There are no changes in Android 4.4 which improves USB Audio, and Google has not gone public on any such improvements in the future. Basically, it is up to chip suppliers and OEM's to do such changes, which is difficult since the whole Android framework is buiot upon resampling into 48kHz/16 bits.
However, Sony Mobile presented two new products yesterday, the Xperia Z2 phone and T2 tablet, which offers high-res audio over USB, through what we call "Direct mode". Basically we completely bypass the audio framework and send the decoded audio data directly to the USB driver without any processing or any mix-in of notifications, ring signals, et c. We also replace the USB driver and the FLAC decoder, to support 192kHz and asynchronous USB Audio Class 2. The only thing we change in the data stream is that we pad 16 bits to 24 and 24 bits to 32 when required by the DAC. Together this gives us the ability to support replay of FLAC and WAV at any sample rate from 44.1 to 192kHz at either 16 or 24 bits.
This is part of the overall Sony High-Res initiative, by which we want to bring back the excitement of high quality music reproduction and leave hard-compressed MP3 behind us.
As product owner for this feature I will be available in this forum to try to answer your questions and note any criticism we can use to improve our products.
do you have some news about high res files and the xperia range.
I am using xperia z with a usb dac,
today i must use the app usb audio player pro tio get the files played at their native sample rate.
Just got an update on the walkman app but nothig about usb output in it (as seen on z2)
Is it coming with 4.4 maj for xperia z owners ?