djloewen
27th April 2010, 22:57
I'm making the transition from Gordian Knot to MeGUI, from DivX to x264 and from mp3 to aac. I'm very picky about my workflow, I like to understand exactly what's going on every step of the way to be sure that I'm using the best possible tools/filters/settings for my own needs. As such, I suspect I'll have more questions over the next few days, but be assured that I'm searching extensively before posting!
1.)
As much as there are a number of previous posts on the subject, "Clever Anamorphic Encoding" is still a bit of a mystery to me. My intention is to never use crop, and to only use resize if I want to bring 1080 down to 480. For anamorphic sources such as DVDs, I want anamorphic. Now, I would have imagined that the very act of choosing the "Input DAR" from the drop-down list would be all that I need to do. In fact I see that if I check "Clever Anamorphic Encoding", two lines are added to the script.
Then, when i hit "save" and get to the (second) video preview window, I can check the "DAR" box to show the correct AR, but only if I previously checked the "Clever" box. Otherwise I can still preview it correctly by re-choosing the AR from the drop-down list.
Presumably then, the way anamorphic is accomplished in the final encoded video is by setting a switch in the x264 line. Whether or not I check the "Clever" box, however, I see no such addition in the preview line at the bottom of the x264 config page.
The reason I'm posting this rather than encoding various videos and examining the results is that I'm hoping for a little clarification on what's actually going on here, rather than just some black-box testing. Particularly confusing is the MeGUI documentation:
"Clever (TM) Anamorphic Encoding: Checking this box will enable anamorphic encoding.This is for 16:9 (squished )features and ensures the aspect ratio choice selection at the last step is accurate. It is usually safe to leave this off for 4:3 features."
-4:3 and 16:9 are both anamorphic from a DVD source, so if "checking this box will enable anamorphic encoding", then why should I only check it for 16:9 sources?
-"usually" safe? When is it not safe for 4:3 features?
What's going on? What, exactly, does the "Clever" option do?
2.)
Colormatrix. Again, I've found some posts, none of which ease my troubled mind. I never used it with Gordian Knot, although maybe I should have. Anyway MeGUI says "Safe to leave enabled 99% of the time" - so, again, what's the other 1%?
The colormatrix documentation suggests that it was created specifically when using the chain MPEG-2 -> DivX/XviD -> TMPGEnc/QuEnc, which I'm obviously not doing. The bottom line is that I want the colours to be exactly accurate, but it's not clear to me what that entails. A little guidance would be much appreciated :) If it's smart enough to pass-through anything that doesn't need adjusting then great, and if all DVD sources need adjustinig then that's good to know, but I'm sure you can understand my nervousness and just sticking a filter in the chain without knowing what's going on! (btw I also encode from Blu-Ray sources - is it not used for those?)
3.)
Using the automated "DG creator" process, I am never asked whether I want to "honor pulldown flags" or to "force film". Is this automatically detected? If so, at what "FILM %" point does it switch from one to the other? Also as a lesser issue, do I have the ability to change the iDCT algorithm in the automated process? (Presumably the "DG creator" is just sending a command-line to DG - is there a way to see or alter that command-line?) And yes, I'm aware that I can just run DG the old-fashioned way :)
Thanks in advance!
1.)
As much as there are a number of previous posts on the subject, "Clever Anamorphic Encoding" is still a bit of a mystery to me. My intention is to never use crop, and to only use resize if I want to bring 1080 down to 480. For anamorphic sources such as DVDs, I want anamorphic. Now, I would have imagined that the very act of choosing the "Input DAR" from the drop-down list would be all that I need to do. In fact I see that if I check "Clever Anamorphic Encoding", two lines are added to the script.
Then, when i hit "save" and get to the (second) video preview window, I can check the "DAR" box to show the correct AR, but only if I previously checked the "Clever" box. Otherwise I can still preview it correctly by re-choosing the AR from the drop-down list.
Presumably then, the way anamorphic is accomplished in the final encoded video is by setting a switch in the x264 line. Whether or not I check the "Clever" box, however, I see no such addition in the preview line at the bottom of the x264 config page.
The reason I'm posting this rather than encoding various videos and examining the results is that I'm hoping for a little clarification on what's actually going on here, rather than just some black-box testing. Particularly confusing is the MeGUI documentation:
"Clever (TM) Anamorphic Encoding: Checking this box will enable anamorphic encoding.This is for 16:9 (squished )features and ensures the aspect ratio choice selection at the last step is accurate. It is usually safe to leave this off for 4:3 features."
-4:3 and 16:9 are both anamorphic from a DVD source, so if "checking this box will enable anamorphic encoding", then why should I only check it for 16:9 sources?
-"usually" safe? When is it not safe for 4:3 features?
What's going on? What, exactly, does the "Clever" option do?
2.)
Colormatrix. Again, I've found some posts, none of which ease my troubled mind. I never used it with Gordian Knot, although maybe I should have. Anyway MeGUI says "Safe to leave enabled 99% of the time" - so, again, what's the other 1%?
The colormatrix documentation suggests that it was created specifically when using the chain MPEG-2 -> DivX/XviD -> TMPGEnc/QuEnc, which I'm obviously not doing. The bottom line is that I want the colours to be exactly accurate, but it's not clear to me what that entails. A little guidance would be much appreciated :) If it's smart enough to pass-through anything that doesn't need adjusting then great, and if all DVD sources need adjustinig then that's good to know, but I'm sure you can understand my nervousness and just sticking a filter in the chain without knowing what's going on! (btw I also encode from Blu-Ray sources - is it not used for those?)
3.)
Using the automated "DG creator" process, I am never asked whether I want to "honor pulldown flags" or to "force film". Is this automatically detected? If so, at what "FILM %" point does it switch from one to the other? Also as a lesser issue, do I have the ability to change the iDCT algorithm in the automated process? (Presumably the "DG creator" is just sending a command-line to DG - is there a way to see or alter that command-line?) And yes, I'm aware that I can just run DG the old-fashioned way :)
Thanks in advance!