Allow to Use Server-Specified Transcoding Format and Bitrate

[sudoape]

Currently the app forces mp3 only transcoding. In Navidrome I have set a specific transcode format and bitrate for the Amperfy player, but it is always overwritten by the app settings with no way of preferring it.
It would be nice to have the option to get max bitrate and streaming format from the server values.

[BLeeEZ]

What needs to be changed to support this? Omit the transcoding attribute from the URL?

[sudoape]

If you omit the format attribute in /rest/stream then Navidrome will use the format set in DefaultDownsamplingFormat configuration or the one set in the Amperfy Player from the UI.

[amandasystems]

Aha, so there's no way of selecting a different codec for transcoding than mp3? The drop-down list suggests there may be other formats but it only shows mp3 and raw for me, which had me confused since I have other transcoding formats configured in Navidrome. Leaving this comment here for anyone else who may be similarly confused!

[BLeeEZ]

I am currently revisiting this feature. Two points:

1. How can I identify the MIME type of the received file if the server is deciding which transcoding codec should be used. I need to specify the received MIME type in the database to configure the player correct.
2. If I can't get the actual used transcoding codec (MIME type) which hardcoded codecs should I offer to the user? (mp3, raw, ALAC?, FLAC?)

[amandasystems]

For me at least, the correct MIME type is set in the header of the response to the stream endpoint. This is for ogg opus. For mp3 I get audio/mpeg.

$ curl 'https://[redacted]/rest/stream?u=amanda[redacted] -I -s 
server: nginx/1.26.2
date: Wed, 11 Dec 2024 09:25:42 GMT
content-type: audio/ogg
content-length: 13680581
accept-ranges: none
permissions-policy: autoplay=(), camera=(), microphone=(), usb=()
referrer-policy: same-origin
...
x-content-duration: 367.87
x-content-type-options: nosniff
x-frame-options: DENY

[BLeeEZ]

@amandasystems thank you. I found the counterpart in the Apple network session. I will rework the download manager to support that and I will add an option to let the server side which codec should be user.

[amandasystems]

n i c e, thanks!

[BLeeEZ]

Done in c40d262 and 18f5e2c.