16:9 Aspect Ratio Issues (0.8.5)

[squawkBOX]

I have just updated to 0.8.5 and there is a problem with resizing files to 16:9. I have a few recordings which have been incorrectly encoded in 4:3, so use the 16:9 options to display in the right ratio. In the < 0.8.4 VLC versions, this worked perfectly.

However, since downloading 0.8.5, the 16:9 ratio is incorrect. It appears that the video needs to stretch further to the left and the right.

If I take the video and display it in 16:9 in another application, then the differences can be seen.

[squawkBOX]

Here is an image of the issue:

The image at the top is the actual file being resized by VLC, the image at the bottom has been resized by another application and is how VLC <0.8.4 showed images.

(sorry about the black image at the top - not sure how to switch the image acceleration)

[DJ]

To the best of my knowledge the Crop and Aspect Ratio functions have not changed through the versions of VLC. A video that has not been Cropped is generally 4:3 and the Aspect Ratio will not work as expected. A Video that has been Cropped the Aspect Ratio will work as expected.

[Guest]

Thanks for the reply. However there has certainly been a change in the crop feature when changing from 0.8.4 to 0.8.5

The menu has changed with two other options in it which were not there before (16:10 and 4:5 have been added). The aspect ratio which the content is being changed to is not right as shown by the image above.

I only noticed it as I felt that the people looked wrong. This is confirmed when I play the same video on another PC with 0.8.4 - this displays the image in the right dimension, whereas the 0.8.5 doesn't.

[DJ]

Yes! Additions were made for people who owned wide screen monitors. No reports of improper aspect or crop have been confirmed as a result of this change.

I have tried these functions and it seems that the 16:9 and 16:10 have been reversed since the addition of the 16:10 selection. If for example 16:9 were 720x405 then 16:10 would be 720x450 and this is not how it is responding in VLC 0.8.5 final. These functions were added for convenience. The real problem is improper aspect ratio during the encode process.

[squawkBOX]

Yes, but I'm not sure if you are aware of broadcasting in the UK. We went widescreen before many countries around the world.

i.e. US went from analog(ue) to HDTV

where the UK went from analogue to digital then to HDTV. When we moved to digital, we effectively kept the same analogue ideas but with a digital twist. Take for example 16:9 broadcasts, they are actually broadcast in a 4:3 frame. It is the job of the set top box to decode and display correctly. Therefore they are broadcast over the air in the format that they have been recorded and I am just resizing them to watch them at the right aspect ratio.

However it doesn't explain why other software when converting to 16:9 does it properly and prev versions of VLC does it properly.

I was so sure of the change, I went to a PC where 0.8.4a is installed and installed a 0.8.5 along with it. As you can see the vertical height is correct, its the horizontal that is not.

Both of these 16:9 as been selected and the image at a 1:1 ratio.

[p.s. I have not put the image on the post due to the massive size]

URL: http://www.billyfinlay.com/miscfiles/ratio2.gif

[DJ]

Yes! I am aware of the tests that are going on through out the EEC and the new satellite systems under test.

I'm not quite sure how this applies to an error in VLC though regarding the crop or aspect ratio function. All DVDs have been using a 4:3 format like forever to allow compatibility to older TVs. The crop function was designed to do away with the black borders and the aspect ratio has never worked well for uncroped video. I'm not surprised that the broadcasting tests are being presented in 4:3 uncroped form. But this has little to do with the usage of crop and or aspect ratio other than aspect ratio will not work properly with uncroped video in 16:9 format. This also has nothing to do with the obvious reversal of 16:9 and 16:10 (in both crop and aspect ratio functions) as mentioned in my earlier post.

If you really have done the comparison of versions this error should be obvious to you and occurred in the tests of 0.8.5 before the final release.

[squawkbox]

Hi thanks again for the reply.

I am not too sure what exactly you mean above. But why is it that all the other pieces of software that can convert a 4:3 video to 16:9 are doing so correctly and all versions of VLC before 0.8.5 did but not 0.8.5?

