From Newsgroup: comp.mobile.android

I simplified the tutorial for the patients to use at the hyperbaric oxygen therapy clinic. The main takeaway is you can essentially convert anything
on the Internet that is text to an audiobook, no matter how large it is.
<https://i.postimg.cc/Lsjs3tj8/hyperbaric01.jpg> hyperbaric oxygen chamber

============================================================================= Tutorial: =============================================================================
Convert any ebook or PDF or HTML text to audiobook spoken English on
Windows; then copy to & play on your mobile device for your chamber.

Freeware:
All items suggested in this tutorial are legally free & open to use.

Basic process
1. Obtain any textual ebook on Windows (e.g., .epub)
2. Convert the input format to written text (e.g., .txt)
3. Optionally edit out non-narrative material (such as the bibliography)
4. Convert the text to a spoken-audio file (e.g., .opus)
5. Copy that spoken-audio file to a mobile device
6. Play that audio file on your mobile device

Free or open-source Windows software used to create the audiobook:
a. Free open-source Epub reader & converter software
Calibre <https://calibre-ebook.com/>
b. Free text-to-audio conversion software
Balabolka <https://www.cross-plus-a.com/balabolka.htm>
c. (Optional) Additional free audio conversion software
FFmpeg <https://ffmpeg.org/download.html>

Free or open-source Android software used to play the audiobook:
a. VLC audio/video player
<https://play.google.com/store/apps/details?id=org.videolan.vlc>
b. Voice Audiobook Player
<https://play.google.com/store/apps/details?id=de.ph1b.audiobook>
c. Smart AudioBook Player
<https://play.google.com/store/apps/details?id=ak.alizandro.smartaudiobookplayer>

Free or open-source iOS software used to play the audiobook:
a. VLC audio/video player
<https://apps.apple.com/app/id650377962>
b. BookPlayer
<https://apps.apple.com/app/id1138219998>
c. Everlisten++
<https://apps.apple.com/app/id1116483197>

Step 1:
Obtain any free textual epub book you wish to convert to spoken audio.
Example book:
Special & General Theory of Relativity, by Albert Einstein, 1916
<https://www.gutenberg.org/ebooks/5001>
<https://www.gutenberg.org/ebooks/5001.epub.noimages>
File name pg5001.epub size 177 KiB
SHA256 07D0F0F8CD9D3AC3CBE251F2CA4DAAF11183E3C755001B80A729EC310074AE6B

There are many free no-registration ebook (.epub) sites on the Internet.

A. The largest & oldest free ebook library with 70k plus titles in EPUB
<https://www.gutenberg.org/>

B. Public domain books in HTML format, no login needed
<https://authorama.com/>

C. Beautifully formatted EPUBs, no account required
<https://standardebooks.org/>

D. Index of free books hosted elsewhere
<https://onlinebooks.library.upenn.edu/>

E. Public domain texts with EPUB export, no account required
<https://en.wikisource.org/wiki/Main_Page>

F. Curated list of external sources
<https://ilovephd.com/60-legal-websites-to-download-millions-of-free-books-in-2025/>

G. Curated free ebooks across genres, no login needed
<https://www.getfreeebooks.com/>

H. Informational article with links to other sites
<https://howtogeek.com/these-are-the-best-sites-for-drm-free-ebooks-and-comics/>

I. Nicely formatted classics in EPUB or PDF, no ads
<https://www.planetebook.com/>

Step 2
Convert that ebook to text with Calibre freeware
a. On Windows, launch the main Calibre program
b. Click the green "Add books" icon at the top left
c. Select the epub book you just downloaded
d. Click the brown "Convert books" icon near the top left
e. At the top right of the form that pops up, select "Output format = TXT"
f. At the bottom right of that form, click the "OK" button
g. Wait for the bottom right "Jobs" count to go from "1" back to "0"
h. Press the blue "Save to disk" icon at the top bar to save the text file
i. Choose a location for saving the text file
j. Right click on the selected book & choose Open Book Folder
k. You should be able to locate the newly created TXT file

Note Calibre input formats include
EPUB MOBI AZW AZW3 AZW4 PDF DOCX RTF TXT ODT HTML CBZ CBR
Calibre output formats include
EPUB MOBI AZW3 PDF DOCX RTF TXT HTML LRF ZIP FB2

My suggestion for your first attempt is:
Input format = EPUB
Output format = TXT (or DOCX)

Step 3 (optional)
Edit out any non-narrative text
a. Open the resulting TXT (or DOCX) file in any Windows editor
b. Remove non-narrative text such as the table of contents,
or the bibliography or other extras such as images.
c. Save the edited text (or DOCX) file

Step 4
Convert the text file to spoken audio using Balabolka freeware
a. On Windows, launch the Balabolka audio-file-creation program
b. Select the edited TXT (or DOCX) input file
Balabolka:File > Open > file.txt
c. (Optional) If desired, edit the text in Balabolka
to remove non-narrative text such as the dedication or
table of contents or the bibliography, etc. and save
d. Select the desired Microsoft Voice (e.g., David or Zira)
Balabolka:Voice > Voice > Microsoft David Desktop
e. Set desired options for an efficient audio file size
Balabolka:Options > Audio Files > Options
Click on the "OPUS" tab to set .opus options
Set the "Bitrate" to either 24 kbps or 48 kbps
Leave the "Audio Format" at "Default for voice"
Press the "OK" button to save these settings
f. Save the audio file
Balabolka:File > Save Audio File
In the "Save as type" dropdown, select "Opus audio files (.opus)"
Click OK, then save your file.

