Best re-sample quality in MPD/Alsa

otec

I'm running Odroid C2 with external XMOS and DAC. C2 is connected to XMOS via USB.

I'm using MPD via ALSA to play MP3s at 32bit/192khz.

I would like to configure Alsa to use SRC re-sampler at the best quality.

My asound.conf looks like:

pcm.sl32 {
    type rate
    slave {
        pcm "hw:1,0"
        rate 192000
        format S32_LE
    }
    converter "samplerate_best"
}

It works, but I'm getting stuttering/crackling sound and MPD CPU usage is at 100%.

If I change converter to "samplerate" it works all fine, sound is okay. CPU usage ~30%.

If I reconfigure MPD to use pulseaudio and use:

resample-method = src-sinc-best-quality
default-sample-format = s32le
default-sample-rate = 192000

It works better, but occasionally sound stutters.

Is there some parameters to tune in regards to buffer size or something to make best converter workable ?

silvrr

Why are you re-sampling MP3s to 32/192? There is no reason for up sampling your music.

otec

Yes there is, it sounds much better.

Sent from my Nexus 6P using Tapatalk

hondagx35

Hi otec,

Yes there is, it sounds much better.

From technical perspective this is impossible.
Putting a porsche engine in a volkswagen may be fun, but will not make a porsche.

Frank

ACX

The only good reason for upsampling your source is when you use a DAC which works with automatic upsampling (i.e. 24/192), but the resampling hardware is poorly implemented. Only in this case it's preferable to leave that operation to the software, otherwise it's a waste of CPU and you are possibly degrading the signal with the resampling.

otec

I run DAC that supports such freq. so hence I'm doing this.

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