[FFmpeg-user] subtitles extraction

[Carl Eugen Hoyos]

Alessandro Magni <magni <at> inrim.it> writes:

> 1) ffmpeg -i mpfc.iso -vn -an -c copy a.srt
> 
> ffmpeg version 1.2.4 Copyright (c) 2000-2013 the FFmpeg developers

(This is old.)

>    Stream #0:2 -> #0:0 (copy)

The srt file format only supports srt (and text and subrip) 
subtitles, you cannot mux ("copy") dvdsub into the file, just 
as you cannot put mp3 into an aac file.

>    Stream #0:2 -> #0:0 (dvdsub -> srt)

dvbsub is a bitmap subtitle format, srt is text-based but 
since FFmpeg does not contain any ocr routines, you cannot 
convert a bitmap subtitle into a text-based subtitle format.

Merry Christmas, Carl Eugen