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View Full Version : AutoMKV Aspect Ratio & other questions


valnar
30th December 2007, 21:34
OK, new to x264 and AutoMKV. 'Came from years of DVD shrink /DVDRebuilder without worries of PC playback, cropping or aspect ratio concerns. It's been even longer since I did DIVX/XVID stuff with (non-auto) Gordian Knot. I have forgotten everything I learned about AR since then.


Sizing:
I read the Wiki on AutoMKV but am still fuzzy on some of the definitions as well as AutoMKV best practices. I used Gordian Knot ages ago for XVID files and because of it's Bits/(Pixel*Frame) calculator with Compressibility test, it helped me know how big to make the output file and approximately what I could expect the quality to be.

1) Can I do that in AutoMKV? I noticed people try to size DVD's, HD 720p and HD 1080p to exactly DVD-5 or DVD-9 sizes (for obvious reasons) but is there a way to know how good the encode will turn out to be? I may or may not care if it fits.


Aspect Ratio options:
I will not want to resize any of my movies. My purpose is to preserve almost identical quality on my DVD's (soon HD-DVD).

2) Do users generally trim the vertical black bars on widescreen movies? If so, under what circumstances would you use the Anamorphic or Force ITU resize options?

3) What would be the circumstance to use the "PAR in XviD/X264" option? Doesn't NONE just automatically choose the correct one?


Compatibility with hardware players and DXVA on video cards:
There have been some posts about H.264 options and compatibility with ATI AVIVO and NVidia with DXVA (HD) acceleration. I also plan on buying the Sage HD Extender which has the Sigma Em8620 chip, which supports H.264 MPEG4 HP 4.1. Unfortunately, I don't know yet what the limitations of this hardware player is (and others like it).

4) In reference to (2) above, would it be best to leave original black bars in from DVD rips? Would that mess up the aspect ratio in hardware players?


AutoMKV profiles:
I'd rather learn from the best than spend weeks through trial-and-error, so forgive the questions which are easily figured out on my own.

I plan on ripping and converting my (HD)DVD's for viewing mostly through a PC, but with the intent on the widest compatibility possible and minimal quality loss compared to the original. Which profiles are best for DVD and HDDVD-BluRay?

5) Any special profiles I should choose to increase both the quality and compatibility in hardware players or PC Video DXVA? If so, what do I lose by choosing said options over the basic 2_Pass_Balanced or 2_Pass_Better_Quality profiles?
I'm willing to sacrifice some file size and use generic options in order to increase compatibility.

That's all I can think of for now. Thanks!

Robert

buzzqw
31st December 2007, 15:57
1) automkv will run an internal compression test (as autogk) for determining a good visual movie. the compression test , as usually , is based on compressione profile (the codec profile) and avaiable space (disk settings)

remember that Bits/(Pixel*Frame) mean absolutely nothing. every film has its bitrate and moreover new codecs (x264) have "blasted" away this formula..

i can suggest to first try a constant quality encoding on a small sample, with your codec (xvid or x264), then use the approsimative size for judging overall quality

2) i usually crop, but for "true" trasparent quality (and enough cpu to spare) i will not crop.
The Force Itu is usually to check.. most depends on source film. The dvd standards will have ITU.. but not always..
Again is to your feel, and check, to signal or not ITU.
About anamorphic i have mixed feeling.. never used.. but i am a little bit confused about this options....
3) About signaling par.. isn't needed if you mux in MKV container

4) no idea

5) the difference between balanced and better aren't so high. I use balanced if i can have enough "disk settings" to spare.. but if i need a smaller encoding i will go for better/insane.

Remember that profile are more tuned for speed/quality, so isn't so obvius or so VISIBLE the difference between a "balanced" and a "better" profile

If i have "unlimited" or big enough HardDisks free i will use the Constant Quality profile.

best regards

BHH

valnar
1st January 2008, 02:12
Thanks Buzz. Your program is wonderful so far. The perfect amount of options.

I think I will go with my own constant quality profile I figured out within the last 24 hours. It melds the best of PS3/XBox compatibility with a quality one-pass.

I'm doing an encode this very moment so I don't know how it will turn out, but this is for DVD's. It trades file size for compatibility (I think).

--pass 1 --crf 20 --stats "F:\DVD\.stats" --progress --keyint 300 --bframes 3 --qpmin 10 --qpmax 51 --no-psnr --mixed-refs --trellis 1 --ref 3 --filter -2,-1 --direct auto --vbv-maxrate 20000 --me umh --no-ssim --level 4.1 --weightb --b-rdo --bime --analyse p8x8,b8x8,i4x4,i8x8 --8x8dct --threads auto --thread-input --no-dct-decimate

-Robert

buzzqw
1st January 2008, 10:16
it's a good command line.. the resoult will satifact you :)

BHH