Tweak

[John Wessel]

For the conversion of .avi movies I use the program The Film Machine. One of the files automatically included in this program is Avisynth containing Avisynth_256.exe and ResampleAudio.avs. Furthermore I installed as a separate program Avisynth 2.5 with three files viz. Docs, Examples and Plugins. After conversion and burning, the movies, when played on a stand-alone dvd-player, are too dark. Since The Film Machine has no possibility of adjusting the brightness, I have been informed that Avisynth offers this feature with Tweak. I downloaded Tweak in the file Avisynth 2.5 – Plugins. However, I do not know how to put it into operation and I therefore should like to be instructed how to do this.

[neuron2]

Welcome to the forum!

Please read the extensive documentation that comes with Avisynth. You'll find Tweak documented under Core Filters/Filters for Image Processing.

Here is an example that increases the brightness and contrast:

Tweak(bright=20,cont=1.3)

Tweak is now a built-in function and you do not need to download it and place it in your plugins folder.

[John Wessel]

OK. I understand that Tweak is built-in. Nevertheless, there is a thing I don't understand: you refer to an example that increases the brightness and contrast:
Tweak(bright=20,cont=1.3). Where and how do I adjust bright=20,cont=1.3, when using either The Film Machine or Avi2Dvd for conversion of an .avi/mkv movie? In neither of these conversion programs I see this feature.

[mg262]

AVISynth works by using .AVS files (AVISynth script files), which are text files containing a sequence of commands to be performed on the video; you need to add the command into that file. It is possible that those two programs you mention generate .AVS files,and it is possible (but unlikely) that they have some mechanism for letting you input additional commands which added to the AVISynth script files... but you would need to ask on the appropriate support channels for those programs. I would recommend starting with one of the guides on using AVISynth and walking through the first few pages, trying out the scripts...

[IanB]

For too dark or too light you may get better results adjusting the Gamma rather brightness and constrast. See the Levels filter in place of the Tweak filter (also internal)...
Levels(0, 1.1, 255, 0, 255) # Brighten image
-----
Levels(0, 0.9, 255, 0, 255) # Darken image

[AVIL]

HI,

For dark videos, i use levels instead of tweak. You can use the levels filter from virtualdub to visually adjust the video and, after, use the same numbers for the plugin in your avisynth's script.

After that you can use HDRAGC filter (search in this forum) to enhance contrast, saturation, etc.

Mi experience with dark videos (very dark) is to obtain a very grainy result. After that, you must use filters (search again) to clean the grain. At end you can use colourizesmooth filter to smooth the croma like the luma and give a good finishing to your footage.

Good luck