Optionally, you can set up Balabolka to use FFmpeg to enable
more output formats than Balabolka normally enables on its own.
a. Download the Windows FFmpeg build
<https://ffmpeg.org/download.html>
<https://www.gyan.dev/ffmpeg/builds/>
b. Extract the ZIP & locate ffmpeg.exe in the bin folder
c. In Balabolka Options Audio File Options check Use external program
d. Browse to ffmpeg.exe & save settings

Step 5
Transfer the spoken-audio file to your mobile device.
Android
Connect by USB
Copy file to device storage

iOS
Install VLC <https://apps.apple.com/app/id650377962>
Enable Sharing via WiFi in VLC
Note IP address shown
On Windows open browser to that IP
Drag & drop audio file to upload
File appears in VLC library on iOS

Step 6
Play your newly created audiobook on your mobile device.
On Android open VLC or another player such as Audiobook Player & press play
On iOS open VLC or another player such as BookPlayer & press play

Summary
1. Get any free electronic book text on the Internet
2. Convert the textual ebook with Calibre to TXT or DOCX
3. Optionally edit out non-narrative text using any Windows text editor
4. Convert the text file with Balabolka to a spoken audio file
5. Transfer the spoken-audio file to Android by USB or to iOS by VLC WiFi
6. Play on the mobile device with VLC or any other free audio file player ============================================================================= --- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: comp.mobile.android

Marion wrote:

I simplified the tutorial for the patients to use at the hyperbaric oxygen therapy clinic. The main takeaway is you can essentially convert anything
on the Internet that is text to an audiobook, no matter how large it is.
<https://i.postimg.cc/Lsjs3tj8/hyperbaric01.jpg> hyperbaric oxygen chamber

<OT> How does a hyperbaric oxygen chamber work anyway?

You're locked inside a "propane tank" where you're not allowed to bring anything with you - not even your own clothes. So you're bored to death.

To stave off boredom, they allow you to play anything you want on the
speakers. Always wanting to learn something new, I decided on playing
audio books of my own choosing (e.g., Einstein's Theory of Relativity
from 1916 which is out of copyright since it only lasts for 100 years).

That's why I wrote the attached guide.
So the clinic patients can do likewise.

With this tutorial, you can take anything on the Internet and convert it
to an audiobook - which is usually about five or ten hours long.

That's suddenly useful because you have to spend two hours each day locked
in that "500-gallon propane tank" where they send you "down" to about 85
feet (if it were a freshwater dive) and you go through 7 cycles from:
1. About 10 minutes of pressurization from 1ATM to 2.5ATM on air
2. Then they switch you to about 30 minutes of high-pressure oxygen
3. Then an "air break" of 5 minutes (to forestall oxygen toxicity)
4. Then back to about 30 minutes of high-pressure oxygen
5. And again, a short "air break" of about 5 minutes
6. Back again to about 30 minutes of high-pressure pure oxygen
7. And then about 10 minutes to bring us back up to the surface on air.

The total therapeutic time is 90 minutes on high-pressure oxygen.
The main dangers are oxygen toxicity & nitrogen narcosis.

It's all about partial pressures, which everyone learned long ago.
It's basic scuba-diving stuff that every diver studies in detail.
Q: How does it work?
A: It fills your body with oxygen molecules at high pressure.

Oxygen molecules are of a relative size of a grain of sand compared to a
truck when it comes to how big red blood cells are, so they can get all
over the body through tiny roads (arteries & capillaries) and walls in our tissues and organs. The perfusion only lasts a short while though.

So you have to do it again.
And again.
And again.

If a truck (RBC) can't get through a narrow artery, the grain of sand
can get through it - where the hope is the oxygen does some good.

Anyway, that's why I wrote the tutorial for how to convert anything
textual on the Internet to an audio file for people who are bored,
and stuck inside a propane tank for a couple of hours with nothing
else to do to keep their mind occupied (other than clear their ears).

The hope, as always, is that it helps everyone easily do what I can do.
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: comp.mobile.android

Marion wrote:

Anyway, that's why I wrote the tutorial for how to convert anything
textual on the Internet to an audio file

One unexpected "problem" is that the Windows 10 Microsoft David desktop
voice can't handle apostrophes like those in "don't" or "can't or
especially "isn't) where it says "eye ess enn tee" instead.

You'd think Microsoft would have better voices given these words are common
(I wonder if the Windows 11 version handles apostrophe's better?)

If you know of a fix, let me know, but the easiest way I know of to fix
that is to just convert all the contractions to the full word or just
remove the apostrophe.

To test the difference, I just downloaded the famous Xenophon's Anabasis.
I took two sources and converted the contractions in one to
'uncontractions' and in the other, I simply removed all the apostrophe characters.

