Could you help me understand that prevents the use echo cancellation in FS On the one hand SpanDSP library compiled with FS and contains functions for echo canceler libs/spandsp/src/echo.c On the other hand FS does not contain applications of echo canceler. Also, I found the discussion in which states GPL is not compatible with the MPL1.1 and it prevent use Oslec (SpanDSP is uses Oslec). Sergey
Missed url http://markmail.org/message/ouxh772ethgpmzko On Sat, Apr 18, 2015 at 9:40 AM, Sergey Safarov <s.safarov@gmail.com> wrote:
Could you help me understand that prevents the use echo cancellation in FS On the one hand SpanDSP library compiled with FS and contains functions for echo canceler libs/spandsp/src/echo.c On the other hand FS does not contain applications of echo canceler. Also, I found the discussion in which states GPL is not compatible with the MPL1.1 and it prevent use Oslec (SpanDSP is uses Oslec).
Sergey
On 04/18/2015 02:40 PM, Sergey Safarov wrote:
Could you help me understand that prevents the use echo cancellation in FS How would you expect to use echo cancellation in FS? On the one hand SpanDSP library compiled with FS and contains functions for echo canceler libs/spandsp/src/echo.c Not really. Look carefully at those routines. On the other hand FS does not contain applications of echo canceler. Correct. Also, I found the discussion in which states GPL is not compatible with the MPL1.1 and it prevent use Oslec (SpanDSP is uses Oslec). SpanDSP does NOT contain OSLEC. OSLEC has its origins in the work in progress echo canceller in SpanDSP.
Regards, Steve
How would you expect to use echo cancellation in FS?
I thinking it can be used like t38_gateway application (audio to image
converter). In echo canceler application audio with echo converted to audio
without echo.
> On the one hand SpanDSP library compiled with FS and contains
> functions for echo canceler libs/spandsp/src/echo.c
Not really. Look carefully at those routines.
In source
* echo.c - An echo cancellor, suitable for electrical and acoustic
* cancellation. This code does not currently comply with
* any relevant standards (e.g. G.164/5/7/8). One day....
And other 70 string of following comments describe file as echo canceler
Also in echo_can_update()
at string 429
clean_rx = rx - echo_value;
at string 569
if ((ec->adaption_mode & ECHO_CAN_USE_NLP))
{
/* Non-linear processor - a fancy way to say "zap small signals, to
avoid
residual echo due to (uLaw/ALaw) non-linearity in the channel.".
*/
Look in echo.h comments ....
in the echo_tests.c
The echo cancellation tests test the echo cancellor against the G.168 spec.
At http://www.rowetel.com/blog/?page_id=454 I read
spandsp : A subset of spandsp to support testing and development of Oslec.
The echo canceller and G168 test suite source code live in here.
I thinking it really echo canceler functions.
SpanDSP does NOT contain OSLEC. OSLEC has its origins in the work in
progress echo canceller in SpanDSP.
If it two different product then echo canceler may be realized by
1. SpanDSP library
2. Oslec kernel driver
I has find relation In source files between OSLEC kernel driver
(drivers/staging/echo) and SpanDSP functions:
oslec_create(int len, int adaption_mode) - echo_can_init(int len, int
adaption_mode)
oslec_adaption_mode(struct oslec_state *ec, int adaption_mode) -
oslec_update(struct oslec_state *ec, int16_t tx, int16_t rx)
- echo_can_update(echo_can_state_t *ec, int16_t tx, int16_t rx)
oslec_hpf_tx(struct oslec_state *ec, int16_t tx)
- echo_can_hpf_tx(echo_can_state_t *ec, int16_t tx)
And FS may use two echo canceler engines (SpanSDP or OSLEC kernel driver).
What is prevent to do it?
On Sat, Apr 18, 2015 at 12:39 PM, Steve Underwood <steveu@coppice.org>
wrote:
> On 04/18/2015 02:40 PM, Sergey Safarov wrote:
> > Could you help me understand that prevents the use echo cancellation in
> FS
> How would you expect to use echo cancellation in FS?
