Is there a way to find out the frame-rate of a subtitle file?

Question

While I can find the frame rate of movie via -

$ mediainfo $somemovie.$format  | grep Frame rate 

Is there anything which tells the frame-rate of a sub file, (.srt) ?

Solution

srt-files are based on running-time, so the frame-rate doesn't matter. If a text is supposed to be shown at 0h10m10s to 0h10m15s, then it will be shown then - it doesn't matter if there are 10, 25, 50 or 100 frames video for each second.

However, sometimes the video-files may be slightly edited, so a subtitle-file made to another "version" of the video (eg. a movie), may not line-up perfectly or may drift. But this is not due to frame-rate.

From a srt-file - note the times, eg. from 0h03m22,520s to 0h03m23,873s:

(...)
18
00:03:22,520 --> 00:03:23,873
Manu...

19
00:03:24,040 --> 00:03:26,918
Manu, come please.
Where is Radouan?

20
00:03:27,680 --> 00:03:29,989
Where is Radouan?
-Come here.
(...)

Comments

[heemayl]

Hey, which movie is this? :)

[curious_cat]

Yes! And that can be an annoying problem to correct that mismatch. Video players like VLC do offer some options to fix the issue but it is still hard.

[slebetman]

@curious_cat: I used to have a script that fixes linear distortions by identifying two translations and the actual time that they should appear. Linear time distortion is much more common than mismatch due to edits. They're generally caused by digitising different source media. VHS for example tend to have slightly shorter running time compared to cinema reel even if you don't delete any scenes.

[muru]

@heemayl seems to be script-o-rama.com/movie_scripts/b/…

[heemayl]

@muru hehe, nicely done :)

[tcoolspy]

This can be due to frame rate if the rip/encode/decode process was botched and the output is getting displayed at a subtly different frame rate than the input was supposed to generate. A trained eye can see this, but it can also go unnoticed especially in lower quality recordings and account for subtitle "drift" if the subtitles were matched to the correct playback rate.

[Baard Kopperud]

@heemayl Yep, it's "Baise Moi" (F*** Me) - what can I say, it was the first title find spat out...