What are my options for grabbing subtitles from a DVD's IFO files?

[Jeff Mott]

Hi. Sorry that this will seem like a basic question. I would read the stickies, but most of them are several hundred posts long, and I can't tell what's relevant in there and what's not. And the doom9 guides don't seem to be kept up-to-date anymore.

I'm hoping to get a quick run-down of my options for grabbing subtitles from a DVD's IFO files and using them with my MPEG4 encode.

If it's helpful, my encode process is: DGIndex -> AviSynth -> ffmpeg -> MP4 container.

Thanks for any help anyone can give me.

[nurbs]

The mp4 container natively supports ttxt subtitles. You can use SubRip (sticky in this forum) to OCR your dvd subtitles. When you mux the mp4 using mp4box it wil automatically convert the srt subtitles SubRip creates into ttxt.
You can also mux vobsubs into mp4, but there may be compatibility issues since it's not natively supported by the container.

BTW why use ffmpeg for encoding the video? Assuming you encode to AVC using x264 directly would be less complicated.

[Jeff Mott]

... to OCR your dvd subtitles.

I'm surprised... so DVD subtitles are stored only as images, not text? That's a bit disappointing.

[nurbs]

DVD, Blu-Ray and HD-DVD subtitles are all pictures.

[Ghitulescu]

I'm surprised... so DVD subtitles are stored only as images, not text? That's a bit disappointing.

Why disappointing? Because you use the Latin alphabet and you know all its 26 letters? Images are worth a thousand of word each. ;)

Think of Arab, Chinese, Japanese, Sanscrit, Thai ....

[Jeff Mott]

Hi, nurbs. I could use a little more help.

First, what I got working: I used SubRip and created an SRT file. Then I used mp4box to mux the MP4 and the SRT file. And voilà... subtitles.

Though, the text was a serif font and also a little small.

In SubRip, I noticed that I could set the output format to ttxt, and if I did that, then I could set other options like font, size and color. So I did that and I generate a ttxt file. Problem now is that when I use mp4box to mux the ttxt subtitles with the video, I get an error that the ttxt file is invalid and can't be imported.

[Jeff Mott]

[/COLOR]

Why disappointing? Because you use the Latin alphabet and you know all its 26 letters? Images are worth a thousand of word each. ;)

Think of Arab, Chinese, Japanese, Sanscrit, Thai ....

Hi, Ghitulescu. Aren't there universal character sets that handle all those languages?

[Jeff Mott]

...I get an error that the ttxt file is invalid and can't be imported.

Sorry, that's not quite right. The exact error message is:

Error importing VTS_01_1.English.ttxt: Corrupted Data in file/stream

[Jeff Mott]

I still don't know why SubRip-saved ttxt files are considered corrupted by mp4box, but I've abandoned that method now for an easier way.

I had successfully muxed SRT subtitles, and the only problem was the font. But now I discovered the :font=Sans-serif command-line argument, so all is well.

Thanks, guys! :thanks: