IRE or black level problems with a PAL/NTSC international DVDR - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 11 Old 08-12-2010, 02:16 PM - Thread Starter
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I recently purchased a Panasonic international DVDR. It's mainly meant for the European market(SCART connectors etc.) but also works in the US to record a NTSC line input from it's S-video or composite inputs. The problem I'm having is when I feed the DVDR a NTSC line output(from a DVD player, VCR or Tivo HD etc.) the recordings(or even line input feed through(from HD outputs)) look too light.
US Panasonics have a line input DARK LEVEL adjustment which I always set to DARKER(instead of the other option LIGHTER). The problem is this international DVDR doesn't seem to have that particular option and it's more like the US Panasonics set to LIGHTER(which have light darks).
Now I could just adjust my TVs brightness to compensate but I want my NTSC recorded DVDs to be able to be played on a properly calibrated US TV. I've read various articles about 0 IRE vs 7.5 IRE(apparently the US uses 7.5 while Europe(the rest of the world??) uses 0. Could this be what's causing my problem and if so is their a easy remedy? If I'm copying a DVD via line inputs, some DVD players have brightness adjustments that may be able to overcome the overly bright recordings(I'd set my DVD player to output a overly dark picture knowing the recorder would up the brightness) but many devices don't have output brightness adjustments(like my Tivo HD, VCR etc.) how would I handle those?

I'm hoping somebody like sneals2000 or another European poster would know how these international recorders are setup AFA black level. That or someone from the US that's well versed on black levels and international products.
I only ever record NTSC sources which are recorded to DVD as such and played on a US NTSC TV.
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post #2 of 11 Old 08-14-2010, 09:14 AM
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Sounds like a black level set-up issue to me. North American NTSC (and associated S-video, but AFAIK not component and HDMI) uses a 7.5IRE set up, so black level is 7.5IRE above blanking. PAL, SECAM and NTSC outside if North America (Japan, Korea etc.) don't have this set-up and have black at the same level as blanking.

DVD uses digital component recording, and there is no black level set-up on the recording, so North American DVDRs will remove the NTSC setup when recording and add it again on replay. International DVDRs may have the option to remove 7.5IRE set-up on recording, and add it again on replay, for use in North America, but I suspect most don't - so when presented with a US NTSC signal, they will record it as if the blacks are grey. When replayed on a North American DVD player then a second 7.5IRE set-up will be added... (Ironically, a non North American player will not add the 7.5IRE on replay, so will probably look OK...)

If your DVDR doesn't have the option to work in North American style then for copying your DVDs running your player in 'International' mode (i.e. Darker) will work, as this will output with 0IRE setup and so will record correctly. For recording other US analogue NTSC sources it is more difficult.

I know my UK multi-region, multi-standard players have an option to add 7.5IRE but I don't use this as I use RGB analogue outputs or HDMI neither of which should have 7.5IRE on them...
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post #3 of 11 Old 08-14-2010, 02:08 PM - Thread Starter
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Then I believe you've confirmed my fears, that is without somehow darkening the input(-7.5 IRE) to my international DVDRs line input(S-video) the resulting DVDs will be too bright by 7.5 IRE(when played on a US player).
Personally I've never seen a US device(DVD player etc.) that such a setting(at least using those terms). Like I said earlier I have seen more top of the line DVD players that have incremental brightness as well as color, sharpness etc. settings, but none had a ON/OFF setting labeled as IRE correction(unless you count the DARKER setting on US Panasonic DVDRs, which even Panasonic makes no mention to IRE or why one would want to use one setting over another). I'm guessing devices intended only for the US don't really consider IRE to be a issue since so few people would run into the problem (only US residence looking for a well built DVDR w/HDD and willing to go to the grey market)
Thanks for your assistance.
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post #4 of 11 Old 08-14-2010, 03:12 PM
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Quote:
Originally Posted by jjeff View Post

Like I said earlier I have seen more top of the line DVD players that have incremental brightness as well as color, sharpness etc. settings, but none had a ON/OFF setting labeled as IRE correction(unless you count the DARKER setting on US Panasonic DVDRs, which even Panasonic makes no mention to IRE or why one would want to use one setting over another).
Jeff

The "darker" setting is an IRE level control. It's not labeled that way because the average consumer doesn't know what an IRE is.