> > On the one hand SpanDSP library compiled with FS and contains
> > functions for echo canceler libs/spandsp/src/echo.c
> Not really. Look carefully at those routines.
> > On the other hand FS does not contain applications of echo canceler.
> Correct.
> > Also, I found the discussion in which states GPL is not compatible
> > with the MPL1.1 and it prevent use Oslec (SpanDSP is uses Oslec).
> SpanDSP does NOT contain OSLEC. OSLEC has its origins in the work in
> progress echo canceller in SpanDSP.
>
> Regards,
> Steve
>
>
> _________________________________________________________________________
> Professional FreeSWITCH Consulting Services:
> consulting@freeswitch.org
> http://www.freeswitchsolutions.com
>
> Official FreeSWITCH Sites
> http://www.freeswitch.org
> http://confluence.freeswitch.org
> http://www.cluecon.com
>
> FreeSWITCH-users mailing list
> FreeSWITCH-users@lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> http://www.freeswitch.org
>
OSLEC works with FreeTDM DAHDI-mode.
On Sat, Apr 18, 2015 at 7:13 PM, Sergey Safarov <s.safarov@gmail.com> wrote:
> How would you expect to use echo cancellation in FS?
> I thinking it can be used like t38_gateway application (audio to image
> converter). In echo canceler application audio with echo converted to audio
> without echo.
>
> > On the one hand SpanDSP library compiled with FS and contains
> > functions for echo canceler libs/spandsp/src/echo.c
> Not really. Look carefully at those routines.
> In source
> * echo.c - An echo cancellor, suitable for electrical and acoustic
> * cancellation. This code does not currently comply with
> * any relevant standards (e.g. G.164/5/7/8). One day....
> And other 70 string of following comments describe file as echo canceler
> Also in echo_can_update()
> at string 429
> clean_rx = rx - echo_value;
>
> at string 569
> if ((ec->adaption_mode & ECHO_CAN_USE_NLP))
> {
> /* Non-linear processor - a fancy way to say "zap small signals,
> to avoid
> residual echo due to (uLaw/ALaw) non-linearity in the
> channel.". */
>
> Look in echo.h comments ....
>
> in the echo_tests.c
> The echo cancellation tests test the echo cancellor against the G.168 spec.
>
> At http://www.rowetel.com/blog/?page_id=454 I read
> spandsp : A subset of spandsp to support testing and development of Oslec.
> The echo canceller and G168 test suite source code live in here.
>
> I thinking it really echo canceler functions.
>
> SpanDSP does NOT contain OSLEC. OSLEC has its origins in the work in
> progress echo canceller in SpanDSP.
> If it two different product then echo canceler may be realized by
>
> 1. SpanDSP library
> 2. Oslec kernel driver
>
> I has find relation In source files between OSLEC kernel driver
> (drivers/staging/echo) and SpanDSP functions:
> oslec_create(int len, int adaption_mode) - echo_can_init(int len, int
> adaption_mode)
> oslec_adaption_mode(struct oslec_state *ec, int adaption_mode) -
> oslec_update(struct oslec_state *ec, int16_t tx, int16_t rx)
> - echo_can_update(echo_can_state_t *ec, int16_t tx, int16_t rx)
> oslec_hpf_tx(struct oslec_state *ec, int16_t tx)
> - echo_can_hpf_tx(echo_can_state_t *ec, int16_t tx)
>
> And FS may use two echo canceler engines (SpanSDP or OSLEC kernel driver).
> What is prevent to do it?
>
>
>
>
>
>
>
> On Sat, Apr 18, 2015 at 12:39 PM, Steve Underwood <steveu@coppice.org>
> wrote:
>
>> On 04/18/2015 02:40 PM, Sergey Safarov wrote:
>> > Could you help me understand that prevents the use echo cancellation in
>> FS
>> How would you expect to use echo cancellation in FS?
>> > On the one hand SpanDSP library compiled with FS and contains
>> > functions for echo canceler libs/spandsp/src/echo.c
>> Not really. Look carefully at those routines.