Many Thanks

[DJ]

The key word here is "convert"! This is a crop function not an aspect ratio function. VLC 0.8.5 does appear to work like previous versions if you will only realize that the 16:9 and 16:10 settings appear to be reversed or miss-labeled if you want to look at it that way. The 16:10 was an addition on or about 1/15/06 and is available in the nightly builds. It was confirmed to work correctly at that time. As to when the error or reversal crept in is anyones guess as I do not use these functions often. Only when the encoding is incorrect (aspect ratio) or I want cropped video for a 4:3 source encoded as 16:9 and want to do away with the black bars.

http://nightlies.videolan.org/

[squawkBOX]

I'm getting rather confused here - why mention crop at all. The aspect ratio is not a crop function though, surely its function is to simply resize the video. Crop is cutting away at the video and none of it is happening, therefore I feel that it would be best to keep it out of this discussion as they are two completely different things.

If you think when clicking aspect ratio that the creation of black bars is cropping this is incorrect - I suppose its just an error in VLC. Once you have clicked the aspect ratio of 16:9, you can then click Zoom 1:1 Original. Therefore your image is back to the original size but at the right ratio.

As a long term user of 16:9 content in a 4:3 frame, I consider the change to 0.8.5 to be a bug as its very clearly not sizing up to the right ratio (neither is 16:10 - even if they were the incorrect way round), the ratios are simply not right.

Therefore I believe that this is a bug. The Aspect Ratio is not making the image in the correct ratio therefore needs to be resolved?

Thanks DJ for your input so far. Is there any other readers who feel the same way as I do?

[DJ]

Would you care to reconsider your statements?

There is no way using aspect ratio can be correct for a 16:9 video presented in a 4:3 frame without cropping the video first. This is why the subject of cropping was introduced into this thread. It is a 4:3 after all and when the image fills the screen the 16:9 content is considered to be correct. The image includes the black bars that are encoded as a part of the video for compatibility to 4:3 TVs.

I'm not quite sure I understand the rest of your problem. I did the comparison of three different versions of VLC and have agreed with you that at some point an error with both the crop and aspect ratio functions has appeared.

At this point I suggested a simple work around until the problem can be addressed and or fixed. Of coarse you are welcome to use an earlier version if you feel this is not adequate for you.

The source code is also available to everyone and contributions and or patches are welcomed.

[nw42]

Hi!

I have problems with the VLC aspect ratio settings - as reported before 16/9 seems to be not correct - and why differs default ratio with an 1:1 video on a 1:1 display???

VLC 0.8.5 win


input: DIVX 1024x576 1:1 ratio

VLC outup:

1024 x 576 px - default - ok
576 x 576 px - 1:1 - ??
896 x 576 px - 16/9 - ??
921 x 576 px - 16/10 - ok
768 x 576 px - 4:3 - ok


correct values would be:

1024 x 576 px - default
1024 x 576 px - 1:1
1024 x 576 px - 16/9
921 x 576 px - 16/10
768 x 576 px - 4:3

can anybody explain why this happens or confirm the problem??

best regards

Danko

[nw42]

hmm - this seems to be complicated even to me - and normaly I havn't problems to set my aspect right

I've tested some additional settings with this result:

setting --> I set up source aspect ratio at startup to 16:9 and monitor pixel aspect to be save to 1:1 in preferences

result --> I got an additional aspect ratio entry in the menu called 16:9 so I have it twice. If I call the setting by hotkey the on screen display says aspect ratio "null" - this setting gives me the right 16/9 aspect - but the original 16/9 entry in the list is even wrong (preadjusted to 4/3 displays??)

very confusing...

best regards

Danko

[Guest]

I absolutly agree that the '16:9' aspect ratio in the context menu of the Windows version of V.L.C. 0.8.5 is wrong, but I'll also add that the '4:3' scaling is also wrong.

I am feeding a PAL DV camera into the firewire port of my WinXP PC and selecting it in VLC's 'Open Capture Device' menu.