This black level issue goes way back to the beginning of DVD recorders. The Panasonic HS2 was clearly flawed, and Panasonic added the "darker" setting in the E80. Here's a post where I compare the settings on the E80.

http://archive.avsforum.com/avs-vb/s...36#post4777336

The original DMR-HS2 Black Level "bug" thread from 2002.

http://archive.avsforum.com/avs-vb/s...hreadid=175019

Ron

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post #5 of 11 Old 08-14-2010, 04:42 PM - Thread Starter
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Thanks Ron for those archived posts.
Since the Panasonic international DVDRs don't have such a darker setting, would it be your belief that they might not be able to retain a proper black level if fed a output from a US device, like a DVD player, Tivo or even VCR?
If so are you aware of any reasonably priced product that I could put in-line to correct the black level? Back in the VCR days I used a device(proc amp I believe) that I could correct tapes with incorrect color, tint, brightness or contrast, it went in line with the composite video signal. I haven't really had to use such a product recently since most DVDs are properly calibrated and do not require alterations. This device was also only analog(potentiometer) so it wouldn't really be precise like a digital setting and lacks S-video for a better recording but of course would be better than nothing.
Kind of bummed that this DVDR seems to lack this basic setting otherwise it's a fine product.
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post #6 of 11 Old 08-14-2010, 11:00 PM
 
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Can you just get a different DVDR?
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post #7 of 11 Old 08-15-2010, 05:35 AM
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I should just re-iterate that the DVD discs themselves don't contain the 7.5IRE offset, it is purely a function of the way the DVD recorder handles inputs with and without 7.5IRE, and the way DVD players handle output in 7.5IRE territories. (i.e. a DISC should always have the same black level irrespective of the input set-up)

It SHOULD, on recording, strip the 7.5IRE set-up if present - i.e. when presented with a North American NTSC signal - but not if presented with a Japanese NTSC signal or PAL/SECAM as this will already be at 0).

It SHOULD, on replay, add 7.5 IRE set-up if configured to output North American NTSC but not add 7.5 IRE set-up if configured to output Japanese NTSC or PAL/SECAM.

It sounds like you need a device that will remove 7.5IRE set-up from NTSC sources to bring black level down to 0IRE (as Japanese NTSC and PAL/SECAM have as standard) to use your DVDR to record standard DVDs that will replay correctly, if your DVDR won't remove the 7.5IRE itself prior to recording.
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post #8 of 11 Old 08-15-2010, 11:20 AM - Thread Starter
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OK I think I got it, anyone let me know if I'm wrong in my thinking.

US devices (VCRs, DVD players, Tivos, STBs, DVRs etc.) via SD outputs, output a signal that is +7.5 IRE for blacks. US displays (via SD inputs) are calibrated for black at a input of +7.5 IRE(unlike the rest of the world that uses 0 IRE for black). US devices output a 0 IRE from HD outputs(component, HDMI or DVI) if so equipped. In this case our displays are calibrated for black at 0 IRE(the international standard).

A standard US DVDR via it's SD inputs(basically all DVDRs have) drops it's +7.5 IRE input to 0 IRE(DVD standard) for blacks. Upon playback the DVDR(or any US DVD player) must add +7.5 IRE to SD outputs to retain correct blacks.

US Panasonic DVDRs (other than the old HS2 with the so called black level bug) have a setting(called DARKER) for SD line inputs to subtract 7.5 IRE(knowing US SD devices output a +7.5 IRE), this retains compatibility with the DVD standard of 0 IRE. Upon playback the DVDR adds 7.5 IRE(for SD outputs) to be compatible with our +7.5 IRE displays.

