IRE settings

[Leoslocks]

// Alright, we'll just make this thread the sticky. It's probably as publish-ready as it'll ever be. -- moderator lordsmurf

Lordsmurf wrote: (as originally posted in this thread)

Well, this post may not be 100% perfect scientific way to explain all this, but given the alternate, images really would help. Lots of jibber-jabber and jargon only goes so far. I'm simply amazed at how confounding video information has to be. What should be basic principles of video (think "atoms have protons, electrons and neutrons") seemingly require advanced degrees in video theory. Uggh. Anyway, here goes an attempt to convey knowledge to the layman....

- DVD MPEG is IRE 0.0
- IRE is the name of the group that set the standard
- 0.0 is the "total black" side of the scale. It goes to "total white" at 100.0.
- North America (will call it "USA" for purpose of this article) has black set at 7.5 and not 0.0. Blame lazy engineers from a long time ago. Because of this, all of our equipment is different from Japanese stuff. Or at least is SUPPOSED to be different.
- When a NTSC USA player gets a DVD, it's output is stepped up +7.5 IRE so the tv understands it and it looks correct. When an analog signal (VHS, cable, tv, etc) is inputted into a digital device, the device steps down the IRE by -7.5 so it is at proper 0.0 for digital needs (playback, capture, encode, etc).

NOTE! Because IRE shares a relationship with 0-255/16-235 YUV scale, I have mushed them together for the purpose of this conversation, even though they are not "the same thing" necessarily.

Master scale for reference:


Proper DVD recorder and playback activity for NTSC USA:


Wrong IRE input, creates bad output for NTSC USA:


Wrong IRE input, but will look OK on the record (ONLY!):


This is an example of how Panasonic has NOT AT ALL addressed the IRE error, but rather shifted the luminance ("brightness" spectrum, which in turn holds mostly green color in NTSC USA):



++++++++++++++++++++++++++++++++


Some references:
http://www.thx.com/mod/techlib/contrast.html
http://www.signvideo.com/dv-black-levels-dvd-authoring-mpeg-2-part-1.htm

Related videohelp topics:
https://www.videohelp.com/forum/viewtopic.php?t=163667
https://www.videohelp.com/forum/archive/t219752.html
https://www.videohelp.com/forum/viewtopic.php?t=258753&postdays=0&postorder=asc&start=30

Other sites/forums with related info:
http://www.avsforum.com/avs-vb/showthread.php?s=&threadid=416292
http://www.smr-archive.com/forum_6/messages/438.shtml
http://ultimateavmag.com/dvdplayers/904ayre/


++++++++++++++++++++++++++++++++


On a related note, in TMPGENC, that stupid "OUTPUT YUV DATA ..." settings is quite easy to understand (or at least IN THEORY should be). It was specifically made for DV input, but applies to anything with the wrong set of values.

OUTPUT YUV DATA ... CHECKED
>>>> LEAVE AS 0.0 IRE
>>>> FOR DV SOURCES AND DIGITAL 0-255 SOURCES

OUTPUT YUV DATA ... NOT CHECKED
>>>> CONVERT FROM 7.5 DOWN TO 0.0 IRE
>>>> FOR TRADITIONAL ANALOG SOURCES 16-235

.... then again, it DOES say 8-235 .... and I've been re-encoding MPEG files from capture cards for a long time with it .... and leaving it UNCHECKED did not in any way adversely affect the file .... so much for theory applying here .. then again, we already know that software is screwy, as is the setting data...

I'll have to come back to the TMPG stuff, not quite right yet.

And the RGB interface (not YUV) may have something to do with it .... at least the DVD recorder part of this conversation is correct (and "easy" by comparison!)


++++++++++++++++++++++++++++++++


None of this is really "final publish" quality, I'm still trying to catch mistakes, iron out any bugs, and make sure this is really the best way to VISUALLY explain this entire mess. So while helpful feedback is fine, derogatory feedback is not (and I prefer it be PM'd anyway, not clutter this thread).

.
.
.
.