If you take a CCIR 601 / ITU Rec 601 (720x576) picture and scale it correctly to display a 4:3 picture you should be scaling up to 780x576. If the '601 picture is 16:9 you should scale it up to 1050x576.

What I'm actually getting is 768x576 for 4:3 (which would be right if, and only if, you are only displaying the center 702 active pixels - which I do not think VLC is doing) and 896x576 for 16:9 - which is very odd!

Please see the following URL for a good explanation of TV picture sizes:
http://www.bbc.co.uk/commissioning/tvbr ... size.shtml

[Guest]

I also have that problem with the aspect-ratio.

input: mpeg2 720x576

default (768x576), 1:1 (576x576), 4:3 (768x576), 16:10 (921x576), 221:100 (1272x576) and 5:4 (720x576) are OK.

But 16:9 is not 1024x768 but 896x576 what is 14:9.

[Guest]

But 16:9 is not 1024x768

I mean 1024x576, of course.

[DJ]

I have just updated to 0.8.5 and there is a problem with resizing files to 16:9. I have a few recordings which have been incorrectly encoded in 4:3, so use the 16:9 options to display in the right ratio. In the < 0.8.4 VLC versions, this worked perfectly.

However, since downloading 0.8.5, the 16:9 ratio is incorrect. It appears that the video needs to stretch further to the left and the right.

If I take the video and display it in 16:9 in another application, then the differences can be seen.

I'm going back to the beginning here, because of the conjecture that is being created in this post. I have asked one of the developers to take a look at this post and VLC's code to try to see where the error is. At this point he has not responded. But given the conjecture and seeming misunderstanding without any attempt to correct what was said versus what was meant. I'm not sure I want to respond either.

1. Most 16x9 videos are presented in a 4x3 frame for compatibility to 4x3 TVs. When this is changed by an end user with another program using a crop function you (or they) are:

A. Removing the compatibility to portray the video correctly on 4x3 TVs. There is no longer a way to correct the 16x9 content if sending this content to a 4x3 TV.

B. You are rewriting the header information for these flags so hopefully the player you will use will recognize this. Most of the time when a player displays the wrong aspect ratio of a cropped video it is because the flags are not correct.

2. There are flags encoded in the video so that a program will select the correct aspect ratio. VLC recognizes these flags correctly.

3. There have been two modules added to VLC to provide Crop and Aspect ratio functions for the end user. The Crop function is for 16x9 material presented in a 4x3 frame that has never been edited or changed from the original. The Aspect Ratio function to provide for Cropped video where the flags are incorrect. Aspect Ratio was not intended for unCropped video. Now, I know of many DVD programs that have incorrectly labeled CROP -- ASPECT RATIO. Perhaps at some point they thought that it would be easier to understand. But VLC will allow transcoding and a distinction was necessary and the options separated into proper categories. Expecting the end user to understand the intended purpose. But to date the confusion continues.

4. I have been seeing more 14x9 videos show up. For a while it was 16x9 enhanced. Both presented in a 4x3 frame (UNCROPED VIDEO) and the end user goes nuts in complaining to player vendors that something is wrong. The video doesn't fill my screen. The aspect ratio is not correct. There are short fat people. There are tall skinny people. It goes on -- and on. But the easy solution at the moment for 14x9 uncropped videos is to choose 16x10 in the crop menu. Not saying this is right, only that it works.

5. In cropped video there still seems to be problems that show up for players. Probably old or outdated encoders that are not writing the flags correctly. Aspect Ratio most generally will correct these.

6. Manufactures have created 16x10 monitors and the standard is 16x9. Many users feel they have been gypped and have sought solutions for the video to fill their screen. VLC offered this to the end user after much conjecture as to why this is incorrect. At the time it was checked and supposed to be correct for both the CROP and ASPECT RATIO options. As it was verified by quite a few users. When VLC 0.8.5 was released it was made obvious that it's not correct and needs to be changed once again.

I truly hope this clarifies some of the conjecture in this post.

