Retrieve subtitle file embedded in an MP4 video

[kasfig]

Dear colleagues
I wish to retrieve a subtitle file (soft coded) that is within an mp4 file (I can turn subtitles on or off in VLC)
I would like to extract the subtitle file so that I can edit it.
I cannot find how to do it.
I tried loading the file into subtitle edit, which usually works for me , but on this occasion it is not satisfactory.
Any advice how to do this free of charge would be much appreciated please.

[sneaker]

Try ffmpeg and mp4box.

What does MediaInfo say about the file?

[kasfig]

Dear Sir or madam
Thank you for your kind help.
Forgive me for my lack of knowledge as I try to explain
I have uploaded a screenshot of the file info from medianinfo
With previous mp4 files containing the subtitle file that I have handled, when I have loaded them into subtitle edit, I have been able to save the srt file and they have always been fine.
In this instance however, when I load the mp4 file into subtitle edit, when I have saved the .srt file, I subsequently notice when trying it out, that the subtitles are not properly synchronized with the text (although they fine when as embedded subtitles, turned on in vlc )
I guess this subtitle file might be a more complex file than subtitle edit recognizes
using subtitle edits synchronize function is not really helpful because some lines seem to be out of sync to different amounts than others.
Thank you, Ian

[sneaker]

In MediaInfo use "View"->"Text" for a more complete info.

If you extract the subtitles using ffmpeg or mp4box are they identical to the ones you got when opening the mp4 using Subtitle Edit? If it's a Subtitle Edit bug it might be best to simply report the problem (with sample file) to the author.

[dannyboy48888]

Try my mp4box GUI or ccextractor. Its worked for me where YAMB crashed. Also I've seen some mp4 files have chapter names flagged as subtitles and ended up getting Nada as there was nothing to extract

[netmask56]

A roundabout way to check if there are subs in a mp4 file is simply drag it into MKVToolnix All the components will appear. If the sub is there then save the mp4 file as a mkv, then using either MKVExtract or MKVCleaver to extract the subtitle file. If you don't need or use mkv then you can delete the file. You could in MKVToolnix simply untick the audio and video leaving just the sub track - it will save as a MKS file and probably you would have to convert it to SRT. DSRT Editor for Windows Version 3.22 Freeware