OK - on the input side of things, it appears the black level settings the Pioneer provides are referring to the source video black level. For NTSC 7.5 IRE black level sources (VHS, 8mm, Hi8, laserdisc, broadcast and cable signals, etc.), set the Pioneer input black level to 7.5 IRE. It apparently compensates by adjusting the black level down to 0 IRE for a proper DVD encode. For MiniDV, Digital8, and other 0 IRE black level sources... set the Pioneer input black level to 0 IRE. No adjustment by the DVD recorder will actually be made - it will encode the source video exactly as it is sent.

For playback, set the output black level to whichever standard works best on your display. Most newer TV's can handle 0 IRE black level signals and benefit from the "blacker" looking blacks.

I'm really looking forward to checking out the 220 now. 8)

I would like to see a format for setting up different DVDR's.

• Pioneer > For VHS, 8mm, Hi8, laserdisc, broadcast and cable signals, etc., input black level to 7.5 IRE.
• For MiniDV, Digital8, and other 0 IRE black level sources... set the input black level to 0 IRE.

[BJ_M]

some dv is 0 and some is 7.5

[lordsmurf]

I'm about to write a sticky for this topic in the DVD recorder forum. There is some more that needs to be added/re-worded first.

Patience. Good stuff is on the way.

[edDV]

Getting close but not quite,

All CCIR-601 derived digital video including DV, SDI, DVD, etc. have black defined as 16 and white defined as 235 for 8bits (64-940 for 10bit formats like Digital Betacam)

So in your first drawing above, the Blue line should read.
"IRE 0.0, PURE BLACK 0(ANALOG), 16(DIGITAL)"

Setup should exist only on the analog NTSC (composite and S-Video) outputs (not on component out). Setup gets added for broadcast equipment. Consumer and most prosumer equipment incorrectly output with no setup on NTSC composite. Most home theater equipment will correctly have no setup on the component analog Y out (e.g. DVD players and set top boxes).

On the input side, broadcast equipment is supposed map 7.5 IRE to level 16 digital and 100IRE white to level 235.

Consumer capture cards vary on how they handle this with most doing it wrong without manual intervention with the setups.

[lordsmurf]

Yeah, the re-mapping of black thing is the complex part. I may just have to make some sort of notation about this, and hope nobody gets confused. Probably put a carefully worded warning for newbies that are trying to learn too much too fast.

I may just say "16 remapped" or something for the 7.5 IRE.

[edDV]

The good thing, if I/O levels are handled correctly, CCIR derived digital video is 16-235 anywhere in the world.

Let everyone catch up with this before introducing RGB remapping (0-255 to 16-235) and the gamma screwups (e.g. Final Cut Pro).

Also, on the first graph, the 255 level isn't really "PURE WHITE", 235 is. The area between 235 and 255 is there to handle transient overshoots and to provide some safety margin for out of spec white levels. If this safety zone wasn't there, any overshoot would cause serious clipping errors.

The area from 0-16 prevents clipping at the black level during transmission but is also used in a controlled studio environment to provide a below black clip level for keying graphics (sort of a poor man's alpha). These below black uses are removed before the final program gets out of the studio.

[gshelley61]

Thanks for the clarification, edDV. Your professional perspective is definitely appreciated here.

I have tried to explain very carefully several times why 7.5 IRE black level NTSC sources must be adjusted to 0 IRE prior to DVD transfer, but it can be confusing and even folks who have been around the forum for a while may not quite understand the issue completely. As a video hobbyist, I have observed that different capturing devices deal with source black levels in different ways... which makes it even more confusing because it is impossible to suggest one method (or setting) that will work on every piece of equipment. This is one of the main reasons I use a high quality proc amp with an accurate luma/black level meter in my signal chain.

[edDV]

The addition of waveform monitors to Premier, Vegas, FCP, and AVID will help much for setting black and white levels correctly for NTSC inputs. Hopefully, these will get built into capture programs and encoders as well.


A great reference on all this is Adam Wilt's DV-FAQ http://www.adamwilt.com/DV-FAQ-tech.html

[Marvingj]

0 IRE FOR DIGITAL & 7.5 FOR ANALOG.....HEHEHEHE!!!!

[zorankarapancev]

I have tried to explain very carefully several times why 7.5 IRE black level NTSC sources must be adjusted to 0 IRE prior to DVD transfer, but it can be confusing and even folks who have been around the forum for a while may not quite understand the issue completely.

gshelley61 this is the point that still confuses you.

