Size & resolution

[dagtt]

Why is it that two different 90 min movies have the same size but a big difference in resolution.
Is it because of different ripping software??

[Enchanter]

It is possible (very), because the encoder (a person) can choose what resolution the video will have. Filesize does not determine what the resolution is fixed at.

[Mac Sidewinder]

If the filesize is the same but the res is different, you may find that the larger res file doesn't look as good when you play it at fullscreen (depending on what bitrate it was encoded at). The bit/pixel per frame is lower for the larger res file.

Mac

[dagtt]

I always thought that higher resolution used more space??
Is what you are saying, Mac Sidewinder, that a high bitrate with a low resolution, can give better quality than low bitrate and high resolution?

that sort of makes sense, I think..... maybe..

[benderman]

Higher resolutions mean more details and to keep the details you need a high bitrate. But if the bitrate is to low, the details will get lost and the picture gets blocky. Then you will have to increase the bitrate or lower the resolution. Lowering the res will also result in loosing small details, but the picture will be less blocky and the video plays more smooth.

[dagtt]

High resolution and high bitrate, makes big files, right?
Then you have to experiment with res and bitrate to get good quality movies which isnt`to big.
Is it possible to use the "perfect" settings from one rip on another movie?

[benderman]

There is not ONE perfect setting, because videos have different lengths and a different amount of motion and contrast. The only thing that can help you to choose the best resolution is the bit-per-pixel-value that describes how many bits are used per pixel. A few bitrate-calculators have that feature. I would suggest to use Gordian Knot. A value of 0.2 or higher would give a good video-quality. The rest is a lot of experience.

[dagtt]

Thank you, I`ll try that out!

[Mac Sidewinder]

I always thought that higher resolution used more space??

As Benderman was hinting at - Encoding with a higher resolution will not make the video file larger.

If you encode a file at 640 by xxx and encode the same file at 512 by xxx both at 800kb they will end up with the same file size. Increasing or decreasing the bitrate will determine filesize. Depending on what is in the file (lots of action, explosions, etc.) you may find that the lower resolution will look better than the higher one. The lower resolution has more bit/pixel to expend on a lower screen size.

Finding the perfect resolution is trial and error. Using a bitrate calculator with a bit/pixel calculator included is one way.

Using GordianKnot (which has both built in) to me is a better way. (Simpler).

Mac

[Billou]

There are many things which can explain the phenomen :

- the quality of the images of the movie on the dvd sure
- perhaps ripping software
- the resolution of encoding sure
- the resolution of your screen very sure, that why it is important to give the resolution of encoding when you burn your movie
It is important that your screen resolution is an integer multiple of your encoding resolution
- it depends also of the 16/9 or 4/3 widescreen of the film. When you encodec a 16/9 movie you can dicrease the length of the movie of about 3 minutes because there is less images to encode in comparaison with a 4/3 movie where is about the full screen to encode