как извлечь субтитры из M4V формата? Исползовал Yamb не помогло ошибку пишет.

http://my-mp4box-gui.zymichost.com/

List of features:

Create mp4 files containing:
- video streams with m4v, cmp, h264, 264, h263, 263 as input format or from avi, mpg, mpeg, vob, mp4, mov, ogg, qcp and 3gp format.
- audio streams with aac, ac3, amr, awb, evc, mp3 as input format or from avi, mpg, mpeg, vob (mp2 only), mp4 and 3gp format.
- subtitle streams in srt and idx/sub format
- chapter streams in xml, ogm and ttxt format
Add up to 20 tracks to an mp4 file.
Delay every audio and/or video track separately.
Change the framerate of added video.
Save a list of jobs to be completed at a later date.
Join supported files(mp4, 3gp) end-to-end aka concatenate joining.
Demux supported files(mp4, avi, mov, ts, idx/sub, srt) to their raw formats.
Hint tracks to ready for streaming.
Split files by size or duration. eg. 700mb CDs or 60min
Support for most MP4Box advanced options
Ability to set priority of mp4box
Logging of mp4box output and GUI input
Set language and title for every track
Adjust Pixel Aspect Ratio of video without transcoding
Extract clip from video at specified length and time, eg. 00:31:00-00:33:00(would extract 2 minute clip begining 31 minutes into the video)
Edit command line before processing
Full drag and drop support
Demux only needed tracks
Output fully 'Apple Compatible'
32 bit and 64 bit compatible

ps: правда Yamb использует эту же программу, поэтому лучше было бы указать какая ошибка происходит.