# Writing wav file in GMSK TX, RX **URL:** \ **Category:** GNU Radio\ **Created:** [June 9, 2014, 7:59am UTC](https://www.ruby-forum.com/t/writing-wav-file-in-gmsk-tx-rx/230290 "2014-06-09T07:59:08Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![jason\_sam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/7993a0/32.png) [@jason\_sam](https://www.ruby-forum.com/u/jason_sam)\ **Post date:** [June 9, 2014, 7:59am UTC](https://www.ruby-forum.com/t/writing-wav-file-in-gmsk-tx-rx/230290/1 "2014-06-09T07:59:08Z")
Hello list, I am simulating Voice transmission system in GRC using ‘GMSK Mod’, ‘GMSK Demod’ in loop without any channel in between & My flow graph configuration is as follows: Wav file source → Throttle → Packet encoder → GMSK Mod → GMSK Demod → Packet decoder → Wav file sink/Scope/FFT Sink. When I execute the above flow graph, I get output at Scope, FFT Sink. Also it writes wav file using ‘Wav file sink’ block, but I am not able to play that wav file, it gives error. Please help me on above issue. Thanks & Regards, Dushyant – View this message in context: [http://gnuradio.4.n7.nabble.com/Writing-wav-file-in-GMSK-TX-RX-tp48857.html](http://gnuradio.4.n7.nabble.com/Writing-wav-file-in-GMSK-TX-RX-tp48857.html) Sent from the GnuRadio mailing list archive at [Nabble.com](http://Nabble.com). ---
**Author:** ![dushyant.marathe](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/5f8ce5/32.png) [@dushyant.marathe](https://www.ruby-forum.com/u/dushyant.marathe)\ **Post date:** [June 9, 2014, 8:32am UTC](https://www.ruby-forum.com/t/writing-wav-file-in-gmsk-tx-rx/230290/2 "2014-06-09T08:32:48Z")
On Mon, Jun 9, 2014 at 1:57 PM, dushyant.marathe [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Also it writes wav file using ‘Wav file sink’ block, but I am not able to > play that wav file, it gives error. You didn’t mention how you played the wave file. Take note that in gnuradio, audio sink accepts floating point samples in the range of -1 and +1. [1] Beyond the range you will get clipping error. 1. [http://gnuradio.org/redmine/projects/gnuradio/wiki/TutorialsWritePythonApplications#A-first-working-code-example](http://gnuradio.org/redmine/projects/gnuradio/wiki/TutorialsWritePythonApplications#A-first-working-code-example) ---
**Author:** ![dushyant.marathe](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/5f8ce5/32.png) [@dushyant.marathe](https://www.ruby-forum.com/u/dushyant.marathe)\ **Post date:** [June 9, 2014, 8:58am UTC](https://www.ruby-forum.com/t/writing-wav-file-in-gmsk-tx-rx/230290/3 "2014-06-09T08:58:47Z")
Hi Activecat, Thanks for the reply. I am playing wav file using windows media player. When I execute the flow graph it writes wav file. Wav file’s size increases, unless I stop the flow graph. But when I played it using media player it doesn’t play any more. Also I am ensuring that amplitude is in the range of -1 and +1. Plz note that I am not using Audio sink. I am using ‘Wav sink block’ I want to tell you that, I am using Gnu Radio 3.7.3. Moreover My Ubuntu 12.04 is installed on Virtual machine. Regards, Dushyant – View this message in context: [http://gnuradio.4.n7.nabble.com/Writing-wav-file-in-GMSK-TX-RX-tp48857p48860.html](http://gnuradio.4.n7.nabble.com/Writing-wav-file-in-GMSK-TX-RX-tp48857p48860.html) Sent from the GnuRadio mailing list archive at [Nabble.com](http://Nabble.com). ---
**Author:** ![dushyant.marathe](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/5f8ce5/32.png) [@dushyant.marathe](https://www.ruby-forum.com/u/dushyant.marathe)\ **Post date:** [June 9, 2014, 9:13am UTC](https://www.ruby-forum.com/t/writing-wav-file-in-gmsk-tx-rx/230290/4 "2014-06-09T09:13:33Z")
Make sure you close the .wav file by pressing ‘x’ (close) button on a graphical sink, otherwise it won’t write the wav file correctly. Check here: [http://gnuradio.org/redmine/issues/544](http://gnuradio.org/redmine/issues/544) Otherwise, try playing in VLC. On Mon, Jun 9, 2014 at 4:57 PM, dushyant.marathe [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![dushyant.marathe](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/5f8ce5/32.png) [@dushyant.marathe](https://www.ruby-forum.com/u/dushyant.marathe)\ **Post date:** [June 9, 2014, 9:24am UTC](https://www.ruby-forum.com/t/writing-wav-file-in-gmsk-tx-rx/230290/5 "2014-06-09T09:24:46Z")
On Mon, Jun 9, 2014 at 2:57 PM, dushyant.marathe [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Plz note that I am not using Audio sink. I am using ‘Wav sink block’ > > I want to tell you that, I am using Gnu Radio 3.7.3. Moreover My Ubuntu > 12.04 is installed on Virtual machine. > > Regards, > Dushyant To isolate the problem, try this: 1). Execute this flowgraph: Wav File Source → Packet Encoder → Packet Decoder → Wav File Sink. 2). Try to play the wav file produced. This is to ensure there is no problem with the settings of Packet Encoder/Decoder. ---
**Author:** ![dushyant.marathe](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/5f8ce5/32.png) [@dushyant.marathe](https://www.ruby-forum.com/u/dushyant.marathe)\ **Post date:** [June 9, 2014, 9:50am UTC](https://www.ruby-forum.com/t/writing-wav-file-in-gmsk-tx-rx/230290/6 "2014-06-09T09:50:45Z")
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