Strange Image Reversal

Hi,

Has anyone else encountered this odd effect. Listening to a flac file
of a jazz piano trio with the drums on the right. Suddenly the drums
are on the left, then a few seconds later they are back on the right.

The player is a Raspberry Pi with HiFiBerry DAC + Pro.

There is nothing wrong with the file which plays ok on the Mac

I suppose it could be a flac decoding error or perhaps a hardware error
with the I2S clocking.

Arthur

--
real email arthur at bellacat dot com

On Sun, 5 Mar 2017 14:23:17 +0000, Arthur Quinn
wrote:

Hi,

Has anyone else encountered this odd effect. Listening to a flac file
of a jazz piano trio with the drums on the right. Suddenly the drums
are on the left, then a few seconds later they are back on the right.

The player is a Raspberry Pi with HiFiBerry DAC + Pro.

There is nothing wrong with the file which plays ok on the Mac

I suppose it could be a flac decoding error or perhaps a hardware error
with the I2S clocking.

Arthur

I've never heard anything like that. If it is a decoding error you've
suffered an unbelievably rare error in so many numbers being wrong by
exactly the right amount to perform a 16-bit word shift without any
checksum flagging the problem.

Is it repeatable, or did it just happen the once? If it is repeatable,
perhaps you could put the file somewhere we could download it.

d

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On 05/03/2017 14:29, Don Pearce wrote:
On Sun, 5 Mar 2017 14:23:17 +0000, Arthur Quinn
wrote:

Hi,

Has anyone else encountered this odd effect. Listening to a flac file
of a jazz piano trio with the drums on the right. Suddenly the drums
are on the left, then a few seconds later they are back on the right.

The player is a Raspberry Pi with HiFiBerry DAC + Pro.

There is nothing wrong with the file which plays ok on the Mac

I suppose it could be a flac decoding error or perhaps a hardware error
with the I2S clocking.

I2S clocking error sounds right - except I2S word clock is high for one
channel, low for the other. I can't see how it could be in the I2S bus.


Arthur

I've never heard anything like that. If it is a decoding error you've
suffered an unbelievably rare error in so many numbers being wrong by
exactly the right amount to perform a 16-bit word shift without any
checksum flagging the problem.

Is it repeatable, or did it just happen the once? If it is repeatable,
perhaps you could put the file somewhere we could download it.

That is of course the big question. IMHO if it's repeatable it must be a
SW bug.

Andy

On 2017-03-05 21:32:31 +0000, Vir Campestris said:

On 05/03/2017 14:29, Don Pearce wrote:
On Sun, 5 Mar 2017 14:23:17 +0000, Arthur Quinn
wrote:

Hi,

Has anyone else encountered this odd effect. Listening to a flac file
of a jazz piano trio with the drums on the right. Suddenly the drums
are on the left, then a few seconds later they are back on the right.

The player is a Raspberry Pi with HiFiBerry DAC + Pro.

There is nothing wrong with the file which plays ok on the Mac

I suppose it could be a flac decoding error or perhaps a hardware error
with the I2S clocking.

I2S clocking error sounds right - except I2S word clock is high for one
channel, low for the other. I can't see how it could be in the I2S bus.


Arthur

I've never heard anything like that. If it is a decoding error you've
suffered an unbelievably rare error in so many numbers being wrong by
exactly the right amount to perform a 16-bit word shift without any
checksum flagging the problem.

Is it repeatable, or did it just happen the once? If it is repeatable,
perhaps you could put the file somewhere we could download it.

That is of course the big question. IMHO if it's repeatable it must be
a SW bug.

Andy

I have now been told that it is a software problem in an older version
of the Linux kernel so it has been cured by upgrading.

I presume that it was a glitch causing a reversal of the phase of the
I2S left-right clock relative to the data.

Arthur

--
real email arthur at bellacat dot com

No but then I've never tried it that way.
Flac I thought was merely just a file compression technique, ie not really
a codec. Its wav inside surely?

Do wavs exhibit this issue?
Maybe the processing is just too much.
Brian

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"Arthur Quinn" wrote in message
news
Hi,

Has anyone else encountered this odd effect. Listening to a flac file of a
jazz piano trio with the drums on the right. Suddenly the drums are on the
left, then a few seconds later they are back on the right.

The player is a Raspberry Pi with HiFiBerry DAC + Pro.

There is nothing wrong with the file which plays ok on the Mac

I suppose it could be a flac decoding error or perhaps a hardware error
with the I2S clocking.

Arthur

--
real email arthur at bellacat dot com

My feeling is that there is an option in the decoder or other software to
reverse channels and its somehow being messed with.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Vir Campestris" wrote in message
...
On 05/03/2017 14:29, Don Pearce wrote:
On Sun, 5 Mar 2017 14:23:17 +0000, Arthur Quinn
wrote:

Hi,

Has anyone else encountered this odd effect. Listening to a flac file
of a jazz piano trio with the drums on the right. Suddenly the drums
are on the left, then a few seconds later they are back on the right.

The player is a Raspberry Pi with HiFiBerry DAC + Pro.

There is nothing wrong with the file which plays ok on the Mac

I suppose it could be a flac decoding error or perhaps a hardware error
with the I2S clocking.

I2S clocking error sounds right - except I2S word clock is high for one
channel, low for the other. I can't see how it could be in the I2S bus.


Arthur

I've never heard anything like that. If it is a decoding error you've
suffered an unbelievably rare error in so many numbers being wrong by
exactly the right amount to perform a 16-bit word shift without any
checksum flagging the problem.

Is it repeatable, or did it just happen the once? If it is repeatable,
perhaps you could put the file somewhere we could download it.

That is of course the big question. IMHO if it's repeatable it must be a
SW bug.

Andy