>> > On the other hand FS does not contain applications of echo canceler.
>> Correct.
>> > Also, I found the discussion in which states GPL is not compatible
>> > with the MPL1.1 and it prevent use Oslec (SpanDSP is uses Oslec).
>> SpanDSP does NOT contain OSLEC. OSLEC has its origins in the work in
>> progress echo canceller in SpanDSP.
>>
>> Regards,
>> Steve
>>
>>
>> _________________________________________________________________________
>> Professional FreeSWITCH Consulting Services:
>> consulting@freeswitch.org
>> http://www.freeswitchsolutions.com
>>
>> Official FreeSWITCH Sites
>> http://www.freeswitch.org
>> http://confluence.freeswitch.org
>> http://www.cluecon.com
>>
>> FreeSWITCH-users mailing list
>> FreeSWITCH-users@lists.freeswitch.org
>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
>> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
>> http://www.freeswitch.org
>>
>
>
> _________________________________________________________________________
> Professional FreeSWITCH Consulting Services:
> consulting@freeswitch.org
> http://www.freeswitchsolutions.com
>
> Official FreeSWITCH Sites
> http://www.freeswitch.org
> http://confluence.freeswitch.org
> http://www.cluecon.com
>
> FreeSWITCH-users mailing list
> FreeSWITCH-users@lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> http://www.freeswitch.org
>
According "Installing OSLEC with DAHDI" - DAHDI may use OSLEC. But I cant
find DAHDI requirements to compile and use OSLEC. In other words OSLEC may
be used without DAHDI.
On Sat, Apr 18, 2015 at 2:25 PM, Nandy Dagondon <nandy1925@gmail.com> wrote:
>
> OSLEC works with FreeTDM DAHDI-mode.
>
> On Sat, Apr 18, 2015 at 7:13 PM, Sergey Safarov <s.safarov@gmail.com>
> wrote:
>
>> How would you expect to use echo cancellation in FS?
>> I thinking it can be used like t38_gateway application (audio to image
>> converter). In echo canceler application audio with echo converted to audio
>> without echo.
>>
>> > On the one hand SpanDSP library compiled with FS and contains
>> > functions for echo canceler libs/spandsp/src/echo.c
>> Not really. Look carefully at those routines.
>> In source
>> * echo.c - An echo cancellor, suitable for electrical and acoustic
>> * cancellation. This code does not currently comply with
>> * any relevant standards (e.g. G.164/5/7/8). One day....
>> And other 70 string of following comments describe file as echo canceler
>> Also in echo_can_update()
>> at string 429
>> clean_rx = rx - echo_value;
>>
>> at string 569
>> if ((ec->adaption_mode & ECHO_CAN_USE_NLP))
>> {
>> /* Non-linear processor - a fancy way to say "zap small signals,
>> to avoid
>> residual echo due to (uLaw/ALaw) non-linearity in the
>> channel.". */
>>
>> Look in echo.h comments ....
>>
>> in the echo_tests.c
>> The echo cancellation tests test the echo cancellor against the G.168
>> spec.
>>
>> At http://www.rowetel.com/blog/?page_id=454 I read
>> spandsp : A subset of spandsp to support testing and development of
>> Oslec. The echo canceller and G168 test suite source code live in here.
>>
>> I thinking it really echo canceler functions.
>>
>> SpanDSP does NOT contain OSLEC. OSLEC has its origins in the work in
>> progress echo canceller in SpanDSP.
>> If it two different product then echo canceler may be realized by
>>
>> 1. SpanDSP library
>> 2. Oslec kernel driver
>>
>> I has find relation In source files between OSLEC kernel driver
>> (drivers/staging/echo) and SpanDSP functions:
>> oslec_create(int len, int adaption_mode) - echo_can_init(int len, int
>> adaption_mode)
>> oslec_adaption_mode(struct oslec_state *ec, int adaption_mode) -
>> oslec_update(struct oslec_state *ec, int16_t tx, int16_t rx)
>> - echo_can_update(echo_can_state_t *ec, int16_t tx, int16_t rx)
>> oslec_hpf_tx(struct oslec_state *ec, int16_t tx)
>> - echo_can_hpf_tx(echo_can_state_t *ec, int16_t tx)
>>
>> And FS may use two echo canceler engines (SpanSDP or OSLEC kernel
>> driver). What is prevent to do it?
