[SOLVED] Editor to increase brightness of half of screen only?

[yetanotherlogin]

Hello

I shot a conference that was badly lit and, to make matters worse, I had to include the screen where the speaker showed slides. I included a screenshot.

Is there an application that can brighten up only part of the screen vertically, and leave the other half untouched?

I tried AviDemux, but it doesn't seem to support that feature.

Thank you.

[smrpix]

The classy way -- free -- is to use Resolve Lite. Depends on the codec of your original.
Assuming this is a static shot, you can create a mask in any half-decent NLE.
Slightly harder:
Create a mask in a paint program and combine two instances of your shot with Avisynth.

[poisondeathray]

Another approach is to use a luma mask. That would work even if there was motion / handheld shot . Essentially the filter(s) are only applied differentially to either brighter or to darker areas. So you might darken the screen but brighten the other areas. Most NLE's can do this, and you can do it in avisynth

[yetanotherlogin]

Thanks. Is it easy to use?

"DAVINCI RESOLVE 11
Entry level DaVinci color correction software for use with third party panels."
https://www.blackmagicdesign.com/products/davinciresolve

I don't really need to create a mask: Simply splitting the screen in half vertically would be good enough.

[smrpix]

I don't really need to create a mask: Simply splitting the screen in half vertically would be good enough.

Whatever you want to call it -- that's a mask.

Davinci Resolve Lite (13) does not require external hardware. Yes there is a learning curve and you'll want to look at some tutorials. It offers exquisite control over color corrections. This basic stuff isn't particularly difficult.

[poisondeathray]

Resolve is incredible software, even the free version is amazing, but it's probably more difficult to use for most people

You can do this in almost any editor that has more than 1 layer. Something also free, easy to use and will import almost anything is aviutl. (Resolve has very limited formats it can import)

cropping (called "clipping" in aviutl) example


luminance key example


I've included both project files in the zip file. This is just a quick example of how to apply filters differentially - you'd spend more time fixing the brightness and contrast.

Short description:
What you 're basically doing with either case, is compositing 2 layers. The top layer #1 is actually the "bottom" (layer order is reversed). So in the screenshots, layer #1 is the original, with no effects applied. Layer 2 is a copy of the same video, but has the effects applied

In the "clipping" (cropping) example, The right side of layer 2 is cropped. This is sort of what you wanted, to brighten the "left" side. Thus the layer #1 right side "shows" through on the right side , and only the left side on layer 2 has the color compensation effect applied with the lightness adjusted

The other example is the luminace key , where brights show through. This is the method I would use. Basically, it's masking out either bright or dark areas. In this case, the bright areas are keyed out (transparent) so the bright areas on layer 1 are shown through, but the filter is applied to the dark area on layer 2. Same basic idea, but the mask is based brightness levels instead of a static crop

So you might composite a 3rd layer, where you adjust the visibility with brightness/contrast/levels of the screen, so it's more legible



Additional basic instructions:
1) You need the "adv editing timeline" activated by going in the menu => filter+ => adv. editing timeline.
2) drop and drag your video(s) onto the timeline. In this example you would drop one onto layer 1 as-is , then another one onto layer 2 (or make a copy of layer 1 by ctrl+c to copy, ctrl+v to paste). The effects are applied on layer 2 as described above

To open the "image file [standard drawing]" dialog box shown in those screenshots, you just double click a layer. Clicking The "+" button in the top right corner of that dialog box gives you access to the filter list

All parameters are "keyframeable" - meaning they can vary over time. Lets say you want to adjust the brighness due to different exposures etc..Go to the aviutl thread and look at the tutorials posted by maverick tse and racer-x if you want more info. There are video and written tutorials on basic usage

[jagabo]

AviSynth script to cut the video in half, adjust the two halves, then put them back together:

ImageSource("vlc.snapshot.bt.peniche.png").ConvertToYV12()
left=Crop(0, 0, width/2, height).ColorYUV(gain_y=600, off_y=-30)
right=Crop(width/2, 0, width/2, height).ColorYUV(cont_y=400, off_y=-170)
StackHorizontal(left,right)

I can't upload images anymore. Maybe someone else can use the script and upload the result.



