Re: different when dealing with a wave sound

[Juan Pablo Carbajal]

On Wed, May 14, 2014 at 7:03 AM, Stephen Zhang <address@hidden> wrote:
> Thank you for replying.
> I added the" y=0.999*y/max(abs(y));" before wavwrite(), as you said. but I
> guess it got nothing better :-)
> I just can't understand why it is different between my octave(linux version)
> and other octave or matlab QAQ
>
>
> 2014-05-13 23:53 GMT+08:00 Macy <address@hidden>:
>>
>> oops forgot to post to group...
>>
>> did you normalize the signal?
>>
>> y=0.999*y/max(abs(y));
>>
>> wavwrite must use signals within +/- 1
>>
>>
>>
>> --- address@hidden wrote:
>>
>> From: Stephen Zhang <address@hidden>
>> To: Juan Pablo Carbajal <address@hidden>
>> Cc: Octave Help <address@hidden>
>> Subject: Re: different when dealing with a wave sound
>> Date: Tue, 13 May 2014 20:19:15 +0800
>>
>> Thank you for replaying me. I did it again just now, it was the same the
>> result.
>> My OS is Arch Linux x86_64 with kernel 3.14.2. My Octave version is 3.8.1
>> with "Signal" package version 1.3.0, "General" package version 1.3.4 and
>> "Control" package version 2.6.4.
>> I did test other wave files just using wavread() and wavwrite(), it works
>> fine.
>> I didn't get any warning or error when doing wavwrite(), as you can see
>> here[1].
>> The output file can be downloaded here[2].
>> Thanks.
>>
>> [1]http://imagebin.org/310671 (this link may be invalid some time later)
>> [2]http://pan.baidu.com/s/1bnAI6ar
>>
>>
>>
>> 2014-05-13 14:39 GMT+08:00 Juan Pablo Carbajal <address@hidden>:
>>
>> > On Mon, May 12, 2014 at 6:15 PM, Stephen Zhang <address@hidden>
>> > wrote:
>> > > Hi, all
>> > > I have a wave sound here[1], which mixed a man's sound with some
>> > > "beeee"
>> > > sound. I tested this sound in matlab(windows version), octave(windows
>> > > version) and octave(linux  version), but get diffenrent result.
>> > > Details
>> > are
>> > > here:
>> > > I use these commands:
>> > >
>> > > [wav fs bps] = wavread('buzz.wav');
>> > > b = fir1(50, [X Y], 'bandpass');
>> > > y = filter(b, 1, wav);
>> > > wavwrite(y, fs, bps, 'test.wav');
>> > >
>> > > When I set X=0.3, Y=0.7 (in line 2),In matlab and octave(windows
>> > version), I
>> > > can clearly hear the man's sound saying "zhe li shi dian zi ke ji da
>> > > xue"(Chinese) without any "beeee" sound while in octave(linux
>> > > version), I
>> > > can only hear "beeee" sound. Only when I set X=0.8 and Y=0.99 can I
>> > > hear
>> > the
>> > > man's sound(not very clearly) with "beeee" sound in octave's linux
>> > version.
>> > > I'd really like to know what causes difference? Is it a bug or just my
>> > > fault?
>> > >
>> > > Thanks a lot to read this email.
>> > > Regards,
>> > > Stephen
>> > >
>> > > [1]http://pan.baidu.com/s/1dDtcTwt
>> > >
>> > > _______________________________________________
>> > > Help-octave mailing list
>> > > address@hidden
>> > > https://lists.gnu.org/mailman/listinfo/help-octave
>> > >
>> >
>> > I can't reproduce. Without filtering I hear the annoying sound, when I
>> > run your code with X=0.3, Y=0.7 I hear a male person speaking.
>> > What version of Octave(linux) and signal package are you using?
>> > What OS?
>> > Do other wav files play fine?
>> > Do you get any warning when doing wavwrite?
>> >
>>
>>
>> _______________________________________________
>> Help-octave mailing list
>> address@hidden
>> https://lists.gnu.org/mailman/listinfo/help-octave
>>
>>
>>
>> _______________________________________________
>> Help-octave mailing list
>> address@hidden
>> https://lists.gnu.org/mailman/listinfo/help-octave
>
>
>
> _______________________________________________
> Help-octave mailing list
> address@hidden
> https://lists.gnu.org/mailman/listinfo/help-octave
>

Stephen please answer at the bottom of the message not at the top.

Could you please plot the result of your filtering step? Maybe is not
a problem of the wav function but of your filter.
Is the wave effectively filtered?