>>
>>
>>
>>
>>
>>
>>
>> On Sat, Apr 18, 2015 at 12:39 PM, Steve Underwood <steveu@coppice.org>
>> wrote:
>>
>>> On 04/18/2015 02:40 PM, Sergey Safarov wrote:
>>> > Could you help me understand that prevents the use echo cancellation
>>> in FS
>>> How would you expect to use echo cancellation in FS?
>>> > On the one hand SpanDSP library compiled with FS and contains
>>> > functions for echo canceler libs/spandsp/src/echo.c
>>> Not really. Look carefully at those routines.
>>> > On the other hand FS does not contain applications of echo canceler.
>>> Correct.
>>> > Also, I found the discussion in which states GPL is not compatible
>>> > with the MPL1.1 and it prevent use Oslec (SpanDSP is uses Oslec).
>>> SpanDSP does NOT contain OSLEC. OSLEC has its origins in the work in
>>> progress echo canceller in SpanDSP.
>>>
>>> Regards,
>>> Steve
>>>
>>>
>>> _________________________________________________________________________
>>> Professional FreeSWITCH Consulting Services:
>>> consulting@freeswitch.org
>>> http://www.freeswitchsolutions.com
>>>
>>> Official FreeSWITCH Sites
>>> http://www.freeswitch.org
>>> http://confluence.freeswitch.org
>>> http://www.cluecon.com
>>>
>>> FreeSWITCH-users mailing list
>>> FreeSWITCH-users@lists.freeswitch.org
>>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
>>> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
>>> http://www.freeswitch.org
>>>
>>
>>
>> _________________________________________________________________________
>> Professional FreeSWITCH Consulting Services:
>> consulting@freeswitch.org
>> http://www.freeswitchsolutions.com
>>
>> Official FreeSWITCH Sites
>> http://www.freeswitch.org
>> http://confluence.freeswitch.org
>> http://www.cluecon.com
>>
>> FreeSWITCH-users mailing list
>> FreeSWITCH-users@lists.freeswitch.org
>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
>> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
>> http://www.freeswitch.org
>>
>
>
> _________________________________________________________________________
> Professional FreeSWITCH Consulting Services:
> consulting@freeswitch.org
> http://www.freeswitchsolutions.com
>
> Official FreeSWITCH Sites
> http://www.freeswitch.org
> http://confluence.freeswitch.org
> http://www.cluecon.com
>
> FreeSWITCH-users mailing list
> FreeSWITCH-users@lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> http://www.freeswitch.org
>
Missed link http://www.rowetel.com/blog/?page_id=454
On Sat, Apr 18, 2015 at 2:55 PM, Sergey Safarov <s.safarov@gmail.com> wrote:
> According "Installing OSLEC with DAHDI" - DAHDI may use OSLEC. But I cant
> find DAHDI requirements to compile and use OSLEC. In other words OSLEC may
> be used without DAHDI.
>
> On Sat, Apr 18, 2015 at 2:25 PM, Nandy Dagondon <nandy1925@gmail.com>
> wrote:
>
>>
>> OSLEC works with FreeTDM DAHDI-mode.
>>
>> On Sat, Apr 18, 2015 at 7:13 PM, Sergey Safarov <s.safarov@gmail.com>
>> wrote:
>>
>>> How would you expect to use echo cancellation in FS?
>>> I thinking it can be used like t38_gateway application (audio to image
>>> converter). In echo canceler application audio with echo converted to audio
>>> without echo.
>>>
>>> > On the one hand SpanDSP library compiled with FS and contains
>>> > functions for echo canceler libs/spandsp/src/echo.c
>>> Not really. Look carefully at those routines.
