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Android and USB audio

In have a question about Android and how it handles USB audio. I know that USB has a unified audio layer that is standardized and requires little in order to be seen and operated by the os. Its that reason why most usb audio class devices are simply plug and play, however some devices require add'l drivers for extra fucntions, i.e. dsp functions. What I'm trying to understand is how Android handles usb audio, does it conform to usb audio class stipulations as well, so audio devices are generally plug and play, or is there something extra that would be required?
I'm asking because I hope to get a G-Tablet this Xmas and use it in my car. I could just use the analogue outs but I want something a bit more robust, and was hoping to get an external usb audio device with multiple outputs. Maybe write a driver if needed depending on the complexity, of course. any help would be appreciated.

USB audio works on my Allwinner A10 tablet witn "Unofficial CyanogenMod 9 for many AllWinner A10 tablets" firmware from Christian Troy

[Q] USB sound card on Android?

I have a Android pad running 2.1 and it has 2 x USB ports and a lousy audio out (3.5 Jack).
I was wondering if USB soundcards work on Android? I am under the impression it is plug&play in linux, and that android uses the same audio driver? (just not via USB).
Beeing able to use a USB soundcard with propper sound would greatly improve sound quality (I want to use my pad in my car) :/

+1
I also want to know about USB sound cards support under Android. I have SB Live 24 (USB) and it works with my ARM-based Asus Wi-Fi router, but what about Android 2.2 and MIDs with USB-host port? ;-)

Anyone tried it?

It could be possible

Any update on this thread, would like to get this for my asus transformer if anyone can confirm it works. http://www.asus.com/Multimedia/Audio_Cards/Xonar_U3/#overview

It could be possible!

I tray it on acer iconia tab a500 and noting happend.
It not working.
It maybe need a driver but i don't see any driver anywere
:-(

USB audio in Android progress
Just for note, it works! I recently added self-compiled snd-usb-audio modules to allwinner based tablet. Found corresponding /dev/snd/* devices. Hard part is to add switch to USB audio to java, if there are no full alsa support in ROM. If alsa used, I need only edit /etc/asound.conf ;-)

tsynik said:
Just for note, it works! I recently added self-compiled snd-usb-audio modules to allwinner based tablet. Found corresponding /dev/snd/* devices. Hard part is to add switch to USB audio to java, if there are no full alsa support in ROM. If alsa used, I need only edit /etc/asound.conf ;-)
Click to expand...
Click to collapse
could you give some more details on how this was done?
USB OTG gets mouse/keyboard/mass storage working, but USB soundcard doesn't get sound through it (though the card is receiving power) and I cant see a way to check if it can see the device.
the USB soundcard I'm using was seen by my linux pc (kernel 3.0.0-15) straight away no drivers or config needed.

