How to make opaque box of subtitles semi-transparent?

[victorbireaud]

Hello everyone,

I have been trying in Aegisub to have subtitles with a regular "opaque box" that would be slightly transparent, but to no avail. I am exporting .ssa files and hardcoding them on .mp4 video files with VirtualDubMod. On Aegisub it actually looks fine; I can change the transparency in the Outline and Shadow colors settings. But when I add the .ssa subtitle file in VirtualDubMod with the VSFilter (or TextSub), the opaque box shows completely opaque, without any transparency.

In this post from some time ago, one person says that by adding this: {\bord1\3a&c0\an5} in each dialogue line, we can obtain the transparency. It does indeed give a transparent box behind the subtitles, but there are two problems with it that I can see: First, you would have to add this to every line of dialogue, and two, it overrides the subtitles' position defined in the subtitle style.

I have found a good way to have a transparent box with an editable size here (Masaf Automation script), but unless you add the background line for every dialogue line, the transparent box will show constantly, even when there are no subtitles. Do you know if there is any way to get the transparency of the opaque box on Aegisub to work on VirtualDub, or with any other encoding software?

Thanks in advance.

[sneaker]

You already had it working?
https://forum.videohelp.com/threads/383537-Hardcoding-subtitles-on-a-transparent-box

[victorbireaud]

Hey sneaker, thank you for making mention of last year's post. Yes, indeed, that was very good - you had helped me make a background image which was semi-transparent. But I was now looking for something more close to the subtitles. You know what, I have found something quite satisfactory this morning. I will copy it here for the sake of others who might come across this thread:

With FFmpeg (the basic Windows Buildup), using the following command line, I have managed to have the transparency being taken into account in hardcoding. Here is the line:

ffmpeg -i input.mp4 -vf "ass=subtitle.ssa" -codec:v libx264 -codec:a ac3 -b:a 160k -preset slow -crf 22 output.avi

I found out that FFmpeg is quite useful after all, although I was very discouraged at first, having never used something like that (without any interface). The transparency is taken care of here, and I could even use the option "BorderStyle=4" if I wanted to make a rectangular box every time that two lines appear. Thanks a lot for chipping in.