I have a newbie question, I'm totally new in encoding and after I encode DVDs I got different aspect ratio. I tried to calculate like that "original height / original width x new width = new height" but this didn't work at all with me, any idea?
+ Reply to Thread
Results 1 to 7 of 7
Let the converter do it automatically.
WHat do you convert with? ANd what format?
Thanks for your reply, Baldrick, this my way:
1 - Play the DVD in VLC (I prefer this because it seems to always respect the correct AR, unless the DVD producers messed up - in which case face/circles will appear distorted.)
2 - Do a print screen(default key is alt+ctrl+s) in a scene with bright colors on the edges (so choose an outside scene). You should typically get a screecap with one of those resolutions: 1024x576, 720x576, 800somethingx480, 720x480, and maybe 640x480 as well(I think this was for fullscreen NTSC)
3 - Open the screencap in an image editing app. Select and crop the image without any black borders. If the faces/circles looked wrong then manually resize only the horizontal resolution(disable any "keep aspect ratio" option) until they look right.
4 - Note down the resolution that resulted(I call this the Original Resolution). Also, divide width/height so you get smth like 1020/552=1.85:1 This is the Display Aspect Ratio
Don't set the SAR. MeGUI will take care of that. If you've enabled anamorphic encoding in the script creator, just apply your desired cropping. If you use the anamorphic option "encode non mod16" there'll be no resizing. MeGUI will set the SAR and the remaining picture (after cropping) should display correctly, assuming the player in question supports anamorphic video in MKVs/MP4s. All software players do. Many hardware players (TV media players, Bluray players) don't. They ignore the aspect ratio and will display the video as though it consists of square pixels. If your hardware player is one of those, you're better off resizing to square pixels (ie disable anamorphic encoding). I resize to square pixels this way:
Go into the Script Creator's Avisynth profile configuration. It's the Config button next to the drop down box which will probably have *scratchpad* displayed. In there you'll find the setting to enable "upsizing". It's disabled by default which I find rather silly.
Assuming no cropping, you'll now be able to resize a DVD to dimensions such as 1024x576 or 854x480 etc. With the "upsizing" option disabled you can only resize to a maximum width of 720. Either way you're resizing to square pixels (anamorphic encoding disabled). 1024x576 will retain more detail than 720x404 etc, but for a given quality the file sizes will also be larger. I often resize 16:9 PAL DVDs to 960x540 as it's a compromise, but still 16:9. Once again MeGUI will take care of the SAR (which will be 1:1 when resizing to square pixels).
In the Script Creator window under "Input DAR", MeGUI will display the input aspect ratio. By default it uses ITU resizing for DVDs so you'll see something like ITU NTSC 16:9 or ITU PAL 4:3 etc. You can change it if you like. Once that's correct you can let MeGUI take care of everything else.
Your method of checking circles for roundness using screenshots is sound..... I do the same myself if I'm not sure.... but MeGUI will resize a little differently according to which Input DAR you use, or for anamorphic encoding it'll set the SAR a little differently, so if the correct Input DAR is used, encoded circles should be round. Here's a quick example of what MeGUI does.
Open a 16:9 DVD and select 16:9 as the Input DAR. Enable anamorphic encoding. Without cropping switch to the script tab. You'll see 16:9 at the top. Change the Input DAR to the appropriate 16:9 ITU DAR (PAL or NTSC). Check the script tab again. The display aspect ratio is no longer 16:9. MeGUI uses the DAR and resolution in the script to set the SAR. If you crop the video the DAR in the script will change. MeGUI knows what it's doing.
For anamorphic encoding let MeGUI set the SAR. When resizing to square pixels adjust the cropping and resizing a little if need be to get the aspect ratio distortion close to 0%. I generally aim for something less than 0.1%, but it depends how fussy you are.
My rule of thumb for setting the correct Input DAR (others may disagree)....
99.99% of 4:3 DVDs use ITU resizing so 99.99% of the time ITU 4:3 PAL or ITU 4:3 NTSC as the Input DAR will be correct.
The majority of 16:9 DVDs, unless they're very old, use straight 16:9 resizing. PAL or NTSC, just select 16:9 as the Input DAR (no ITU). If a 16:9 DVD has a lot of black crud down each side which needs cropping (around 12 pixels or more) it probably uses ITU resizing. There's no guarantee that'll be correct every time, but in my opinion it will be most of the time.
PS For the record, every software player I know of always resizes DVDs to exactly 16:9 or 4:3. They don't use ITU resizing. Once the video is encoded though, they should display it using the exact aspect ratio set when encoding.
Last edited by hello_hello; 19th Mar 2014 at 06:19.
Last edited by TeNSoR; 19th Mar 2014 at 11:54.