Here is a what I found on USB AUDIO output with Android (maybe it makes sense to put and update this table to the first topic)
NOTE: as of now SOME (not all!) USB AUDIO Android support implementations stream data through Android MUX that disturbs the original PCM stream for changing volume which means re-sampling original media, but also limited to 44.1kHz(some 48) 16 bit, so for SOME Android:
1) max all your volume controls while using external DAC
2) there is no reason to have / use DAC with higher rates then 44.1/16
3) there is no reason to have / use files of more then 44.1/16 quality. Trying to play 96kHz 24bit file will result in forcing Android to re-sample it on the fly with limited resources and not perfect algorithms leading to degrading output quality lower then proper done in studio or desktop 44.1/16!
There might be a way bypassing the Android layer and going right to ALSA you can do 24 bit.
If you specify a hardware device ("hw:0") in ALSA you can bypass any potential sample conversions.
*there is way around it in linux ALSA http://blog.agdunn.net/?p=434 but i have not seen such for Android
Supporting Devices
---------
Galaxy S III $700 Android phone
ARCHOS G9 $250+ Android tablet (looks like the key is OMAP chipset kernel drivers)
Squeezebox Touch $250 - propriatary logitech linux box
Ainol Novo 7/8 Advance 8gb 100$ Android tablet or Allwinner with a modded Android kernel
Nook Touch with custom rom
any A10 Android tablet http://www.slatedroid.com/topic/33373-rom-cm9-nightlies/
* Hyundai A7HD tablet with Cm9
* Mediacom 907c, Momo11 Bird, JXD S9000, Eken A90
* Visture V3
* Mediacom 910i, Teclast A10t
* ICOO D90W
* CEMA10N7 "unknown" device
* Bmorn V99
* Mediacom 711i, Momo9
* Protab2XXL
* Sanei N83
* Hyundai A7HD
* MOMO9 needs
http://forum.xda-developers.com/showthread.php?p=22280857#post22280857
http://www.slatedroid.com/topic/29289-usb-audio-cards-support-drivers-and-libs/
. B&N Nook Colour with a modded Android kernel
http://forum.xda-developers.com/showthread.php?t=1459892
. WitsTech A81G with a slightly modded Android kernel
http://android.modaco.com/topic/343858-external-usb-devices/page__st__20
Suported DACs:
for Galaxy S III
List of USB DACs with known USB controller that interwork with Samsung Galaxy S III for the time being:
+ AMB Labs Gamma2 with USB controller TI Burr-Brown PCM2707
+ FiiO E7 with USB controller TI Burr-Brown PCM2706
+ HifiMan Express with USB controller TI Burr-Brown PCM2702
+ Topping TP30 with USB controller TI Burr-Brown PCM2704
+ ODAC Tenor TE7022
List of USB DACs with known USB controller that don't interworking with Samsung Galaxy S III for the time being:
. FiiO E17 with USB controller Tenor TE7022
. iBasso D6 with USB controller TI TAS1020B
. Grant Fidelity TubeDAC-11 with USB controller Tenor TE7022
Hegel HD20 with USB controller Tenor TE7022 has also some issue
Audiotrak Prodigy Cube with USB controller Tenor TE7022
for Archos G9
+FiiO E17
+BEHRINGER UCA222
- E10 not supported
for Ainol Novo 7/8 Advance
+FiiO E7
+Burr-Brown PCM2704 USB DAC
+Creative
for Squeezebox Touch
+ Red Wine Audio Isabellina and an
+ HRT Music Streamer II+.
B&N Nook Colour
+Logitech DAC A-5572A |
+Beresford TC-7520SE Caiman |
+FiiO E7
B&N Nook Touch
+C-Media $5 USB adaptor
+Lexicon Alpha 24 bit adaptor
please reply here if you find more info on DAC/devices suppot so i'll keep this post up to date.

I use either a C-Media $5 USB adaptor or a Lexicon Alpha 24 bit adaptor on my Nook Touch.
By bypassing the Android layer and going right to ALSA I can do 24 bit field recording.
If you specify a hardware device ("hw:0") in ALSA you can bypass any potential sample conversions.

Renate NST said:
I use either a C-Media $5 USB adaptor or a Lexicon Alpha 24 bit adaptor on my Nook Touch.
By bypassing the Android layer and going right to ALSA I can do 24 bit field recording.
If you specify a hardware device ("hw:0") in ALSA you can bypass any potential sample conversions.
Click to expand...
Click to collapse
why you are sure that it is 24 bit coming out of Nook Touch tablet?
what ROM / kernel you are using?
where you specify a hardware device? this should be done editing config file or there is a menu items in settings interface?

I'm sure that it's 24 bit because I can look at the file and see that all the bits are exercised.
Moreover, since the microphone only hits about -30dBFS, I have to crank the gain.
Compared to a 16 bit recording (which is effectively 11 bits when using 30 dB gain), the 24 bits (effectively 19 bits) sounds much better.
The Nook doesn't have any builtin audio, except for Dummy which is hw:0
My application uses hw:1
There's really no need to select the audio adapter because there is usually just the one.

