Convert Base64 encoded subtitles?

[jimbolaya]

I downloaded the most recent Venture Brothers from Adult swim using youtube-dl and I was hoping to get a subtitle file from that. I found out that the subtitles are embedded in the .flv file. After some research I found that the only thing I can use to extract the subtitles is MP4Box. I get an srt file, but it's got lines like:

cc608:AAAAJsz//JQg/YCA/wow/oj//oz+/pkY/gAA/g4f/hGX/sAA/k4A/gAA

My research on that indicates that this is some sort of Base64 encoding perhaps with gzip compression. Does anyone know of other programs I can try to extract the subtitles than MP4Box that will convert the Base64?

I've loaded this up in SubtitleEdit and a few other subtitle editors (SubtitleEditor, gnome-subtitles) but nothing seems to understand this. Other searches have tantalizing clues about what to do, but nothing definitive.

I would be happy with either pointers of what else to read or other programs to try, though I would prefer Linux based to Windows based.

James

[Atak_Snajpera]

can you post whole file with subtitles? I will check if this is indeed base64 format.

[jimbolaya]

Since youtube-dl retrieved this in 4 parts, I have 4 files, one for each part.

I can also extract the subtitiles in ttml or raw format (whatever that is).

James

[Atak_Snajpera]

This is definitely not base64 format. This might be this https://en.wikipedia.org/wiki/EIA-608

[jimbolaya]

I just realized you might want the whole file.

I'll post just one of the flv files.