Can't get the aspect ratio on X.264 right!

[Gew]

Oh, what a pity. I'm so sad, crying endlessly. Really need your help guys. I'll state my issue short. I just got a DV camera (I'm pretty/totally new on this whole video stuff anyways) and want to preserve my footage in a smooth way, where both quality _and_ those megabytes of storage is a real issue.

So, I found that H264/X264 would be the perfect sollution, where X264 even offers a 'lossless' option for those really great moments (weddings, funerals, etc). So, perfect, I thought.

Everything works fine. I needed a simple ACM hook that could integrate the encoder directly into Sony Vegas encoding options. So, X264vfW (http://sourceforge.net/projects/x264vfw/) seemed like the best solution around. Worked like a charm - almost(!!).

Let me start from the beginning. My raw DV video is 720x576 (DAR 4:3). At first, when I encoded the video as MPEG1/MPEG2 streams, they appeared correct in my "to-be-burned-as-dvd simulation" (which I used Nero Vision for), with only some "black area" in the top/bottom area, just like when you watch a movie on your 4:3 television, if you know what I mean.

However, then when I finally got to try out the Xvid codec, annoying black field in (not only) the bottom/top area appeared in the Nero Vision preview, but also in the left/right. From what I've heard, this flaw(?) is what's called "letterboxing", "panscan", or whatever.

However, I'm not that interested in all the tech stuff, 'cuz I really just need a simple template to get the (to me) proper 4:3 look in my DVD 4:3 project. So, anyways. I was stuck to the more-megabyte-demanding MPEG2 encoding,, until..! One day, I found a new tab in the Xvid encoding dialogue box. I could chose encoding "via" Display Aspect Ratio (with choices square, 4:3, 16:9) and Pixel Aspect Ratio (same values). I had guessed that default would do, since I assumed that 4:3 _were_ default. However, just-simply-because, I tried entering DAR/4:3 and push just one more encode. Whoa, when I dragged the .avi into my Nero Vision project and previewed it, it looked alright. No loss of the video (croping or what-so-ever), just wonderful.

So, anyways..

Now I'm sitting here with the X264 codec. The problem is, I can't find any DAR/PAR dialogue (or even a command-line syntax for the pure x264.exe). All I find is a setting over "Sample Aspect Ratio". So, I've done some research, and found that SAR is apparantely the same as PAR, just a more "l33t" way of saying it, an expression to be used only by the most wise of the four wise guys, so to speak! ^^ Cool, so I tried entering "4:3" for SAR value; pushed encode. But when I drag the resulting .AVI file to my Nero Vision project, I have those annoying black "letterbox" (???) fields in the left plus right. Gaaaaaaaaaaaah, I thought I'd never have to see them again.

I'm really stuck, and I only need a quick and easy "newbie template" on how to set this with X264. The worst answer I can get on this post is "I'm sorry, but you can't!". That would make me cry out a river. However, I hope for someone to have a smooth solution.

Thanks for every single answer. And please excuse me for my poor english, I'm a Scandinavian boy under stress.

[Gew]

So, after a bit more of research I guess my question would be: What's the correct Sample AR value for ordinary 720x576 DV material over DAR 4:3..? Would that be 12:11? Strange, in that case. I sort of tried 12:11 first thing I did ('cuz I had those digits somewhere in the back of my head, dunno where they came from, really), but it didn't work out.

[jagabo]

Yes, assuming the inner 704x576 contains the 4:3 image, set x264's SAR to 12:11. If the full 720x576 contains the 4:3 image use 16:15. Does your playback software not respect the setting?

[Gew]

Well, when I watch the resulting .AVI files at my computer (using recent-build MPC) I get the same view regardless of setting the SAR at 4:3, 1:2, or 100:3 (I've tried). It's when I throw the video file into Nero Vision (making it to a DVD project) I get to see how the result will look on a television screen (I gotta give the Nero Vision 'tv simulation' a bit of props 'cuz it has helped me alot hehe). Here, I see that when I burn this .AVI on a DVD, I will get the black fields all around the picture (left,right,top,bottom). In other words, exactly the same way as when encoding my 720x576 DV footage with Xvid, _not_ setting the DAR to 4:3 but leaving it to default 'square pixels'. So, my guess is that, well, I'm not sure at all.

This question about whether inner/full, I cannot really give a 100% answer to, not being so familiar with the terms. Anyhow, I'm working with raw/unmodified DV footage from a Sony Handycam DCR-53E, which is told to be 720x576.

[jagabo]

MPC: make sure View -> Video Frame -> Keep Aspect Ratio is enabled. Also make sure your Directshow h.264 decoder is passing the AR information along to MPC.

[poisondeathray]

One option is you can set any aspect ratio at the container level by using the .mkv container (using mkvmergegui). This works on all software players for PC playback; but the problem is if you plan to convert to DVD, I'm not sure if your DVD software will ignore it.

I don't use the vfw x264 version, but for the cli version in MeGUI, you have to signal the encoder in avisynth in the .avs script. I'm 100% certain this works, I've used it for different aspect ratios and it is encoded at the "stream level" regardless of container. For a 4:3 DAR you would put:

global MeGUI_darx = 4
global MeGUI_dary = 3

Did you try using --sar 4:3 manually in the vfw add command line box? (I'm not sure if the GUI is broking in the vfw version, there's a few things missing)

Finally, I don't use Nero Vision, but is it possible that it might be causing the issue?


Good Luck

[Gew]

Thanks for all the help guys. In some way, it must have overlooked the SAR that first time I tried (using 12:11 as I - like I said - had those numbers in my head from somewhere). Tried it again, and now it works like a charm. Problem solved!