Hanbrake Anomorphic Settings

[comp1mp]

I am a little confused about the anamorphic settings for HandBrake.

My source is a 1080p H264 encoded MP4 file. It is not anamorphic.

HandBrake defaults anamorphic to Loose with a modulus of 2.

What will happen if I select None for Anamorphic?

[aedipuss]

anamorphic was used for dvds. not a good choice for mp4. do it as 1:1 square pixel for mp4.

[hello_hello]

Anamorphic "none" always resizes the video to "square pixels". Or the output video always has a pixel aspect ratio of 1:1. As does your source video. The resolution and display aspect ratio are one and the same. If you open a video (as an example) with 1280x720 dimensions and resized it to 1278x720, the picture would end up squished a tiny bit.

When you use anamorphic "loose" and you resize, Handbrake can adjust the pixel aspect ratio to keep the display aspect ratio a little more accurate (effectively it's adjusting the display aspect ratio). For example if you resized that same 1280x720 video to 1278x720, Handbrake would probably still show 1280x720 as the display size because it's adjusted the pixel aspect ratio a tiny bit so the display aspect ratio remains unchanged.

Anyway, if you don't resize, and the source video is not anamorphic, "anamorphic none" and "anamorphic loose" with a modulus of two should result in exactly the same output. As would anamorphic strict. The output video would have the same pixel aspect ratio as the input video (it always does for anamorphic strict as it doesn't allow you to resize). It's only when you resize the result might be slightly different, as with anamorphic none the output resolution and display aspect ratio are always the same. With anamorphic loose they can be slightly different.

I resize everything to square pixels myself, but I use a calculator such as this one to adjust the cropping and resizing for minimum aspect ratio distortion. If you just resize with anamorphic none and a modulus of 2 using Handbrake though, the resizing will still be pretty accurate. Using anamorphic loose with a modulus of 2 could potentially make it even a tad more accurate of your player supports anamorphic video.

[sopclod]

I have a similar question. I'm resizing HD movies which are 1920x1080 to fit my handheld device which is 1280x720. However when I tell handbrake to preserve the aspect ratio it want so to crop it or resize it to 1280x568. Why is it doing that?

[comp1mp]

Anyway, if you don't resize, and the source video is not anamorphic, "anamorphic none" and "anamorphic loose" with a modulus of two should result in exactly the same output. As would anamorphic strict. The output video would have the same pixel aspect ratio as the input video (it always does for anamorphic strict as it doesn't allow you to resize).

Nice. I posted this thought on HandBrake forum, and you have confirmed it.

The interesting thing is, I have seen some posts about blu ray not being anamorphic. In reality some blu rays are anamorphic, just in the reverse of DVD (2.x and above). ie aspect ratios which exceed 16.9 and must be letter boxed appropriately to display as accurately as possible.

For a smart default, I have created a profile which uses Anamorphic Strict for sources which are comparable to what I am doing.

Thanks!

[Selur]

In reality some blu rays are anamorphic,...

Can you name an original Blu-ray which is anamorphic and HD (720p or 1080p)?
Because afaik. HD requires a 1:1 PAR, so it can't be anamorph. (different story for AVCHD, there's also 1440×1080)

[hello_hello]

The interesting thing is, I have seen some posts about blu ray not being anamorphic. In reality some blu rays are anamorphic, just in the reverse of DVD (2.x and above). ie aspect ratios which exceed 16.9 and must be letter boxed appropriately to display as accurately as possible.

Back in the dark ages, when most DVDs were 4:3, widesceen images were placed on them by adding black borders top and bottom. As 16:9 DVDs became more mainstream, widescreen images were also placed on them by adding black borders top and bottom. The industry decided to call the 16:9 widescreen DVDs "anamorphic". I guess it does fit the definition of the term. http://en.wikipedia.org/wiki/Anamorphic_widescreen
No DVDs use square pixels though, so if you consider any video which doesn't use square pixels as being anamorphic, then all DVDs are anamorphic. Generally when any video with non-square pixels is being discussed here the description of anamorphic would be used.

There's no such thing as anamorphic Bluray (Edit: looks like I got that wrong. corrected in post#12). It's all square pixels (the exception being support for the old DVD resolutions). http://en.wikipedia.org/wiki/Blu-ray_Disc#Video
The Bluray resolution is 1920x1080. When it contains a widescreen image, black bars are used top and bottom for a total of 1920x1080 and a total aspect ratio of 16:9, but there's nothing anamorphic going on.

I have a similar question. I'm resizing HD movies which are 1920x1080 to fit my handheld device which is 1280x720. However when I tell handbrake to preserve the aspect ratio it want so to crop it or resize it to 1280x568. Why is it doing that?