Archive.org Anabasis by Xenophon, circa 370 BC, 125 pages <https://ia801605.us.archive.org/view_archive.php?archive=/33/items/GutenbergENzip/02.zip&file=Anabasis%20-%20Xenophon%2C%201997%20%28125p%29.pdf>

Gutenberg Anabasis by Xenophon, circa 370 BC, 125 pages https://www.gutenberg.org/ebooks/1170.epub.images

I saved the PDF as text (assessable text versus plain text) using the last known good version of Adobe Acrobat version 6, and converted the EPUB to
text using Calibre and ran wc (word count) on the file in Windows.

Archive.org Anabasis
Lines Words Characters
----- ----- ----------
5480 97820 555094

Gutenberg Anabasis
Lines Words Characters
----- ----- ----------
3180 97701 549528

Hmm... Gutenberg is 60% fewer words, so I'm not sure what that tells us. Looking at the text belatedly, they're both Project Gutenberg. Go figure.

Title: Anabasis
Author: Xenophon
Translator: Henry Graham Dakyns
Release date: January 1, 1998 [eBook #1170]
Most recently updated: October 29, 2024
Language: English
Credits: Produced by John Bickers, and David Widger

It had 310 apostrophes, but it didn't use contractions like "can't".
Most of the apostrophes were denoting possessives (e.g., Cryus's).
This removed them all in a flash:

gvim anabasis.txt

:%s/'//g (delete apostrophes)

Although I belatedly found out that it could be that curly apostrophes
are treated as pauses versus plain apostrophes in Balabolka. You can
normalize apostrophes in Balabolka using Options > Text Correction
and set up a rule to replace all curly apostrophes with straight ones.

Later, when I converted it to an opus file, I realized there were pauses
at the end of every line, because, I guess, there were empty lines
between every line, so I removed all blank and/or empty lines using
:g/^\s*$/d (delete blank lines)
:g/^$/d (delete empty lines)

I found out later Balabolka has a text-cleanup options such as
Format > Remove Empty Lines, and that blank lines are considered pauses
since they're generally before each paragraph. Also, I found out
belatedly that an export from Calibre to RTF or DOCX instead of to
plain TXT preserves paragraph structure better than text export.

In Balabolka, I saved as an "opus" file for compatibility with mobile platforms (i.e., iOS & Android) and will listen to it soon in the HBOT.

Here is the word-count program I wrote.
@echo off
REM Usage: wc.bat "C:\path\to\file.bat"
REM wc.bat v1.0 20250927
REM Show line, word, and character counts of a text file
REM wc.bat v1.1 20250927
REM Also show how many characters must be deleted to fit under 10240
REM wc.bat v1.2 20250927
REM Also show how many characters must be deleted to fit under 10240
::
@echo off

if "%~1"=="" (
echo Usage: %~nx0 filename
exit /b 1
)

set "TARGET=%~1"
set "LIMIT=10240"

echo File: %TARGET%
echo.

REM Full breakdown (lines, words, characters)
powershell -NoProfile -Command ^
"Get-Content -Raw -LiteralPath '%TARGET%' | Measure-Object -Line -Word -Character"

REM Capture exact character count as a plain integer
for /f "usebackq delims=" %%C in (`powershell -NoProfile -Command "[int](Get-Content -Raw -LiteralPath '%TARGET%').Length"`) do set COUNT=%%C

REM Safety: remove any stray commas or spaces (should not be present, but just in case)
set COUNT=%COUNT: =%
set COUNT=%COUNT:,=%

echo.
echo Character count: %COUNT%

REM Compute and report overage
set /a OVER=%COUNT% - %LIMIT%

if %COUNT% GTR %LIMIT% (
echo Characters over limit %LIMIT%: %OVER%
echo You must delete at least %OVER% characters to fit under %LIMIT%.
) else (
echo File is within the %LIMIT% character limit.
)

REM Ask PowerShell to emit just the character count as plain text
REM powershell -NoProfile -Command ^
REM "(Get-Content -Raw -LiteralPath '%TARGET%').Length"

Flow Calibre > Balabolka > OPUS (Microsoft David voice)

1. Export from Calibre
Prefer RTF or DOCX
Use TXT only if necessary

2. Open the file in Balabolka

3. Normalize line breaks
Edit > Text Cleanup > Remove Empty Lines
Format > Join Lines

4. Fix apostrophes and quotes
Options > Text Correction > Add Rules
Replace curly quote with '
Replace curly open doublequote with "
Replace curly close doublequote with "

5. Remove hidden or odd characters
Edit > Text Cleanup > Remove Unnecessary Symbols
(Optional) Replace non-breaking spaces with normal spaces

6. Test a short sample
Listen for pauses or spelled-out words
If issues remain, repeat steps 3 > 5

7. Save your cleanup rules in Balabolka for reuse

8. Export audio
Choose OPUS format
Generate final file

9. Copy to mobile device
For Android, it's trivial (and need no explanation)
For iOS, it's a bitch (best to use VLC over Wi-Fi)

10. Play in VLC (the OPUS file will be in the audio tab)
--- Synchronet 3.21a-Linux NewsLink 1.2