Re: [Discuss-gnuradio] query regarding wav file recording through wav file sink block

[Maitry Raval]

Hello,

Please check the flowgraph, as there is a wav file sink at output side, that 
record the incoming signal, but when I use that same recorded wav file in wav 
file source and check the output in time sink and FFT sink, then amplitude 
changes.

With Best Regards,
Maitry Raval,


----- Original Message -----
From: "Marcus Müller, CEL" <address@hidden>
To: "maitry raval" <address@hidden>
Cc: "discuss-gnuradio" <address@hidden>
Sent: Tuesday, 4 June, 2019 13:01:55
Subject: Re: query regarding wav file recording through wav file sink block

Ok, there's no Wave file involved here; instead, you read a file as
complex 2×3bit floating point binary that has a .txt ending. Have you
read [1]?
Then, you're doing *way* more than just multiplying with a constant, so
really, I'm not sure this flow graph has *anything* to do with your
question.

[1] 
https://wiki.gnuradio.org/index.php/FAQ#What_is_the_file_format_of_a_file_sink.3F_How_can_I_read_files_produced_by_a_file_sink.3F

On Tue, 2019-06-04 at 15:17 +0530, Maitry Raval wrote:
> Hello,
> 
> Please check the flow graph.
> 
> 
> With Best Regards,
> Maitry Raval,
> 
> 
> ----- Original Message -----
> From: "Marcus Müller, CEL" <address@hidden>
> To: "maitry raval" <address@hidden>
> Cc: "discuss-gnuradio" <address@hidden>
> Sent: Tuesday, 4 June, 2019 08:56:22
> Subject: Re: query regarding wav file recording through wav file sink block
> 
> Frankly, multiplication with a constant doesn't offer any benefit. The
> numbers stay the same, just scaled.
> 
> However, 8 bit might be the giveaway here: are you maybe trying to
> multiply 8 bit numbers with a constant that leads to values larger than
> what can be represented in 8 bits?
> 
> A screenshot of your flowgraph rather than just its result would be
> most interesting here.
> On Tue, 2019-06-04 at 13:58 +0530, Maitry Raval wrote:
> > Hello,
> > 
> > Thanks for your response.
> > 
> > My requirement is to use GNU generated wav file into MATLAB. But when I 
> > record the wav file with 48k sample rate and 8 bits per sample, my recorded 
> > wavfile shows a very low amplitude signal, the screenshot is attached, 
> > please check.
> > 
> > 
> > With Best Regards,
> > Maitry Raval,
> > 
> > 
> > ----- Original Message -----
> > From: "Marcus Müller, CEL" <address@hidden>
> > To: "maitry raval" <address@hidden>
> > Cc: "discuss-gnuradio" <address@hidden>
> > Sent: Tuesday, 4 June, 2019 08:02:48
> > Subject: Re: query regarding wav file recording through wav file sink block
> > 
> > I assume you do the multiplication with a constance to change the
> > amplitude, and so that's right.
> > 
> > A multiplication with a constant does however not change the shape of
> > the signal at all, unless you're running into numerical limits. 
> > 
> > We'll need more info on what exactly you're doing and what exactly
> > you're seeing.
> > 
> > Best regards,
> > Marcus
> > 
> > On Tue, 2019-06-04 at 10:22 +0530, Maitry Raval wrote:
> > > Hello,
> > > And when I use multiply constant block in order to increase the amplitude 
> > > of the wav file, It slightly change the amplitude and change the shape of 
> > > the signal. PLease someone guide.
> > > 
> > > 
> > > With Best Regards,
> > > Maitry Raval,
> > > 
> > > ----- Original Message -----
> > > From: "Maitry Raval" <address@hidden>
> > > To: "Marcus Müller, CEL" <address@hidden>
> > > Cc: "discuss-gnuradio" <address@hidden>
> > > Sent: Monday, 3 June, 2019 10:14:11
> > > Subject: Re: [Discuss-gnuradio] query regarding store transmitted signal
> > > 
> > > Hello,
> > > 
> > > PLease someone guide about wav file recording signal's amplitude. as I 
> > > have a requirement of using GNU generated wav file to my application, but 
> > > as amplitude of wav file is very low, I couldnot use that in my 
> > > application.
> > > 
> > > Thanks for your support in advance.
> > > 
> > > With Best Regards,
> > > Maitry Raval,
> > > 
> > > ----- Original Message -----
> > > From: "Maitry Raval" <address@hidden>
> > > To: "Marcus Müller, CEL" <address@hidden>
> > > Cc: "discuss-gnuradio" <address@hidden>
> > > Sent: Monday, 20 May, 2019 05:16:52
> > > Subject: Re: [Discuss-gnuradio] query regarding store transmitted signal
> > > 
> > > Hello,