>>> In source
>>> * echo.c - An echo cancellor, suitable for electrical and acoustic
>>> * cancellation. This code does not currently comply with
>>> * any relevant standards (e.g. G.164/5/7/8). One day....
>>> And other 70 string of following comments describe file as echo canceler
>>> Also in echo_can_update()
>>> at string 429
>>> clean_rx = rx - echo_value;
>>>
>>> at string 569
>>> if ((ec->adaption_mode & ECHO_CAN_USE_NLP))
>>> {
>>> /* Non-linear processor - a fancy way to say "zap small signals,
>>> to avoid
>>> residual echo due to (uLaw/ALaw) non-linearity in the
>>> channel.". */
>>>
>>> Look in echo.h comments ....
>>>
>>> in the echo_tests.c
>>> The echo cancellation tests test the echo cancellor against the G.168
>>> spec.
>>>
>>> At http://www.rowetel.com/blog/?page_id=454 I read
>>> spandsp : A subset of spandsp to support testing and development of
>>> Oslec. The echo canceller and G168 test suite source code live in here.
>>>
>>> I thinking it really echo canceler functions.
>>>
>>> SpanDSP does NOT contain OSLEC. OSLEC has its origins in the work in
>>> progress echo canceller in SpanDSP.
>>> If it two different product then echo canceler may be realized by
>>>
>>> 1. SpanDSP library
>>> 2. Oslec kernel driver
>>>
>>> I has find relation In source files between OSLEC kernel driver
>>> (drivers/staging/echo) and SpanDSP functions:
>>> oslec_create(int len, int adaption_mode) - echo_can_init(int len, int
>>> adaption_mode)
>>> oslec_adaption_mode(struct oslec_state *ec, int adaption_mode) -
>>> oslec_update(struct oslec_state *ec, int16_t tx, int16_t rx)
>>> - echo_can_update(echo_can_state_t *ec, int16_t tx, int16_t rx)
>>> oslec_hpf_tx(struct oslec_state *ec, int16_t tx)
>>> - echo_can_hpf_tx(echo_can_state_t *ec, int16_t tx)
>>>
>>> And FS may use two echo canceler engines (SpanSDP or OSLEC kernel
>>> driver). What is prevent to do it?
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> On Sat, Apr 18, 2015 at 12:39 PM, Steve Underwood <steveu@coppice.org>
>>> wrote:
>>>
>>>> On 04/18/2015 02:40 PM, Sergey Safarov wrote:
>>>> > Could you help me understand that prevents the use echo cancellation
>>>> in FS
>>>> How would you expect to use echo cancellation in FS?
>>>> > On the one hand SpanDSP library compiled with FS and contains
>>>> > functions for echo canceler libs/spandsp/src/echo.c
>>>> Not really. Look carefully at those routines.
>>>> > On the other hand FS does not contain applications of echo canceler.
>>>> Correct.
>>>> > Also, I found the discussion in which states GPL is not compatible
>>>> > with the MPL1.1 and it prevent use Oslec (SpanDSP is uses Oslec).
>>>> SpanDSP does NOT contain OSLEC. OSLEC has its origins in the work in
>>>> progress echo canceller in SpanDSP.
