Bug: Chapter names not displayed for EAC3 + Atmos m4b file

[halpz]

Environment

• OS Version: 26.0.2
• App Version: latest App Store

Description

The chapter names are not displayed for this particular file

Steps to reproduce the behavior

1. import the M4B file
2. play the book and click on the chapter menu
3. only chapter 1, chapter 2 etc is displayed

ffprobe output:

paul@M-FVFFL27ZQ05P % ffprobe /Users/paul/Downloads/Harry\ Potter\ and\ the\ Philosopher’s\ Stone\ \(Full-Cast\ Edition\).m4b
ffprobe version 8.0.1 Copyright (c) 2007-2025 the FFmpeg developers
  built with Apple clang version 17.0.0 (clang-1700.4.4.1)
  configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/8.0.1 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libaribb24 --enable-libbluray --enable-libdav1d --enable-libharfbuzz --enable-libjxl --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox --enable-audiotoolbox --enable-neon
  libavutil      60.  8.100 / 60.  8.100
  libavcodec     62. 11.100 / 62. 11.100
  libavformat    62.  3.100 / 62.  3.100
  libavdevice    62.  1.100 / 62.  1.100
  libavfilter    11.  4.100 / 11.  4.100
  libswscale      9.  1.100 /  9.  1.100
  libswresample   6.  1.100 /  6.  1.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0xa70c20000] stream 0, timescale not set
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/Users/paul/Downloads/Harry Potter and the Philosopher’s Stone (Full-Cast Edition).m4b':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: dby1isomiso2mp41
    creation_time   : 2025-10-29T19:29:30.000000Z
    title           : Harry Potter and the Philosopher’s Stone (Full-Cast Edition)
    album           : Harry Potter and the Philosopher’s Stone (Full-Cast Edition)
    artist          : J.K. Rowling
    album_artist    : J.K. Rowling
    genre           : Science Fiction & Fantasy, Growing Up & Facts of Life, Literature & Fiction
    comment         : <p>The beloved stories as you’ve never experienced them. Get ready to be transported to the world of Harry Potter in a captivating production that features hundreds of unique voices and immersive sound design that brings the wizarding world vividly to l
    date            : 2025
    composer        : Full Cast
    PUBLISHER       : Pottermore Publishing and Audible Studios
    LANGUAGE        : English
    AUDIBLE_ASIN    : B0F14RFHS6
    SERIES          : Harry Potter (Full-Cast Editions)
    PART            : 1
  Duration: 08:41:27.58, start: 0.000000, bitrate: 769 kb/s
  Chapters:
    Chapter #0:0: start 0.000000, end 63.500000
      Metadata:
        title           : Opening Credits
    Chapter #0:1: start 63.500000, end 1970.500000
      Metadata:
        title           : Chapter 1 - The Boy Who Lived
    Chapter #0:2: start 1970.500000, end 3318.500000
      Metadata:
        title           : Chapter 2 - The Vanishing Glass
    Chapter #0:3: start 3318.500000, end 4847.500000
      Metadata:
        title           : Chapter 3 - The Letters from No One
    Chapter #0:4: start 4847.500000, end 6368.920000
      Metadata:
        title           : Chapter 4 - The Keeper of the Keys
    Chapter #0:5: start 6368.920000, end 9145.920000
      Metadata:
        title           : Chapter 5 - Diagon Alley
    Chapter #0:6: start 9145.920000, end 11528.920000
      Metadata:
        title           : Chapter 6 - The Journey from Platform Nine and Three-Quarters
    Chapter #0:7: start 11528.920000, end 13377.430000
      Metadata:
        title           : Chapter 7 - The Sorting Hat
    Chapter #0:8: start 13377.430000, end 14542.430000
      Metadata:
        title           : Chapter 8 - The Potions Master
    Chapter #0:9: start 14542.430000, end 16428.430000
      Metadata:
        title           : Chapter 9 - The Midnight Duel
    Chapter #0:10: start 16428.430000, end 18035.430000
      Metadata:
        title           : Chapter 10 - Hallowe'en
    Chapter #0:11: start 18035.430000, end 19293.549979
      Metadata:
        title           : Chapter 11 - Quidditch
    Chapter #0:12: start 19293.549979, end 21440.549979
      Metadata:
        title           : Chapter 12 - The Mirror of Erised
    Chapter #0:13: start 21440.549979, end 22614.549979
      Metadata:
        title           : Chapter 13 - Nicolas Flamel
    Chapter #0:14: start 22614.549979, end 23896.549979
      Metadata:
        title           : Chapter 14 - Norbert the Norwegian Ridgeback
    Chapter #0:15: start 23896.549979, end 25904.909979
      Metadata:
        title           : Chapter 15 - The Forbidden Forest
    Chapter #0:16: start 25904.909979, end 28241.909979
      Metadata:
        title           : Chapter 16 - Through the Trapdoor
    Chapter #0:17: start 28241.909979, end 30492.909979
      Metadata:
        title           : Chapter 17 - The Man with Two Faces
    Chapter #0:18: start 30492.909979, end 31287.582292
      Metadata:
        title           : End Credits
  Stream #0:0[0x1](und): Audio: eac3 (Dolby Digital Plus + Dolby Atmos) (ec-3 / 0x332D6365), 48000 Hz, 5.1(side), fltp, 768 kb/s (default)
    Metadata:
      creation_time   : 2025-11-04T08:38:31.000000Z
      handler_name    : SoundHandler
      vendor_id       : [0][0][0][0]
    Side data:
      audio service type: main
  Stream #0:1[0x2](mis): Data: bin_data (text / 0x74786574) (default)
    Metadata:
      creation_time   : 2025-11-04T08:38:31.000000Z
      handler_name    : ?Apple Text Media Handler
      title           : End Credits
      comment         : End Credits
  Stream #0:2[0x0]: Video: mjpeg (Progressive), yuvj420p(pc, bt470bg/unknown/unknown), 2400x2400 [SAR 1:1 DAR 1:1], 90k tbr, 90k tbn (attached pic)
Unsupported codec with id 98314 for input stream 1

