View source for Recording phonecalls

'''A desktop widget to record phone calls is now available from Maemo Extras. Search for [http://maemo.org/downloads/product/Maemo5/recaller/ "recaller"] using your Application Manager.'''

This page describes a method for recording calls from an N900, using pulseaudio command line tools to stream audio from input & output devices, which requires command line tinkering.

This method was inspired by [http://www.outflux.net/blog/archives/2009/04/19/recording-from-pulseaudio/ a blog entry detailing how to record from pulseaudio], and [http://talk.maemo.org/showpost.php?p=441501&postcount=41 documented] by [http://talk.maemo.org/member.php?u=13228 iKneaDough on Talk.maemo.org].

== Install pulseaudio-utils ==

First you will need to get the pulseaudio-utils package. You can install this either from [http://repository.maemo.org/pool/fremantle/free/p/pulseaudio/pulseaudio-utils_0.9.15-1maemo27+0m5_armel.deb the online Fremantle repository], or by enabling the tools repository and running

 apt-get install pulseaudio-utils

You can enable the tools repository by following [[Documentation/devtools/maemo5#Installation|the instructions for installing devtools]].

The pulseaudio-utils package provides two applications which can be used to record audio in scripts: '''parec''' to record raw audio streams, and '''pacat''' to play back raw audio streams.

The streams involved are: '''sink.hw0.monitor''' for incoming sounds and '''source.hw0''' for outgoing sounds when using the phone handset, and '''sink.hw1.monitor''' for incoming sounds and '''source.hw1''' for outgoing sounds when using a bluetooth headset.

== Creating scripts ==

Create the following shell scripts in your home directory:

# Put the following in a script called '''simpleRec.sh''', which you can run to record a call using the handset:

 NOW=`date +%F-%H-%M-%S` 
 echo $NOW > simpleDateTime
 parec -d "sink.hw0.monitor" > MyDocs/tmp/$NOW.pulse.in.raw &
 parec -d "source.hw0" > MyDocs/tmp/$NOW.pulse.out.raw

# Put the following in a script called '''simpleRec.sh''', which you can run to record a call using a Bluetooth headset:

 NOW=`date +%F-%H-%M-%S` 
 echo $NOW > simpleDateTime
 parec -d "sink.hw1.monitor" > MyDocs/tmp/$NOW.pulse.in.raw &
 parec -d "source.hw1" > MyDocs/tmp/$NOW.pulse.out.raw

These scrips will create two files, one for the input stream and one for the output stream, in the directory MyDocs/tmp, with a name which contains the month, day, hour and minute of the phone call.

For example, a phone call on the 13th of November, at 09:15, will be stored in the two files '''11-13-09-15.pulse.in.raw''' and  '''11-13-09-15.pulse.out.raw'''

== Playing back phonecalls ==

# To play back the most recent recorded call, use the following script (call it '''simpleLastPlay.sh''') :

 LAST=`cat simpleDateTime`
 pacat MyDocs/tmp/$LAST.pulse.in.raw &
 pacat -v MyDocs/tmp/$LAST.pulse.out.raw

# To play back an older call using a unique date or time, use the following script (call it '''simplePlay.sh''') :

 pacat MyDocs/tmp/*$1*pulse.in.raw &
 pacat -v MyDocs/tmp/*$1*pulse.out.raw

for example if you know you recorded a call on Dec 1 at 12:00 am, you could run ' ./simplePlay.sh 12-01-00-00 ' or any part of the date or time that you can remember, as long as it is unique.

To stop recording or playback just press ctrl+c.

Here is another useful script to stop any recording or playback if you can't get back to its original terminal window, called 'simpleStop.sh' :

 killall parec
 killall pacat

== Disclaimer ==

Please use this only where it is legal to do so, and please do not use it for any nefarious purpose.


[[Category:Power users]]
[[Category:Media]]
[[Category:HowTo]]
[[Category:N900]]