Quick Question about Android Auto Hi-Res.

[Rowdyhorse4]

Hey ho!

Quick question to the community. Does Poweramp v3 Output Hi-Res via Android Auto to the car's headunit/audio system? or is it just at CD quality?

[andrewilley]

That would depend on the particular device. If I understand it correctly, audio doesn't actually go via the USB connection anyway, but is routed through the Bluetooth connection, but I could be wrong. Some high-end BT devices support high-res, but most don't. 

Andre

[Rowdyhorse4]

56 minutes ago, andrewilley said:

That would depend on the particular device. If I understand it correctly, audio doesn't actually go via the USB connection anyway, but is routed through the Bluetooth connection, but I could be wrong. Some high-end BT devices support high-res, but most don't. 

Andre

when i first used AA, i thought that as well but from my experience (with the new Mazda's Bose and BMW's Harman Kardon w/ iDrive 7) i think it actually routes through the USB and/or WIFI-Direct (For Wireless Android auto) considering that in both cars, the BT is registered to only be used for telephony with music audio disconnected when AA is connected. and i can definitely hear the difference with AA vs BT. Though question is, is does Poweramp stream hi res to AA or is it stuck with the standard 16/44.1khz mode?

[maxmp]

@Rowdyhorse4 from my testing, the approach used by Android Auto is always re-encodes audio into lossy format, so any hi-res output makes little sense (it just adds extra processing to resample it back to 44.1 or 48kHz).

[Rowdyhorse4]

Ooh Really? damn. I was told that it was lossless PCM by people irl and google forums. good to know, thanks for the info max

[andrewilley]

My own honest (if perhaps cynical) take on car stereo playback is that there's road noise, wind noise, engine noise, other vehicles... etc, etc. And probably an underpowered amplifier and crap speakers vibrating in the doors.

There's no way that anyone can actually tell the difference between CD quality and high-res while driving - you're probably lucky to hear it at all!

Andre

[iamgabrieler]

Hi! I know Android Auto a fair bit, so allow me to explain some things.

Android Auto does output audio via USB when connected in wired mode and via Wi-Fi when connected Wirelessly.

Bluetooth is not used for media streams in Android Auto. It's used for routing phone calls to the car and for comunicating WiFi SSID + Encryption key to the phone for wireless connection. 

Android Auto has a AAC Encoder which outputs in MP4A-LATM at 512000 bits per second. Basically Android Auto takes the whole audio processing and whatever it receives from a media stream it outputs it to the car with its encoding solution. 

 

[Rowdyhorse4]

13 minutes ago, andrewilley said:

My own honest (if perhaps cynical) take on car stereo playback is that there's road noise, wind noise, engine noise, other vehicles... etc, etc. And probably an underpowered amplifier and crap speakers vibrating in the doors.

There's no way that anyone can actually tell the difference between CD quality and high-res while driving - you're probably lucky to hear it at all!

Andre

you're probably right. Could be just my internal biases kicking in making me believe i'm enjoying it more (which is fine by me then haha)

For most cars you are right, Car speakers taken from generic Speaker maker XYZ and stuff...  but on the higher end luxury cars now with their superb external noise isolation and speaker design with whopping power. it actually sounds great imo at least. the BMW 8 Series gran coupe with the 1500w Bowers & WIlkin set up/ S class w/ 1800w Burmester or even the cheaper Mazda 3 with Bose sounds great (not as good as an actual studio though) [last i tested these cars was using a USB Removable device with music stored in]

but for the most part yeah you're right.

Edited April 19, 2021 by Rowdyhorse4

[Rowdyhorse4]

8 minutes ago, iamgabrieler said:

Hi! I know Android Auto a fair bit, so allow me to explain some things.

Android Auto does output audio via USB when connected in wired mode and via Wi-Fi when connected Wirelessly.

Bluetooth is not used for media streams in Android Auto. It's used for routing phone calls to the car and for comunicating WiFi SSID + Encryption key to the phone for wireless connection. 

Android Auto has a AAC Encoder which outputs in MP4A-LATM at 512000 bits per second. Basically Android Auto takes the whole audio processing and whatever it receives from a media stream it outputs it to the car with its encoding solution. 

 

wow really? MP4A AAC? that sucks. what about Apple carplay?

[iamgabrieler]

@Rowdyhorse4

4 hours ago, Rowdyhorse4 said:

wow really? MP4A AAC? that sucks. what about Apple carplay?

I'm sorry but I really don't know. 

[andrewilley]

On 4/19/2021 at 10:16 AM, iamgabrieler said:

Android Auto does output audio via USB when connected in wired mode

Mine doesn't appear to, it seems to send the audio via BT not via the USB cable. If I disconnect the BT, the audio stops until Android Auto re-enabled and re-connects BT after a few second, then playback resumes.

My head-unit connects at 44.1kHz/16-bit SBC, and offers no other options (either in Poweramp or Android Developer Options). But I guess it's down to the individual manufacturers.

Andre

[Kutt 1977]

When the audio format is not supported it will be down sampled (16bit - 48kHz)