Bitrate vs. Quality on normal DVDs

[oil]

well most common DVD´s are 720x480 resolution, and we all know thats not a very good one, so my questions is

if i encode a .wmv from such a 720*480 DVD to 720*480 .wmv when does the relation to kbps in comparison to quality stops

example:
is there a real viewable difference from a 1000K wmv to a 2000K wmv?

so the question is whats the best kbps setting to fit best possible quality compared to filesize & quality

 

[lostinlodos]

Here's the best way to think about video, much like professional photography.
The higher the resolution the lower the bitrate needed. The higher the bitrate the lower the resolution needed. They counter and offset each-other like a balance-beam.

 

[oil]

Here's the best way to think about video, much like professional photography.
The higher the resolution the lower the bitrate needed. The higher the bitrate the lower the resolution needed. They counter and offset each-other like a balance-beam.

so in other words it would make sense to encode a normal DVD with 2000k since the resolution is not that well?

 

[Hawk]

Here's the best way to think about video, much like professional photography.
The higher the resolution the lower the bitrate needed. The higher the bitrate the lower the resolution needed. They counter and offset each-other like a balance-beam.

Actually it's another way around, The higher the resolution the higher the bitrate needed to display video information and vice versa.

 

[lostinlodos]

well most common DVD´s are 720x480 resolution, and we all know thats not a very good one, so my questions is

if i encode a .wmv from such a 720*480 DVD to 720*480 .wmv when does the relation to kbps in comparison to quality stops

example:
is there a real viewable difference from a 1000K wmv to a 2000K wmv?

so the question is whats the best kbps setting to fit best possible quality compared to filesize & quality

Between 1000k and 2000k, probably. Between 1500k and 2000k; probably not.

Most people (based on posts at another forum I can't discuss here per rules) who looked at a series of pictures and video found little, if any difference above 720k +/- when the jump between br was less than 500k at a time. Surprisingly, people can also be sequentially "walked-down" from 12M to 760K at 400k per clip and not see a difference until they go from 760 directly back to 12M. So it's all depending on the viewer.
Try what you can and find your own sweet spot where the quality is watchable for you and small enough for what you want to use it for.

 

[mike20021969]

Actually it's another way around, The higher the resolution the higher the bitrate needed to display video information and vice versa.

i agree.
i thought i was going bonkers when i read what lostinlodos wrote.

 

[lostinlodos]

i agree.
i thought i was going bonkers when i read what lostinlodos wrote.

Let me try this again, higher resolution uses more space per frame, but can be coded at a lower bitrate, such as HVD discs. They use a lower bitrate (avg around 1-3mbps) on 1880p.

A frame of film, coded at 3mpbs at 720p will take up less room than a frame of film coded at 3mpbs at 1880p.

However, a frame of film coded at 9mpbs at 1880p can be downscaled to 3mpbs with less of a noticeable loss/disruption than a frame of film equally downscaled from a 720p source. Does that explain it better?!


I'd suggest you check out Video Help and AVS for detailed consumer and industry discussions, respectively for the comparisons of gains and losses between high bitrate:low res and VV. They have some articles and threads plus photo-comparisons.

Honestly, asking someone else what they think isn't going to help you. Try it yourself and find what you're comfortable with!

 

[profcolli]

well most common DVD´s are 720x480 resolution, and we all know thats not a very good one, so my questions is

if i encode a .wmv from such a 720*480 DVD to 720*480 .wmv when does the relation to kbps in comparison to quality stops

example:
is there a real viewable difference from a 1000K wmv to a 2000K wmv?

so the question is whats the best kbps setting to fit best possible quality compared to filesize & quality

The real question is what are you watching the output on? For a 2inch handheld device screen, you won't see much difference at 400kbps compared to 1000kbps. For a 120inch projector screen, you will see a huge difference and should be looking at a much higher bitrate.

