question about extracting subtitle (srt ) file from IDX/SUB files

[jimdagys]

As an exercise, I am trying to get the subtitle (srt) files from a DVD on my hard drive. I am trying several methods but having a few problems. I have a DVD (with subtitles) on my hard drive that I just created with DVD Flick, which plays fine. First method (method 1) I used to extract the srt subtitles was by using Subrip as described at
https://forum.videohelp.com/topic267416.html
I loaded the Vobs from the movie and after typing OCR letters for about 5 minutes, I appeared to have the complete subtitle file. So this method seemed to work fine.
So I decided to try another method (method 2). I used VSRip to get the IDX/SUB files (from the same movie on my hard drive). It went though the process of extracting, but at the very end of the process, it said something about not being able to find a "key". I don't understand that since a DVD created with DVD Flick shouldn't need a "key". Why does VSRip say that I need a "key"? So I decided to use VobSub Configure. Using that software I got the IDX/SUB files with no problem. Then I loaded the IDX file and followed the same process to get the subtitles described at
https://forum.videohelp.com/topic267416.html
As before, I typed in the OCR letters. But after awhile I frequently got the warning, "This subtitle item can't be processed". (See screenshot.) All I could do in this case was press "Skip Subpicture" and continue typing letters, although the warning frequently would come up again and again. Eventually I finished the process and apparently got the correct srt file, but my question is this:
Why when going through method 2 did I frequently get the warning, "This subtitle item can't be processed", but when using method 1, I never got this warning? Is this the fault of using
VobSub Configure? If so, can someone suggest another software to get IDX/SUB files that won't give me these frequent warning messages when using the IDX/SUB files in Subrip.

[manono]

Hi-

I can't see anything about 2 methods at that link, but maybe I didn't look closely enough. When I get that message you showed, either I go into the settings and fool with the spacing, or (more usually), I give up after getting that message a few times and typing in whole lines and use SubResynch for the OCR. It comes in the VobSub package and sometimes works better than does SubRip. You open the IDX, set it to save as SRT or SSA or whatever you want, and then the OCR begins.

The problem you're encountering is that SubRip is seeing the individual letters as one long line of text. Maybe the outline is too thick. It's not picking up on any spaces between letters. Like I said, you can fool with the settings to see if you can fix it, or you can OCR using a different method. DVDSubEdit can also OCR, but I've never used it for that purpose. It works off of the VOBs, and not an IDX/SUB file.

[Udumahop]

When you try to get a .srt file or bitmaps from .idx/.sub, to be sure that the method you used actually worked, compare the number of subtitles in the .srt file or the number of bitmaps with the number of "timestamp: xxxxxx, filepos: yyyyyyyyy" lines for that subtitle in the .idx file. If they don't match, something is wrong.


The warning "This subtitle item can't be processed" appears because SubRip 1.5b4 (and SubtitleCreator 2.2, SubToSup 0.9) assumes that pack_stuffing_length (see PACK header for details) is always 0, expecting the subpicture PES header (see PES header for details) to be at offset 0Eh (14) in the current PACK header. If the subpicture PES_packet_length is 07E6h...07EBh, there is no way to use a padding stream PES in the current PACK. In a .sub file, a PACK is always 0800h long and the minimum length for a padding stream PES is 7 (00 00 01 BE 00 01 FF). When pack_stuffing_length is not 0, the corresponding number of stuffing_byte (FFh) is inserted at offset 0Eh in the PACK header and the subpicture PES header is located at offset pack_stuffing_length + 0Eh. VobEdit 0.6 lists the PACKs that have a pack_stuffing_length greater than 0 as "LBA n [Unknown Pack], zzzz" (don't click on this line in VobEdit, the program will crash). To make SubRip process these PACKs, hex edit the .sub file, cut the stuffing bytes from the PACK header and paste them at the end of the PACK.