The DVD recorders sold in North America, that are in compliance with the NTSC standard, are designed to be connected with the incoming analog signal of 7.5 IRE. Their internal setting removes this setup in order to make the correct digital black level of 0 IRE. This corrected analog signal is encoded and burned on a DVD disc. When the disc is played back, the decks will add 7,5 IRE to make the analog signal again compliant to the NTSC standard.

If you change the legal NTSC black level from 7,5 to 0 IRE it will make the incoming analog signal out of the NTSC spec! With the automatic internal removing of the setup the black level will become negative 7,5 IRE! That is why the picture recorded this way will be “too dark”.

The only situation when you have to “correct” the black level, as you are doing, is when the DVD recorder is not compliant with the NTSC standard – black level set on 0 IRE.

I don’t think that this is hard to understand.

If you play a DV tape (black level 0 IRE on the line output), the playback will be fine in Japan, but it will be "too dark" in the North America. In order to make the correct DVD recording with NTSC compliant stand alone DVD recorder you will have to add 7.5 IRE.

It is important to keep the black levels always on their legal levels. Going from analog to digital and back again, if the specifications are followed, analog black goes to digital black and digital to analog. The same recording should play correctly in Japan with 0 IRE setup and in the USA with 7.5 IRE setup.

[Harpmaker]

This is an example of how Panasonic has NOT AT ALL addressed the IRE error, but rather shifted the luminance ("brightness" spectrum, which in turn holds mostly green color in NTSC USA)

Could this be the cause of the Green Tint problem with the LiteOn and iLO recorders?

[lordsmurf]

This is an example of how Panasonic has NOT AT ALL addressed the IRE error, but rather shifted the luminance ("brightness" spectrum, which in turn holds mostly green color in NTSC USA)

Could this be the cause of the Green Tint problem with the LiteOn and iLO recorders?

Yes, possibly. But keep in mind not all of them have this issue. It still seems rather isolated. For example, my 5001 has no such problems.

[vhelp]

Evening guys

As for the Pioneer 220S unit, I've seen good results from NightWings posting
on this unit. I liked the results so far. And, I like that image he posted
(dark scene) but I don't know what DVD movie that was from
I also want to see a head-to-head w/ the JVC DR-M10 unit vs. Pioneer 220S.

--> Lite-On DVD Recorder Model: 5101 at Sams for $139 any good?

Excuse me for buttin in here. I've had my share this issue, and then some.

There is a missing piece to this puzzle. Yes. But first, we (and I) need
to know something. And this makes sense to me, in my head. Now, I have to
place it her in writing, for you all to digest and depick with your comments
and theories (just like I have) ...

The problem is, we need to know weather or not, the source is at fault, or
the hardware, or both. We need to first determine this, and get it straight.

But..

.. I've often (and always) wondered why commerical dvd movies look so rich
.. and vibrant in color, and I always couldn't put my hand on it. I blaimed it
.. on a theory (which doesn't seem to hold up) on a color space YV12. But, then
.. further questions were ask inside my head. Color space. DVD is YUV 4:2:0
.. and YV12 is just a subset of YUV, just as YVU-9 is (spelling) they're all a
.. subset of YUV, which is broken down into an 8x8x8 color matrix, or 24bit bumped
.. down to 16bit or 8x4x4 (16bit) color space, which is then processed futher
.. through various other color/chrom/luma minipulations, etc. Anyways.
.. If this YV12 is on commercial DVD's (and is assumed a standard for DVD format)
.. then why are there any Encoders out there (ie, CCe; TMPG; MC; Procoder, etc)
.. with a swith or option or whatever, to encode with YV12, so that we could get
.. this Vibrant and Richness in color output in our MPEG-2 encodes. And, to add
.. another blow, of all encoders, CCE (and its heavy price tag) does not have this
.. feature ?? And, then final answer came to me. You got it. It's not YV12.
.. It's 4:2:0 but the missing piece still eludes me and you all. Or, perhaps it
.. has something to do with the way video is being minipulated and finalized through
.. the devices output channel. IRE. But, there lies another question (or two) Anyways.