[halpz]

I suspect it is to do with the Apple - specific stream on the file for end credits
Unsupported codec with id 98314 for input stream 1

[GianniCarlo]

@halpz could you share the file for testing purposes?

[halpz]

I can - but it's 3gb (and copyrighted)

[halpz]

I have sent the file to your email address

[GianniCarlo]

Yeah possibly an issue with Apple and the EAC3 stream, if encoded to aac, it works well (I ran the following command), I also sent the final book back to you via WeTransfer

ffmpeg -i "Harry Potter and the Philosopher’s Stone (Full-Cast Edition).m4b" \
  -map 0:0 -map 0:2 \
  -c:a aac -ac 2 -ar 44100 -b:a 128k \
  -c:v copy \
  -movflags +faststart \
  -f mp4 \
  harry_fixed_with_cover.mp4

[halpz]

The eac3 has atmos data which will be lost if re-encoded

I think it is just a problem with the extra metadata you can see in the ffprobe , not the audio stream itself.

[GianniCarlo]

🤦‍♂️ you're right @halpz , I tried again, and this time with this command to keep the EAC3 stream intact, and just remove the extra metadata

ffmpeg -i "Harry Potter and the Philosopher’s Stone (Full-Cast Edition).m4b" \
  -map 0:0 -map 0:2 \
  -map_chapters 0 \
  -c copy \
  -movflags +faststart \
  -f mp4 \
  "Harry Potter and the Philosopher’s Stone (Full-Cast Edition) - atmos-fixed.m4b"

Which ended up removing this

And the resulting file also works well with the app

I don't have a good connection right now to send 3 gb, but I can do it later today, or let me know if you can run the ffmpeg command and it outputs the same result?

[halpz]

It's okay - you don't need to send a fixed file , I can trim the metadata myself.
I might have a go at a PR if I get time - to make the app ignore unsupported metadata.

[GianniCarlo]

for context I'm using the built-in way by extracting it from the AVAsset (although now everything is async/await, and I have yet to migrate this to that, hence the warnings), I'm open to any good alternative though

[AbsenceJam]

Libation? This is touted as a (Windows) fix for these chapters not working in some apps like Prologue, requires a recent ffmpeg:
md .output & for %f IN (*.m4b) DO ffmpeg -i "%f" -map 0:a -map 0:v? -c copy -movflags disable_chpl+faststart -metadata encoding_tool=cm4b -metadata media_type=2 -disposition:v:0 attached_pic -brand "M4B " -f mp4 ".output%~nf.m4b"