noises when playing music and when seeking

[tsiros]

apparently these things are unable to even play music properly

latest firmware, latest walkman update as of half an hour ago

this is what happens every minute or two:

always two missing samples always 5 milliseconds apart

for months i thought my ears or my files had problems... until i sat down and investigated. turns out my files and my ears are fine, but the phone just can't play music without failing. jesus christ it's 2015, we have four cores, 2+ GHz and 2 GB of ram... this is not acceptable. We're not talking about details here, we're talking about the device failing to play a song from beginning to end without errors.

Onto the next one

noise when seeking

this is what happens whenever you seek in a song:

first of all it's the gap which creates unwanted noise, instead of smoothly transitioning from end to start.

second, is the completely irrelevant waveform before the song continues where you tapped.

in total, this creates a crack whenever you seek.

this behaviour is completely unacceptable. winamp for about a decade now has solved this issue and even has options how to handle it . What is sony's excuse? will you fix it?

Of course the sound issues on the z ultra are not limited to this problem only. Sound on the z ultra is problematic in general.

[Phy]

Take a look at this


http://talk.sonymobile.com/t5/WALKMAN/Walkman-Beta-Test/m-p/953659#U953659

You can contact walkman developers directly

[tsiros]

it's a problem with the soundcard device driver, not the walkman application.

[sjesudasan]

I don't have any problem with my z ultra playing music. I always play 1000kbps flac files. What is the music file extension and bitrate you are trying to play?

[tsiros]

the file format is irrelevant. Any audio file will produce this. It is very difficult to notice if you don't have sensitive ears. Only way to objectively verify that the problem exists is to record the z ultra playing a file and observing the waveform.

use adobe audition or cooledit pro and create a 440 Hz tone, about 10 minutes long and with -6 dB amplitude and transfer it to the phone.

use a male-to-male adapter and connect the headphone out of the phone to the computer's line-in

play the tone on the z ultra, set it on repeat. start recording at 48 KHz and adjust the volume so that it does not clip.

let it play and record for at least 10 minutes. set adobe audition (or cooleditpro) to display the frequency spectrum. 

This is what the frequency spectrum looks like when it loses the samples, look on the right (vertical purple line indicating noise) of the cursor (yellow dotted line)

the waveform zoomed in at the problem point looks like the one above.

I hope i made it clear.

[sjesudasan]

Did you try testing with poweramp and with good amount of buffer?

[toothpaste]

same behavior with maximum buffer (+750 ms) and highest priority in poweramp.

same exact behavior in all players i have tried until now: vlc, poweramp, walkman, deadbeef

[toothpaste]

Description of glitch on xperia z ultra running stock android 4.4.4 (14.4.A.0.108)

Every 2 minutes and 54 seconds, a noise is introduced to music.

Reproducing the glitch

This is for the xperia Z ultra, but every phone can be tested the same way.

1. Set the volume to maximum. Doesn't have to be uncomfortable, but the higher it is, the easier it is to tell when it happens. Note that if you plug headphones after setting the volume, you must set the volume again. With the loudspeaker just set it to maximum. With headphones, just half is enough. Headphones or loudspeaker, it doesn't seem to matter, the glitch always happens.  Optimally, a male-to-male 3.5 mm adapter cable connecting the device's headphone out and a computer's line-in should be used and the phone's output recorded.  
2. Download this audio file to the phone under testing. It is a 44.1 kHz, 16 bits per sample, stereo, 4 minutes long, 75 Hz sinusoidal tone. A very long, bass beep with high quality.  
3. Load it into your prefered music player. VLC, deadbeef, walkman, poweramp, all the music players i have tried so far produce the glitch.
4. After everything has been set up, wait at least five seconds before pressing "play". This is to verify that the audio subsystem has powered down. The glitch happens at a specific time after the sound subsystem has been running continuously.
5. Press play and wait. Try to not use the phone otherwise. Just look at the player. It is ok if the screen turns off, I think. Put your ear near the loudspeaker. It's on the bottom right corner. You can hear a continuous hum. This is the normal sound of the file. This is what 75 Hz sounds like.
6. Exactly 2 minutes and 54.7 seconds after starting playback, there should be a *tic*. This is how it looks when recorded.
7. If you do not trust me, you can load it up in adobe audition/cooledit pro/audacity and look at the audio to verify that i did not do anything funny.
8. To verify that i did not insert the glitch in there myself, you can either check the waveform with an audio program, listen to it on your computer with winamp or just rewind to the spot you did hear the glitch.

What to do if you did not hear anything interesting

Try the same process, exactly, but use only this file instead and wait for 3 minutes and 10 seconds (instead of 2 minutes and 54 seconds). The reason for this is explained later.

What to do if you did hear it

I do not know. It might have been fixed in android 5.0 and later. Possibly. Maybe.

Comments

I am pretty sure this is a problem with the resampler. The z ultra plays at 48 kHz. The sound file is 44.1 kHz. It resamples the sound from 44.1 kHz to 48 kHz before sending it to the amplifier. When playing a 48 kHz file the glitch doesn't happen.

Crystalaudio+ has no effect on whether the glitch will happen, but it changes how it will happen. This is because CA+ is in the audio chain after the resampler.

Every 2^23 (8388608) samples, or 2 minutes and 54.7 seconds, two samples will be lost, these two samples being 160 samples apart (1/300 seconds or 3.333 milliseconds). The result, depending on what kind of music is being played, is a *tic* or *pop* noise.

Thank you for your attention.

[Rickard]

Sorry to hear that you have audio issues.

It's not something i've heard of but i'll forward your information and see if can get more information about this.

[Rickard · Accepted solution]

I've received more information about this and this should not happen in Android 5.0 so please update your phone when it's available for your unit.