Software Signal: Subtitle Edit timing practice
https://www.softwaresignal.net/guides/fix-subtitle-timing
Checked 3 October 2026

These original synthetic practice texts may be copied, adapted and reused.
They are not subtitles for a real video. No matching speech or video is included.

CONTENTS
en-late.srt, zh-CN-late.srt and es-late.srt are the original inputs.
The corresponding *-corrected.srt files are actual outputs from Subtitle Edit's
official seconv 5.2.0 converter. Each input contains four subtitle cues.
result.json records the checks, file hashes and evidence limits.

TASK
Move every start and end time 1.5 seconds earlier without changing the text.
The first input cue starts at 00:00:03,000 and ends at 00:00:05,500.
The first corrected cue starts at 00:00:01,500 and ends at 00:00:04,000.
Every cue retains its original duration.

REPRODUCE WITH THE COMMAND-LINE CONVERTER
Obtain seconv from the official Subtitle Edit release page linked in result.json.
The application itself is not included in this pack.
Run the following with seconv available and the input file in your working folder:

seconv en-late.srt subrip --offset:-1500 --output-folder:./out --output-filename:en-corrected.srt --encoding:utf-8-no-bom

Replace en with zh-CN or es to try the other supplied file.
Use a new output folder to preserve both your input and any previous results.
Later releases may behave differently. This observation uses version 5.2.0.

WHAT WAS VERIFIED
All three conversions exited successfully.
All 24 start/end timestamps moved exactly -1500 milliseconds.
All 12 cue numbers, texts and line breaks were preserved.
The source archive SHA-256 matched GitHub's published release asset digest.

LIMITS
This is an exact file-transformation check.
It is not a speech synchronization, transcription accuracy or translation test.
No desktop-interface, burn-in, performance or competitor comparison is claimed.
On real media, measure the actual offset and replay the saved result against
the matching video. A constant shift cannot fix every kind of drifting subtitle.
