How do I fetch the WAV version of an item?

[antonlyap]

I have a music library, and I would like to get a stream of an audio track in WAV format. Is it possible in Jellyfin? What parameters do I need to specify for that?

Simply setting

Code:

containerType=wav

seems to be insufficient. Jellyfin runs the following command:

Code:

/usr/lib/jellyfin-ffmpeg/ffmpeg -analyzeduration 200M  -i file:"/media/path/to/file.m4a" -threads 0 -vn -ab 256000 -ac 2 -acodec copy -ar 48000 -id3v2_version 3 -write_id3v1 1 -y "/config/transcodes/03fc9fa635e92c205619ec637c295946.mp3"

This command fails, the API request returns error 500. However, changing the output file extension to .wav seems to fix it. How do I get Jellyfin to do that?

[TheDreadPirate]

I'm assuming you are accessing your Jellyfin remotely.  Locally it would just play the file but there is a setting for Internet quality that is probably the default setting (256kbps).

Settings > Playback (not the one in the dashboard)

   

[antonlyap]

Thanks for your reply.

Actually, Jellyfin runs in a Docker container on the same machine I'm accessing it from. The audio files are M4A (AAC), so I assume adjusting the quality won't force JF to transcode them to a bigger format (WAV)?

[TheDreadPirate]

First, why would you want to transcode from AAC to WAV? There is no benefit, only drawbacks (more bandwidth, no quality improvement). Second, Jellyfin supports higher quality (FLAC/WAV) to lower quality (OGG Vorbis, AAC, MP3) but not the other way around.

[antonlyap]

I would like to perform some analysis on the music tracks (BPM, frequencies, language etc), and for that I need raw audio data. In that case fetching the item as is and converting it on the receiving end is probably the best solution.

May I ask where the limitation comes from exactly (when using the API rather than the web UI)? Does Jellyfin put the ffmpeg command together in a specific way that does not allow transcoding to higher quality?

[TheDreadPirate]

The "transcode helper" is written in a way that doesn't support your use case. The transcode helper constructs the ffmpeg command depending on client compatibility and your settings. And AFAIK cannot transcode audio to WAV. FFMPEG can do that, but Jellyfin will never tell FFMPEG to do that.

[antonlyap]

Got it, thank you.

[Gastino Gangster]

First, why would you want to transcode from AAC to WAV?  There is no benefit, only drawbacks (more bandwidth, no quality improvement).  Second, Jellyfin supports higher quality (FLAC/WAV) to lower quality (OGG Vorbis, AAC, MP3) but not the other way around.

I would like to perform some analysis on the music tracks (BPM, frequencies, language etc), and for that I need raw audio data. In that case fetching the item as is and converting it on the receiving end is probably the best solution.

May I ask where the limitation comes from exactly (when using the API rather than the web UI)? Does Jellyfin put the ffmpeg command together in a specific way that does not allow transcoding to higher quality?

Unfortunately I did try, but it didn't make a difference.