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[freeswitch-users at di...]

Hi, I'm recording files using the pcmu extension in order to save them in the g.711 ulaw format, which is what everything in my network uses. It appears that the recorded file is just raw data without a header. Is there any way to save this as a wav type with a header (keeping the ulaw format)?

for example, running the unix command 'file' on the recording prints:
/tmp/185065_f7bb8e0c-e641-11dd-800d-5ffe41c540dd.PCMU: data

if I run it through sox which just outputs the same data (ulaw,8000,mono) but specifying the type as wav
/usr/bin/sox -t .ul -r 8000 -c 1 -b -U file.pcmu -t wav -r 8000 -c 1 -b -U file.wav

it produces a file that shows:
/tmp/185065_f7bb8e0c-e641-11dd-800d-5ffe41c540dd.wav: RIFF (little-endian) data, WAVE audio, ITU G.711 mu-law, mono 8000 Hz

if I try and save it within freeswitch using the wav extension, it trans-codes it to a pcm format
RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, mono 8000 Hz

Is there any way to have freeswitch record the file as ulaw with the RIFF wav header?

Thanks!

[anthony.minessale at g...]

no, there is currently no way to do that.
It would be feasible to add an option to mod_native_file to write wav headers around the raw data but it has not been attempted.



On Wed, Jan 21, 2009 at 10:48 AM, <freeswitch-users@digitaldan.com (freeswitch-users@digitaldan.com)> wrote:

[freeswitch-users at di...]

Thanks for the quick reply.

I'm new to this project so I'm not familiar with the inner workings just yet but at looking at mod_native_file.c it seems this is a thin wrapper around the switch's own file input and output routines? Would it be best to change this class or register a new file type, like .ul? If so, where would be a good starting point.


----- Original Message -----
From: "Anthony Minessale" <anthony.minessale@gmail.com>
To: freeswitch-users@lists.freeswitch.org
Sent: Wednesday, January 21, 2009 10:56:45 AM GMT -07:00 US/Canada Mountain
Subject: Re: [Freeswitch-users] Recording ULAW files

no, there is currently no way to do that.
It would be feasible to add an option to mod_native_file to write wav headers around the raw data but it has not been attempted.



On Wed, Jan 21, 2009 at 10:48 AM, <freeswitch-users@digitaldan.com (freeswitch-users@digitaldan.com)> wrote:

[anthony.minessale at g...]

The default audio framework operates on raw audio.
The mod_native_file triggers a special flag that tells the higher level api's for recording not
to transcode the audio first.

It would probably be easier for you to use the api_hangup_hook variable to trigger a sox command
to wrap the files in a wav or use a batch process in cron to do so than to try to figure it out in the code.


On Wed, Jan 21, 2009 at 1:05 PM, <freeswitch-users@digitaldan.com (freeswitch-users@digitaldan.com)> wrote:

[freeswitch-users at di...]

Thanks, that's what I'm currently doing now.

----- Original Message -----
From: "Anthony Minessale" <anthony.minessale@gmail.com>
To: freeswitch-users@lists.freeswitch.org
Sent: Wednesday, January 21, 2009 12:28:19 PM GMT -07:00 US/Canada Mountain
Subject: Re: [Freeswitch-users] Recording ULAW files

The default audio framework operates on raw audio.
The mod_native_file triggers a special flag that tells the higher level api's for recording not
to transcode the audio first.

It would probably be easier for you to use the api_hangup_hook variable to trigger a sox command
to wrap the files in a wav or use a batch process in cron to do so than to try to figure it out in the code.


On Wed, Jan 21, 2009 at 1:05 PM, <freeswitch-users@digitaldan.com (freeswitch-users@digitaldan.com)> wrote:

[brian at freeswitch.org]

mod_sndfile already registered .ul and .al

/b

On Jan 21, 2009, at 1:05 PM, freeswitch-users@digitaldan.com (freeswitch-users@digitaldan.com) wrote:

[brian at freeswitch.org]

mod_sndfile can record those too

/b

On Jan 22, 2009, at 11:42 AM, Guillaume Renaud wrote:

[guillaume.renaud at gm...]

I use Sun's AU format to make ulaw raw files friendlier, you might find it usefull.

2009/1/21 Brian West <brian@freeswitch.org (brian@freeswitch.org)>