Much video has an aspect ratio wider than 16:9. In order to encode it using a 16:9 resolution, black bars are added top and bottom. As an example, the total Bluray resolution may be 1920x1080, but only 1920x800 of it might be picture (2.40:1 aspect ratio). The rest is just black top and bottom.
Handbrake automatically crops the black bars so all you're encoding is the actual picture. On playback, the player adds them back to fill the screen. So after cropping the black bars and resizing to 720p, resolutions such as 1280x(something less than 720) wouldn't be uncommon. Generally it's still considered 720p though.....
You either encode it at 1280x720 without cropping the black bars or you remove them and encode at 1280x568. Either way, the actual picture is being encoded at exactly the same resolution.

[_Al_]

1440x1080 anamorphic Blu-Ray is allowed, not that I ever done it, but it is in the specs.

[Selur]

@_Al_: are you sure? As far as I know 1440x1080 is only allowed for AVCHD not Blu-ray.

[Cornucopia]

It's allowed on BD also (for 2D).

From the BD spec tech paper (put out by BD forum members):


Scott

[Selur]

Ah, okay. Thanks for clearing that up.

[hello_hello]

Hmmmmmm...... I've never seen a 1440x1080 Bluray, so I simply took Wikipedia's word for it, which labels the 1440x1080 Bluray spec as 4:3, which makes it square-pixelled. According to the chart Cornucopia posted, I guess Wikipedia is wrong, and this pdf seems to confirm the wrongness.

Another article here which seems to indicate Wikipedia is wrong. So I guess I stand corrected and it's possible for a Bluray video to be anamorphic, although I'm sure I've never seen one.

Maybe I'm missing the obvious, but 1440x1080 with a 16:9 aspect ratio.... Why? What's the point?

If the spec included a 1920x1080 resolution with an aspect ratio wider than 16:9 (ie 2.40:1 or something similar) that'd be worth a little excitement. Then you could have widescreen video with a higher resolution instead of wasting it on black bars. Instead though, we have 1440x1080 anamorphic 16:9......

[Cornucopia]

No, it's anamorphic like HDV where the PAR is 4:3, making the DAR 16:9. Basically, directly supporting HDV resolutions (for obvious reasons, since that's where some of the source material would have come from). Yes, the wiki needs to be fixed.

I'm gonna go out on another limb and guess that the next big update to the BD spec (which will likely include 2k/4k and/or UHD, as well as improved color bitdepth, maybe HFR) will possibly also give ~2:40:1 as a DAR option (since some of the GIANT displays now available are coming out with that native DAR and it's always been an option in the general MPEG specs, even since MPEG1).

Scott

[hello_hello]

Ahhhh.... now it makes sense.
Cheers.

[comp1mp]

Much video has an aspect ratio wider than 16:9. In order to encode it using a 16:9 resolution, black bars are added top and bottom. As an example, the total Bluray resolution may be 1920x1080, but only 1920x800 of it might be picture (2.40:1 aspect ratio). The rest is just black top and bottom.

This is why I thought some BR was anamorphic. How can you have square pixels with a 2.40:1 aspect ratio? Or maybe the better question - is the Storage Aspect Ratio square?

[hello_hello]

This is why I thought some BR was anamorphic. How can you have square pixels with a 2.40:1 aspect ratio? Or maybe the better question - is the Storage Aspect Ratio square?

Yes, some Bluray video can be anamorphic. You were correct about that. But not if it's 1920x1080. Then it's always square pixels.
You can have a 2.40:1 aspect ratio because the 2.40:1 video is encoded with black bars added. The video aspect ratio plus the black bars gives you a total resolution of 1920x1080 and aspect ratio of 16:9. If you removed the black bars the remaining picture would consist of 1920x800 worth of square pixels.

Without trying to be to scale......

Green plus black = 1920x1080 or 16:9.
Green on it's own is 2.40:1
So for wider than 16:9 images, some of the resolution is nothing but black (for wider than 16:9 video, you could look at it as the video being reduced in size until it fits inside the 1920x1080 frame). That's why if you crop the black bars when encoding, you can be left with resolutions such as 1920x800 etc. It's all square pixels for 1920x1080 Bluray though.



DVDs work exactly the same way, expect for DVDs the 16:9 picture, which for NTSC would be something like 854x480 (16:9), is squished down to 720x480. On playback, it's resized back to 854x480 to display correctly.
For DVD video, it might start out looking like the first pic below (854x480, which is 16:9) but it's resized to 720x480 (bottom pic) for encoding. On playback it's resized to the same dimensions as the top pic again to display correctly. That's what makes DVDs anamorphic.
DVDs can contain a 16:9 picture, or like the example below, they can have a 2.40:1 picture inside the 16:9 frame, with black bars top and bottom.

