[Bug]: Can't fastforward .aac file on Android

[PanZWarzywniaka]

What was the Problem?

As you can see on the screen recording, I tried to fastforward the book to the middle so I could resume when I finished.

Screen_Recording_20240901_094235_Audiobookshelf.mp4

Moving the slider doesn't work (backs to the beggining) neither does using the button to skip 10 seconds.

As you can hear the file is healthy, and it starts playing the book from the beggining.

I suspect it's to blame the file format.

File details

Here is the output of `ffprobe -show_format`

Input #0, aac, from './Niezwyciężony.aac':
Duration: 06:57:39.80, bitrate: 133 kb/s
Stream #0:0: Audio: aac (LC), 44100 Hz, stereo, fltp, 133 kb/s
[FORMAT]
filename=./Niezwyciężony.aac
nb_streams=1
nb_programs=0
format_name=aac
format_long_name=raw ADTS AAC (Advanced Audio Coding)
start_time=N/A
duration=25059.801256
size=417424242
bit_rate=133257
probe_score=51
[/FORMAT]

Steps to Reproduce the Issue

1. Add .aac file to your library.
2. Play it on android app.
3. Try to fastforward using the sliders or skip ahead buttons.

What was Expected?

File should be played from requested timestamp.

Phone Model

Samsung Galaxy S10

Phone OS

Android 12

Audiobookshelf App Version

Android App - 0.9.76

Installation Source

Google Play Store

Additional Notes

I solved the issue by converting the file to mp3 format:

$ ffmpeg -i ./input.aac -acodec libmp3lame ./output.mp3

Then it works without an issue.

[nichwall]

A file being able to play does not mean that the file supports seeking. Can you try converting the file from aac to aac using the -c copy parameter?

https://www.audiobookshelf.org/guides/ffprobe/#fixing-an-audio-file

[PanZWarzywniaka]

I am sorry, I missed that section in the docs, however now I tried to ffmpeg -i input.aac -c copy output.aac, but it's still not seekable. Same problem with skipping.

Created separate book folder and copied the file to avoid caching.

[PanZWarzywniaka]

I forgot to add that it works perfectly fine on Desktop (web client).