LAB - Interlace vs. Progressive to MPEG, quality 'wise ??

[vhelp]

The goal here, is to produce two actual LAB test example MPEG source
files from both Progressive and Interlace source content and determine which is
the better quality..

However, I have not completed my tests. To be continued..

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** LAB CLOSED **

LAST UPDATED:
* Thu - June 9, 2005.pm
* SEE "Latest LAB Progress Notes" below, at bottom on this LAB.

REVIEW DATE:
* Sun - June 5, 2005.pm


TYPE: -- ARTICLE / SUBJ
* Interlace vs. Progress - which has the better quality.


PURPOSE:
* To determine which has the better quality after an MPEG encode process.


HISTORY:
* Based on a thread topic dated around June 5, 2005:
** What causes jagged edges?
.
.
I commented on this topic, and in one paragraph, I wrote:
".. - Progressive always encodes better than interlace. Always."

I made this statement because it was based on my past expereinces. But..

A user had responed with a 'Don't Agree' answer. (This was a second time by
another user)

(I'm sure this user was speaking for a group at large) ..and, that bothered me,
because in my experinece with Interlace and Progressive sources, I have
only found that Progressive content encodes better - less macro blocks.
(And this was always the flavor of aroma floating everywhere on these
forums for many years that I can count) And this is what I was speaking on..
less macro blocks. I was not talking about how they play better,
(on screen or on TV set) but rather, how they encode better in quality.


COMMENTS:
[1]
Vaguely, I recall reading someone remarking me with a similuar response as this user
on the topic of Interlace vs. Progressive. At this time of writing, I don't recall the
thread topic. I think it was indicated to me, that the encoder processes Interlace
sources by its fields, hence the same result (or better) for Interlace sources.
That sounds great to me, since a lot of my sources are DV (pure interlace) but, to
date this has never been the case, all except for when the encoder software I use,
is Procoder.., that and add the fact that I have some knowledge and skills with it.

[2]
So, I made this LAB because I wanted to demonstrate my reason for
believing this. And, if I were to come up with a different outcome (proved wrong
in my own LAB results) then, I would agree and correct myself, or add a
note specifiying the options or overcomings that result in the opposite of opinion
(and corrected findings) of this LAB.

[3]
My prefered Encoder software is TMPGenc, for most my AVI source files. And,
I base most of my testings from this encoder. However, in other areas of needs,
I have used another encoder application, Procoder v1.5 for the final MPEG
project. Procoder (IMO) is best for Interlace sources. I can't argue at this time,
when the encoder is such. So, my LAB test will include both encoders..,
though not to compete between the two. That is not what this LAB is
about. This LAB is about weather or not, Interlace encodes in better quality
than when Progressive. That is all.


SPECIAL NOTES:
[1]
This LAB test may not prove entirely true for either side. It may all boil down
to some simple basic attributes.. Encoder software; Source and it's pros/cons;
Devices used during the importing of source content; Editing of content; User
knowledge; Skill; Technique, etc. As a result, both source types (Interlace vs.
Progressive) may yield equal levels of quality.. at user descresion.

[2]
I am not expecting this to be a tug-a-war, or a prove-you-wrong outcome. It is
just a LAB test experiment and learning excercise, for all to share in,
and/or learn from.


CONS:
* NONE A.T.T.


PROS:
* NONE A.T.T.


EXPECTED OUTCOME:
* To produce a LAB test example of an encoded Progressive MPEG
source, proving that it is better, quality 'wise.


FUTURE PLANS:
* NONE A.T.T.


REFERENCES:
* NONE A.T.T.

As of this writing, I have not completed these tests.

-vhelp 3380


LATEST LAB PROGRESS NOTES: -- June 9, 2005

I feel that this LAB was flaud because it started out based off a flaud
argument.
.
A Telecine (3p:2i) source can not be used in a Interlace vs. Progress test.
.
In my haste, I had stated it based on my knowledge and experience with
working with Interlace and Progressive sources. But that goes further
than the argument of Interlace vs. Progressive, because of the various
techiques in processing..
[ie, a straight [3p:2i] 30 fps encode, vs. a [3p:2i] 30 fps w/ IVTC[24p]
process] The IVTC process would win no doubt. And, this is what I was
comparing, and was the bases for my argument.
And, since I do not have an actual source type matching these fps's,
the argument is flaud, and the LAB test is complete.

It is my opinion, that only a true source type of 30i and 30p, using the same
video scene to encode, would produce a valid Interlace vs. Progressive
argument. This might be produced with a camera (dv cam) source, as
long as the cam allows 30i and 30p video recording of footage/scene
taken identically.

Still, this is not a practicle argument to be making. I realize this now. And
the next time the opportunity makes it way in my direction, I will will try and
remember to rephrase my response/argument

That's about it. I consider this LAB test closed.

-vhelp 3383

[vhelp]

Purposely left blank.. for followup results

-vhelp 3381