a cleaning filter to try and make it more compressible.

Fire Foxer posted 2009 Nov 05 13:47

no such thing and i also deleted the vdenc.log file and opened new season of movie with d2v file and did compressebility check and it didn't saved me any file name vdenc.log maybe i skipped something?

manono posted 2009 Nov 05 14:15

You open the D2V and get a picture of the video. Then you do your cropping and resizing, choose the final size and the audio bitrate. Click 'Save And Encode' in the bottom left of the picture and you'll see: Then make yours like the picture, with 5% ticked in the compress test box. Then hit the 'Save And Encode' button, do some other stuff in the Encoding Control Panel to which it'll send you, 'Add Job To Encoding Queue', and 'Start Encoding'. You should get a vdenc.log which when loaded should get you a compress test percentage. I can't play that video you uploaded.

Fire Foxer posted 2009 Nov 05 15:21

so only in the end of the encoding i will get the vdenc.log?

manono posted 2009 Nov 05 15:53

Fire Foxer : so only in the end of the encoding i will get the vdenc.log? If you set it up to do the compress test (tick the 5% box), then all it encodes is the 5%. You'll do the main encode of the entire movie separately, perhaps after adjusting the resolution and/or the final size. If you take a look at the .avs created for the compress test, near the bottom you'll see this: : #  COMPRESSIBILITY CHECK #  !!!!Snip Size now has to be 14 for use in GKnot! SelectRangeEvery(280,14) That says to encode 14 frames out of every 280 frames.

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