SubViewer with higher precision do not work

[Ilario Gelmetti]

The conversion of SBV subtitles (downloaded from Youtube) to SRT seems broken to me. According to this page ​https://trac.ffmpeg.org/wiki/HowToConvertYouTubeSBVtoSRT it should be supported.

Tested with:
ffmpeg version N-96995-g9a2d950f96
built with gcc 9.3.0 (Arch Linux 9.3.0-1)

How to reproduce:
create file a.sbv with content:

0:00:17.880,0:00:22.320
Mira esos delfines lo bien que viven debajo

0:00:22.320,0:00:36.199
Bajo el mar Bajo el mar

convert it to SRT with

$ ffmpeg -i a.sbv a.srt

the result is wrong in various ways: the first and second phrases are switched, the times are unrelated to the original ones and the second phrase ends after 1193 hours.

$ cat a.srt
1
00:00:25,200 --> 00:00:37,990
Bajo el mar Bajo el mar

2
00:00:25,800 --> 1193:03:12,496
Mira esos delfines lo bien que viven debajo

using the -fix_sub_duration option, the result does not improve (times are still unrelated to the original ones and there is only one phrase):

$ ffmpeg -fix_sub_duration -i a.sbv a2.srt
$ cat a2.srt
1
00:00:25,200 --> 00:00:25,800
Bajo el mar Bajo el mar

Thanks!

[Carl Eugen Hoyos]

Where can I download such a subtitle?
Which other software reads it?

[Carl Eugen Hoyos]

​https://support.google.com/youtube/answer/2734698?hl=en
I wonder if Google maybe misunderstood the format...

[Ilario Gelmetti]

Where can I download such a subtitle?

Seems that Youtube allows just the video owner to download the subtitles file. The example I posted is a simplified version of the subtitles from this video:
​https://www.youtube.com/watch?v=dVSm1OWy_LA

Which other software reads it?

According to Wikipedia, there are various:
​https://en.wikipedia.org/wiki/Comparison_of_subtitle_editors
like SubtitleComposer and fiveLoadSub.

There is a bash script here
​https://github.com/kf106/sbv2srt
which explicitly mentions in its readme the face that ffmpeg fails with these files and which produces this output:

1
00:00:17,880 --> 00:00:22,320
Mira esos delfines lo bien que viven debajo

2
00:00:22,320 --> 00:00:36,199
Bajo el mar Bajo el mar

which looks correct.

​> ​https://support.google.com/youtube/answer/2734698?hl=en

I wonder if Google maybe misunderstood the format...

In the example included in the link you posted, there are three decimal digits for the milliseconds. In other examples I found on the internet there are only two decimal digits.

Seems that ffmpeg supports only the case in which SubViewer files have only two decimal digits.

I could try to make a patch, in case I manage to do that, where should I post it?

[Carl Eugen Hoyos]

Replying to ilario:

Which other software reads it?

According to Wikipedia, there are various:
​https://en.wikipedia.org/wiki/Comparison_of_subtitle_editors

I doubt it but feel free to prove me wrong.

https://ffmpeg.org/pipermail/ffmpeg-devel/2020-March/258621.html

[Ilario Gelmetti]

Replying to cehoyos:

https://ffmpeg.org/pipermail/ffmpeg-devel/2020-March/258621.html

Tested the patch, it fixes this issue! Thanks!

[Carl Eugen Hoyos]

Too bad Keir hid his bug report so well...

[Carl Eugen Hoyos]

Should be fixed in 559ce9c8454fda5fe7fc0debf94cbcfbba33c66a, thank you for the report!