Renate NST said:
The Nook doesn't have any builtin audio, except for Dummy which is hw:0
My application uses hw:1
There's really no need to select the audio adapter because there is usually just the one.
Click to expand...
Click to collapse
I am a bit confused.
can you explain step by step how to archive it on stock NOOK touch?
1)install custom ROM with kernel and USB host support?
2)install specific media player? which one do you use?
3)plug in USB DAC, player will use it as output by default so no hw:0 tweaking needed?

The whole USB host mode on Nook Touch is covered here.
You will need a modified kernel.
The stock mediaplayer works but there is an unresolved bug that you need a little utility app to get over.
You need to put in an asound.conf

Renate NST said:
The stock mediaplayer works but there is an unresolved bug that you need a little utility app to get over.
You need to put in an asound.conf
Click to expand...
Click to collapse
So putting asound.conf from the thread you'd mention will solve it and it will be transparent output 24bit 96khz?
can I use other media player such as Astro or PoweAMP?

The Android layer only supports 16 bits.
The MediaPlayer can not play 24 bit files.
To do anything 24 bit you need an external USB adaptor that supports it and an application that directly uses ALSA.
I believe that there are other 24 bit apps on the market.
24 bit is really only useful for recording when there is a large dynamic range.

Renate NST said:
The Android layer only supports 16 bits.
The MediaPlayer can not play 24 bit files.
To do anything 24 bit you need an external USB adaptor that supports it and an application that directly uses ALSA.
I believe that there are other 24 bit apps on the market.
24 bit is really only useful for recording when there is a large dynamic range.
Click to expand...
Click to collapse
I think we are talking about different use-cases.
My question was on plugging external 24bit/96kHz capable DAC (not ADC) to Android device and playing high quality 16bit/44.1 and higher .flac files using one of android players through that external DAC.
As i understand you've done it at least for 16bit DAC? and even mentioned that there is a way to bypass Android layer to get up to24 bit transparently out to the DAC and can highlight the steps for Nook Thouch to archive it.
Can you share your experience, settings and apps you've used?

Most USB adapters you will find are 16 bit.
To get 24 bit, you have to go to a "pro" interface, M-Audio, Lexicon, whatever.
ALSA supports 24 & 32 bits, but does not directly support MP3 or FLAC.
The Android layer supports MP3 (maybe FLAC?) playback, but not record.
You can get 24 bit playback just by using the ALSA utility aplay on PCM files only.
I do not know what there is on the market for 24 bit record/play.
You'd need an app with a JNI interface to the ALSA library.
I wrote a recording application for the Nook Touch that does that.
I cited it in the thread mentioned.

Renate NST said:
Most USB adapters you will find are 16 bit.
Click to expand...
Click to collapse
Just got stock Nook Simple Touch. Can you guide what steps to do to let it play music to external DAC?

Android tablet to run linux computer

Hey all!
I would like to know if there is a way to create a linux computer, which would communicate to a Android tablet for input/output functions.
Ideally I envision a small (like mini PC) linux computer sitting in my room. The tablet would be dockable to it it- where it would act as a simple touchscreen interface for the linux computer. Press a button, and the tablet can be removed as an Android tablet.
The tablet could access files (like music) on the linux computer and hopefully control something like a sound card also.
Perhaps a linux computer could run android? The tablet portion would simply be a wireless touchscreen essentially.
Any thoughts?

