Hi. I've done a fair bit of searching but haven't yet found a definitive answer to this: given that anamorphic is all to do with widescreen images, am I correct in saying that, when converting a DVD containing 4:3 material, I can happily set 'anamorphic' to 'none' (Handbrake)?
Assuming that's right, next question. Handbrake, using no anamorphic, sets a resolution of 720x558. I use PotPlayer to test for correct AR as you can switch easily between DAR and other ratios. With a 720x558 movie, DAR and 4:3 are not quite the same (which I like them to be).
If I set the resolution to 720x540 (and uncheck 'Keep Aspect Ratio') I get a movie which stays exactly the same size whether PotPlayer is set to DAR or 4:3. Is this a good strategy or are there better ways of ensuring a 4:3 ratio?
For example, would it be better to set a size of 720x544 on the basis that the file is more efficient if the dimensions are divisible by 16?
Thank you for your time.
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720* 544 is preferred.
But 768 * 576 is better since there is then no resizing on the vertical which could result in interlacing issues.
Handbrake are concerned anamorphic means the pixel aspect ratio isn't 1:1 -- ie, the frame aspect ratio doesn't match the display aspect ratio. DVD uses a 720x480 (3:2 FAR) or 720x576 (5:4 FAR) frame to hold the 4:3 or 16:9 DAR image. None of those is square pixel, all are anamorphic.
Yeah, DVD is always anamorphic, widescreen is just "even more anamorphic".
Thanks all. To date, my conversions with 'anamorphic - none' all look fine. I've done samples with 'strict' and 'loose' (all with 4:3 content remember) and can't see a difference. But is there some kind of 'under the bonnet' difference, perhaps? Would you go none, loose or strict with a 4:3 DVD?
You can't really see a 1 or 2 percent difference in aspect ratio unless you A/B switch, use a tape measure, or look for small black pillarbox or letterbox bars.
Thanks, but it wasn't that I was thinking of, it was picture quality (should have clarified). Is PQ affected by none/loose/strict?
Any time you resize the frame you reduce picture quality.
Well now, that's given me something else to think about. I now have two ways of getting a copy of my DVD in 4:3 (one) specify a size of 768x576 or (two) specify a size of 720x576 and then run the resultant mkv through mkvtoolnix changing the AR to 4:3.
Does anyone think that one method's better than the other?
As regards anamorphic (I'm currently setting Handbrake to 'none'), does anyone think it should be used when the DVD content is 4:3?
Keeping the original frame size and flagging the SAR/DAR is preferable in my opinion. But not all players will obey the SAR/DAR flags in h.264 MKV videos -- 720x576 4:3 DAR videos will play as 5:4 DAR in some players. So you have to decide which is best for you.
Handbrake probably always sets an aspect ratio. For anamorphic none it probably uses 1:1 for the pixel aspect ratio. If you run the MKV through MKVMergeGUI and change it, the video stream could have a different aspect ratio to the one written to the MKV container, then a player has to decide which one to use....
You might be misunderstanding a few things.
The display aspect ratio of the DVD is 4:3, including any black bars and or crud around the edges. If Handbrake crops the crud (is auto-cropping enabled?) the display aspect ratio will probably change as some of the "picture" has been cropped. If you want exactly 4:3 you need to manually adjust the cropping to make it 4:3, but that's another story....
When the resolution and aspect ratio aren't the same, that's the definition of anamorphic. 720/576=1.25, not 1.33. The pixels aren't square as such..... therefore it's anamorphic, but while the source type might influence your decision as to which one to use, Handbrake's options are more about the output....
Anamorphic none = resize to square pixels. When "keep aspect ratio" is checked, Handbrake will work out the correct resizing. Any cropping is accounted for. An anamorphic source makes the calculations a bit harder, but that's Handbrake's job. You'd generally use "anamorphic none" when the source is non-anamorphic.... square pixels in, square pixels out.... but the principle is the same for anamorphic sources. Some people prefer to resize everything to square pixels.
The idea of anamorphic encoding is to not change the shape of the pixels. If the source has to be stretched by "X%" on playback to display correctly, the same will apply to the encoded version.
