RE: help:loud noise in the madplay

Ah, yes I had that issue as well... output was big endian... using COOL EDIT
you can view little or big endian PCM. If that doesnt work... I had to write
a routine to write out samples the other way around... using fwrite(). SHARC
embedded processors have some quarks with regular C code.... it isnt exactly
"portable" as one might think. Whatever your platform is, my adivce is to
get a HEX viewer that allows you to see exactly what you are writing out to
a file... and compare that output to what you should be getting (maybe make
a windows implementation of minimad to compare to, as I did).  Its a battle
but it makes sense when you can see the data.  Good luck.

Matt

-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Nigel Sinfield
Sent: 10-Nov-05 11:35 AM
To: 'Joe Drew'; feiye
Cc: [email protected]
Subject: RE: [mad-dev] help:loud noise in the madplay


When I had this problem it turned out to be an 'endian' issue.  mad output
the samples one way, but the audio hardware required the other.

-----Original Message-----
On Nov 8, 2005, at 1:12 AM, feiye wrote:

>    I have transplant madplay to embedded linux2.4.18. When I play
> the mp3,it has a loud noise in the music.
>     Has anybody met this before? Can anybody help?

I remember problems very much like this when I was first creating
mpg321, and IIRC the problem was a 'signed' issue. Perhaps 'char' is
signed on your platform, and your output needs unsigned?

I do remember the fix not making sense to me. PCM samples can be
negative, I think, but I believe that I had to change to using
unsigned char explicitly.

Hope this helps,

Joe


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