convert avi to svcd (resolution question)

[James]

Archived from groups: rec.video.desktop (More info?)

If I start with an avi file which has been encoded at 352x288, and I
want to convert this to vcd or svcd, will the quality be any better by
choosing svcd rather than vcd? I understand svcd is something like
480x576, but is it possible to 'up' the resolution and hence improve
the quality, or should I simply stick to vcd?

 

[Guest]

Archived from groups: rec.video.desktop (More info?)

james wrote:

> If I start with an avi file which has been encoded at 352x288, and I
> want to convert this to vcd or svcd, will the quality be any better by
> choosing svcd rather than vcd? I understand svcd is something like
> 480x576, but is it possible to 'up' the resolution and hence improve
> the quality, or should I simply stick to vcd?

VCD will probably be fine. The main advantages of SVCD over VCD is
higher resolution and interlaced video, at a cost of running time.

Since your original is already VCD resolution, you should probably stick
with VCD as the output. But you could always do one of each to compare
for yourself.


-WD

 

[James]

Archived from groups: rec.video.desktop (More info?)

Will Dormann <wdormann@yahoo.com.invalid> wrote in message news:<dMMDc.167760$DG4.152373@fe2.columbus.rr.com>...
> james wrote:
>
> > If I start with an avi file which has been encoded at 352x288, and I
> > want to convert this to vcd or svcd, will the quality be any better by
> > choosing svcd rather than vcd? I understand svcd is something like
> > 480x576, but is it possible to 'up' the resolution and hence improve
> > the quality, or should I simply stick to vcd?
>
> VCD will probably be fine. The main advantages of SVCD over VCD is
> higher resolution and interlaced video, at a cost of running time.
>
> Since your original is already VCD resolution, you should probably stick
> with VCD as the output. But you could always do one of each to compare
> for yourself.
>
>
> -WD

mmm...still not clear. I fully understand that "The main advantages of
SVCD over VCD is higher resolution and interlaced video". But as I
say, is it possible to 'up' the resolution to improve quality? I'm
thinking that if I start with 352x288 then re-encoding to 480x576 is
merely 'stretching' the video, without improving the quality (similiar
to increasing image size of a jpg in Photoshop). Is this not correct?
Without "doing one of each to compare" as you suggest, I would like to
understand the theory behind this.
Thanks in advance.

 

[Guest]

Archived from groups: rec.video.desktop (More info?)

On 27 Jun 2004 20:59:10 -0700, droogiedubstar@hotmail.com (james)
wrote:

>If I start with an avi file which has been encoded at 352x288, and I
>want to convert this to vcd or svcd, will the quality be any better by
>choosing svcd rather than vcd? I understand svcd is something like
>480x576, but is it possible to 'up' the resolution and hence improve
>the quality, or should I simply stick to vcd?

Stick to 352x288. Turning into a higher resolution means inventing
pixels that do not exist, which can only deteriorate the image.
Besides, both res0lutions shall end up filling the screen. For this,
the player needs adjust the image to the screen -and 480x576 is a very
weird resolution to adjust.

 

[Guest]

Archived from groups: rec.video.desktop (More info?)

james wrote:
> If I start with an avi file which has been encoded at 352x288, and I
> want to convert this to vcd or svcd, will the quality be any better by
> choosing svcd rather than vcd? I understand svcd is something like
> 480x576, but is it possible to 'up' the resolution and hence improve
> the quality, or should I simply stick to vcd?

I don't think the advice given so far is sound -- I might be
mistaken, though, so I'll give you my point of view, and
others will correct me if I'm on the wrong track.

It is true that pushing up the resolution of a source that
is already at 352x288 won't give you much (it depends on
the specific conditions, but in this case, I don't think
you'll gain much).

BUT, from what I've seen in my experiments so far, the
difference in resolution is the least of the factors that
make a difference between VCD and SVCD. SVCD uses a better
encoding, and thus introduces less artifacts. So, it's not
a matter of having two JPEG images, one 300x200 and one
200x150; it's more like having two JPEG images, one with
99% compression, and one with 80% compression. The file
with 99% compression will look horrible, full of weird
artifacts, stains, damaged spots, etc.

My advice would be to use SVCD if possible. Of course, if
you are happy with the quality that you obtain with VCD,
then there is no question about it (but do make sure
that you really are happy with that quality, as opposed
to you *think* that you are happy with it -- i.e., compare
it to the quality you obtain with SVCD and see if you can
notice a difference that you consider important).

HTH,

Carlos
--

 

[Guest]

Archived from groups: rec.video.desktop (More info?)

james wrote:

> mmm...still not clear. I fully understand that "The main advantages of
> SVCD over VCD is higher resolution and interlaced video". But as I
> say, is it possible to 'up' the resolution to improve quality? I'm
> thinking that if I start with 352x288 then re-encoding to 480x576 is
> merely 'stretching' the video, without improving the quality (similiar
> to increasing image size of a jpg in Photoshop). Is this not correct?
> Without "doing one of each to compare" as you suggest, I would like to
> understand the theory behind this.


You can increase the resolution by tenfold if you like. But the truth
of the matter is, you're not going to increase the quality of your
original source video. In fact, every time you increase the
resolution you will need a higher bitrate to represent the same quality
video. You're better off just sticking with the original video
resolution and having your DVD player scale it to fit the screen.


-WD