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VSO ConvertXtoDVD v4.x Guidelines / Recommendations

Posted: Wed Dec 02, 2009 5:47 am
by Netranger
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[NOTE]

This 'guide' is based on info that i've found out there, from personal trial and errors and from comments/recommendations by a friend of mine that works with Video related stuff as a profession and have done so for around 20 years.

It's up to the reader of this 'guide' if they want to give the contents of it a try or not.




Changelog :


2010-06-12
Project lengths adjusted and text adjustments/tweaks (#5)
Resize Filters text adjusted/tweaked (#7)
Multicore Processor Section Added (#8 )
Re-numbered old 'sections' (Old '8' is now '9' etc.)

2010-02-22
Fixed some spelling errors.
New Download link added for AVI-Mux GUI (v1.17.8.3)

2010-01-15
Text adjustments/tweaks.

2010-01-05
Project lengths adjusted and text adjustments/tweaks (#5)

2009-12-07
Made some text adjustments/tweaks to #5

2009-12-01
Fixed some spelling errors etc.

2009-11-26
Info added to #5

2009-11-25
Made some text adjustments/tweaks

2009-11-13
Made some tweaks and added info in the 'guide'


Download :

Code: Select all

http://hotfile.com/dl/47928509/81f3ae4/CX4x_Guidelines_Recommendations_2010-06_12.rar.html

Posted: Wed Dec 02, 2009 9:20 am
by ckhouston
Looks good to me except
ConvertX uses a near CQ (constant quantization/quality) encoding mode. CQ encodes are not controlled by bitrate other than the limitations imposed by DVD standards. In other words, the user has no control over the bitrate to be used. CQ encodes produce bitrates that depends primarily on the scenery content of the movie, and can vary widely between videos with different content.

MPEG Encoder Modes Explained
http://tangentsoft.net/video/mpeg/enc-modes.html
Cx2D can only do a near CQ encode for projects that will not fill the DVD. It must impose an average bitrate for projects that will fill the DVD, so the encode for those projects essentially becomes the less desirable bitrate controlled VBR that most people are familiar with.
I recommend that the encoding options are set manually and that these project lengths is used instead of the Automatic option.

'Short projects' - up to 2.5 hours
'Medium projects' – 2.5 to 4 hours
'Long projects' - 4 hours+

These project lengths was recommended to me by a friend of mine that works with video encoding as a profession after that he have done a number of tests.
Those recommended option switch times will cause the DVD to be filled for almost any video type. Switch times that will generally keep the DVD from being filled, for typical video, so the CQ encode can be done are given in the Sticky topic http://forums.vso-software.fr/2-how-man ... t7894.html

Short Projects - up to 80 minutes
Medium Projects - 80 to 160 minutes
Long Projects - more than 160 minutes

Those recommendations are based on extensive analysis (not just personal opinion of viewed conversions) of many tests as detailed in that Sticky and many other posts.
Always have the 2-Pass encoding option enabled. This will help out with the bitrate distribution and improve the quality of the finished output.
Leaving 2 pass enabled does no harm. But it is a waste of time in most cases except for the special cases mentioned in the Sticky, namely
Conclusions

I personally do not find much benefit for using 2P except for a couple of cases. If pixelation in dark scenes is a problem for projects less than about 110 minutes, try SP 2P. And for projects longer than about 160 min, use LP 2P if you want the best possible and are willing to allow the increased conversion time for 2P.
2 pass does not significantly improve bitrate distribution, and therefore quality of the finished output, for projects that do not fill the DVD. It makes a significant difference only for projects that do fill the DVD. However, it is best to switch to an encoding option that does not fill the DVD, if possible, than to rely on 2 pass to make up for using the wrong setting.


Update 3/5/2010: I did discuss this with Netranger privately as he suggested. I just discovered he has now changed his recommendation to change encoding options at 120 and 160 minutes. Better but still doesn't agree with my researched guidelines of 80 and 160 minutes.

I recommend using the Automatic encoding option because it now switches options with my test file at 78 and 156 minutes, very close to my guidelines. The text in settings does not reflect that yet though.

Posted: Wed Dec 02, 2009 1:06 pm
by Netranger
Thanks for your comments, I guess we all have different opinions, as this section is not a "discussion" section, so can we have a discussion about this in the other forum or through PM.