Strip out subtitles as SRT files

[jchaps]

SRT subtitle files have better compatibility with Roku, Chromecast, and iOS devices.

Step 1 - Demux the subtitle file
Step 2 - Convert subtitle if needed

[jchaps]

Demuxing:

ffmpeg -probesize 50M -analyzeduration 100M /
-i Avatar.2009.Extended.Cut.CE.Bluray.1080p.DTS-HD.x264-Grym\@BTNET.mkv /
-ss 360 -t 600 /
-map 0:2 -c:s copy /
~/Avatar_subs_test.mkv

• -probesize 50M -analyzeduration 100M seem to be necessary to identify the subtitle stream.
• -ss 360 starts conversion 6 minutes in, and -t 600 converts 10 minutes worth of the video. Useful for testing
• -map used to map a specific stream from the input file
• -c:s copy copies the existing subtitle stream

[jchaps]

Don't bother trying to rip out the bitmap-based subs (e.g. PGS). Just head to opensubtitle.org instead

[jchaps]

Formats:

TX3G - OK on Roku, iOS, and Chromecast with Direct Stream.
SRT supposed to work on all