Anamorphic strict is the "never change the shape of the pixels" option, because resizing is disabled. Cropping is allowed, but it'll likely change the display aspect ratio, because it removes some of the "picture" (even if it's just crud). What's left is encoded "as-is".
Anamorphic loose works much the same way, only with resizing enabled. Generally you'd only re-size a little (otherwise the benefit anamorphic encoding is reduced and you might as well use anamorphic none). Resizing doesn't change the display aspect ratio as it normally would (it doesn't stretch or squish the picture) because the shape of the pixels (pixel aspect ratio) is altered to compensate.
You can use anamorphic encoding regardless of the source, but it's predominantly used for anamorphic sources.
Pick the method you prefer and let Handbrake take care of the math and the aspect ratio while it knows best.
Last edited by hello_hello; 29th Mar 2016 at 21:52.
Hello hello_hello and thank you so very much for that. It's really clarified things for me and that you would take the time to go into such detail is amazing. You're a star.
Yes, I probably did have automatic cropping enabled in past encodes. I just did a test using 'strict' with autocrop ticked (accidentally) and the output file was slightly different when played using the 4:3 and DAR settings of PotPlayer. Did the test again (strict plus custom crop 0,0,0,0) and the output file was perfect, no need for using toolnix to change the DAR (although that strategy was fine – my lounge TV/WDTVLiveHub recognised the DAR).
Looks like I've now found the ideal setting for my PAL interlaced 4:3 DVDs: decomb/bob/50fps/strict/NoCrop.
Thank you once again.
If you don't crop 4:3 DVDs with widescreen material you will retain their letterbox bars. When you play those videos on a widescreen display that 4:3 frame will be pillarboxed to fill out the display. So you'll end up with big black bars all around a tiny picture. Better to crop.
Thanks, jagabo, although I'm not sure what kind of DVD that would be. Do you perhaps mean a DVD of an old TV program in 4:3 but with trailers for recent widescreen stuff?
Many old widescreen B movies are released on 4:3 DVD because they were made from studio video tapes.
Those 4:3 DVDs of yours aren't really 4:3. It's a PAR thing. Old school vs new school. It's a long story, but your 4:3 DVDs are actually a tad wider than 4:3. The Handbrake explanation is at the bottom of this page: https://trac.handbrake.fr/wiki/AnamorphicGuide#itu
Aside from the fact the whole page seems out of date and the PAR part might be hard to follow, the final claim regarding HandBrake's PAR cleverness isn't one I've ever witnessed.
And yes, when Potplayer resizes to exactly 4:3 it's getting it wrong, just as every other software player does. And most hardware players, now everything's HDMI.
If you want to be fussy, because I'm guessing your DVDs mostly have a bit of crud down each side anyway, here's how to remove it with Handbrake, still output 4:3, and be more technically correct while you're at it..
I should admit I don't quite understand Handbrake's custom anamorphic setting, but here's what works for me.
Open your DVD.
Select Anamorphic Custom.
Change cropping to "custom" and crop 8 pixels from each side. None from top and bottom.
Set the width to 704x576. The modulus doesn't matter.
Set the display width to 768.
Set the PAR width to 12 and the PAR height to 11. That seems to be for entertainment value only. The resolution and display width seem to determine the PAR.
If all goes well you'll have a 704x576 encode that's exactly 4:3, and much of the crud down each side will be gone. There's still no resizing involved.
To be extra sure you can check HandBrake's Activity Log. What you want to find buried in there is something like this:
[17:44:06] + storage dimensions: 704 * 576, mod 4
[17:44:06] + pixel aspect ratio: 12 / 11
[17:44:06] + display dimensions: 768 * 576
The reason I've never got my head around the custom settings, aside from the fact I don't use HandBrake much, is because they can be set independently despite the fact they're not independent. For example the storage dimensions and the display dimensions dictate the PAR, or the PAR and the storage dimensions determine the display aspect ratio etc. Anyway, if you set them all correctly you shouldn't go wrong.
Wow, thanks, I'll give that a go.