No matter what the IRE channel is on any front (device etc) we also need to
know weather or not the final capture and/or encode to, is permanent, w/ respect
to IRE. For instance. If I capture from my DVD, and it is outputing an IRE 7.5
level, then THAT is what is being captured; recorded; or encoded to a final
source based on that level (assuming you can't alter the IRE produced source at
any juncture) and so.. If the IRE is 7.5 on my source (ie, dvd recorder's mpeg-2
or captured source, (though now my head is spinning because of the complications
that arrises from the codec and the color space and other attributes, when left
in the hands of casual/newbie users - oh well)) ..again, the final source is
IRE 7.5 now, on the source file in question. If the source is, shall I say,
"burned" or permanant on the source, say it be an AVI capture, then that means
that our capture (w/ its other attributes of codecs and color space) is a capture
of IRE 7.5 level. If we proceed to alter this with minipulations (ie, TMPGeng's
YUV filter) are we really bumping it back to wehre it should be, or are we just
"filtering" it to some other level of blackness. That is the question. My belief
is that once we capture it, then there is nothing we can do about it now.
.
If I capture something that is say IRE 7.5 level, and that is *suppose* to be
that level, then I should be encoding it at that *same* level. At least that is
what I beleive it should be. But tests need to be made (see below) in order to
know for sure. Anyways.
.
My understanding is this. If I capture something that is IRE 7.5 that is the
level of output richness I'm expecting to obtain when I view this source. However,
when things get dumped onto a pc screen, there is yet another issue with the color
space and IRE level and Vibrant and Richness in colors we see from this capture.
Things are beginning to get really confusing here. And this is why some are
starting to ask questions now. Anyways. As I was saying. things are beginning to
get messy here. Is IRE values getting re-IRE 'ed again, or un-IRE 'ed in all these
video transferences ?? And if so, How can one gain *control* of this before things
truely get messed up - like today. Things are just too messy and out of control.

About a month ago, I shared in a test scenario, where I recorded my DVD movie,
"The FIfth Element" onto a VHS tape. From my perspective, when played (VHS) on
my tv set, the movie looked pretty good, and colors *seemed* to match closely
to the dvd if I didn't count the dots, etc. But, afterward, when I proceeded to
capture this VHS tape I just recorded from DVD from, things got really ugly. I
could not match the same level of color space or output quality as that of the
DVD, let alone, the VHS tape. I don't know exactly what happended in between
the steps, but even I got lost in the shuffle of things - transferences of video
sources from one item to the other and back and forth, and so on and so forth
.
BUT, lets say, they are airing "The Fifth Element" on cable tv, and I capture it,
(just as I did with the VHS tape) and I process it.., guess what ?? Things look
just like the source Cable that aired my capture.
.
Something (and element) is surely missing. And, it aint "the fifth element"

So. If we are cerious in this endeavor, to finaly reveal the trueth to this
missing element (could be anything) then we need to setup a standard set of
tests, and a number of us should perform this test.
.
A certian test scenario or platform should be devised. One that we all can
share in and do.
.
Our setup should be consistant, and equipment should be the same. Only time
different, is when we're testing which *brand* is at fault with certain quality
attributes. ie, Pioneer vs. Panna. vs. iLO vs. Emerson, etc.

I would like to start a test, and have others join in if they can.
Using the following setup/equipment:

* Source: commerical DVD movie (matrix / 5th element / etc)
* Scenes: decide on several scenes to standardize (for the test disk, maybe)
.
* DVD player: Apex AD-1500 (region and MV hacked free)
* LD players: Pioneer CLD-V2600 / CLD-D701
.
* capture devices: advc-100 / trv22 / DVDR04 dvd recorder /
.
* Software Editor: vdub (nothing fancy here)
* Pic format: PNG

Perhaps a test disk could be made and a part of the new standard here, and
we could D/L the VOB file. If we create a standardized test disk, then that
will rule out any inconsistance w/ source. At least thats a start.
.
For an idea, here is a good example of a test scenario of making a test disk.

--> Panasonic E55 video recording test

Then, you could upload your results here. I (or someone) could tally the results
into a database, for a record, and to add bruse to this forum, we could add this
into the "dvd recorder" section, it's IRE values.

I don't know. I had much more to say, but my head is hurting, and I didn't get
a chance to do my other fun test and projects and things.

