Very long mp4 (mp3 audio, minimal video) audiobook playback issues

[moddie 2]

Hi,
I am converting AAX files from AMZN, to per chapter mp3 files:
https://bitbucket.org/kleberj/aax2mp3.git
which are then glued together in an mp4 with chapters:

ffmpeg -i "$OUTPUT.meta" -i "concat:$(cat "$OUTPUT.parts")" -codec copy "$OUTPUT"

This works about 33% percent flawlessly, in my use case.
- on my android phone: no issues at all
- on any linux pc i've tried. instant start of playback with extreme stutter. if i pause a short time, it's okay for maybe 30-60 secs. but sure to stutter again.
  some sort of buffering issue, related to VERY long files? 14+ Hours in this specific case. but slightly shorter ones are also affected.
- on my SHIELD TV Pro, not working at all (too many errors, giving up)

i've attached logs for all three of the described cases and an ffprobe for the file.

need more info? let me know...

I am open to any alternatives that support chapters as well.

Thanks for your feedback!

ps, one further bit of strangeness:

# This ffmpeg map command should use metadata from input 1 (which is the meta file) but it just does not,
# making the meta file the first input seems to prioritize it as the metadata source.
# not sure if i am just too stupid for ffmpeg, or there is some kind of bug
#ffmpeg -i "concat:$(cat $OUTPUT.parts)" -i $OUTPUT.meta -map_metadata 1 -codec copy "$OUTPUT"

i've tried several variations of mapping input number N to be the metadata source, none of which have worked...

audiobook_ffprobe.txt emby_shield_fail.log emby_firefox_linux_extreme_stutter.log emby_android_works.log

[Luke 42077]

Hi.  Can you try searching for our standard android app (Just "Emby" on Amazon and "Emby for Android on Google) on the same device's app store and see how that compares?

Thanks.

 

[moddie 2]

Thanks for the swift reply!

I see now there are 2 Apps where there was previously only one...
 "emby for Android TV" (did not work with the audiobook) and "emby for Android" which does work just fine! \o/
is the "for TV" app no longer supported? might be worth popping up a notice in the TV app, pointing users to the other one.

that still leaves the stuttering issue in browsers which, i forgot to mention, also happens in chrome... so i'd assume the chunks sent by the server are not buffered enough on the web-app side, or something along those lines. The server is certainly fast enough to transcode multiple 4K x265 HDR videos.

[Luke 42077]

Hi, we are working on unifying the two apps into just the "emby for android".

Thanks for the feedback.

Anyway, please attach the corresponding ffmpeg log file as well. thanks.

[moddie 2]

Hello,

just noticed something weird as well, if i just start from the beginning there is no stutter initially but if i skip further into the file, it starts to stutter. Same stutter as when i resume.

I've attached 2 ffmpeg logs. The bigger one should be start at beginning, then skip to around 45 minutes. The small one is a resume from that place.

ffmpeg-transcode-91947c4b-ca29-417d-8ad1-7efbe52217f4_1.txt ffmpeg-transcode-8e758cb8-e2cd-404c-8d1c-e97ee4162a84_1.txt

[Luke 42077]

7 hours ago, moddie said:

Hello,

just noticed something weird as well, if i just start from the beginning there is no stutter initially but if i skip further into the file, it starts to stutter. Same stutter as when i resume.

I've attached 2 ffmpeg logs. The bigger one should be start at beginning, then skip to around 45 minutes. The small one is a resume from that place.

ffmpeg-transcode-91947c4b-ca29-417d-8ad1-7efbe52217f4_1.txt 69.99 kB · 1 download ffmpeg-transcode-8e758cb8-e2cd-404c-8d1c-e97ee4162a84_1.txt 406.63 kB · 1 download

Hi, please attach the corresponding emby server log as well. thanks.