Any harm in using ConvertToRGB24() by default?

[manono]

Yeah, an improperly calibrated TV set is what I thought several days ago, when this issue first cropped up. But since this isn't my speciality, and since I'm sometimes wrong when venturing opinions in this area, and since jagabo had the situation well under control, I kept my nose out.

But I'm sticking it back in to also suggest doing a calibration. Most TV sets are very poorly calibrated "out of the box", with the brightness and contrast (and sharpness) often way too high, partly to make them look good in a brightly lit store TV display area, but very bad for the home environment. Since this seems to be a brightness/contrast/gamma problem, the THX Optimizer included with all the Star Wars DVDs and hundreds of others should get you calibrated quickly, and then you can resume discussing the issue if calibrating the TV set doesn't work for you. And depending on how good your player is, sometimes it can be calibrated as well. Here's a list of the other DVDs with the THX Optimizer included:

http://www.thx.com/home/dvd/search.html

Click on "entire list" to see the complete list.

[DRP]

The only problem I have with adjusting the TV picture to compensate for the MPEG video is that then the picture becomes far too dark and dull when watching standard OTA broadcast transmissions on it. My TV is not high tech enough to keep and remember picture settings specific to individual sources, so I need a decent compromise setting which will work for everything.

I'll keep doing what I am now (without the (Matrix="PC.601") bit) for a while and see how I like it. In my quick and dirty test encodes, it seems to produce exactly the same result as when I use VDub as the frameserver instead (which I continue to do when I need to blur a station logo or DOG) and I'm very happy with that result.

[jagabo]

The only problem I have with adjusting the TV picture to compensate for the MPEG video is that then the picture becomes far too dark and dull when watching standard OTA broadcast transmissions on it. My TV is not high tech enough to keep and remember picture settings specific to individual sources, so I need a decent compromise setting which will work for everything.

A lot of DVD players have a high/low or dark/bright output setting. Check for that.

I'll keep doing what I am now (without the (Matrix="PC.601") bit) for a while and see how I like it. In my quick and dirty test encodes, it seems to produce exactly the same result as when I use VDub as the frameserver instead (which I continue to do when I need to blur a station logo or DOG)

That's because VirtualDub uses the rec601 matrix, the same thing you get without specifying the PC.601 matrix in AviSynth.

and I'm very happy with that result.

You are destroying your videos forever in order to temporarily compensate for an improperly calibrated TV.

Or... are you talking about material you've recorded off air or cable? Maybe your recording device is miscalibrated? And your black levels are too high to start with.

[edDV]

The only problem I have with adjusting the TV picture to compensate for the MPEG video is that then the picture becomes far too dark and dull when watching standard OTA broadcast transmissions on it. My TV is not high tech enough to keep and remember picture settings specific to individual sources, so I need a decent compromise setting which will work for everything...

There are two types of TV or monitor calibration. Internal adjustments allow the TV to make an optimal picture when connected to a series of standard test signals produced by a service shop's test signal generator. User adjustments allow adjusting brightness, contrast, saturation and hue to match incoming video (e.g. an on-air tuner or cable box) which may be producing slightly off levels. It is the responsibility of the TV broadcaster to maintain video at consistent levels so that the viewer doesn't have to adjust his TV for each new program.

Home video system calibration is a process where all source equipment is adjusted to produce similar video levels at the TV. The TV tuner or cable box is normally used as the reference since these usually lack user levels adjustment. Ideally, one will use video tapes or DVD with standard test signals to perform display card, VCR and DVD player internal or "user" levels adjustments. The idea is to make a standard source look the same at the TV when played on the VCR, DVD player or directly from the computer. Good levels references are the Standard SMPTE color bar, the Bell Nuit color bar (see link above) and/or the THX optimizer. The should all produce similar results.

Assuming your system is in calibration, it is now your responsibility to encode and author a DVD to match the industry levels standards used to produce a commercial DVD or TV broadcast. That means black at level 16 and white at level 235.

Remember the idea here is to avoid the need to adjust the TV controls when you switch between live video sources, your computer or your self produced DVD on the DVD player.

[DRP]

You are destroying your videos forever

I think that's going over the top a bit. Most people today will happily listen to their music collections on their iPods but no-one is screaming at them about how they're destroying their music by listening to it in a lossy compressed format.

At the end of the day, I only watch what I watch once, and then it is deleted. I very rarely ever keep anything for longer than it takes me to be able to watch it. All I'm looking for is a way of making the end result that gets displayed as good as possible on my screen as it is right now. I think I've now found a way of doing this be it via VDub or AviSynth. If it isn't technically correct according to arbitrary standards, then I'm sorry, but that method doesn't work for me for some reason. I can clearly see when black isn't quite completely black.

I am more than aware that the default settings of TVs are set way too high in almost all respects for display purposes in showrooms. I get a headache very quickly watching other people's TVs when I visit their homes. I am routinely turning down the colour (a lot) and the brightness settings whenever I get a chance. I assure you that I am not watching a TV set with very high colour or brightness settings which allow me to see blacks as dark blue when that shouldn't be visible.

are you talking about material you've recorded off air or cable?

No. I don't have the equipment to enable capturing or recording my own digital videos. My only sources are download and DVD.

[FulciLives]

If you really only watch stuff once and then delete THEN please re-consider using something else like HCenc ... why? ... it is a hell of a lot faster than TMPGEnc Plus and it is YV12 which is what most download stuff and DVD Video is already. Granted you will have to get used to using YV12 capable filters but such do exist. You keep the chain the same and no reason to worry about anything.

Although after your last remark about "watching once and deleting" my main reason for mentioning HCenc is not so much the "chain of filters all in YV12" aspect (although it is a nice idea) but simply the speed of it. Yes the SPEED!!! You will be kicking yourself once you try HCenc and see how much incredibly faster it is than TMPGEnc Plus.

I even wrote a bunch of guides. Here is the link ---> CLICK HERE

Trust me and others when we say that if you can use AviSynth and TMPGEnc Plus then you can fairly easily adapt to AviSynth and HCenc. Granted my mini-guides are using a slightly older version of HCenc but the current version uses an almost identical interface and the "new" stuff can be left at default if you are unsure about what is what etc.

- John "FulciLives" Coleman

P.S.
Normally I don't advocate speed over quality but in this case I'm not doing so because HCenc is a damn fine MPEG-2 DVD spec encoder. It is as good as CCE and TMPGEnc Plus etc.

[DRP]

Thanks for the suggestion but speed is of little to no concern to me. I know that sounds weird but honestly, the computer has to be switched on anyway for other reasons, so it is no harm at all for it to be encoding slowly at the same time just for something to do. Even at the glacial pace of TMPGEnc it still encodes several times faster than I'm capable of watching the end result, so it really isn't an issue at all. In fact, a faster encoder would create more problems for me than it solves. I would quickly find myself running out of HDD space to store all the MPEG-2 files on for long enough before I could get around to watching them.

I've made an interesting observation which seems to me to confirm my suspicion that using the PC601 matrix is wrong for encoding already TV-scaled video as input. I had reason to make an NTSC disc which needed no cropping at all. In line with previous advice I remarked out the Convert & Crop lines entirely to reduce the number of colour conversions to the fewest possible. The end result looks the same as my PAL conversion when using the plain ConvertToRGB24() without the PC601 matrix bit. ie. I cannot see any difference between a black background picture and the black letterboxing added by AddBorders. Everything points to the matrix PC601 line messing up the black shade.