-vhelp 3140

[vhelp]

Lets create a check list, shall we.

A - [TRUE/False] - IRE is a device-only thing. Not software filter.

B - [TRUE/False] - Commercial DVD movies that we buy are encoded MPEG-2 and
.................... @ 4:2:0 (not 4:2:2)
B - [TRUE/False] - but, if they are actually 4:2:2 then that might explain the
.................... missing element, because of the Vibrant and Richness in
.................... color quality we see when we view them on TV or rip them to
.................... our desktop pc harddrives. If this is TRUE, then we need a
.................... test app that can open a ripped VOB from a commercial dvd
.................... movie, and examine the video for 4:2:0 or 4:2:0 color space

C - [TRUE/False] - Commercial DVD movies are sub color space YV12.

D - [TRUE/False] - Most DVD player output an IRE 7.5 (NTSC) (lets assume all do,
.................... for now)

E - [TRUE/False] - VHS is IRE 0

F - [TRUE/False] - Laserdisc is IRE 0

G - [TRUE/False] - Cable / Satellite / Antenna sources are IRE 0

H - [TRUE/False] - CCE; MC; Procoder; TMPG; encoders feature an IRE 0 / 7.5 switch

more..

-vhelp 3142

[BJ_M]

Lets create a check list, shall we.

A - [TRUE/False] - IRE is a device-only thing. Not software filter.

B - [TRUE/False] - Commercial DVD movies that we buy are encoded MPEG-2 and
.................... @ 4:2:0 (not 4:2:2)
B - [TRUE/False] - but, if they are actually 4:2:2 then that might explain the
.................... missing element, because of the Vibrant and Richness in
.................... color quality we see when we view them on TV or rip them to
.................... our desktop pc harddrives. If this is TRUE, then we need a
.................... test app that can open a ripped VOB from a commercial dvd
.................... movie, and examine the video for 4:2:0 or 4:2:0 color space

C - [TRUE/False] - Commercial DVD movies are sub color space YV12.

D - [TRUE/False] - Most DVD player output an IRE 7.5 (NTSC) (lets assume all do,
.................... for now)

E - [TRUE/False] - VHS is IRE 0

F - [TRUE/False] - Laserdisc is IRE 0

G - [TRUE/False] - Cable / Satellite / Antenna sources are IRE 0

H - [TRUE/False] - CCE; MC; Procoder; TMPG; encoders feature an IRE 0 / 7.5 switch

more..

-vhelp 3142

main profile (dvd type) mpeg2 can not be 4:2:2 , it's not possable ..


d is false

e is false

f is false - somewhat - it is machine dependent also .. i think it accually is 3.5 for some odd reason ...

g is false

procoder doesnt have a switch per say ... it a filter you load that does a bitmore than just lop off (core) the top and bottom - there are several choices on which way to go .. cce and mc - yes,they do have..

I make commercial dvd's and the color you see is because of the color correction and also because of the straight transfers from digital sdi or files and/or 10bit+ and/or log color space vs. 8 bit lin color space (for the source) (though log has to be converted to lin. of course) ... i really dont know how to explain it well ..

[lordsmurf]

To further complicate matters .... ....

Let's take a gander at everbody's favorite MPEG encoder, TMPGENC PLUS... and that mystic setting .... you know the one...




Now... I know this isn't the prettiest VHS source in the world, but it was something I was converting (the tape is already dying, as you can see). Also note that I did some noise reduction and matted widescreen in the encodes, but the thing to pay attention to is the black/pastels changes by using this setting.

source (direct JVC DVD recorder MPEG capture, proper tonal values)


re-encode of MPEG .. unchecked ... blacks/whites/pastels remain the same


re-encode of MPEG .. CHECKED!... darks and black are pitch black (bad!) and the pastel blue turned several shades lighter, almost towards white


So..... what's going on here?

This "CHECKED EFFECT" is what happens on Panasonic E10/E20/E30 encodes. Too freaking bright.

.
.
.
.

Another thing people keep forgetting is VHS was never "pure black" anyway. It's always a dark muddy gray at best. Yes, even commerial releases.

