EricLNZ,

Several AVCHD camcorders shoot modified levels, which are ~16-255. Yours may be one of them. Needs a modified Studio RGB on the output.

vjsouza, once again, thank you for the post...

We will forward your suggestion to the developers and hopefully they considered about it.

EricLNZ,

Several AVCHD camcorders shoot modified levels, which are ~16-255. Yours may be one of them. Needs a modified Studio RGB on the output.

Thanks. After reading Nick's thread that Marco gave a link to I suspect you are correct. It's a Canon HFG10. Until I started reading about the problem it had never been an issue as I'm happy with my camera and Vegas MS output. But I'm not a pro and I do sometimes tweak my shots bringing up the Input Start in Levels. Perhaps that's why.

NormanPCN, you said: "Basically Vegas leaves levels untouched from import to output."

Really? Try to export my project "RGB Exported with Vegas Pro 14.veg" as Sony AVC, and compare the source file "Sample RGB Full HD.png"with your exported MP4 file, in a player, as VLC Media Player, Media Player Classic, or other.
If in your exported MP4 file you can read the text "Foreground RGB 16, 16, 16" and "Foreground 235, 235, 235" in your TV or VLC Media Player, I will send to you a box with chocolates from Brazil.

You fundamentally do not understand the topic of levels.

In your example PNG, which is full range, I would not expect to be able to read the text you describe in a Vegas AVC MP4 encode. No need to send me chocolates. For reasons previously described at least in part.

The PNG is full range data. Any image file is full range data by definition. It (full range) will look fine in the Vegas computer preview window. Video preview devices will typically clip the preview. Encoding to AVC, which expects studio levels will cause problems. This because players which play the resulting file in the computer digital world normally clip/expand levels from 16..235 to 0..255.

It should be noted that levels 1..254 are actually legal. What happens to levels outside the 16..235 range is simply undefined. Back in the days of analog TV you could adjust your TV to display output of range data. In the current world things are more hard edged but for legacy/transition reasons we still have the levels duality. And thus the potential for confusion like yours.

I wrote a much longer and more detailed answer but the "awesome" MAGIX self written forum software sent it into a black hole. My bad for expecting it to operate to standards. Live and learn.

I wrote a much longer and more detailed answer but the "awesome" MAGIX self written forum software sent it into a black hole. My bad for expecting it to operate to standards. Live and learn.

OT: Lesson learned...

I guess for safety purposes, when we need to write a much and more detailed answer for this post here, it's better to copy paste it to Notepad...

Or exercise brevity, of which I am equally guilty of deferring.

@NormanPCN

+1

👍 ✌️

I suspect the biggest problem, or misleading item, here is the use of VLC Media Player.

Following NormanPCN's post three up I exported my full range test png file to MP4 using SonyAVC. My computers graphics are set to show full range and not let applications exercise their own preferences. With VLC I lose the letters as it's presumably only showing the limited Studio RGB range. But with MPC-HC I get everything. The letters are there i.e. the full 0-255 range. So there's nothing wrong with the mp4 file produced by Vegas MS14. I dug through VLC's options to see if I could persuade it by altering a setting but without success. For years I had noticed VLC, on the rare occasions I used it, made my videos look more contrasty. Now I know why.

Although I haven't got VLC to display the file correctly I have got MPC-HC to do so. Where do I stand with the offer of Brazillian chocolates?

Yes, VLC uses the flags in files to set playback levels, except when it doesn't.

Yes, VLC uses the flags in files to set playback levels, except when it doesn't.

Does that mean Vegas places a flag in the exported file to indicate play with Studio RGB even though the file contains full Computer RGB?

Yes, e. g. when you export to MP4 H.264 there will be a color range flag which is set to "limited" instead of "full" (shown in MediaInfo). If Vegas Pro would set this flag to "full" even VLC Player would display all information of 0-255 signals without clipping.

Some players read this flag, some ignore it.

But how to optimize Vegas Pro? How would Vegas Pro know you used full range or limited range? And if then many player ignores the flag in the end - how useful is it?

You could use FFmpeg to render same level 0-255 video source once with flag set to limited range once with flag set to full range. Controlled via Vegas Pro you will see hardcoded level of both versions is same. But if you open both videos in VLC player one version will show all data (flag set to "full") and one version will be clipped (flag set to "limited").

Edit:
I just did that FFmpeg render and uploaded both versions which are basicly exactly same, except of that color range flag. If you download and unzip the file, put both files into the Vegas Pro timeline and playback both files within VLC player to see the difference.

-> Levels_02

The point is - tricky world starts here. On my system both WMP and Film&TV player displays the limited flagged version same as Vegas Pro does, they ignore the flag and display data range. My TV also ignores the flag. Vice versa Chrome player ignores the flag of the full range version and displays limited data (clipped video). That makes me doubt that flag is really useful, but we have to deal with it.

I've discovered with MPC-HC (which is my preferred player) that View/Renderer Settings/Output Range gives the options of 0-255 or 16-235. Possibly VLC has something similar but I cannot find it. Both players have options/settings which are way over my head.

I've discovered with MPC-HC (which is my preferred player) that View/Renderer Settings/Output Range gives the options of 0-255 or 16-235.

I use MPC-HC with the fix setting to use 0-255 but

this setting is ignored as the color range flag in Marcos two Clips. However, the Windows 10 internal player does it correct and uses the flag setting. This can also be see in the thumbs within the Windows Explorer.

EricLNZ,

Of course Vegas honors and writes to legal REC 601/709 colorspace, as expected. The actual levels conformity is entirely up to the editor, and no change to native levels takes place without purposeful intervention.

