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+--- Thread: m4a playback (/showthread.php?tid=1198)
m4a playback - jgee@vsgpartners.com - 03-16-2019
I set up Moode on my raspberry pi 3 and connected my Mpow d7 bluetooth headphones through Moode's bluetooth interface.
I can play radio stations and mp3 music files with no problem. Sounds great.
At this point, I am just using the Raspberry PI's inbuilt sound system, no DAC, etc.
But, I get the following error when I try to play an m4a file:
Failed to open "ALSA bluetooth" [alsa]; Error opening ALSA device "btstream"; snd_pcm_hw_params() failed: Invalid argument
I have researched the Web but cannot find a solution. I assume there is a configuration setting I am missing?
RE: m4a playback - TheOldPresbyope - 03-16-2019
(03-16-2019, 06:27 PM)jgee@vsgpartners.com Wrote: I set up Moode on my raspberry pi 3 and connected my Mpow d7 bluetooth headphones through Moode's bluetooth interface.
I can play radio stations and mp3 music files with no problem. Sounds great.
At this point, I am just using the Raspberry PI's inbuilt sound system, no DAC, etc.
But, I get the following error when I try to play an m4a file:
Failed to open "ALSA bluetooth" [alsa]; Error opening ALSA device "btstream"; snd_pcm_hw_params() failed: Invalid argument
I have researched the Web but cannot find a solution. I assume there is a configuration setting I am missing?
@"jgee@vsgpartners.com"
I'm away from my home at the moment so can't test this.
I seem to remember running into something like this before. IIRC, my workaround was to go to MPD Config and enable SoX Resampling with a Sampling rate such as 16 bit/* kHz or 24 bit/* kHz.
See if that helps.
Regards,
Kent
RE: m4a playback - jgee@vsgpartners.com - 03-17-2019
(03-16-2019, 06:52 PM)j gee@vsgpartners.com Wrote: [quote pid='8832' dateline='1552760845']
I set up Moode on my raspberry pi 3 and connected my Mpow d7 bluetooth headphones through Moode's bluetooth interface.
I can play radio stations and mp3 music files with no problem. Sounds great.
At this point, I am just using the Raspberry PI's inbuilt sound system, no DAC, etc.
But, I get the following error when I try to play an m4a file:
Failed to open "ALSA bluetooth" [alsa]; Error opening ALSA device "btstream"; snd_pcm_hw_params() failed: Invalid argument
I have researched the Web but cannot find a solution. I assume there is a configuration setting I am missing?
[/quote]
I figured out the problem. I needed to add format "44100:16:2" to my mpd.conf. M4A files playing fine now.
RE: m4a playback - Tim Curtis - 03-17-2019
Hi,
To which audio output did you add the format statement?
Maybe this should be a config setting.
RE: m4a playback - TheOldPresbyope - 03-17-2019
I regained my memory...http://moodeaudio.org/forum/showthread.php?tid=724&pid=6917#pid6917
There it was certain .wma files in question, which by definition are WMA encoded; here it's .m4a, which really means AAC-encoded. In both cases we don't know what the encoding parameters were.
I've already confessed that the internal audio processing involved in MPD decoders, ALSA, and bluez-alsa is murky to me, but I remember something @borine said in our github bluez-alsa discussion:
Quote:Bluealsa only accepts pcm streams sampled at 48kHz. If the application configures the alsa device with any other sample rate then by default alsa invokes its own internal resampler - meaning that the application is actually interacting with the resampler and not directly with bluealsa.
This implies to me that explicitly defining "44100:16:2" does just this. Hence, do my hack and this hack accomplish the same goal in different ways?
Regards,
Kent
RE: m4a playback - jgee@vsgpartners.com - 03-17-2019
(03-17-2019, 11:36 AM)Tim Curtis Wrote: Hi,
To which audio output did you add the format statement?
Maybe this should be a config setting.
audio_output {
type "alsa"
name "ALSA bluetooth"
device "btstream"
mixer_type "software"
format "44100:16:2"
}