ExtSub is a software tool for extracting and decoding subtitle data from VOB files. It is a powerful utility that enables users to easily access and use subtitle information in their video projects.
The command line parameters for ExtSub are as follows:
- infile= indicates the VOB file from which subtitles will be extracted.
- videofile= is an optional parameter that allows users to specify a file to which to write MPEG 2 video stream data. However, it's important to note that this feature is highly experimental.
- subname= allows users to specify the prefix of all subtitle files.
- convscript= is an optional shell script that will invoke ImageMagick's "convert" utility to turn raw subtitle image files into TIFF files.
- id= is an optional parameter that specifies the ID of the subtitle stream to be extracted. The default ID is 0, but the specification allows IDs 0-31.
When subtitles are extracted using ExtSub, each caption in the source file generates 3 output files with the suffixes ".gray", ".sub" and ".info". The ".gray" file is a raw 8bpp bitmap image of the caption, however DVD subtitles are only 2bpp - so it may be necessary to use the Enhance->Normalise function when viewing with a program such as Imagemagick's "convert". The ".info" file contains information about the caption, such as its resolution and alpha channel data. Finally, the ".sub" file is the raw data as extracted from the VOB source.
Overall, I found ExtSub to be a useful and reliable tool for extracting subtitles from VOB files. If you need to extract subtitles from DVDs, I would definitely recommend giving this program a try. For more details on the .sub file's syntax, additional information is available from the program's documentation.
Version 1.00: N/A