[BJ_M]

thats why i said false for vhs ... dark muddy gray is a good description EXCEPT on broadcast quality s-video machines which can have a somewhat decent picture .. or my old sony 1000 svideo top of the line machine ....
I knew some stations that even used svideo (gag) for some things - on air

[gshelley61]

Another thing people keep forgetting is VHS was never "pure black" anyway. It's always a dark muddy gray at best. Yes, even commerial releases.

Yes. NTSC VHS black level is at 7.5 IRE, which is dark grey... not true video black. All my NTSC laserdiscs are that way, too. I do have one Japanese market laserdisc - Song of the South. I wonder if that is 0 IRE? I am going to have to check that out tonight...

[lordsmurf]

Oh, and just as a note, the raw JVC source encode, as well as the new UNCHECKED TMPG encode, both look proper on the tv set. The original video is a little lighter than that, as it should be. I was unable to use a proc amp on it, as the source was too flawed, some goofy side effect happening.

[edDV]

Hi again guys,

I've been playing with color bars and the waveform monitor (both in Vegas 5) and have been discovering some interesting things about NTSC DVD players.

First I'll describe how I calibrated my editing environment. I'll come back tonight and insert some wfm displays.

First let me describe the Vegas NTSC color bar (includes white, black and pluge) It has CCIR-601 (DV) levels: black = level 16, white is 235, pluge extends below black about 5% (~level 4).

I record this bar to my DV camcorder and calibrate the monitor (a HDTV monitor connected S-video to the DV camera) using the color bar.

Next I DV capture (IEEE-1394 transfer) the color bar back to the Vegas timeline. The levels from the DV cam are identical to the original.

Next I capture the NTSC composite output from the DV cam to the Canopus ADVC-100 over IEEE-1394 to the Vegas timeline. The ADVC is set to 0 IRE black mode. The captured levels are essentially identical (i.e. black is zero IRE, no setup, white bar is approx 96 IRE indicating an analog gain problem with either the camcorder or the ADVC). Pluge is present indicating the ADVC is capturing black to level 16.

Next, I record the Canopus ADVC NTSC composite color bar to the DV camcorder (analog in). On the Vegas timeline, Canopus bars show black at 0 IRE and white almost exactly at 100 IRE. Perfect.

OK, a calibrated environment with the exception of the composite 96 IRE white coming out of the camcorder.

Next, I create a timeline of Vegas bars and other test signals and known good video clips. I also include some direct captures off the cable box (via the ADVC still set for 0 IRE) capturing scenes that include both black and white.

The first thing I notice on the waveform monitor for thse clips is black shows at 7.5 IRE and whites at about 108 IRE.

I repeat some captures with the ADVC set for 7.5 IRE (Sw2 on). For most channels black is is at 0IRE and white is near 100IRE on the Vegas timeline. Exception was HBO that was showing some blacks extending below 0IRE (probably a Comcast problem).

Next, using the Vegas MainConcept encoder, I make a DVD MPeg2 (default 8Mbps max, 6Mbps ave. VBR) file and then drag this to the timeline. All levels are identical to the original except pluge is gone (i.e. all info gone below 0IRE).

Next, I author a DVD with chapter points on each test signal and sample clip. I drag the VOB file to the timeline and again all levels are identical to the original at OIRE and above. I burn the DVD.

Now it gets interestiing. I play the DVD through several DVD players and capture the analog outputs with the Canopus ADVC-100 and double check the results with the camcoder analog capture. Here is what I found.

Pioneer DV-363
Composite NTSC out - Black at 7.5 IRE (pluge missing below 7.5 IRE), White bar clipped ~ 109 IRE !
Chroma levels were down 15% ! Hue was OK.
Clips with setup in the original now had double setup (i.e. blacks ~ 15-18 IRE) and whites were clipped at ~109IRE. This gets you very gray blacks and washed out contrast. Detail is lost in the clipped white areas.
Componet Y output was identical to the NTSC output with 7.5 IRE setup, clipped pluge and 109 IRE whites.