PS: Just in case someone decides to come back and say I'm not interested in Crop, my problem is with Aspect Ratio. It is impossible to have a discussion about one and not talk about the other. Please go back to the top of this post and read the whole thing again.

[a_graham]

Here is a solution for the 16:9 bug:

Open the preferences, and go to the settings tab. In "video cropping" put 16:9. Restart VLC.

Now 16:9 will appear twice in the crop menu. One will crop correctly and one will crop incorrectly. It should be obvious which is which, but on mine the correct one is the lower one and it appears between 16:10 and 221:100.

[Cobra951]

I also can state with confidence that the aspect-ratio functionality has changed drastically in 0.8.5 from previous versions. I noticed this recently when trying to play a 400x192 MP4 file, encoded for the Sony PSP. It has a square-pixel aspect ratio, which does not correspond to any of the pre-canned entries available in the VLC menu. (The closest is 221:100, which looks clearly too wide when used.) To complicate matters, and frustrate yours truly, no ratio which I input manually on the command line at launch has any effect at all. It always acts exactly as the "default" setting does. I've even entered very un-square numbers to test this, like 0.25.

As of the previous version which I used consistently (0.8.1), 1:1 aspect meant square-pixel. Now, 1:1 means square image on the screen, regardless of the proportions of the video's dimensions. My opinion is that this new paradigm is entirely incorrect, but perhaps there are complexities that I am not aware of, which forced this issue. I hope that's not the case, even if the current, unworkable rigidity is eventually fixed.

In any case, thank you for the great program. I've been using earlier versions for years, with excellent results.

Edit: I should add that the "default" aspect is also incorrect during playback of this file, looking too vertically stretched. Otherwise, I may never have noticed this issue.

Edit 2: After playing with this AVC MP4 on Media Player Classic, I now think there is something in its header telling the software to produce vertically elongated pixels. MPC allows me to defeat this behavior (untick "Maintain aspect ratio"), which then produces the desired square pixels. The file works as desired on my PSP also, but I'm guessing there are two separate problems here, and one of them has nothing to do with VLC. I think the encoding software I used, or something I did wrong, is to blame for that one.

[dionoea]

I'm kind of too lazy to read everything here but it looks like this might be interesting :p.

Are you saying that some of the default aspect ratio/crop settings aren't correct in VLC ? or were you just looking for a way to add custom settings to those lists ?

[Cobra951]

I'm saying the aspect ratio is not being set correctly. If I choose "1:1", then I should get square pixels, but this is not happening. I discovered since my last post that Media Player Classic reports the dimensions of the movie as "400x192 (AR 16:9)", so there's direct evidence that the wrong aspect has been inserted into the MP4's header (which is the encoder's fault, not VLC's).

I solved the problem for future encodes, by adding "-aspect 400:192" into the "Custom FFMPEG Flags" field in the (PSP Video 9 Encoder) profile. (Yeah, I realize I could have reduced that quantity to a single number accurate to a few decimal places; but that way it's obvious why I'm doing it, and it works.) I reencoded a 3-minute segment of the same movie to test it, and now it looks correct without playing tricks on the player software, and MPC reports the dimensions simply as "400x192". Success, but this does fix the issue in VLC. There is no way I could find to set an aspect ratio manually in 0.8.5. I could do this easily in 0.8.1.

[John G.]

I've also encountered this bug--

In case there's still any confusion as to exactly what this bug does, here's the problem: selecting Crop|16:9 from the Video menu DOES NOT crop the video to 16:9-- it appears to instead crop it to 14:9 or thereabouts.

Here is a solution for the 16:9 bug:

Open the preferences, and go to the settings tab. In "video cropping" put 16:9. Restart VLC.

Now 16:9 will appear twice in the crop menu. One will crop correctly and one will crop incorrectly. It should be obvious which is which, but on mine the correct one is the lower one and it appears between 16:10 and 221:100.

I've tried this, but can't figure out what he means by "settings tab." The only video cropping option in the preferences is one that will force that crop on any material, and that's not what I want. Can anyone elaborate on how to get VLC to properly crop to 16:9 from the video menu?