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when i import 2.mp4 to sony vegas its color same as vlc. how to fix this on virtualdub?
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Add the Alias Video filter. You probably want rec.709 and Full (0-255).
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Notice you said "import mp4". That is your answer: Vdub does NOT open mp4 directly, it uses an input plugin. That plugin is changing things. So, change your plugin to something that doesn't, or correct/compensate for how it's changing (you could use a histogram & waveform monitor to figure it out).
Just a guess, but it looks like Constrained vs. Full RGB levels (after colorspace conversion from Y'CbCr).
Scott
...doh! jagabo beat me to it. -
will it be original color depth then? i did and it worked. but i am not sure if it is same as the source color depth. And what rec.709 and Full (0-255) mean? are these settings for original color depth of any kind of hd video?Originally Posted by jagabo
same thing on avi without alias filter:Notice you said "import mp4". That is your answer: Vdub does NOT open mp4 directly, it uses an input plugin. That plugin is changing things. So, change your plugin to something that doesn't, or correct/compensate for how it's changing (you could use a histogram & waveform monitor to figure it out).
Just a guess, but it looks like Constrained vs. Full RGB levels (after colorspace conversion from Y'CbCr).
Last edited by chazz spacey; 11th Nov 2014 at 04:08.
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Video normally uses limited range luminance levels (16-235). PCs use full range levels (0-255). For video to display correctly on a PC monitor the limited levels need to be expanded to full range otherwise it can look "washed out". For normal video "16" is black, but for a PC "0" is black, which means "16" will display as dark grey on a PC monitor.
I suspect in your case VirtualDub is correct and the other programs are not. I have my video card set to expand the video levels so they're always correct regardless of the player used, but as a quick test I disabled that setting and opened an AVI with VirtualDub. The video still displayed correctly (levels expanded). I opened the same video in VLC and it looked like it had less contrast, so VLC doesn't expand the levels by default (whether it does may depend on the renderer being used). VLC may have a setting.... I don't know, I rarely use it. After I reset my video card to expand the levels once more, the video looked fine again in VLC too.
For Nvidia, the setting is in the Nvidia control panel under "adjust video colour settings". Selecting "with Nvidia settings" and then "full (0-255)" from the from down list expands the video levels. Other cards have a similar option somewhere.
Not that it should matter unless you need to adjust the colours and therefore need to preview the video accurately, because it shouldn't effect the levels used for encoding, just for previewing.
The above applies when converting video to RGB for display on playback. It can also apply when re-encoding if the video is being converted to RGB in the process (some VirtualDub filtering maybe?), but even if it is, normally the limited range video would be automatically converted to full range RGB and then back to limited range when it's encoded. Not all programs follow the same rules though....
There's also different "formulas" for converting the colours to RGB on playback which produce slightly different results. Standard definition uses rec.601 and high definition uses rec.709. If the wrong one is used for converting to RGB on playback, the colours can look a little "off". Some programs (Avsynth, VirtualDub etc) default to rec.601 if video is being converted to RGB during the encoding process. That's okay even if it's HD as long as it's converted to RGB using rec.601, filtered, and then converted back to YUV using rec.601 for encoding. It's a whole other topic really.....Last edited by hello_hello; 11th Nov 2014 at 06:32.
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hmm Nvidia...
https://www.youtube.com/watch?v=vH1YTlLn0FM
I had to know!
even after i change nvidia to Full (0-255) there is a little difference:
why you players can't show the original color?!
and why in virtualdub when i set Alias Video filter to rec.709 and Full (0-255) it goes grey dark?
all i want is to compress video at original color in virtualdub. -
They look the same to me, I think, although maybe they're resized a bit differently? It's hard to tell.Originally Posted by chazz spacey
You could check the display setting in Virtualdub's preferences, but other than that, I'm not sure. Maybe VLC is doing something to the video. Are any of it's filters enabled?
I've no idea. I don't use VirtualDub much and I had no idea the Alias filter existed. The info for it says, "re-label video with a different colour space or colour encoding without changing video data" which seems like it's a way of writing the info but maybe it doesn't actually change the levels or colours. I don't know, but that's the way I read it.....Originally Posted by chazz spacey
If you're re-encoding YUV video there's no real need to use the Alias filter, unless I'm missing something. In fact you attempted to set it incorrectly, if you specified "Full (0-255)" as the video would most likely be limited range. You're not expanding the levels when re-encoding, they're just being expanded for the display.
If you're re-encoding without filtering, choose the "fast re-compress" option. The video should be decompressed and re-encoded without changing format, levels or colour space etc.
"Normal re-compress" makes the Color Depth option available. I think by default the video is converted to RGB for the output. I'm not sure why, but maybe it'd be an idea to change the output format to the same as the input format, which would be fine for "typical" video re-encoding. As far as I know "full re-compress" is the same as "normal re-compress" with the addition of filters. VirtualDub's filters only work with RGB (unless that changed at some stage) so if you use filtering the video would be converted to RGB and back again.
For re-encoding movies etc, that's normally all you'll be doing. The video should be re-compressed without changing the colour or levels, unless you deliberately choose to change them. Although as VirtualDub can open lots of types of video with the help of plugins, and some of them do the decoding (ie the ffmpeg plugin), it's possible one of them might mess with things. Not likely, but possible.Originally Posted by chazz spacey
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how to know source RGB color level of video? i mean how to know if it is 0-255 or 16-235?
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Very likely your source is "YUV", not "RGB" . You can use mediainfo (view=>text) to find out more information on the source fileOriginally Posted by chazz spacey
It gets converted to "RGB" for display purposes, but underlying video is most likely YUV. Different software, graphics cards , drivers & settings, monitor calibration & settings can all affect how it gets converted to RGB, and how it finally "looks"
If source is YUV, then you use a YUV waveform monitor to examine levels. If source is RGB, then you can use a RGB histogram or RGB parade -
I used to have a lot of trouble with an ATI card, always having to adjust the settings and when I first got the Nvidea card, I had to reset after updates but now it seems to remember my settings when I update. Setting to 0-255 as recommended fixed the problems for me. The way to tell is the input and output frame in Virtualdub will look the same. If not then I have to reset the 0-255 setting with the card. A very noticeable problem for me is the contrast gets messed up and a dingy film look covers the output pane. Resetting the 0-255 always corrects the problem for me.
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How to solve washed-up colors in processed videos (lower contrast, VirtualDub)
VirtualDub misinterprets parameters of the original video such as the Color Space and the Chroma Subsampling. Its automatic interpretation can be cancelled from command Video/Color Depth...
You will find that the "Decompression format” is set to Auto, which causes this problem. Use MediaInfo to identify the original Color Space and Chroma Subsampling of your video/camera and select that specific format from the list, or the best approximation. For example I had to use 4:2:0 planar YCbCr for my Canon compact camera videos. You can leave the Output format as it is.
Another way to repair the lower contrast is the "Alias format" filter, which you have to raise highest in the filter list, if you use more than one filter.
Both these ways will need a bit of trial. I wouldn't recommend using the "Auto levels" filter, although it may produce interesting alterations of the image.
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