International DVDRs(like my Panasonic) have no such IRE settings and only go off the international standard of 0 IRE in, 0 IRE out for ALL inputs/outputs.

Using a Panasonic international DVDR in the US runs into a problem for recording(and playing via it's SD outputs), that is it's expecting line inputs to be a 0 IRE. The problem is, US devices output a +7.5 IRE. DVDs recorded in such a manner will be overly bright when played back from the DVDRs HD outputs(HDMI or Component) because again US displays are looking for a 0 IRE output and not a +7.5 IRE. If played from the DVDRs SD outputs the DVDs will be fine, not because the DVDR is adding +7.5 to the output but rather the DVD was recorded +7.5(not DVD spec). These recorded DVDs played back on a US DVD player will be +7.5 IRE too bright from it's HD outputs and a terrible +15 IRE from it's SD outputs(because the US player adds +7.5 IRE to a DVD that is already +7.5 IRE hot).

I see no ideal way to correct this because if I install a -7.5 IRE attenuating device on my international DVDRs line input I'll get proper spec DVDs(that will play worldwide on any NTSC DVD player) but they will look too dark coming from the DVDRs SD outputs. I guess this is the best scenario because I don't want all my recorded DVDs to be out of spec by +7.5 IRE making them incompatible with basically all US DVD players from any output. I'll probably only use HD outputs of my DVDR anyway.

Agree, disagree? boy this whole +/- 7.5 IRE thing can sure get complicated, all because the US didn't want to stick with a worldwide standard Don't get me started on ATSC

edit:moderator Ken H, I hope this thread is OK in the Technical forum. I tried to get answers in the DVD Recorders forum(on a thread specific to my DVDR) but had no bits. I thought since this was more of a technical question(and involved more devices than just DVDRs) it might be OK in the Technical forum, besides we seem to get more international members in this forum. If not you could certainly move it to the DVDR forum. This was my original post in the DVDR forum. In the end I think I'll put a link in that thread to this one since I'm getting important information here.
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post #9 of 11 Old 08-16-2010, 02:10 AM
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Quote:
Originally Posted by jjeff View Post

OK I think I got it, anyone let me know if I'm wrong in my thinking.

US devices (VCRs, DVD players, Tivos, STBs, DVRs etc.) via SD outputs, output a signal that is +7.5 IRE for blacks. US displays (via SD inputs) are calibrated for black at a input of +7.5 IRE(unlike the rest of the world that uses 0 IRE for black). US devices output a 0 IRE from HD outputs(component, HDMI or DVI) if so equipped. In this case our displays are calibrated for black at 0 IRE(the international standard).

You understand correct - though I'd replace "SD outputs" with "Composite / S-video outputs" as SD component outputs shouldn't have +7.5IRE on them either AIUI (so it isn't an SD vs HD thing it's a composite/S-video vs HDMI/Component thing)

Quote:


A standard US DVDR via it's SD inputs(basically all DVDRs have) drops it's +7.5 IRE input to 0 IRE(DVD standard) for blacks. Upon playback the DVDR(or any US DVD player) must add +7.5 IRE to SD outputs to retain correct blacks.

Yes - though because DVDs record digitally they don't really use IRE in the same way - they keep black at digital 16 for all frame rates and resolutions, so the 7.5IRE analogue composite/S-video set-up is removed prior to recording to digital video on the disc, where black is the same all over the world.

Quote:


US Panasonic DVDRs (other than the old HS2 with the so called black level bug) have a setting(called DARKER) for SD line inputs to subtract 7.5 IRE(knowing US SD devices output a +7.5 IRE), this retains compatibility with the DVD standard of 0 IRE. Upon playback the DVDR adds 7.5 IRE(for SD outputs) to be compatible with our +7.5 IRE displays.

I'm afraid I have no experience of this - and don't know if the darker setting was on input or output.

My first UK DVD player sold here in the UK had an option for black level set-up which optionally added 7.5IRE to the output (for use when feeding a North American display I guess) I never used it for replay of any discs as my European display was configured for 0IRE blacks.

