Low res in Text presentation

[jairovital]

Hi all

I'm working on video that is 352x480. I'm tryng to put some text at the beginning. I used Sony Vegas to do it, with font size 16. I make a small video with text and joined it with the opera using Womble Mpeg. All is OK. But when I put this joined video into DVD-Lab it produces a DVD with low res text...



Curiously, this image above isn't looks low res text... But when I play it on PowerDVD it looks like the image below:



I run the video in DVD-Lab preview window and it is aceptable resolution for text, but when I make DVD the result resolution is very low... In despite res is 352 it shows 720 on PowerDVD. With GSpot I saw something like display size from sequence display extension. I think it says to player what res to play. At Vegas I checked write it to final file. Is it important here?

I spent all my day yesterday and this morning, trying to make text in 720x480, but when Womble join the videos it goes to 352x480. Because I want the final size this. Womble re-encode first part (text) and direct copy the other.



It's important to say that I'd like to use this res, because I wouldn't like to resize the whole opera. Just direct stream copy it. But to resize only the text intro is fine.

But no way to have an aceptable result... I hesitated a lot to put this on forum to ask some help, because it looks so basic tasks...

Some suggestions are very welcome

[poisondeathray]

This is to be expected. You have low res video. DVD Lab isn't changing anything about the nature of the video (it just authors, not re-encode).

It deteriorates from what you see in vegas preview for several reasons:

1) Vegas working in RGB colorspace , you re-encode to YV12 (less color information)

2) You re-encode with lossy format (MPEG2) = quality loss

3) You are using interlaced format; modern displays and players (LCD, monitor, HDTV) will deinterlace +/- post processing so you lose more effective resolution

4) Resize algorithm . Your video is not square pixel. It's half D-1 (not standard DVD resolution, low resolution already). It gets "stretched" on playback. The 1st picture was displayed at 1:1 pixels. Different scaling algorithms use by different players will make it better or worse. In some players you can specify the resize method

The only way to make the text more crisp is to use higher definition. You might increase a little bit of quality by using better MPEG2 encoder (Womble is known to be worse, and produce soft results), or changing your playback scaling algorithm

[jairovital]

Thank you poisondeathray

It deteriorates from what you see in vegas preview for several reasons:

I said DVD-Lab preview. Its preview gives an aceptable resolution to read. But final DVD doesn't. After render the VOBs files I see different from its preview, like it's cheating me...

About higher definition you mean I need to rescale the whole video to 720x480? I usually work with TMPGenc to re-encode, not Womble.

Also, I didn't understand about playback scaling algorith. Is it a specific DVD-Lab setting? Because the final result must be a DVD.

[poisondeathray]

Thank you poisondeathray

It deteriorates from what you see in vegas preview for several reasons:

I said DVD-Lab preview. Its preview gives an aceptable resolution to read. But final DVD doesn't. After render the VOBs files I see different from its preview, like it's cheating me...

About higher definition you mean I need to rescale the whole video to 720x480? I usually work with TMPGenc to re-encode, not Womble.

Also, I didn't understand about playback scaling algorith. Is it a specific DVD-Lab setting? Because the final result must be a DVD.

Curiously, this image above isn't looks low res text... But when I play it on PowerDVD it looks like the image below:

You are viewing 1:1 (square pixels). Notice how "skinny" the image is. People look think and tall. You can tell by your 2 screenshots. The letters are too skinny in the first, but they are stretched to proper width in the 2nd.

When viewing on a DVD or media player it will scale to a 4:3 AR resolution . e.g. in a software media player it will resize to 352x480 => 640x480 upon playback. The width is streched out back to normal. Any time you upscale , it won't be as sharp. There is no such thing as a 1:1 DVD. They are either 4:3 or 16:9 AR

Different players have different algorithms. Some are very blurry. Some are sharp. Some apply post processing. You can test this out yourself: a bilinear resize will be blurry compared to a lanczos resize. This is something that is applied upon playback and specific to the player or hardware, not a setting in dvd lab.

In order for text to be clear it needs to be larger (larger font), and/or higher resolution (if you scale whole video to 720x480 there is not as much scaling as from 352x480 - i.e. the text is already close to the final size so there is less scaling and less quailty loss) . But the negative side, is the rest of the video will require more bitrate too.

[jagabo]

If you want to leave the frame 352x480 use a bigger font for the text. It will be more readable.

[jairovital]

Thank you all

I think the problem is solved.

In Vegas Media Generator I put a bigger font. The lines became bigger than the width... At preview the aspect is thin and tall, like poison said.

But I could see that Media Generator has a field "Frame Size" that it can be greater than the Project Properties Frame Size. I put 720x480 there and kept 352x480 in Project Properties. At preview the lines fitted on screen, but remains tall aspect.

When I render, the preview changed to 4x3 (???)

After the render, it came back to tall aspect. The final file is 352x480 and resolution in DVD-Lab final VOB is great!

Solution found!

Conclusion: I can have low res video (352x480) and good (acceptable) text in it.

Thx jagabo and poisondeathray.

Jairo