Gapless (groan) with RoPieee and BubbleUpnp

[bubbleguuum]

Thanks for the appreciation for BubbleUPnP.

A bit of clarification about BubbleUPnP and 'BubbleUPnP Server' transcoding to PCM with FFmpeg.

Android BubbleUPnP and BubbleUPnP Server do not transcode with FFmpeg blindly:
if it is transcoding, there is a reason for it caused by a mix of settings and renderer reported capabilities.
Sometimes it may be unwanted or done without, hence the option to entirely disable transcoding unconditionally.

When playing to UPnP AV renderer with Android BubbleUPnP, the default is to transcode audio formats the renderer does not claim to support in its protocolInfo (that list can sometimes be bogus with formats missing). For example if you play an ALAC track to a renderer not supporting ALAC, it will be transcoded to either WAV or LPCM if the renderer support these (99% of renderers support one or the other or both).

Moreover, transcoding can also be triggered to enforce some setting in 'More > Settings > Renderer settings (Pick renderer)' such as 'Max supported sample rate', 'Convert 24-bit to 16-bit' and 'Downmix multi-channel to stereo' (all of them being disabled by default). Enabling ReplayGain in the 'Now Playing' tab will also force PCM decoding for tracks that have ReplayGain metadata.

For playing to OpenHome renderers managed by 'BubbleUPnP Server', the same than all the above apply but with settings taken from the BubbleUPnP Server web configuration page for the renderer.

Finally, if you play to an OpenHome renderer not managed by BubbleUPnP Server (such as upmpdcli), all of the above do not apply and Android BubbleUPnP never transcode.

If you notice Android BubbleUPnP or 'BubbleUPnP Server' is transcoding when it shouldn't (taking into account all of the above) let me know and send me a log file.