Looks like the problem was in my router! A week or so ago I was playing with the router's filtering options. I must have screwed something up. Reset to factory defaults then setup again appears to have fixed the problem.

[poisondeathray]

jagabo try pm baldrick or post in the feedback section

maybe you posted too many "naughty" images and got a suspension

[aedipuss]

jagabo - have you added anything to your browser lately? i added privacy badger to chrome and lots of website buttons don't work unless it's turned off.

[El Heggunte]

With the (optional-?) help from the DScaler filters, one can get similar results through ffdshow's raw video filter.

Yes, I like to complicate things needlessly

[yetanotherlogin]

2) drop and drag your video(s) onto the timeline. In this example you would drop one onto layer 1 as-is , then another one onto layer 2 (or make a copy of layer 1 by ctrl+c to copy, ctrl+v to paste). The effects are applied on layer 2 as described above

Thanks much for the infos.

I'm giving AviUtl a try, but can't figure out how to copy/paste the video into Layer 2 after successfully (?) dragging and dropping it onto the Layer 1 section in the timeline:

I hit CTRL+C and CTRL+V, but nothing happens, and there are no Edit > Copy/Paste Video menu either.

FWIW, here's the video I'm trying to import:

Input #0, mpeg, from 'full.mpeg':
  Duration: 02:26:46.56, start: 0.226767, bitrate: 8810 kb/s
    Stream #0:0[0x80]: Audio: ac3, 48000 Hz, 5.1(side), fltp, 448 kb/s
    Stream #0:1[0x1e0]: Video: mpeg2video (Main), yuv420p(tv), 720x576 [SAR 64:4
5 DAR 16:9], max. 9100 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc

[smrpix]

Returning to Resolve for a moment -- once you learn how to get your material in and out, the actual correction is fairly easy.


For your file I created a new serial node, added an oval power window with soft edges to the dark section and lifted the gamma and highlights.

For the fun of it, I added a second node and brought down the gamma on the screen display to add a bit more contrast.

This image shows the circular window node selected -- note the gamma and gain settings under the color wheels.

[poisondeathray]

I'm giving AviUtl a try, but can't figure out how to copy/paste the video into Layer 2 after successfully (?) dragging and dropping it onto the Layer 1 section in the timeline:

Were you able to drop it onto layer 1 ? (it's not shown in the screenshot). If not, make sure L-smash has higher priority as an import plugin (file=>settings=>import plugin priority => move L-smash up higher in the list and push ok)

I hit CTRL+C and CTRL+V, but nothing happens, and there are no Edit > Copy/Paste Video menu either.

In the version I'm using there is edit => copy/paste in the menu aviutl 1.10 (not installed version, portable) . It's also there in 1.6 version which I have on a different WIN XP computer


Make sure the layer is selected. If you click away, copy / paste won't work. CTRL+C to copy, put the cursor onto layer 2 and left click to select the destination (eg. you might have wanted to use track 7), then CTRL+V and the start of the layer will be pasted where you clicked (e.g. for another project you might want the IN point to start at frame 4636 on track 8)

[yetanotherlogin]

Were you able to drop it onto layer 1 ? (it's not shown in the screenshot). If not, make sure L-smash has higher priority as an import plugin (file=>settings=>import plugin priority => move L-smash up higher in the list and push ok)

Yes, but indeed, it's not shown in the timeline.

There are no trace of L-smash in the list:


Incidently, I downloaded "Download AviUtl Extra Pack 1.11 (direct link) (39.4MB)" through the direct link provided by VideoHelp, but it's actually release 1.00: https://www.videohelp.com/software/AviUtl

[poisondeathray]

Some people don't like 1.11 because it's an installed version. The previous versions were all "portable" and ran within a folder, could be put on usb key etc..