NextBase DVD 9000 (cheap Chinese player)
Composite NTSC out - Black at 0 IRE (no setup, pluge missing below 0 IRE), White bar near ~ 101 IRE. This is very good!
Chroma levels were +/- 2%, Hue was OK.
Clips with setup in the original have blacks ~ 9IRE and whites are at ~102IRE. There is no clipping in the whites.
Componet Y output - no setup, black at 0 IRE (pluge missing below 0 IRE), White bar near ~ 96 IRE

CyberHome CH-DVD-300 (even cheaper Chinese player)
Composite NTSC out - Black at 0 IRE (no setup, pluge missing below 0 IRE), White bar near ~ 108 IRE.
Chroma levels were ~ 20% low, Hue was OK.
Clips with setup in the original had blacks ~ 8 IRE and whites were clipped at ~109IRE but not as bad as with the Pioneer.
Componet Y output - no setup, black at 0IRE (pluge missing below 0 IRE), White bar near 108 IRE.

Observations so far:
This is a work in process. I'm surprised the Pioneer is this bad. Maybe I'm missing something in the menus. I hope there is a way to turn off setup in the Pioneer, otherwise I'll need 2 HDTV monitor presets, one for the DVD player (with setup) and one for the DV computer (no setup).

It looks like 109IRE = digital level 255. Hot video clips off there.

The Mainconcept encoder isn't passing anything below 0IRE. Does this mean 0IRE = digital zero rather than 16 for Mainconcept? I don't know yet. This is bad for that Canopus ADVC capture of Comcast HBO mentioed above. HBO had it's blacks clipped. Maybe HBO on my Comcast doesn't have setup. Need to go back and check.

I also learned that the Vegas (digital) and Canopus ADVC (analog) color bars matched perfectly for black and white levels when both are recorded to the DV camcorder or to the Vegas timeline.

In conclusion, levels are all over the place with DVD players. My two Chinese players had no setup, the Pioneer did even on the component output. DVD recorders have all these issues plus input issues as well. Nothing is easy.

Edit Add >> I found the "Video Adjust" settings in the Pioneer DVD player and should be able to Preset proper settings for video and chroma gain. I haven't found a way to defeat the 7.5 IRE setup yet.

[gshelley61]

In conclusion, levels are all over the place with DVD players. My two Chinese players had no setup, the Pioneer did even on the component output. Recorders have all these issues plus input issues as well. Nothing is easy.

Amen. An awesome, educational post, edDV. If there is one constant in electronics gear... it is that they all perform differently! Which makes it difficult and confusing - but interesting, too.

[zorankarapancev]

Great job!

[vhelp]

@ gshelley61

Yes. NTSC VHS black level is at 7.5 IRE, which is dark grey... not true video black. All my NTSC laserdiscs are that way, too. I do have one Japanese market laserdisc - Song of the South. I wonder if that is 0 IRE? I am going to have to check that out tonight...

On your laserdisc IRE observation tests, how did you test it and then
determin it was "dark grey". The reason why I ask, is because yesterday,
I did a quick test with my CLD-V2600 and found the blacks to be black.
But, then, I wasn't using the tipicle tests approach -- s-video to s-video
Actually, I was feeding the source like this:

v2600[s-video OUT] --> advc-100[s-video IN] - [dv OUT] --> dvdr04[fw IN]

I was experimenting on another approach w/ the advc-100 device.

I would like to post some pics on some LD movies w/ the iLO dvd recorder
I have, just for topic/conversation sake.

The advantage I *might* have w/ the advc-100 is that I can switch the IRE
values from 0 to 7.5 for this scenario when feeding the output source's video
through the OUT's of the iLO 's s-video or fireiwre ports. But, I'm still working
this out to see if this could serve as a temporary fix to the IRE issues w/ certain
source types.. ie, VHS; dvd; cable; satellite etc.

-vhelp 3147

[BJ_M]

this is what I have mentioned probably about 50 times on this site as well as many others -- that dvd players are all over the map ...

we have tested around 50 players in the last 5 - 6 years .....

also why ive said that dvd set up disks are not useful in a broadcast/pro situation to set up your monitors - i get into big arguments on this ...

[gshelley61]

@ gshelley61

On your laserdisc IRE observation tests, how did you test it and then
determin it was "dark grey".

I run all my sources through the SignVideo Proc Amp (even if I bypass the adjustments), so the luminance and black level meter make it easy to see what you've got. During "fade to black" transitions, my NTSC laserdiscs and VHS tapes all read 7.5 IRE black level on the meter. If I run a MiniDV tape or DVD as the source, during the black transitions the meter will read 0 IRE black level. You can tell from observing the monitor that the digital video sources have darker blacks, too.