[quote]
Quote:


International DVDRs(like my Panasonic) have no such IRE settings and only go off the international standard of 0 IRE in, 0 IRE out for ALL inputs/outputs.

Using a Panasonic international DVDR in the US runs into a problem for recording(and playing via it's SD outputs), that is it's expecting line inputs to be a 0 IRE. The problem is, US devices output a +7.5 IRE. DVDs recorded in such a manner will be overly bright when played back from the DVDRs HD outputs(HDMI or Component) because again US displays are looking for a 0 IRE output and not a +7.5 IRE. If played from the DVDRs SD outputs the DVDs will be fine, not because the DVDR is adding +7.5 to the output but rather the DVD was recorded +7.5(not DVD spec). These recorded DVDs played back on a US DVD player will be +7.5 IRE too bright from it's HD outputs and a terrible +15 IRE from it's SD outputs(because the US player adds +7.5 IRE to a DVD that is already +7.5 IRE hot).

Yes - though you may see some issues at white levels - not sure what happens with 7.5IRE set-up at the other end of the scale.
Quote:


I see no ideal way to correct this because if I install a -7.5 IRE attenuating device on my international DVDRs line input I'll get proper spec DVDs(that will play worldwide on any NTSC DVD player) but they will look too dark coming from the DVDRs SD outputs. I guess this is the best scenario because I don't want all my recorded DVDs to be out of spec by +7.5 IRE making them incompatible with basically all US DVD players from any output. I'll probably only use HD outputs of my DVDR anyway.

Yep - I think that is the case.

Quote:


Agree, disagree? boy this whole +/- 7.5 IRE thing can sure get complicated, all because the US didn't want to stick with a worldwide standard Don't get me started on ATSC

To be fair the US was quite early in adopting TV specs. The UK 405 line system (aka 377/50i) we ran from 1936 until 1985 didn't have set-up, but there was a reason the US introduced it when they launched their 525 (aka 480/60i) system a little bit later. (We also used positive modulation and AM sound...)
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post #10 of 11 Old 08-16-2010, 02:50 PM - Thread Starter
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Thank you very much for your assistance sneals2000 and Ron(dr1394). I now know more about IRE and black level than I ever cared to
For ease, from this point on I've I'll refer to S-video/composite simply as SD, although as pointed out SD can also be component.

The good news, upon more checking I found out some interesting things regarding US DVD players. Most include in the setup a option for darkening the output, sometimes called DARKER sometimes only called BLACK LEVEL. This simple setting darkens the SD outputs by what I assume is 7.5 IRE. Most of the time the manuals don't explain this setup option other than to say if the SD output is too bright to set to darker(or black level). This setting is obviously for darkening the composite/S-video outputs for use with a non North American(I shouldn't really say US since Mexico and Canada(for sure) use the same 7.5 IRE) TVs. For me this will work nicely to darken the output to record on my international Panasonic DVDR and I won't have to monkey with incremental brightness adjustments which are on some DVD players.

The bad news, without some type of line input darkener I won't be able to use(and maintain 0 IRE DVD compatibility) my international Panasonic to record N. American VHS players, STB outputs, Tivos etc. Personally I have several other US DVDRs so I'll just use those for such copying and my international DVDR for DVD copying from a compatible DVD player.

I've confirmed from another(thanks Church AV Guy) that the international Panasonics contain no Darker setting for line inputs or brightener for SD outputs(unlike North American Panasonics) making it not such a good fit for most US recording or playing from SD outputs. Personally I'll use it's HDMI output which is the same 0 IRE standard as the US for such a output.
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post #11 of 11 Old 08-17-2010, 03:50 PM - Thread Starter
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OK I think this thread has answered the question about using a 0 IRE international Panasonic DVD Recorder in America. For anyone interested in more IRE talk this is a valuable(although a bit old) thread I learned a lot from. Note it can get quite technical at times. http://forum.videohelp.com/threads/201765-IRE-settings
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