Amp+ streaming radio problem

I'm running two identical RPi 2 Model B, both running identical distros of OSMC with the same radio add-on- only difference is one is HDMI audio, while the other runs through an Amp+. The Amp+ build is intended primarily as an internet radio, so this is a significant issue.

Some streamed radio sources work fine through both, while others yield nothing but static through the Amp+. There doesn't seem to be a pattern as to bitrate, etc., and the logs are clean with no substantive differences.

Is there something I'm overlooking here?

Not working:

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NOTICE: -->Python Interpreter Initialized<--
NOTICE: [xbmcswift2] Request for "/station/19407" matches rule for function "get_stream_url"
NOTICE: [plugin.audio.radio_de] get_station_by_station_id started with station_id=19407
NOTICE: [plugin.audio.radio_de] __api_call started with path=broadcast/getbroadcastembedded, param={'broadcast': '19407'}
NOTICE: [plugin.audio.radio_de] __urlopen opening url=http://rad.io/info/broadcast/getbroadcastembedded?broadcast=19407
NOTICE: [plugin.audio.radio_de] get_stream_url result: http://flume.opb.org/radio_lbr.mp3
NOTICE: Thread ShoutcastFile start, auto delete: false
NOTICE: Thread FileCache start, auto delete: false
NOTICE: Thread ShoutcastFile start, auto delete: false
NOTICE: Thread FileCache start, auto delete: false
NOTICE: Thread PAPlayer start, auto delete: false

Working:
********************************************************
NOTICE: -->Python Interpreter Initialized<--
NOTICE: [xbmcswift2] Request for "/station/19407" matches rule for function "get_stream_url"
NOTICE: [plugin.audio.radio_de] get_station_by_station_id started with station_id=19407
NOTICE: [plugin.audio.radio_de] __api_call started with path=broadcast/getbroadcastembedded, param={'broadcast': '19407'}
NOTICE: [plugin.audio.radio_de] __urlopen opening url=http://rad.io/info/broadcast/getbroadcastembedded?broadcast=19407
NOTICE: [plugin.audio.radio_de] get_stream_url result: http://flume.opb.org/radio_lbr.mp3
NOTICE: Thread ShoutcastFile start, auto delete: false
NOTICE: Thread FileCache start, auto delete: false
NOTICE: Thread ShoutcastFile start, auto delete: false
NOTICE: Thread FileCache start, auto delete: false
NOTICE: Thread PAPlayer start, auto delete: false
NOTICE: Thread LanguageInvoker start, auto delete: false

********************************************************

HiFiBerry team February 15, 2016 05:19

The Amp+ doesn't support samplerates below 44.1kHz. Some radio stream use lower sample rates. You need to upsample them to 44.1 or 48kHz first.

Best regards,
Daniel

Steve Emerson February 15, 2016 05:33

Yep, that's it, the culprits were 24 and 32k sample rates.

hifi February 15, 2016 06:16

How can I upsample? If I use 'mpd' should it be done in 'mpd' or 'alsa'?

Thanks!

Edited by hifi February 15, 2016 06:17

HiFiBerry team February 15, 2016 06:19

In mpd, you can fix the sample rate in the configuation and resample. Check the mpd documentation.

hifi February 15, 2016 17:36

I found the following mpd parameter:

auto_resample <yes or no>Setting this to "no" disables ALSA's software resampling, if the hardware does not support a specific sample rate. This lets MPD do the resampling. "yes" is the default and allows ALSA to resample.

So hopefully setting it to yes (which is default) should enforce software resampling:

audio_output {
	type "alsa"
	auto_resample "yes"
}

Could you give URL to the station which uses 24 or 32K rates? I'd check that
it works in my player.
Thanks!

Amp+ streaming radio problem

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