Success Re: ffmpeg guidance, please to convert m4b to mp3

Thanks, Holly.
I got it to work.
The link about seeking was exactly what I needed, but couldn't find.

There is a lingering issue, not a big deal.
When I tried to put input and output as m4b and mp3, I got an error
that the input must be mp3.
I had success when I put the output also as m4b.
So, I've learned how to split an m4b file into segments with several
options.

I have not yet learned how to convert an m4b tile into an mp3 file.

In gratitude,
LeRoy

-- 
There is something glorious birthing within all of us.
I am the Love of God, no matter what.BSA
LeRoy Diener
213-LEROYIZ
213-537-6949
https://leroydiener.com

On Wed, 2022-11-30 at 11:44 -0700, Holly Grimm wrote:
> LeRoy,
> If you have timestamps, I would try these commands and see if they
> work for you:
> 
> Begin at 0, with a duration of 1214 seconds:
> ffmpeg -i audiobook.m4a -t 1214 -c copy chapter1.mp3
> 
> Begin at 20 minutes and 14 seconds, with a duration of 1214 seconds:
> ffmpeg -ss 00:20:14 -i audiobook.m4a -to 1214 -c copy chapter2.mp3
> 
> https://trac.ffmpeg.org/wiki/Seeking for more details
> 
> Holly
> 
> On Wed, Nov 30, 2022 at 10:06 AM LeRoy Diener
> <[email protected]> wrote:
> > To Wayne and all:
> > 
> > The .m4b file is not corrupted. The 11hr file plays flawlessly in
> > VLC and SMplayer. The first 1hr loads correctly in Audacity, but
> > only as the truncated portion of the larger file. I found that
> > others had a similar experience, as
> > at https://forum.audacityteam.org/viewtopic.php?t=79754
> > 
> > I'm guessing that the issue for Audacity is that the .m4b file
> > includes some encoding which points to a .cue file which has the
> > timestamps for the chapters. Here are snippets of the .cue file:
> > TRACK 1 AUDIO
> > TITLE "Chapter 01"
> > INDEX 01 0:0:00
> > TRACK 2 AUDIO
> > TITLE "Chapter 02"
> > INDEX 01 20:14:56
> > ...
> > TRACK 19 AUDIO
> > TITLE "Chapter 19"
> > INDEX 01 661:19:09
> > 
> > My end objective is to break the 11hr file into smaller files,
> > ideally the chapters of the audiobook.
> > I'm not sure what is the best workflow for this. Here's one idea.
> > If I can convert the .m4b file to a .mp3 file, then I can edit it
> > in Audacity. It might be even easier if I can use ffmpeg to split
> > the file into chapters.
> > I would be happy to have the chapter files in .m4b format
> > (unconverted). I just want to end up with files that are not so
> > long.
> > 
> > Wayne, thanks for your ideas. I have not yet tried using the nitrag
> > script. I'm not sure how to do that, and I'm being cautious, asking
> > for guidance.
> > 
> > I'm still unsure about how to proceed.
> > LeRoy
> > -- 
> > There is something glorious birthing within all of us.
> > I am the Love of God, no matter what.BSA
> > LeRoy Diener
> > 213-LEROYIZ
> > 213-537-6949
> > https://leroydiener.com
> > 
> > On Tue, 2022-11-29 at 15:32 -0800, Wayne wrote:
> > > 
> > > If it can't be opened correctly by Audacity, is it possible the
> > > file is corrupted somehow?
> > > 
> > > Do you really want the results in separate chapters, or is a
> > > single non-chaptered file okay? ffmpeg would be a very simple
> > > command-line if you wish to write to a single file. If you need
> > > to separate by chapters, did you try using the nitrag script?
> > > 
> > > BTW, most video/audio editors use ffmpeg or one of it's
> > > components as it's engine. It is extremely powerful.
> > > 
> > > Wayne
> > > 
> > > 
> > > On 11/26/22 1:16 PM, LeRoy Diener wrote:
> > > > Hi NMGLUG folks,
> > > > 
> > > > I would like to convert an audiobook .m4b file (probably with
> > > > chapters in metadata) to .mp3 files split into chapters.
> > > > I'm trying to learn how to convert files.
> > > > I looked at https://ffmpeg.org/ffmpeg.html but it gets
> > > > overwhelming.
> > > > 
> > > > I'm not sure what the best approach will be.
> > > > I also found https://github.com/sandreas/m4b-tool where the
> > > > author references https://github.com/sandreas/tone
> > > > Additionally, I found this script from nitrag
> > > > https://gist.github.com/nitrag/a188b8969a539ce0f7a64deb56c00277
> > > > Other options appear in
> > > > https://www.videoproc.com/media-converter/m4b-to-mp3.htm
> > > > Indeed, my first idea was to import the .m4b file into Audacity
> > > > to do the conversion. Unfortunately, it doesn't import
> > > > correctly into Audacity.
> > > > I'm able to play .m4b file in VLC and SMplayer. It seems like
> > > > it's possible to use VLC to do the conversion with some help
> > > > from ffmpeg, though maybe not a great option.
> > > > 
> > > > Any thoughts?
> > > > 
> > > > Thanks,
> > > > LeRoy
> > > > 
> > > > _______________________________________________
> > > > nmglug mailing list
> > > > [email protected]
> > > > http://lists.nmglug.org/listinfo.cgi/nmglug-nmglug.org

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