> > > 
> > > there is a amplitude change in signal source and wav file sink(recorded 
> > > wav file), please check the screenshots as well. I think, because of that 
> > > when I use the recorded wav file as source for transmission, I didnot get 
> > > the sucessful reception. Please guide how to record wav file with the 
> > > same amplitude as signal source.
> > > 
> > > Thanks for your support in advance.
> > > 
> > > 
> > > With Best Regards,
> > > Maitry Raval,
> > > 
> > > 
> > > ----- Original Message -----
> > > From: "Maitry Raval" <address@hidden>
> > > To: "Marcus Müller, CEL" <address@hidden>
> > > Cc: "discuss-gnuradio" <address@hidden>
> > > Sent: Saturday, 18 May, 2019 08:29:16
> > > Subject: Re: [Discuss-gnuradio] query regarding store transmitted signal
> > > 
> > > Hello,
> > > 
> > > Thanks for your reply.
> > > I have successfully record one modulated signal transmitted from USRP 
> > > into .txt file and done demodulation offline, i.e of that stored data and 
> > > receive audio from that.
> > > But, I have all this done with wav file which is 48k sampled. but my 
> > > requiremnet is to do AM modulation of 600Hz audio file. for that, I have 
> > > done the following.
> > > 
> > > signal source(600Hz,8K)- wav file sink
> > > 
> > > AM transmission of this wav file from USRP.
> > > 
> > > record AM modulated transmitted signal in .txt file.
> > > 
> > > and demodulate it in order to receive 600Hz, 8k wav file. during 
> > > demodulation, I saw signal in scope sink and figure out frequency of that 
> > > signal through FFT sink, biut when I record received 600Hz signal as wav 
> > > file through wav file sink, then, that wav file's scope is blank, I get 
> > > blank wva file, when am I doing wrong. I think, at transmitter side, 
> > > amplitude of my original wav file source's amplitude is too low.
> > > PLease guide.
> > > 
> > > 
> > > With Best Regards,
> > > Maitry Raval,
> > > 
> > > ----- Original Message -----
> > > From: "Marcus Müller, CEL" <address@hidden>
> > > To: "maitry raval" <address@hidden>
> > > Cc: "discuss-gnuradio" <address@hidden>
> > > Sent: Friday, 17 May, 2019 11:57:45
> > > Subject: Re: [Discuss-gnuradio] query regarding store transmitted signal
> > > 
> > > https://wiki.gnuradio.org/index.php/FAQ#What_is_the_file_format_of_a_file_sink.3F_How_can_I_read_files_produced_by_a_file_sink.3F
> > > On Fri, 2019-05-17 at 17:06 +0530, Maitry Raval wrote:
> > > > Hello,
> > > > 
> > > > Thanks for your reply.
> > > > 
> > > > I.e It is possible to store the transmitted modulated signal (for ex AM 
> > > > modulated signal) through USRP as per below, 
> > > > USRP source - file sink. but in which format, this data can be stored? 
> > > > (.txt, .pdf)_ I have seen.DAT file in one of the example,but when I 
> > > > tried , it does not give proper output.
> > > > 
> > > > Actually, my requirement is to receive the modulated signal through 
> > > > USRP source, store it in a file. and later, I can be able to do 
> > > > demodulation offline from that particular stored data. it will be 
> > > > grateful, if you provide guidance.
> > > > 
> > > > 
> > > > With Best Regards,
> > > > Maitry Raval,
> > > > 
> > > > ----- Original Message -----
> > > > From: "Marcus Müller, CEL" <address@hidden>
> > > > To: "discuss-gnuradio" <address@hidden>, "maitry raval" <address@hidden>
> > > > Sent: Friday, 17 May, 2019 10:50:00
> > > > Subject: Re: [Discuss-gnuradio] query regarding store transmitted signal
> > > > 
> > > > Hi Maitry,
> > > > 
> > > > sorry, we have no idea what lab you're referring to! However, yes, that
> > > > sounds exactly what File Sinks are meant to do.
> > > > 
> > > > Best regards,
> > > > Marcus
> > > > 
> > > > On Fri, 2019-05-17 at 12:01 +0530, Maitry Raval wrote:
> > > > > Hello,
> > > > > 
> > > > > I want to store the modulated transmitted signal through USRP such as 
> > > > > given in lab -3 receiving AM signal and store it as .DAT file. Is it 
> > > > > possible to store transmitted signal as .DAT file through USRP source 
> > > > > and file sink? and use that stored data from file source to do 
> > > > > demodulation.
> > > > > thanks for your support in advance.
> > > > > 
> > > > > 
> > > > > With Best Regards,
> > > > > Maitry Raval,
> > > > > 
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