add native USB DAC playback / direct access (v3, 2019)

[givoltage]

Up till the latest version (v3-build-826-play), hi-res output sampling rate on my galaxy S8 relies on software resampler. All sources are resampled to 48khz (by default, or a specified rate up to 192khz) and passed onto the USB DAC. I've looked through the settings extensively and don't think native playback is supported. Selecting anything higher than 192khz only results in 192khz, while my DAC supports 384khz.

In contrast, Neutron player has long had the option called "direct USB access", and does output at the original sampling rate of the source without any resampling. The stream is sent directly to USB DAC for decoding. If I play a 44.1khz file, the DAC shows 44.1khz; if I then play a 192khz file, the DAC shows 192khz correctly.

It is clearly possible to implement this feature in android as Neutron has demonstrated. The OS does allow direct access to USB DAC despite fixing system sampling rate at 48khz. It would be a very useful addition to Poweramp.

An example of the desired behaviour is shown in the attached screenshot. With USB DAC plugged in, when "direct USB access" is enabled in the player, the OS prompts for permission. Once permission is granted, playback becomes native and volume buttons of the phone can no longer change the volume.

[wolfield]

Inability to properly work with USB DAC's is a deal breaker for me so I had to purchase Neutron instead, even though I liked the feel of Poweramp.

Using builtin Android USB driver and Poweramp with Meizu HiFi DAC Pro gives me only a halved output level of around 1V RMS, while UAPP and Neutron with direct access provide me with the full capability of my DAC and the level of 2.25 Volts RMS. Poweramp + USB DAC is a useless junk at this point, since I need at least 2V to drive my 250 Ohm phones.

To my impression it's a mandatory feature, since the output level in Android is limited more and more due to bullshit regulations.

[wolfield]

If Poweramp will implement direct access it will receive a big piece of USB Audio Player PRO user base, since UAPP has a very poor UI with limited features. You should consider it for the sake of your profits and new sales.

[haddy]

I agree. Furthermore there is another feature from Neutron I really want.

[wolfield]

I guess the problem is that Max programs in Java only and doesn't know low level stuff and native Linux hardware access.

[of them]

Need native Dac playback too. More and more phones are missing headphone jack, with dac as the only option to play stuff. 

[andrewilley]

11 minutes ago, of them said:

Need native Dac playback too. More and more phones are missing headphone jack, with dac as the only option to play stuff. 

As long as a DAC is supported by the device's Android/firmware, PA already supports it. PA does not drive hardware directly though, there are too many varying devices out there in the real world to be able to do that.

Andre 

[of them]

Yes, PA can play sound though tbe DAC, but audio quality is not that great. Also, other apps like USB Audio Player are asking for direct usb access, and the sound quality is vastly better. Tested it with multitude of various dongles/usb dacs, behavior is quite consistent for both players. No idea how UAPP managed to support all these dacs i tried on it but it always works for me.

Does something like "universal/generic usb audio driver" exist on Android? It does on Windows/Mac, almost every dac nowadays works without installing custom driver

 

P.S. e.g. https://m-audio.com/kb/article/1706