Here are older versions. I think l-smash is included with them (l-smash is based on libav/ffmpeg libraries, so you can open basically anything up with aviutl, even MKV , 10bit AVC, HEVC etc...)
https://www.videohelp.com/software/AviUtl/old-versions#download

I can vouch for 1-10[win7] and 1-6[xp] . The 1-6[xp] version actually runs ok on win8 machine too

[racer-x]

Aviutl has a Shadow-Highlight recovery filter that is suited for this type of thing. You'll find it in the "Animation" effects...

[poisondeathray]

I never new aviutl had that; it looks like it's shadow/highlight is sort of like photoshop/ae's shadow/highlight

avisynth also has HDRAGC() to boost shadows without touching brights. You can use histogram() to help guide your levels

ImageSource("vlc.snapshot.bt.peniche.png")
ConvertToYV12()
HDRAGC(coef_gain=1.0, coef_sat=0.75)
HDRAGC(coef_gain=0.2, coef_sat=0.75)

In your screenshot in the 1st post, the brights are clipped, but your camera probably records some usable info that is recoverable in the superbrights (Y >235 ) . It's VLC that is probably clipping in the screenshot

[yetanotherlogin]

Thanks for the extra tips.

After installing AviUtl_ExtraPack1-10[Win7]Release on a Windows7 host, AviUtl complains with this:

System Error: The program can't start because d3dx9_43.dll is missing from your computer. Try reinstalling the program to fix this problem.

Does someone what package I should install?

---

If I wanted to try AviSynth, should I launch it from VirtualDub? If that's the case, is there a good tutorial on how to set things up?

[jagabo]

If I wanted to try AviSynth, should I launch it from VirtualDub? If that's the case, is there a good tutorial on how to set things up?

AviSynth is script based. You use a text editor like Notepad to create a script then open that script in an editor or encoder as if it was a video file. Yes, you can use VirtualDub's File -> Open Video File. I usually use VirtualDub to preview scripts, then use the x264 command line encoder to encode the script. Here's another example of what you could do, whether in AviSynth or some other editor (blending two videos via an alpha mask):



On the top left is a brighter version of the original video. They speaker is more normally lit but the projection screen is completely washed out. On the top right is a darkened version of the video, there's a little more detail visible in the screen but the speaker and background have gone completely black. On the lower left is an alpha mask I created using a paint program (starting with the original image). That controls how the two videos (lightened and darkened) are mixed when they are blended together. The black parts of the mask will select one video, the bright parts of the mask will select the other. Shades of grey in between will be a weighted average of the two. On the bottom right is the final result.

alpha=ImageSource("alpha.png", start=0, end=23, fps=23.976).ConvertToYV12(matrix="PC.601")
ImageSource("vlc.snapshot.bt.peniche.png", start=0, end=23, fps=23.976).ConvertToYV12()

darks=ColorYUV(gain_y=600, off_y=-30) # a lighted version of the video
brights=ColorYUV(cont_y=400, off_y=-170) # a darkened version of the video

Overlay(darks, brights, mask=alpha) # blend the two together

A static mask like this will only work if the camera doesn't move. If the camera is moving you might be able to build a mask from the video itself -- by pumping up the contrast so that the bright screen is totally blown out and the darker background is totally crushed.

Another approach is to use Gradation Curves in VirtualDub. That gives you non-linear brightness adjustments:

[yetanotherlogin]

It's a bit over my head

The camera was kept still the whole time, and the movie is in MPEG.

Since I can't use AviUtl because of the error I reported above, I'll try to use VirtualDub + AviSynth.

[poisondeathray]

System Error: The program can't start because d3dx9_43.dll is missing from your computer. Try reinstalling the program to fix this problem.

