I am considering capturing via FireWire

[Hypersonic1]

What about this? Where is the loss?

[jagabo]

What about this? Where is the loss?

When displayed on a TV dark detail below IRE 0 will be lost. The bright detail over IRE 100 will be lost.

Here's an example from a commercial DVD (I cropped away the black bars at the top and bottom of the frame, and did not resize the frame to correct for the display aspect ratio):



Here I'm using a slightly modified version of AviSynth's Histogram() to draw the waveform graph. It marks the areas below IRE 0 and above IRE 100 with a yellow background. At the top of the image is the picture as it would be displayed on a TV. On the left half of the image is the original DVD data. You can see that everything in the picture fits comfortably between IRE 0 and IRE 100. You can see details in the dark and bright portions of the picture. On the right I intentionally stretched the contrast so that darks fall below IRE 0 and brights fall above IRE 100 (and in fact, some are crushed at each end). Details in the dark and light areas are gone.

[Hypersonic1]

That still doesn't explain the loss in my example. If I brought the contrast down, the highlight and shadow detail would still be there. That is not the case with Premiere, because Premiere didn't display anything above and below 0-100.

What type of TV are you talking about? I don't see how a modern TV would have this problem. If I am going to play the files on the PC, I don't see how I could be losing any detail.

[jagabo]

I don't use Vegas but my understanding is that it uses "studio RGB" when displaying video. Ie, it doesn't perform the standard contrast stretch when converting YUV to RGB for display. I believe they do that so you CAN see details below IRE 0 and above IRE 100 while editing (unlike Premiere which shows you what the video WILL look like on TV). Then they give you the waveform monitor tool so you can adjust your levels to conform the the internationally agreed upon rec.601 standard (used by broadast TV, DVD, Blu-ray, TVs, etc.) of full black at IRE 0, full white at IRE 100.

https://en.wikipedia.org/wiki/Rec._601
https://en.wikipedia.org/wiki/Rec._709

But feel free to ignore the international standards and mangle your video any way you like.

[Hypersonic1]

But feel free to ignore the international standards and mangle your video any way you like.

I appreciate all of the help that you are providing me, but this stuff is really complicated. I am still not understand it well enough to resume my tape conversion projects.

I don't want to mangle my video. Also, there is no way that I could understand those two articles. They are too complicated.

I still don't know what software I should use to prevent from getting the data loss you are talking about. I don't know what process to go through from VirtualDub to NLE to prevent from getting the data loss you are talking about. So, I need a guide that provides that information. I am not aware of an article like that.

[poisondeathray]

That still doesn't explain the loss in my example. If I brought the contrast down, the highlight and shadow detail would still be there. That is not the case with Premiere, because Premiere didn't display anything above and below 0-100.

Premiere does preserve the full range , for some formats that it treats as YUV. I think this was discussed in your other thread

Vegas clips the same formats as Premiere.

The difference is PP has a YUV capable timeline, but vegas uses RGB only. Instead vegas has 2 methods of converting YUV import clips to RGB. Either studio RGB, or computer RGB

What did you import in post 61? Lagarith ? It gets clipped too . In your screenshot in post 61, nothing appears to be clipped because the original YUV signal is within 16-235 (you have no excursions <16 or >235) . If you had superbrights or darks, they would be clipped. You have the studio RGB setting on the scopes, and if you are using default vegas settings, lossless codecs like lagarith get computer RGB treatment

I've attached 2 test clips. They are both full range YUV 0-255. One is UYVY 8bit 422, the other is lagarith 422. In programs that can handle lagarith as YUV, those superbrights and darks are recoverable. Vegas isn't one of them. Notice the banding on the lagarith preview. Try "recovering" the brights and darks - you won't be able to. As explained in your other thread, the UYVY gets "passthrough" treatment in most Windows NLE's. In vegas vernacular, it gets "studio RGB" treatment (vegas doesn't have a native YUV timeline, everything gets converted to RGB by either studio RGB or computer RGB methods). Studio RGB means Y' 0-255 gets "mapped" to RGB 0,0,0-255,255,255 . Thus nothing is clipped. Notice the waveform monitor is a straight line as it should be - black to white. Conversely, lagarith gets computer RGB treament. Y' 16-235 gets "mapped" to RGB 0,0,0-255,255,255 . Values <16 and >235 are clipped

jagabo already said this - the bottom line is you need to either
1) ensure you are capturing between 16-235, or
2) legalize values in YUV to 16-235 before importing, or
3) convert to RGB beforehand with a full range matrix (this will reduce the contrast, making everything look "flatter"), or
4) use a format that gets treated as YUV in premiere (or gets studio RGB treatment in vegas)

uvyv


lagarith 422




Just for completeness, you can see (almost) the same thing occurring in PP. The difference is the slope of the curve is the same, the ends are just clipped. In vegas, because you have 2 different RGB conversions (2 different YUV=> RGB mappings), the contrast is actually different (the slope of the curve is different)

uyvy pp


lagarith 422 pp

[Hypersonic1]

What did you import in post 61? Lagarith ?

Actually it was HuffYUV. I don't think it makes a difference though.

convert to RGB beforehand with a full range matrix (this will reduce the contrast, making everything look "flatter")

That actually seems like the best option.

[jagabo]

VirtualDub and huffyuv will convert to RGB with a rec.601 matrix. That will crush superblacks and superwhites.

[Hypersonic1]

Would changing the input level to lighter, and the output level to darker work?

Panasonic ES-15:

[Hypersonic1]

Actually the input slider on the ES-15 doesn't seem to be doing anything. Only the output slider, so that means I can't adjust both superwhites and superblacks.

I will have to use the VirtualDub levels control before I capture. The problem is that the histogram in VirtualDub doesn't work. It's just all black. It would make it much easier if it worked.

[jagabo]

The problem is that the histogram in VirtualDub doesn't work. It's just all black. It would make it much easier if it worked.

Turn off video preview.

Use the capture devices video proc amp if you can. You can usually adjust that proc amp in another program and see the results in VirtualDub's histogram or preview in real time. GraphEdit is good for this.

Note that VirtualDub's histogram is a true histogram, not a waveform monitor.