>>>>
>>>> Regards,
>>>> Steve
>>>>
>>>>
>>>>
>>>> _________________________________________________________________________
>>>> Professional FreeSWITCH Consulting Services:
>>>> consulting@freeswitch.org
>>>> http://www.freeswitchsolutions.com
>>>>
>>>> Official FreeSWITCH Sites
>>>> http://www.freeswitch.org
>>>> http://confluence.freeswitch.org
>>>> http://www.cluecon.com
>>>>
>>>> FreeSWITCH-users mailing list
>>>> FreeSWITCH-users@lists.freeswitch.org
>>>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
>>>> UNSUBSCRIBE:
>>>> http://lists.freeswitch.org/mailman/options/freeswitch-users
>>>> http://www.freeswitch.org
>>>>
>>>
>>>
>>> _________________________________________________________________________
>>> Professional FreeSWITCH Consulting Services:
>>> consulting@freeswitch.org
>>> http://www.freeswitchsolutions.com
>>>
>>> Official FreeSWITCH Sites
>>> http://www.freeswitch.org
>>> http://confluence.freeswitch.org
>>> http://www.cluecon.com
>>>
>>> FreeSWITCH-users mailing list
>>> FreeSWITCH-users@lists.freeswitch.org
>>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
>>> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
>>> http://www.freeswitch.org
>>>
>>
>>
>> _________________________________________________________________________
>> Professional FreeSWITCH Consulting Services:
>> consulting@freeswitch.org
>> http://www.freeswitchsolutions.com
>>
>> Official FreeSWITCH Sites
>> http://www.freeswitch.org
>> http://confluence.freeswitch.org
>> http://www.cluecon.com
>>
>> FreeSWITCH-users mailing list
>> FreeSWITCH-users@lists.freeswitch.org
>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
>> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
>> http://www.freeswitch.org
>>
>
>
DAHDI source is needed. Downloaded the source from your card mfr website
or from Asterisk, patch OSLEC, compile and install. Run DAHDI driver before
running FS. Take note of the config files DAHDI to use - freetdm.conf and
zt.conf.
On Sat, Apr 18, 2015 at 7:56 PM, Sergey Safarov <s.safarov@gmail.com> wrote:
> Missed link http://www.rowetel.com/blog/?page_id=454
>
> On Sat, Apr 18, 2015 at 2:55 PM, Sergey Safarov <s.safarov@gmail.com>
> wrote:
>
>> According "Installing OSLEC with DAHDI" - DAHDI may use OSLEC. But I cant
>> find DAHDI requirements to compile and use OSLEC. In other words OSLEC may
>> be used without DAHDI.
>>
>> On Sat, Apr 18, 2015 at 2:25 PM, Nandy Dagondon <nandy1925@gmail.com>
>> wrote:
>>
>>>
>>> OSLEC works with FreeTDM DAHDI-mode.
>>>
>>> On Sat, Apr 18, 2015 at 7:13 PM, Sergey Safarov <s.safarov@gmail.com>
>>> wrote:
>>>
>>>> How would you expect to use echo cancellation in FS?
>>>> I thinking it can be used like t38_gateway application (audio to image
>>>> converter). In echo canceler application audio with echo converted to audio
>>>> without echo.
>>>>
>>>> > On the one hand SpanDSP library compiled with FS and contains
>>>> > functions for echo canceler libs/spandsp/src/echo.c
>>>> Not really. Look carefully at those routines.
>>>> In source
>>>> * echo.c - An echo cancellor, suitable for electrical and acoustic
>>>> * cancellation. This code does not currently comply with
>>>> * any relevant standards (e.g. G.164/5/7/8). One day....
>>>> And other 70 string of following comments describe file as echo canceler
>>>> Also in echo_can_update()
>>>> at string 429
>>>> clean_rx = rx - echo_value;
>>>>
>>>> at string 569
>>>> if ((ec->adaption_mode & ECHO_CAN_USE_NLP))
>>>> {
>>>> /* Non-linear processor - a fancy way to say "zap small
>>>> signals, to avoid
>>>> residual echo due to (uLaw/ALaw) non-linearity in the
>>>> channel.". */
>>>>
>>>> Look in echo.h comments ....
>>>>
>>>> in the echo_tests.c
>>>> The echo cancellation tests test the echo cancellor against the G.168
>>>> spec.
>>>>
>>>> At http://www.rowetel.com/blog/?page_id=454 I read
>>>> spandsp : A subset of spandsp to support testing and development of
>>>> Oslec. The echo canceller and G168 test suite source code live in here.
>>>>
>>>> I thinking it really echo canceler functions.
>>>>
>>>> SpanDSP does NOT contain OSLEC. OSLEC has its origins in the work in
>>>> progress echo canceller in SpanDSP.