BTW, 720x480 DVD resolution is as good as you can get (around 9000kbps, which is perfectly watchable converted to wmv at 400kbps on my son's Samsung P2 3inch 480x272 screen) unless you go high-def - but you probably would not be converting HD for a mobile device anyway

 

[mike20021969]

Does that explain it better?!

it does.but you are talking about hi definition.
i'm not sure whether that applies to regular definition but it may well do.

eg with clonedvdmobile,for 1m12s of dvd movie footage (SAW IV):

resolution (320x180):
562kbps=6.67MB
900kbps=9.94MB
1350kbps=14.3MB

resolution (640x360)
562kbps=6.67MB
900kbps=9.94MB
1350kbps=14.3MB

as you increase the bitrate,the movie file size increases.
increase the resolution and use the same bitrates,the file stays exactly the same size.
so if you double the resolution,you have to double the bit-rate to keep the picture quality looking the equivalent of the smaller resolution.

i just done a test.i encoded the trailer for "Bug" (1m12s) from dvd movie saw iv. i did one at 320x180 @ 506kbps (5.11MB),the other at 640x360 @ 1012kbps (9.11MB).
opened them both in quicktime.i draggged the smaller resolution screen to the same size as the larger one.
i played them both.the detail had been lost in the 320x180.
play them both at the respective sizes,and the detail (sharpness) looks the same even though one is 25% the size of the other one.

 

[Fernando]

Encoding rate in Mbps or Mbit/s defines how many bits the encoder can use per time. With 2.0 Mbps (or 2000 kbps) in can use up to 2000000 bits per second or 244 KiB/s

Resolution of source or destination format is completely irrelevant.

 

[lostinlodos]

i played them both.the detail had been lost in the 320x180.
play them both at the respective sizes,and the detail (sharpness) looks the same even though one is 25% the size of the other one.

Exactly. Now if you go the other way, take the higher resolution and play it back on a screen that is 320x180, it will look better the the lower resolution video on the lower resolution screen. But the one coded at the higher resolution is playable on both a larger, higher resolution screen, and the lower resolution screen. The higher resolution can also be reduced in bits per second at that higher resolution and still look good at the lower resolution, while being somewhat watchable on the higher resolution screen as well.

No matter what bitrate you code a lower resolution video at (within reason), you are stuck at the lower resolution.

Which is where the tradeoff comes in. Really this is one of the more complicated sections, and most opinionated ones, of video coding. Again, check out the other two boards I suggested for a better discussion. This is way beyond the ease-of-use that SlySoft products are intended for.

 

[mike20021969]

the high resolution (640x360 @ 1012kbps) file does indeed show more detail when scaled down to 320x180.
but does/will it show more detail at (640x360 @ 506kbps)? i ain't tried.

but unless a device (eg my iPod @ 320x240 screen resolution) supports a larger resolution (640x480 - i really dont know) then it's pointless encoding at high resolution.

now if it does support 640x480 (or less depending on the widescreen formats of each dvd i have),i'm quite prepared to re-encode to give me even clearer sharper picture on the smaller screen.

 

[lostinlodos]

the high resolution (640x360 @ 1012kbps) file does indeed show more detail when scaled down to 320x180.
but does/will it show more detail at (640x360 @ 506kbps)? i ain't tried.

but unless a device (eg my iPod @ 320x240 screen resolution) supports a larger resolution (640x480 - i really dont know) then it's pointless encoding at high resolution.

now if it does support 640x480 (or less depending on the widescreen formats of each dvd i have),i'm quite prepared to re-encode to give me even clearer sharper picture on the smaller screen.

A downscaled video from a higher resolution to a lower resolution (or bitrate, or both) will still show better detail at 640X360 and/or 506k than a 720x480 506k film would:::Most of the time to most people when using a quality coder.


What was the original point of this thread again anyway?!

 

[oil]

can someone post a CloneDVDmobile profile where i can encode a DVD in 640*480 resolution, and a bitrate of 1500 or 2000, i tried it myself, seemed pretty easy but somehow results are never more than 1000 even though CloneDVDmobile says before its starts it would be 1980 kbps, maybe a bug dont know

 

[oil]

can someone post a CloneDVDmobile profile where i can encode a DVD in 640*480 resolution, and a bitrate of 1500 or 2000, i tried it myself, seemed pretty easy but somehow results are never more than 1000 even though CloneDVDmobile says before its starts it would be 1980 kbps, maybe a bug dont know

bump