Audio Output

[hhamster]

hi all of music collection is 24 bit 88.2 / 96khz flac 

i can play the files using poweramp but when playing back through mhl my dac says its 16 bit 48khz and i have read that the kernal converts all audio to 16 bit 44.1khz

how come the likes of lg & iBasso can produce a kernal that doesnt downsample everythink but sony cant

is there a way to stop the downsampling without rooting/custom kernal/custom rom?

also if i get a wifi airstream player would the files be downsampled or would it be the proper bitrate?

cheers

HH

[hhamster]

ive just rememberd seeing this at the bristol sound and vision show

NWZ-ZX1 Walkman

so you already have the software available for android 4.1 so why not port it over to the Z1 & Z2?

[jeroensky1972]

Hey HHamster.

Nice to see i'm not the only one that uses wonderful lossless audio on the Xperia Z1. (i only use mp3 for ringtones )

Anyway, interesting to see what you write about what your amplifier shows as input.

My ears hear the same, see this topic i started.

Can you try something, just to see if their is a difference?

I assume you also use the walkman function.

goto:

menu > settings > sound > sound effects > and turn it all off.

So no clearaudio+ and no dynamic normalizer. (i don't understand why people use dynamic normalizer anyway, but that's a different story).

With the soundeffects off play the FLAC 24 bit file again, and check what the amp shows. is it still 16bit?

If so, try this:

Install VLC app. and play the flac with vlc, what does the amp shows?

I think the bluetooth profile do send 24bit, because i really hear differences between flac 16bit recording and flac 24 bit(from 24bit source of course) on my Bluetooth stereo headset with 2 inch drivers.

By the way, the used bluetooth profile on the Xperia Z1 supports 5.1 audio. Do you know what codecs are supported on the Z1 for 5.1 audio?

Flac is only stereo, but AAC (Advanced Audio Coding, *.m4a=unprotected *.m4p=drm'd) in mp4 container is supported on the phone. Does it play 5.1 over bluetooth with 5.1 aac source file?

My Bluetooth headset is stereo with no display that shows input signal, that's why i ask you this.

Thanks for checking out.

[hhamster]

Hi not currently at home so can't try what you suggested but 5.1 flac is available there are some test files here

http://www.linnrecords.com/linn-downloads-testfiles.aspx

not tried vlc or walkman I use poweramp for 88.2 & 96khz and deadbeef for 192khz

the downscaler is part of the android core system as standard but a developer can modify the system to make it compatible with hq audio

due to that I don't think the app used will make any difference but I will try it later just incase

[hhamster]

just found this information but it doesnt stat bluetooth so you may be onto something if you are correct and bluetooth isnt restricted then i will be getting a Chord Electronics dac

It appears that the system file 'audio_policy.conf' may be of use here. I've opened it using Notepad

This is a couple of snippets of the code which could possibly be modded, perhaps adding in higher sample rates and bit depth:-

audio_hw_modules {
primary {
outputs {
primary {
sampling_rates 44100|48000
channel_masks AUDIO_CHANNEL_OUT_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_EARPIECE|AUDIO_DEVICE_OUT_SPEAKER |AUDIO_DEVICE_OUT_WIRED_HEADSET|AUDIO_DEVICE_OUT_W IRED_HEADPHONE|AUDIO_DEVICE_OUT_ALL_SCO|AUDIO_DEVI CE_OUT_EXTERNAL_WIFI|AUDIO_DEVICE_OUT_ANLG_DOCK_HE ADSET
flags AUDIO_OUTPUT_FLAG_PRIMARY}

hdmi {
sampling_rates 44100|48000
channel_masks dynamic
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_AUX_DIGITAL
flags AUDIO_OUTPUT_FLAG_MULTI_CH
}

lpa {
sampling_rates 8000|11025|12000|16000|22050|24000|32000|44100|480 00
channel_masks AUDIO_CHANNEL_OUT_STEREO|AUDIO_CHANNEL_OUT_MONO
formats AUDIO_FORMAT_PCM_16_BIT
devices

[hhamster]

hi Jeroensky can i please ask where you found out about the bluetooth spec for the z1?

i only ask as i can only find generic bluetooth spec which says mono/stereo 16bit 44.1/48khz 320kbps

cheers

[jeroensky1972]

Well I used 5.1 AAC audio (*.m4a) on my older Samsung Note I. I ripped them from DVD-Audio discs. When i listen to them on bluetooth stereo headset i saw 5.1 at bluetooth icon.

Since the Xperia Z1 is newer i suppose it can do it to, because it's related to A2DP.

A2DP:
Each A2DP service is designed to uni-directionally transfer an audio stream in up to 2 channel stereo, either to or from the Bluetooth host. This profile relies on AVDTP and GAVDP. It includes mandatory support for the low-complexity SBC codec (not to be confused with Bluetooth's voice-signal codecs such as CVSDM), and supports optionally: MPEG-1, MPEG-2, MPEG-4, AAC, and ATRAC, and is extensible to support manufacturer-defined codecs, such as apt-X. Some Bluetooth stacks enforce the SCMS-T digital rights management (DRM) scheme. In these cases, it is impossible to connect certain A2DP headphones for high quality audio.

Mpeg4 + AAC + ATRAC have multichannel support. (Atrac is Sony only)

I'm at work now so cannot give more details. If you like i can upload a 48KHz 5.1 AAC file on mega.co.nz

[hhamster]

Hi I tried the Walkman, vlc, poweramp & deadbeef apps with 44.1, 48, 88.2, 96, 176.4 & 192khz flac files
Walkman & poweramp only play upto 96khz where as vlc & deadbeef played all of them including the 24 bit 88.2khz 6 channel flac file

The denon amp said that the output was always 48KHz pcm
Checked the ps3 on same amp & dvd it was 48KHz (same) cd it was 176.4khz

Was going to pick up my bluetooth interface to try but left it in my car

"A2DP:
Each A2DP service is designed to uni-directionally transfer an audio stream in up to 2 channel stereo"

That's why I was surprised you said it was 5.1

Does anyone know if a wifi (direct streamer) or usb dac can get a original bitrate?

Can purexaudio be put on the phone without rooting?

Cheers
HH