>>>> If it two different product then echo canceler may be realized by
>>>>
>>>> 1. SpanDSP library
>>>> 2. Oslec kernel driver
>>>>
>>>> I has find relation In source files between OSLEC kernel driver
>>>> (drivers/staging/echo) and SpanDSP functions:
>>>> oslec_create(int len, int adaption_mode) - echo_can_init(int len, int
>>>> adaption_mode)
>>>> oslec_adaption_mode(struct oslec_state *ec, int adaption_mode) -
>>>> oslec_update(struct oslec_state *ec, int16_t tx, int16_t rx)
>>>> - echo_can_update(echo_can_state_t *ec, int16_t tx, int16_t rx)
>>>> oslec_hpf_tx(struct oslec_state *ec, int16_t tx)
>>>> - echo_can_hpf_tx(echo_can_state_t *ec, int16_t tx)
>>>>
>>>> And FS may use two echo canceler engines (SpanSDP or OSLEC kernel
>>>> driver). What is prevent to do it?
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Sat, Apr 18, 2015 at 12:39 PM, Steve Underwood <steveu@coppice.org>
>>>> wrote:
>>>>
>>>>> On 04/18/2015 02:40 PM, Sergey Safarov wrote:
>>>>> > Could you help me understand that prevents the use echo cancellation
>>>>> in FS
>>>>> How would you expect to use echo cancellation in FS?
>>>>> > On the one hand SpanDSP library compiled with FS and contains
>>>>> > functions for echo canceler libs/spandsp/src/echo.c
>>>>> Not really. Look carefully at those routines.
>>>>> > On the other hand FS does not contain applications of echo canceler.
>>>>> Correct.
>>>>> > Also, I found the discussion in which states GPL is not compatible
>>>>> > with the MPL1.1 and it prevent use Oslec (SpanDSP is uses Oslec).
>>>>> SpanDSP does NOT contain OSLEC. OSLEC has its origins in the work in
>>>>> progress echo canceller in SpanDSP.
>>>>>
>>>>> Regards,
>>>>> Steve
>>>>>
>>>>>
>>>>>
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>
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On 04/18/2015 07:13 PM, Sergey Safarov wrote:
> How would you expect to use echo cancellation in FS?
> I thinking it can be used like t38_gateway application (audio to image
> converter). In echo canceler application audio with echo converted to
> audio without echo.
How would you propose to do that with a fixed rate type of echo
canceler, like OSLEC?
> > On the one hand SpanDSP library compiled with FS and contains
> > functions for echo canceler libs/spandsp/src/echo.c
> Not really. Look carefully at those routines.
> In source
> * echo.c - An echo cancellor, suitable for electrical and acoustic
> * cancellation. This code does not currently comply with
> * any relevant standards (e.g. G.164/5/7/8). One day....
> And other 70 string of following comments describe file as echo canceler
> Also in echo_can_update()
> at string 429
> clean_rx = rx - echo_value;
>
> at string 569
> if ((ec->adaption_mode & ECHO_CAN_USE_NLP))
> {
> /* Non-linear processor - a fancy way to say "zap small
> signals, to avoid
> residual echo due to (uLaw/ALaw) non-linearity in the
> channel.". */
>
> Look in echo.h comments ....
>
> in the echo_tests.c
> The echo cancellation tests test the echo cancellor against the G.168
> spec.
>
> At http://www.rowetel.com/blog/?page_id=454 I read
> spandsp : A subset of spandsp to support testing and development of
> Oslec. The echo canceller and G168 test suite source code live in here.
>
> I thinking it really echo canceler functions.
Do you also believe in unicorns? I find lots of stuff about them in
children's books. I am the author of SpanSDP. People are always trying
to tell me that half finished chunks of code are fully functional. It
gets rather annoying after a while. I even find people telling me a
problem is solved when there is a project web site somewhere that hasn't
been touched in years, and contains no code. I never really had the
incentive to finish the echo canceler in SpanDSP, because David Rowe
took my work in progress and fleshed it out to the fully functional
OSLEC. I did finish the G.168 test suite in SpanDSP, so David could use
that for his testing.