I haven't done much of that, but I'm sure that it is possible. Also, the Lenovo U1 comes close, although that is a laptop with Windows instead of Linux.

the majority of the functions would not be needed through a hardware I/O interface, all you would need is client server software on both devices.. If you really had to use a hardware interface you could use USB host mode i suppose and create a tcp/ip connection but this could be done over WiFi or Bluetooth.
android devices can already control many features of windows box's like vlc remote, xbmc, boxee and many more, it can also control the desktops mouse..
Linux wise, it shouldn't be much different..
You could just create a custom ui with loads of buttons that go to macros on the machine doing things like volume 0 -50 -100% etc

The lenovo U1 is tight!
What about more of the tablet just being the remote for a computer basically.
Take sound processing for instance- Android only does 2 channel and has very little in processing abilities- power amp is the most I've seen.
In a computer environment however, you can have way more channels, and lot more options like crossovers, time delay, parametric EQ, filters, etc. Things I doubt are possible on an android since they often require sophisticated sound cards not to mention eat up battery if they were possible.
What I want is to have a computer do that processing work, but have a simple tablet control the programs on the computer. I'd prefer to not have a custom UI since I like how people are very comfortable with android and it works very well. Also- perhaps you could use your phone to also control the computer.
I envision this:
A user would be laying in their bed, grab the tablet and select some music from the computer hard drive. Then they could control the sound and playback devices from the tablet. The processed sound from the computer goes to a home receiver as a digital signal, and the room fills with perfect sound. Then they decide they want to watch a blue ray. They toss it in the computer and it plays on their tablet with the sound coming from the receiver.

Have you thought about running vnc. or another type of remote desktop software , you could have the desktop wired up to the receiver etc , and just tell the computer to play the music or movie from the tablet .
Most remote desktop software have very crappy frame rates so playing back video this way kinda sucks but logmein ignition does surprisingly well on my tab211 when controlling my mac to do very similar things
( sorry I missed that post from anarchyuk completely , I was reading through pretty quick and missed it , so you can ignore this post )

Sounds like what I do with my android tablets via Skifta (free on Android Market0 using DLNA protocol.
Skifta app is installed on my EVO3D phone, Kindle Fire (running ICS Beta), and TF201.
When Skifta starts, you select your media source. In my case, 10TB Synology 411j running built-in DLNA media server.
Then select the Playback device. Which could be the tablet itself, my HTPC (XBMC/win7 connected to my home theater), or straight to my TV (Samsung LN46C750 has ethernet and accepts DLNA push request.)
Once source and playback targets are set, I just browse to whatever music or video I want and boom,it plays.
Highly recommend the Synology rigs. They also have built-in Dynamic DNS and OpenVPN server. Their DS Audio app (also free) allows my phone to connect back to my NAS over cellular network and play any song on the NAS via streaming.
Heck, if you plug an USB sound card like the SIIG audiowave 7.1 into the Synology's USB port, it can be an DLNA audio playback device, too.

Webtop to Netbook (NOT Lapdock)

OBJECTIVE:
Webtop from Atrix 2, via standard HDMI, to standard laptop HDMI input.
PROBLEM:
Most HDMI ports on laptops are output only.
SUGGESTED SOLUTION:
HDMI to USB or HDMI to IP converters. not sure this even exists
Update to this post:
The original product link was in error (pointed out by "IceFragmatic"). As suggested by IceFragmatic, most USB video INPUT for laptops/netbooks, are intended as capture devices, although I am not sure what he means by "due to DCHP", regarding HDMI being a very rare capture source.

Has anyone attempted this?

The item you link to is USB to HDMI...again outout only.
You would need to use a capture device (which for HDMI is very rare due to DCHP)
Why not just buy a cheap screen with DVI and/or HDMI input?

I know that for the last few years, that there have been a small handful of expensive giant laptop PC's that provide for HDMI INPUT (yes, input), but there are as yet no netbooks or UMPC's that have a means to provide this .... would you agree with that statement?
(this is interesting from a hardware perspective, not necessarily from a business strategy perspective)

You're better off just using a VNC server program on the phone and a VNC client on the netbook while connected to a solid wifi. That will allow you to control the linux environment running on your phone from your laptop and doesn't require expensive video capture hardware. One does not simply use one's netbook as a monitor.