Now, about an. entirely different kind of flag:

The yuvj420p (--fullrange) flag, which purports to tell players NOT to expand levels from so-called "fullrange YUV" is just another illegitimate stepchild from Apple, and does not work so well. Adoption has been spotty, and as we've found out in VLC, an early adopter, sometimes it works, sometimes it doesn't. Same for YouTube.

Some phones write the flag, some do not. Some players honor the flag, and some do not. That's about as excited as you'll see me get over this.

No, unless something has changed in 14, Vegas does not read, write, nor recognize VUI flags, and Thank God. The possibilities for injecting debilitating bitdepth errors into the workflow are many. Like training pants for dogs.

There are some examples in the Shirley thread.

Remember that a <null> flag is the same as writing yuv420p, meaning vanilla 16-235 source.

If Magix wants to add the "feature" to Movie Studio, I am all for it. Might appease some of the Premiere fanboys and game-obsessed in our presence (if you haven't guessed by now Premiere makes mistakes too.)

But VUI support in Vegas Pro as the default behavior? ¡NUNCA!

Anyway be aware that VUI flags are just a wart, and are in no way the official spec. Same for Color Range, Dynamic Contrast, and the rest of the swamp babies. Render to spec, and leave the rest alone.

"Automatic" NLE decode/encode leveling is for the Trix crowd, not editors.. Just my opinion.

@Marco.

Is it possible to alter this Color range flag with FFmpeg without reencoding?

At least I did not find a way to do so without re-encode. If you use commands like -color_range or -colorspace combined with the copy command they do not seem to work.

I don't use FFmpeg frequently, but may be this can be used for changing the rage flag

http://forum.doom9.org/showthread.php?t=152419

This seems to work, great resource. Thanks for sharing.

Guys, let me leave something very clear. My productions are mostly to run on TV and YouTube / Vimeo. All computer players come pre-set to run YUV 16-235 videos, as well as all LED or LCD TVs, all of which run YUV 16-235 colors. YouTube, Vimeo, DailyMotion, etc. All of these run 16-235 videos only. So, there's no point in exporting Full Range RGB 0-255 to such media because it will not work.

I do not know of any TV device that runs RGB 0-255. All only run YUV 16-235.

I have been a producer of TV commercials for 17 years, and I have sent my productions in MXF XDCAM to the main broadcasters in Brazil, Rede Globo, SBT, Record and Bandeirantes. I have more than 500 commercials broadcast on these stations, and I have never had any disapproval. I KNOW WORKING WITH TV LEVELS.

All other programs I know deal well with mixtures of YUV 16-235 camcorder videos with JPEG / PNG RGB 0-255 photos. The editor does not even need to know that you are mixing RGB with YUV on the same project. I would like things in Vegas Pro to be the same as other NLE programs. Only that! Is that too much to ask?

I know the Vegas program since the old version Sonic Foundry Vegas Video 2.0. I doubt that my critics have as much experience in Vegas as I have. Please respect me, and stop joking. Since then I have worked with all versions.

I have bypassed the problem of mixing YUV 16-236 with RGB 0-255 in the same project by placing the LEVELS plug-in with the "Computer RGB to Studio RGB" preset on RGB objects 0-255. This has worked. But I wish things were different. In other programs, I do not need to make any adjustments. Just put RGB and YUV on the same project with no problems. I know that if there is goodwill, Vegas Pro programmers can do that.

Having written the above, I do not think I need to comment any more!

Bye!

Your request has been noted by moderators, and I support the idea in principle, but in entry level versions such as Movie Studio, only. But no need to impress us with your credentials, which pale in comparison to a couple of cats who have already responded to your lengthy theories.

"All computer players come pre-set to run YUV 16-235 videos, as well as all LED or LCD TVs, all of which run YUV 16-235 colors."

As we mentioned in some of our postings - this is not the case. Most do, some don't. And it's just not true all other NLE would perfectly deal levels. Some of them will clip your camera levels even by import, because the source levels are 16-255 but flagged as "limited range". You would just not know what happens to the levels because you can't compare in these NLEs. We can in Vegas Pro and this is a good thing.

That's what we tried to explain. In many cases it is a matter of how flags are handled. And while Vegas Pro just ignores this flag, other try to read this flag and this isn't always good as the examples we posted show.

"I do not know of any TV device that runs RGB 0-255."

All TV devices I ever inspected were able to reproduce 0-255 (home and broadcast environment) if they were set this way. But the primary calibration you would do is adjusting black level according to a PLUGE test signal so the display will map luma 16 to the darkest output which is meant to be reference black. Then you would set your reference white by mapping luma 235 to a NIT value which follows common specs and which usually is in the area of 80 to 160 NITS dependend on the surrounding. Then you will adjust display's gamma of usually something about 2.2 to 2.4.
Because TV/video displays reach max. NIT values of 400 and more it is likely they will be able to display some of the headroom above luma 235 if them are properly calibrated. All the video displays we use inhouse of several broadcast houses and both all the TV home displays I ever used were/are able to repro some part of that headroom (while none will use footroom, properly calibrated).
This is for EBU.

But this all is some steps further. First thing to realize is Vegas Pro usually does not touch your (hardcoded) input and output levels. There may be issues because of the color range flag which is ignored for input and which is improperly set for output, but similar issues arise if same flag is read for input and if it is properly set for output.

I think we all thoroughly respect your meaning, your input and your knowledge. Please do same for others contributing here.

Peter, the flag and major brand (isom, mp42) can also be written in MP4Box, with a special extension.

"You would just not know what happens to the levels because you can't compare in these NLEs. We can in Vegas Pro and this is a good thing."

Oh yeah, oh yeah...

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