DV to uncompressed darkens/contrasts

[Skul 9]

If I capture and edit NTSC DV in Vegas 5.0 then try to process that file with Avisynth\Virtualdub, it always darkens and adds contrast to the video a noticeable amount. The Sony DV codec in Vegas produces RGB24 video.

If I render my Vegas project as uncompressed and then process with Avisynth, the image stay consistant.

Is this darkening/contrasting a common problem going from DV video to the uncompressed format used in Avisynth or have I got some setting wrong somewhere?

I know the easy answer is just to save my Vegas projects in uncompressed and I won't have any problems, but are there any filters that were designed to correct the DV to uncompressed conversion problem I am having?

[Wilbert]

If I capture and edit NTSC DV in Vegas 5.0 then try to process that file with Avisynth\Virtualdub, it always darkens and adds contrast to the video a noticeable amount. The Sony DV codec in Vegas produces RGB24 video.
So if you edit in Vegas and open that in AviSynth it is RGB?

If I render my Vegas project as uncompressed and then process with Avisynth, the image stay consistant.
Is it in this case also RGB or is it YUY2?

Both can be checked with

AviSource(...)
Info()

[Skul 9]

info() reports the DV file as RGB24 and the uncompressed file as RGB32.

[trevlac]

search for "toggle studio rgb display" in the vegas help.

That will tell you the details and options.

Basically ... the Sony codec outputs RGB in a range of 16-235. AVS expects it to be 0-255.

[FredThompson]

I think I know what you're seeing. Many moons ago I chased this type of behavior when comparing different DV codecs.

What you describe happens when your RGB 16-235 is expanded to 0-255. DV supports 0-255, so to speak, but not every DV source does. Most of them only do 16-235.

Your second sentence doesn't make any sense. DV is DV, not RGB. Vegas converts the DV to RGB. All of its internal routines are RGB. The LAST thing you want to do after that is export as DV. RGB has distinct chroma for each pixel, DV does not. Additionally, the colorspace of DV and RGB are not the same.

There is a freeware frameserver which you will probably find helpful at http://www.debugmode.com/frameserver/

edit: Geez, trevlac, can't a guy type a response without you jumping ahead of him? Sheesh!!! pfbfbfbfbfbhbhbhbhbhbhbtbthththththttttttt!!!!!

[Wilbert]

Trev, Fred,

What happens if he

If I render my Vegas project as uncompressed and then process with Avisynth, (...)
Who is doing the RGB conversion in this case? If it's also the Sony DV codec, it should also produce RGB [16,235] (but apperently he gets RGB [0,255]).

[FredThompson]

When Vegas first came out I was real excited about it and called Sonic Foundry to ask some questions. They told me it works in RGB only. They thought it was the best option. That makes sense considering the CGI functions and price (compared to studio-level editing.)

MainConcept's codec has a toggle to do either range, default is 16-235.

About a year ago a guy contacted me about my (old) filtering chain for DV and we tested some of his source. We found the Sony codec was feeding back 0-255. At the time, it seemed the Sony output was nicer because blacks were blacker. That was before we realized what was happening. I've never used that codec except at that one time and don't know if there is a way to specify the range.

If not, perhaps ffdshow's decoder and setting the precedence with GSpot beta will help.

There ARE some DV devices which will take the full 0-255 range. I don't remember how we were able to determine the native range. Obviously, the codec's range should match the source's range. Otherwise you'll get expansion or contraction.

[Skul 9]

OK, I found the problem and in doing so realized I misstated the original problem.

After reading your replies I did some more testing and found the problem was not in Avisynth\Virtualdub as I had thought. After I processed a file with Avisynth/Virtualdub, I would click on it which opened it in Windows Media Player and that's where I saw the difference but I asummed it was caused by the Avisynth\Virtualdub processing.

After using an avs script that compares two videos, it was clear that Vegas rendered DV-AVI and uncompressed-AVI looked the same in Virtualdub, so the problem had to be in WMP.

I use Windows XP. In WMP, tools-options-performance-advanced, I unchecked "use video mixing renderer" and now the videos look as they do in Vegas and Virtualdub and other AVI viewer I have.

SO you'd think I'd be happy, but...

WMP has "use video mixing renderer" checked by default so I assume everyone uses it this way. But, atleast on my system, this seems to display DV-AVI brighter/less contrast than any other AVI viewer I have. I want to make sure that anyone that sees my DV-AVI's will see it the way I intended so I guess I am going to have to leave it checked.

[FredThompson]

Use GSpot beta to set the precedence of the Sony DV codec below that of the native Windows codec then do your WMP test again.

http://www.headbands.com/gspot/

[Skul 9]

Stupid me, I just found another mistake I was making. Under "use video mixing renderer" there is "use overlays" which I had also unchecked and thought it was this way by defualt. When I restored all the defualts it put "use overlays" back on and everything looks good now.

When I use Gspot, I can't see the Sony Codec, only shows the Panasonic codec. When I open a DV made in Vegas it shows it as Panasonic codec. I thought I remember reading they use the panasonic, it that right?

When I use AVIcodec http://avicodec.duby.info/ it reports my DV's as Sony Digital Video, but when I open the codec page for my system it shows the panasonic, and canopus.

[FredThompson]

Would Ford use Chevy engines?

[trevlac]

Originally posted by Wilbert

Who is doing the RGB conversion in this case? If it's also the Sony DV codec, it should also produce RGB [16,235] (but apperently he gets RGB [0,255]).

According to that help section I pointed out you get a bunch of options. My guess is that he is using the M$ codec to output uncompressed RGB from Vegas but his machine has the sony codec as the default DV codec.

Could be the other way around. Hard to say. I guess "darker with more contrast" means we went from 16-235 to 0-255. I think i got it backwards ... :) regardless the settings are different.


@Fred ....

Vegas 5 must fire up faster on my machine. :)

[Skul 9]

Gspot reports the uncompressed file from Vegas as "BI_RBG RAW BITMAP". When I look that up under the known codec section it says *no codec needed. Is it possible that Vegas only works in 16-235 so it saves uncompressed as 16-235 or is uncompressed always 0-255?

As far Gspot not seeing the Sony codec installed on my computer, I read on another forum where they said the Sony Vegas codec is only available within Vegas and can't be used outside of it. If that's true would this explain why Gspot can't see it, but on the other hand can any of you Vegas users see the Sony codec with Gspot?