I think that is a directx error message . I think if you install DirectX from Microsoft it will stop complaining

[yetanotherlogin]

[strike]The error disappears after installing "VC2010, VC2012 and VC2013 redistributables" as written in that page:
http://mavericktse.mooo.com/wordpress/archives/891[/strike]

It showed up again. It really does go away by installing the following release of DirectX:
http://answers.microsoft.com/en-us/windows/forum/windows_7-gaming/system-error-the-pro...9b31bf5?auth=1


Now I'm back with "AviUtl_ExtraPack1-10[Win7]Release".

However, even after drag 'n dropping the MPEG file onto the "Layer 1" line at the bottom, and clicking on OK in the "Create a new project" dialog, the Layer 1 line is empty, unlike the screenshot in the thread above. Actually, it's not totally empty, as it now shows a thin, blue line on each line:


As shown, I made sure to move the "L-SMASH" item at the top of the list of Imports Plugins Priority.

[poisondeathray]

You might have to close, restart aviutl for change in the import plugins priority to "stick"

[yetanotherlogin]

I did, but still no go

Checking the "Match imported file" option in the import dialog makes no difference.

Incidently, the play button does nothing: The video doesn't play.

[poisondeathray]

Can you drag your still image in post #1 onto track 1 ? or another random video e.g. from youtube ? (does anything else import ?)

[yetanotherlogin]

Yes, I tried with two different MP4 files, and they import OK.

Does AviUtl actually support MPEG files?

c:\>ffprobe.exe -i full.mpeg
ffprobe version N-58043-g0062869 Copyright (c) 2007-2013 the FFmpeg developers
  built on Nov 12 2013 18:01:41 with gcc 4.8.2 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-av
isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab
le-iconv --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetyp
e --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --ena
ble-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-l
ibopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libsp
eex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aa
cenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavp
ack --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib
  libavutil      52. 52.100 / 52. 52.100
  libavcodec     55. 41.100 / 55. 41.100
  libavformat    55. 21.100 / 55. 21.100
  libavdevice    55.  5.100 / 55.  5.100
  libavfilter     3. 90.102 /  3. 90.102
  libswscale      2.  5.101 /  2.  5.101
  libswresample   0. 17.104 /  0. 17.104
  libpostproc    52.  3.100 / 52.  3.100

Input #0, mpeg, from 'full.mpeg':
  Duration: 02:26:46.52, start: 0.226767, bitrate: 8810 kb/s
    Stream #0:0[0x80]: Audio: ac3, 48000 Hz, 5.1(side), fltp, 448 kb/s
    Stream #0:1[0x1e0]: Video: mpeg2video (Main), yuv420p(tv), 720x576 [SAR 64:4
5 DAR 16:9], max. 9100 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc

[poisondeathray]

Yes, it support mpeg2. It supports basically anything ffmpeg can open

Can you cut a small sample , maybe with ffmpeg and post it ?

[yetanotherlogin]

Here's a 20-second sample:
http://dl.free.fr/nDe4EBTEB
(You might need to disable adblockers for that site to see the CAPTCHA)

Incidently, ffmpeg displays a warning when slicing:

[mpeg @ 0428f980] ac3 in MPEG-1 system streams is not widely supported, consider using the vob or the dvd muxer to force a MPEG-2 program stream.

[poisondeathray]

BTW One thing you will have problems with when using 1-10[win7] is keeping the 5.1 audio - it seems to downmix 5.1 to stereo. If you're not' doing any actual editing (only fixing the levels/brightness), then you can just remux the original audio

That is why I keep the 1-6 [xp] around. It's able to keep 5.1 when you enter FL+FR+FC+LFE+SL+SR in the channel layout settings for l-smash (file=>settings => import plugin => l-smash => channel layout)

[poisondeathray]

Yes, it won't open it properly as-is. Probably due to that same error about mpeg1-ps. Just remux it into a mpeg2-program stream and it will open it

eg.
ffmpeg -i input.mpeg -c:v copy -c:a copy -f vob output.mpg

And what I said above about "usable" overbrights was correct - you a tiny bit of usable data >235 which you can manipulate to make the projection screen slightly better. Most consumer cameras actually record ~16-255