Video File properties

[Arunas Jocius]

I am reendering source m2t file that is 1440X1080 50i PAL into avi file using Lagarith codec. Trying to leave other properties unchanged in order to not loose quality. I read out file properties in Vegas and here is what I get:

Source file
Streams
Video: 00:01:00.000, 25.000 fps interlaced, 1440x1080x12, MPEG-2
Audio: 00:01:00.000, 48,000 Hz, Stereo, MPEG Layer 2

Output file
Streams
Video: 00:01:00.000, 25.000 fps interlaced, 1440x1080x24, Lagarith Lossless Codec
Audio: 00:01:00.000, 48,000 Hz, 16 Bit, Stereo, Uncompressed

I can see that 1440x1080x12 turned into 1440x1080x24 . What does that last digit in resolution mean? Is it important to keep it at 12? Where do I select it to be 12? couldn't find in Vegas.

I also attached Vegas Project Media screenshot where I loaded source file and output file. I can see that source file filles complete screen on the icon, where output file does not (has black bars on the top and bottom). Why is that?

[Edward Troxel]

It's the color bit-depth of the image.

[Arunas Jocius]

Thank you. I am beginner, not sure what that means. Does going from 12 to 24 in color bit-depth degrade quality? do unnecessary step? take more time to reender?

Also, I didn't see an option in Vegas to select target color bit-depth...

[Gerald Webb]

You can change the color space that Lagarith encodes to, in the render window go to advanced properties of Lagarith.
Unless you are doing some heavy keying or color correction, just leave it at the defaults, its plenty good enough for most projects.
Your black bars are more of a problem, whenever converting 1440 footage, make your project 1920x1080 with square pixels and convert your footage to these dimensions as well. It avoids all non square pixel probs.

[Arunas Jocius]

Originally Posted by Gerald Webb

You can change the color space that Lagarith encodes to, in the render window go to advanced properties of Lagarith.
Unless you are doing some heavy keying or color correction, just leave it at the defaults, its plenty good enough for most projects.
Your black bars are more of a problem, whenever converting 1440 footage, make your project 1920x1080 with square pixels and convert your footage to these dimensions as well. It avoids all non square pixel probs.

I am confused... if my video camera records video in 1440 lines and my target video is 720, I try to keep 1,333 aspec ratio all they way. How it will help if I define project with higher resolution and different aspect ratio than original???

[Arunas Jocius]

Attached are advanced settings for Lagarith codec, where can I change color bit-depth?

[Gerald Webb]

1440 x 1080 is displaying at 1920x1080, it just does it with rectangular pixels rather than square.
Your delivery format at 1280x720 is a scaled down version of 1920x1080 not 1440x1080.
When you convert to your intermediate codec, in this case Lagarith, to preserve your quality and simplify aspect ratio, myself, and lot of other people,
convert it to the full size of 1920x1080,
do all your editing,
render out a master at 1920x1080
then render out your different delivery formats, ie, a 720p for web, 1024x576 for DVD etc

[Gerald Webb]

On the 'Mode' dropdown.
As mentioned before RGB is plenty good enough for most jobs.

[Arunas Jocius]

Originally Posted by Gerald Webb

1440 x 1080 is displaying at 1920x1080, it just does it with rectangular pixels rather than square.
Your delivery format at 1280x720 is a scaled down version of 1920x1080 not 1440x1080.
When you convert to your intermediate codec, in this case Lagarith, to preserve your quality and simplify aspect ratio, myself, and lot of other people,
convert it to the full size of 1920x1080,
do all your editing,
render out a master at 1920x1080
then render out your different delivery formats, ie, a 720p for web, 1024x576 for DVD etc

Wow, as soon as I think I understood something, I get suggestion to go completely other way...

You are probably right , but I just don't follow the logic. I shoot 1440X1080 or in other words 1,333 pixel aspect ratio. My final format will be PAL DVD or 720 X 576. Still do not understand why would upscalling to 1920X1080 help, especially whent it is different aspect ratio. In my view it will actually take my original aquare pixels and make them rectangular... And it is also resizing (1440X1080 -> 1920 X 1080) , which based on threads in this forums should be done outside Vegas (VD or TMPGenc)

[Adam Stanislav]

Originally Posted by Arunas Jocius

In my view it will actually take my original aquare pixels and make them rectangular...

First of all, all squares are rectangles but not all rectangles are squares.

Your original 1440 x 1080 footage does not contain square pixels because it squeezes the 1920 horizontal pixels to just 1440, so you lose 25% of the horizontal information. Such video is displayed as 1920 x 1080 on a standard 1920 x 1080 HD screen because the player upscales the 1440 non-square pixels to 1920 square pixels. And since you have no control over the player and since different players may be using different upscaling algorithms, the only way to get consistent quality in the various 1920 x 1080 screens is to have Vegas (or whatever editing software you use) to upscale it and then do any editing with the upscaled version. This will not magically recover the missing 25% of information, but it will guarantee consistency among all players.

When later exporting to a DVD, you can have the editor downscale it to the size used by the DVD, while keeping your option to also (or later) release it in proper HD.

[Gerald Webb]

What Adam said :)
Just give it a go the way I said, see if your results are any better than
editing 1440x1080, 1.3333 aspect
then exporting to 720x576. 1.4568 aspect ( arghh, just looking at it like that hurts my brain)

If its no better, discard it.
:)

[Leslie Wand]

without being rude, why?

you state you're a beginner, and we all have to start somewhere, but why dive in with esoteric codecs and the headaches they can cause unless you REALLY need a lossless medium for some other purpose?

[Arunas Jocius]

Originally Posted by Leslie Wand

without being rude, why?

you state you're a beginner, and we all have to start somewhere, but why dive in with esoteric codecs and the headaches they can cause unless you REALLY need a lossless medium for some other purpose?

Well, I shoot with HD camera and get very goot picture if I do playback directly from camera to HD TV. My goal is to be able to do limited editing (with Vegas), downsize video to DVD format and make DVD. All with possible minimal loss in quality. I understand this is possible, just need to find that step by step algorithm. I think I found it in another thread within this forum, but then I got some questions along the way. I believe if make unnecessary steps with resolution and change aspect ratio more than needed, I will certainly loose in quality. This is why I try to avoid it. I am beginner in video editing, but not beginner with PC. So I guess once I understand the logic and find my step by step procedure it will be easy. I didn't quite thought that my camera shoots 1920X1080 and then squezes picture into 1440X1080 making pixels rectangular... But now it is clear, thank to patient helpers in this thread. I will of course change project settings to 1920X1080 and run a test. Will keep that resolution in Vegas, Will reender to 1920X1080 avi file using Lagarith and then move to TMPGenc to do resize. Should i resize to 720X576 (which is PAL DVD aspect ratio) or to 720X405 to keep original 1,7778 aspect ratio?

[Leslie Wand]

please don't let me stop you experimenting.....

however, i think you'll find that going straight from hdv to dvd in vegas / arch will give you almost indistinguishable results as that made by going via an intermediary codec.

please, if you find otherwise i'll be happy to retract that statement.

[Arunas Jocius]

Was away for a week, back to my project now.

Ok, I will of course ready to try various solutions and I am trying with following steps.

Captured video with Sony Vegas into m2t file at 1440X1080 (non square pixels)
Reender with Sony Vegas using Lagarith codec into avi file at 1920X1080 (square pixels 1,7778 aspect ratio)
Resize with TMPGenc to avi file at 720X576 (not sure what kind of pixels 1,25 aspect ratio...)

Will try to keep video interlaced during the whole process.