Increase Resolution or Bitrate?

[borblestump]

I have created about 5 divX's of decent quality, so I have a reasonable understanding of what resolution and bitrate both mean - ie. I understand that, for a given file size, if you lower your resolution, you raise can raise the bitrate and hence quality of the smaller picture.

However, what I don't understand is what happens when the image is blown up to monitor or tv screen size. Since most divX movies are viewed at these much larger sizes I want to know whether to go for higher bitrate or lower reolution.

In other words-
for the same size file, will I get a better picture on my TV screen if I use a small resolution (400ish) with a high bitrate, or a large resolution (640) with a low bitrate?

thanks.

[chickeneater]

Resolution doesn't really matter much for tv. It always looks better on the tv than the computer. I encode my videos (vcd) at ~388x240 and they look great. The bitrate is always 1150 for me. It looks similar to dvd. I did a comparison and the dvd was a bit smoother, but the vcd was excellent.

Do you want to make a (s)vcd, or dvd (if you have a dvd burner)?
if so, look at www.dvdrhelp.com
TMPGEnc is a good encoder, but can be slow.

[borblestump]

Thanks for the reply, but I am still unclear on the answer to my original question.

To restate, I am planning to watch the divx movies I make at a blown up size (eg. to the full size of my laptop screen). So I want to know for a given size file, what would produce a better quality image on the laptop - a higher bitrate with smaller resolution, or a lower bitrate with higher reolution.

Since a higher resolution won't have to be blown up as much to fill the laptop screen- could it have a better picture?

[chickeneater]

if you want to view this on a lap top... Wait...

• Is this a divx or xvid file originally?
  
• do you have a cd burner?
  
• Do you want to watch it through a dvd player on your tv?

if you want the above, read my first post.

If you want to make the movie fullscreen (no borders) then you will have to crop the image. I wouldn't recomend that.

as for the resolution and bitrate, I would definetly get a ~600 ish resolution over the bitrate. The bitrate doesn't affect much quality stuff, but more of a I forget the word... Get a higher res instead of a higher bitrate.

[borblestump]

To answer your questions:

>Is this a divx or xvid file originally?
- I am using GK with divXpro 5.02 to make the movies in question

>do you have a cd burner?
-Yep.

>Do you want to watch it through a dvd player on your tv?

-I will watch them on the TV sometimes, but I would use my laptop to play the divX- not a dvd player.


>If you want to make the movie fullscreen (no borders) then you will have to crop the image. I wouldn't recomend that.

- What is wrong with cropping? I have done it to all the movies I have made to cut out wasted filesize. I use smart crop generally, and I keep the pixel width to multiples of four (I read that in someones GK guide)

>as for the resolution and bitrate, I would definetly get a ~600 ish resolution over the bitrate. The bitrate doesn't affect much quality stuff, but more of a I forget the word... Get a higher res instead of a higher bitrate.

- glad that is your answer. I generally do as you say and have a higher res, rather than raising the bitrate.

cheers.

[Enchanter]

Re: Increase Resolution or Bitrate?

Originally posted by borblestump
for the same size file, will I get a better picture on my TV screen if I use a small resolution (400ish) with a high bitrate, or a large resolution (640) with a low bitrate?

It depends on what bitrate is being used.

As a general guide, a resolution of 640x() is acceptable for bitrates of 1000 and higher. The acceptable resolution scales linearly with the bitrate.