[gshelley61]

also why ive said that dvd set up disks are not useful in a broadcast/pro situation to set up your monitors - i get into big arguments on this ...

Exactly. The DVD test discs are only intended to tweak a display for the specific DVD player the disc is being played back on. That's fine for TV's and monitors that have independent picture adjustments for each input. Professional broadcasting and editing studios use test pattern generators and lots of other measurement tools to calibrate their gear.

[edDV]

I'll try to capture some laserdisc to my calibrated Vegas timeline using the Canopus ADVC in the 7.5IRE mode. Some of my laserdiscs have color bars on them.

[vhelp]

@ edDV

Yes. This just cought my eye and your comment.
You said you have a laserdisc (disk) w/ color bars. And, not to mention
that the advc-100 outputs color bars (holding the the gray button for
5-10 seconds) ..as this is suppose to aid us in adjusting out tv sets.

But, what good is it, if our sources are throwing various levles around
the place ?? After reading the above and other threads/topics here on
this great forum, it makes me wonder what's the use of color bars after
all. Anyways

-vhelp 3149

[edDV]

I learned above that the Canopus ADVC color bar (output to analog) captured perfectly through my DV camcorder (a cheap Sony) and matched exactly the Digital color bar produced by Vegas. This gives me confidence in the Canopus ADVC and DV camcorder as capture devices, and also as a poor man's analog measurement device.

Source levels will vary, broadcast equipment have analog level controls that allow you to match levels at the A/D. For consumer gear, you need to take what you get and either adjust it on the capture device itself (e.g. "capture levels") before the A/D or create correction filters for each device that operate in the 8bit digital domain (less desirable).

Fortunately, most sources are going digital. The wild beast to be tamed is the VHS deck. The way it's done in the professional world is with a TBC/Proc Amp combination with all the level controls adjustable. What is needed to adjust these controls correctly is a color bar source and a waveform monitor/vectorscope on the capturing device.

This is the Vegas digital color bar on the timeline.

Note the "pluge" extending below 0 IRE.

Next this is the Canopus ADVC-100 NTSC composite color bar as captured by the DV Camcorder analog input.


This is the DVD VOB file on the timeline after encoding with the Mainconcept encoder. Levels are good but the "pluge" (below 0 IRE) has been eliminated.


This is the NTSC output of the Pioneer DV-363 DVD player playing the VOB file above. It shows the 7.5 IRE black, clipped white (note no normal noise on white bar) and low chroma (shown on vectorscope) as analog captured by the DV camera


Lastly, this is the Y output of the Pioneer DV-363 DVD player showing the same 7.5 IRE setup and white levels as the NTSC output.



Edit Add >> I found the "Video Adjust" settings in the Pioneer DVD player and should be able to Preset proper settings for video and chroma gain. I haven't found a way to defeat the 7.5 IRE setup yet.


//- Because this is now a sticky, I shrunk all the images to 75% and cropped them. Even on my 1024x768 monitor, this thread was hard to read. Because stickies are for the most people possible, I've done this to make it easier to read, however, you can still download a zip with the original full-sized uncropped images. -- moderator lordsmurf

Original hi-res uncropped images here: images-eddv-ire1.zip

[edDV]

Another thing people keep forgetting is VHS was never "pure black" anyway. It's always a dark muddy gray at best. Yes, even commerial releases.

Yes. NTSC VHS black level is at 7.5 IRE, which is dark grey... not true video black. All my NTSC laserdiscs are that way, too. I do have one Japanese market laserdisc - Song of the South. I wonder if that is 0 IRE? I am going to have to check that out tonight...

Here is laserdisc through the Canopus ADVC-100 in 7.5 IRE (on) and zero IRE (off) modes. Remember this is DV format so camcorder material will have black at 0 IRE.


ADVC 7.5 IRE mode, 7.5 IRE analog captured to 0 IRE (digital 16)



ADVC 0 IRE mode (normal setup, black is defined at 7.5 IRE)



// Same note as above thread. -- moderator lordsmurf

Original hi-res images here: images-eddv-ire2.zip