Alpha plus movie

For an alpha plus movie, both alpha blending and additive blending are performed.
With conventional alpha blending, the edges become darker when there is a lighting effect.
In an alpha plus movie, figures shaped by alpha blending and light effects which are using additive blending are compatible.
An alpha plus movie has the same size than a normal alpha movie. Also, alpha blending and additive blending are conducted in one drawing pass, resulting in the same drawing load than for a normal movie.

At this time, it is only possible to encode alpha plus movies by using the console version of the Sofdec Encoder.
(* We plan to add support for alpha plus movies in the Sofdec2 Encoding Wizard in the future.)
Creating the alpha plus movie file is a bit special so it is described below.

(1) Preparing the video materials

In order to create an alpha plus movie, you need to provide the following video materials:

• Video material for the additive blending
  
• Video material for the alpha blending
  
  The following steps describe how to prepare these two types of materials in AfterEffects.
  

(a) Video material for additive blending

Perform the rendering with additive blending.
In the output module settings, set Channels to RGB.

(b) Video material for alpha blending

Perform the rendering without additive blending.
In the Output Module Settings, set Channels to RGB + Alpha.
Set Color to Premultiplied (Matted).

(2) Encoding

The Sofdec2 Encoding Wizard GUI version does not support the encoding of alpha plus movies. Use the console version of the Sofdec Encoder.
Now we need to create a batch file.
From the menu of the Sofdec2 Encoding Wizard, select Export -> Batch File (New). Configure as for the encoding of a normal alpha movie and export the batch file. A batch file similar to the one shown below will be exported. You can use it as a model.

"sofdec2enc.exe" -video00=".\AlphaPlus_RGB.avi" -alpha00=".\AlphaPlus_Alpha.avi" -scale=256,256 -framerate=29.97 -bitrate=2000000 -output=".\SAYA_AlphaPlus.usm" -work_dir="." -preview=OFF -gop_closed=on -gop_i=1 -gop_p=4 -gop_b=2 

For the -video00= option, specify the video material (a) for additive bending.
For the -alpha00= option, specify the video material (b) for alpha blending.
-output and -work_dir are related to the output. Set the appropriate values.
-scale indicates the resolution after encoding. If resizing is required, specify the scale here.
Change -bitrate as required, depending on the desired image quality.
Do not change the options after -preview.

[Note]
To preview an alpha plus movie in the SofdecViewer, you must change the tool's settings.
From the tool's menu, select Show -> Blend Mode -> Additive. Then start playback.

(3) Playback

To play an alpha plus movie, select the Additive Mode checkbox in the CRI Mana component.