playback garbled (too fast & choppy) on .m4b audiobook (tempo adjustment no effect)

[Simon McKay-Mills]

Poweramp version - build 965 bundle play

file - audiobook. file info: AAC HE-AACV2 44975 sec 44100Hz 16bit mono 65kbps gapless

phone - Samsung S22 ultra

the audiobook seems really fast and choppy (unusable) - but if i pick voice recorder on the phone - it plays back without issue.

 

[andrewilley]

As you say, there is a Tempo control (mainly used for spoken word material) but that should not come into effect unless you manually adjust it.

Could you upload a sample file for testing please, as PA is optimised for music rather than audiobook file formats?

Andre

[Simon McKay-Mills]

hi - thanks.

i tried to cut a sample out of it using audacity, but even a 10 sec sample was 30Mb (and i'm  not sure if it changed any settings) - can you recommend anything that can cut a sample out?

strangely - VLC will play the file fine on the phone

regards

Simon

 

 

[andrewilley]

If 10 seconds of a mono voice recording at 65kbps is 30Mb, something could be wrong with the file. I would have expected that to be well under a Mb. Audacity may be re-encoding though rather than losslessly trimming, better to provide a whole sample file (I assume it's in chapters rather than one huge 12 hour file). 

Andre

 

[Simon McKay-Mills]

more than likely i'm doing something wrong in audacity.

it is in 1 x 12 hr file rather than chapters. i tried again to create a smaller sample using lossless - and that just wouldn't play.

don't worry about it - i like the app, but if i just need to use vlc for the occasional poorly ripped audiobooks - it isn't a big deal.

Regards

Simon

[ScarletNeko]

Do you have a PC available? If so get ffmpeg and do

ffmpeg -hide_banner -loglevel fatal -stats -i "input.m4b" -c:a copy -ss 00:01:00 -t 00:00:30 "output.m4a"

This will seek to around 1 minute and get a ~30 second sample from there without reencoding, which should be pretty small in file size

M4B is a weird extension, don't usually see it, thats why the output is m4a instead since I dont know if ffmpeg would complain about it

Or if you prefer audacity you're probably exporting the file from as lossless, be sure to change it when exporting to some lossy format. Though the reencoding process could mess things up by acidentally fixing it (the ffmpeg command doesn't reencode, it just cuts a section of the audio without doing anything else)

[andrewilley]

Audacity will be simply loading the audio content into its buffer (as uncompressed/PCM) and then re-saving it into the format of your choice, it won't retain the original binary source file data.

Even the ffmpeg solution might not provide a perfect reproduction of the issue as it will probably have to write new header data out even if it keeps the accurate binary content of the audio segment, and the issue could be in the header.

Certainly playing a 12-hour mono lowish-bitrate AAC file is an unusual requirement for an app designed to play music...

Andre

[maxmp]

@Simon McKay-Mills if possible, please share the file with gpmaxmpz@gmail.com - probably some fix or workaround is possible. Thanks!

[andrewilley]

@maxmp This is apparently a single 12 hour audio file, so even mono at 65kbps it's probably too big for email (at a wild guess, it could be 300Mb or more). Dropbox or Google Drive link might be easier?

Andre

[Simon McKay-Mills]

hi,

file shared with the gpmaxmpz@gmail.com gmail account - https://drive.google.com/file/d/1vSp91CnFFYZBv_T0Zd9GeSv3iiSDEJxp/view?usp=sharing

tried the  command line ffmpeg and the file was created (but 0 bytes)

many thanks

simon