Sorry, should have referred to HDCP (not DCHP).
HDCP is a copy protection protocol used to stop digital copying of comercial DVDs and some TV streams.
The movie studios and owners of the HDMI licences do not want HDMI recorders without some form of protection to stop copying of DVDs. If this copy protection did not exist you could make perfect copies of DVDs and BluRay. Therefore HDCP has be introduced. This makes HDMI input/recorders useless for anything but home-made movies (and therefore not a big seller).
Your homework is to read the following....
http://news.cnet.com/8301-17938_105-9870317-1.html
John

Question Newb (to Pixels) question: Is there any way to support multiple external monitors?

I really want to buy a rootable android and Pixels seem to be the way to go. However, I'm reading conflicting info about whether or not I'll be able to use 1-2 external monitors with the Pixel 7 Pro. I hoped this wouldn't be necessary.
I'd really like to replace my laptop with a phone that's capable to using 1-2x external monitors (4k resolution not necessary but would be amazing as well - 1080p would be plenty).
From what I see, using a displayport dock via USB-C can enable at least 1 HDMI output:
Project your Pixel phone's screen - Pixel Phone Help
If you have a Chromecast or other device that casts, you can mirror your Pixel phone's screen and audio on
support.google.com
>Tip: Pixel 3 and later Pixel phones work with the MediaGear USB-C Hub Docking Station (item 853265008171). Other docking stations can also work.
Can someone please confirm this is possible and let me know which dock they're using? Also, is there any chance I could use 2 HDMI outputs through the same dock? Or perhaps one USBC-Displayport-HDMI connection + 1 Chromecast connection to enable 2x monitors?
I'd love to be able to code using a bluetooth keyboard/mouse and skip having the carry my laptop around entirely. I have a 1440p portable/external monitor that works wonderfully for both my laptop and my LG V50 ThinQ.
2x monitors would be my dream; the portable external monitor I have is amazingly light and works great (and supports display over USBC and MicroHDMI - plus power over another USBC port). So I'm sure I'd need to plug in in order to operate these for any extended periods but anyway:
Does anyone have experience with this they can share?
Thanks for any/all help. I'm a dev myself so if the solution to this is a custom rom, I'd be happy to contribute to the solution if anyone's working on one.

I will say: My LG V50 ThinQ USBC to USBC video works really well on my portable monitor... So it may be possible to patch that feature into a pixel kernel.
I will definitely look into it once I have the time, if no one else has any hints/progress on the subject.

I will say "technically"... yes. Practically however, nobody has actually bothered.
Should be just a matter of making sure the kernel is built with support for GUD and setting up a monitor with a GUD interface (such as an rPi with the GUD sdcard).

Pixels do not support native, hardware-accelerated video-out.
Any old dock won't work. Only DisplayLink ones and expect performance to be poor.

LLStarks said:
Pixels do not support native, hardware-accelerated video-out.
Any old dock won't work. Only DisplayLink ones and expect performance to be poor.
Click to expand...
Click to collapse
Not to mention, streaming like Netflix and Hulu won't show. I tried several DisplayLink adapters which claimed HDCP compliance (including this one:
https://www.amazon.com/gp/aw/d/B072FHTZ8V
with the DL6950 chip:
https://www.synaptics.com/products/displaylink-graphics/integrated-chipsets/dl-6000 )
But I could never get any streaming services to work (just black screen once playing started). The rest was acceptable quality (although I wouldn't expect to be able to play games without significant lag and screen tearing). If you find a set up that also works with streaming, please let me know. I'd be very interested in adopting something similar.
***Edit: from DisplayLink's site:
"As the DisplayLink is an app from the Play Store, Android prevents any protected content from video streaming services eg Netflix, Amazon etc, being available to the DisplayLink app. This is an Android restriction to make sure that protected content remains protected and is not available to other applications."
Known issues and limitations with DisplayLink for Android – DisplayLink Support
support.displaylink.com
Maybe there is a root workaround, I don't know.

Didn't even know that. Wow.
I still don't forgive Google for removing Miracast.
I really do like Google Cast but that was really anti-consumer.