resize avi file

[wesburnsco86]

i was wanting to enlarge it.Here is the properties 320x240 (1.33:1) [=4:3]

[BJ_M]

virtualdub or avisynth

[kschang]

On the other hand, you can't really improve the quality by enlarging it... as you are reencoding afterall. Unless you're trying to fit it to a standard, I'd probably skip this step.

[wesburnsco86]

Trying to get it to fit to standard....Using VDub

[mats.hogberg]

Standard AVI frame size? Never heard of that animal.

/Mats

[wesburnsco86]

let me rephrase that.Fit to play on my big screen tv.Which is 16:9
The movie is DivX.And my standalone plays them.

[mats.hogberg]

Wouldn't the picture look very distorted (stretched hirisontally) if you resize a 4:3 video to 16:9?

/Mats

[wesburnsco86]

It might.The trouble I run into is that the small size movies are blocky.Square blocks usually formed in the background of the image playing.Any ideas??

[mats.hogberg]

Sounds like a low bitrate encode to start with.
The blocks won't go away if you resize (which requires reencoding) - it will only get worse.

/Mats

[BJ_M]

dont use sources that are 320x240 .. VERY difficult to make those look good on big screen TV - no mater what you do

[wesburnsco86]

Ok I wont.but I just cant help but wonder.....Whats the ideal size that I should use?Obviously 320x240 is not.

[mats.hogberg]

Around twice that and we're beginning to talk. DVD is 720x480. HDTV 1920x1080 IIRC.

/Mats

[BJ_M]

does your stand alone play DiVX HD ?

if not -- use the highest res. it does play ....

really depends on the source --

[wesburnsco86]

Sounds like a low bitrate encode to start with.
The blocks won't go away if you resize (which requires reencoding) - it will only get worse.

/Mats

Please give me examples of a low bitrate encode /and a good quality encode.
I need the numbers to understand....

[wesburnsco86]

Hello????Anybody????

[guns1inger]

High bitrate = better quality, all else being equal. You want avis with a resolution of 640 x nnn (nnn will vary) and a video bitrate of at least 1000kbps or higher. Anything between 600 - 640 will look pretty good. Smaller means your player will have to resize more, and this will make thing blockier.

FWIW, most Divx capable players I have seen do little if any filtering of the image. This is in contrast to most PC players, which can smooth and blend on playback. This means that the type of blocking that is inherent in Divx files at these types of bitrates will look more pronounced on your TV than they may on your PC. In other words, it will look better on your PC than your TV. To match DVD quality, you probably need bitrates closer to 2000 - 3000kbps (around half the bitrate of your average DVD), which you won't find in most downloaded videos.

[wesburnsco86]

WOW thanx for the info.Seems I do have some poor quality .avi files. The best quality I have is around 232kbps.
HMMMMMMMMM
Is there a legal source for quality downloaded movies(the quality you refer to) from the internet?

[guns1inger]

Only if you are willing to pay. You can download some high quality segments and trailers from the quicktime HD section, then use SUPER or similar to convert them to Divx to test the difference in quality.

[wesburnsco86]

Ok Thanx.One more question.On the thread topic.If I have a low bit avi file.Say around 68kbps.Is there a way for me to improve the quality?maybe with Vdub??Or any other software for that matter.

[guns1inger]

68kbps is very, very low.

There is a simple truth about digital video - once you throw away information, you can't get it back. You might be able to use specialist filters to improve the quality by smoothing over errors and artifacts, but eventually there is a threshhold beyond which nothing is really recoverable. I would suggest that 68kbps for video falls well past that threshhold.

[wesburnsco86]

Yes ok.jeesh.I dissapoint myself in the quality I have.LOL
Anyways just to confirm Im looking at the correct properties.
Right click the file>properties>summary>video data rate........
Am i correct???

[guns1inger]

I would open the file in virtualdubmod and look at file->information to get a more accurate reading.

[kschang]

Though for something only 320x200 it COULD be that low. We're used to seeing bitrates for res of at least 640x480

[wesburnsco86]

Now maybe I was looking at the wrong info.Im sorry for this.
The correct numbers are 463kbps.Is this still way too poor to fix?
From the replies earlier,you cant fix or replace the information that has been lost.So im gonna draw the line around 600.

[guns1inger]

Draw the line at what looks good, not some arbitrary amount. What looks good is dependent on more than just bitrate - content makes a big difference. Talking heads require less bitrate than action scenes, for example. There is no magic number.

[headless chicken]

What app would you use to resize avi on a Mac if it's the *only* change you want in your output file (16:9-->4:3)

[guns1inger]

You would be better off starting your own thread in the Mac forum than waking up a post that is almost a year dead.

[headless chicken]

Heh. So much for using the "search" feature. Oh, the irony.

Thanks.