[comp1mp]

DVDs work exactly the same way, expect for DVDs the 16:9 picture, which for NTSC would be something like 854x480, is squished down to 720x480. On playback, it's resized back to 854x480 to display correctly. That's what makes it anamorphic. The picture can be 16:9 or it can be wider than 16:9 with black bars top and bottom. It's anamorphic either way because once it's squished down to 720x480 it no longer uses square pixels.

So the DVD uses a Storage Aspect Ratio that is not square? The hardware or software player has to convert what is stored into square pixels?

[_Al_]

in DVD language nothing is square pixel, if making no resize and encoding interlace H.264 you have to set SAR for encoder:

if %ar%==4:3 if %h%==480 if %w%==720 (set sar=8:9)
if %ar%==4:3 if %h%==576 if %w%==720 (set sar=16:15)
if %ar%==16:9 if %h%==480 if %w%==720 (set sar=32:27)
if %ar%==16:9 if %h%==576 if %w%==720 (set sar=64:45)

if %ar%==4:3 if %h%==480 if %w%==704 (set sar=10:11)
if %ar%==4:3 if %h%==576 if %w%==704 (set sar=12:11)
if %ar%==16:9 if %h%==480 if %w%==704 (set sar=40:33)
if %ar%==16:9 if %h%==576 if %w%==704 (set sar=16:11)

for Blu-Ray only those bottom values for SAR are valid

[hello_hello]

So the DVD uses a Storage Aspect Ratio that is not square? The hardware or software player has to convert what is stored into square pixels?

Storage aspect ratio = resolution. It's the same as the display aspect ratio if the pixels are square.

I added a new pic to my previous post which might make the way DVDs work a bit clearer.

By the way....
The pixel aspect ratio is often referred to as SAR (sample aspect ratio) these days. I guess because a differente name makes it more confusing.

I stick with resolution (storage aspect ratio), display aspect ratio, and pixel aspect ratio, as my brain seems to cope okay with those.

When encoding with a program such as Handbrake though, there's no need to think about pixel aspect ratios. Just resize to square pixels or use anamorphic encoding.... whichever you prefer..... and Handbrake will take care of the rest.

[Cornucopia]

Yes, all DVDs use non-square pixels, or to put it another way: Everything is anamorphic (whether 1/4 D1, 1/2 D1, or full D1, whether PAL or NTSC, whether 4:3 DAR or 16:9 DAR).

Now, to clarify on what hello_hello said: on playback DVDs output back to it's stored resolutions, but still using non-square pixels. It's only the display device (or OS graphics display software) that does a rescale to the dimensions and PAR of the display screen. So 4:3 720x480 stored is still 720x480 transmitted, but then becomes 1440x1080 with 2 black pillarboxes of 240x1080 on a 16:9DAR 1920x1080 square-pixelled screen set to retain DAR of source. Or if that same signal were displayed fullscreen on a 16:10DAR 2560x1600 square-pixelled monitor, it would come out to 2132x1600 image with 2 black pillarboxes of 214x1600. Or 1024x768 with no pillarboxing on an old monitor with square pixels.

hello_hello's scenario made it seem as if there were some intermediate "square pixel equivalent" that the source had to be converted to prior to being rescaled again to the (square-pixelled) display, but there really isn't.

BTW, regarding the 1440x1080 4:3PAR BD spec, it may be in the spec, but who's to say that all devices fully/appropriately support it. Just like AudioCD and DVD-Video formats before it, the BDMV format has lesser-used options which might be rarely used and don't get incorporated by all makers, thus making them even rarer. Did you know: there's a 4-channel flag that AudioCDs can use? I've made a test disc for it, but so far NOTHING (except my own test processes) which can decode it correctly. Same with DVD's and their disuse of SDDS audio streams or rare use of JacketPicture, SeamlessMultistory, or full-framerate subs or sub color-cycling.

Scott

[comp1mp]

Great stuff!

Thanks for all of the in depth responses.

[hello_hello]

hello_hello's scenario made it seem as if there were some intermediate "square pixel equivalent" that the source had to be converted to prior to being rescaled again to the (square-pixelled) display, but there really isn't.

There is when I encode, as I don't use anamorphic encoding.

hello_hello's scenario made it seem to me like he was referring to how the video would display with the correct aspect ratio on a square-pixelled display, but without any further upscaling.

[Cornucopia]

Bingo!

I stand "corrected".

Scott