2008-03-25 08:23:20     Click sound/noise while playing audio with jpeg

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2008-03-25 08:23:20     Click sound/noise while playing audio with jpeg

Zaahir Khan (INDIA)

Message: 53014    Hello,

 

 

We are using BF561 rev .5  using 1854 audio & 7179 encoder chips the board.

 

We are facing one problem while running mp3 & jpeg images togather , getting small click noise

 

roughly in gap of 8-10 sec.

 

Independently audio working fine.

 

After tracing we find that noise coming when rgb2yuv asm routine is getting called in video driver.

 

So we have commented the routine & tried by calling a rgb2yuv C function in the same driver file.

 

If our computation is as

 

y1 = r1 +g1+ b1;

cb = r1 -g1 +b1 ;

cr = r1 - g1 -b1;

we are not getting noise prob.

 

But if we changed our computation to

 

y1 = (299*r1 + 587*g1+ 114*b1)/1020;

cb = (-169*r1 - 331*g1 + 500*b1 + 128)/1020;

cr = (500*r1 - 419*g1 - 81*b1 + 128)/1020;

 

problem appears & frequency of noise is more..

 

Any help is highly appretiated...

 

thanks & regards

 

Zaahir

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2008-03-25 23:29:13     Re: Click sound/noise while playing audio with jpeg

Mike Frysinger (UNITED STATES)

Message: 53024    seems fairly obvious ... multiplication/division operations are heavy expensive and will take up the core unlike addition/subtraction which are very few cycles

 

you should always avoid colorspace conversion.  make all your software use the same colorspace as the actual hardware.

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