>
> SpanDSP does NOT contain OSLEC. OSLEC has its origins in the work in
> progress echo canceller in SpanDSP.
> If it two different product then echo canceler may be realized by
>
> 1. SpanDSP library
> 2. Oslec kernel driver
>
> I has find relation In source files between OSLEC kernel driver
> (drivers/staging/echo) and SpanDSP functions:
> oslec_create(int len, int adaption_mode) - echo_can_init(int len, int
> adaption_mode)
> oslec_adaption_mode(struct oslec_state *ec, int adaption_mode) -
> oslec_update(struct oslec_state *ec, int16_t tx, int16_t rx)
> - echo_can_update(echo_can_state_t *ec, int16_t tx, int16_t rx)
> oslec_hpf_tx(struct oslec_state *ec, int16_t tx)
> - echo_can_hpf_tx(echo_can_state_t *ec, int16_t tx)
>
> And FS may use two echo canceler engines (SpanSDP or OSLEC kernel
> driver). What is prevent to do it?
SpanDSP doesn't have a working echo canceler.
The OSLEC echo canceler is blocked by licence conditions.
The OSLEC echo canceler is a great addition to the PSTN interfaces -
DADHI and FreeTDM - but has no use elsewhere.
>
> On Sat, Apr 18, 2015 at 12:39 PM, Steve Underwood <steveu@coppice.org
> <mailto:steveu@coppice.org>> wrote:
>
> On 04/18/2015 02:40 PM, Sergey Safarov wrote:
> > Could you help me understand that prevents the use echo
> cancellation in FS
> How would you expect to use echo cancellation in FS?
> > On the one hand SpanDSP library compiled with FS and contains
> > functions for echo canceler libs/spandsp/src/echo.c
> Not really. Look carefully at those routines.
> > On the other hand FS does not contain applications of echo canceler.
> Correct.
> > Also, I found the discussion in which states GPL is not compatible
> > with the MPL1.1 and it prevent use Oslec (SpanDSP is uses Oslec).
> SpanDSP does NOT contain OSLEC. OSLEC has its origins in the work in
> progress echo canceller in SpanDSP.
>
> Regards,
> Steve
>
Regards,
Steve
1)How would you propose to do that with a fixed rate type of echo canceler, like OSLEC? If application can be used only with PCM/8000 call it wil be helpful for me. For other rates OSLEC source code changes may be requered. 2) Do you also believe in unicorns? ... Please accept my apologies. Now I understand what said Steve Underwood 3) The OSLEC echo canceler is blocked by licence conditions. I find it difficult to understand why the FS can use GPL Linux kernel, but can not use one of his GPL drivers (not propritory firmware driver). 4) The OSLEC echo canceler is a great addition to the PSTN interfaces - DADHI and FreeTDM - but has no use elsewhere. Could you help me to see how OSLEC uses DAHDI or FreeTDM api. Why other application cannot use OSLEC without DAHDI? Sergey.
On 04/23/2015 08:12 PM, Sergey Safarov wrote:
1)How would you propose to do that with a fixed rate type of echo canceler, like OSLEC? If application can be used only with PCM/8000 call it wil be helpful for me. For other rates OSLEC source code changes may be requered. In VoIP you don't really have exactly 8000 samples per second. You might have 7999 in one direction and 8001 in the other. OSLEC can't tolerate that. It needs the two directions be using EXACTLY the same sample rate. 2) Do you also believe in unicorns? ... Please accept my apologies. Now I understand what said Steve Underwood
3) The OSLEC echo canceler is blocked by licence conditions. I find it difficult to understand why the FS can use GPL Linux kernel, but can not use one of his GPL drivers (not propritory firmware driver). The kernel is not a part of Freeswitch. The licencing of one piece of software has not bearing on the licencing of some other piece of software it communicates with.
4) The OSLEC echo canceler is a great addition to the PSTN interfaces - DADHI and FreeTDM - but has no use elsewhere. Could you help me to see how OSLEC uses DAHDI or FreeTDM api. Why other application cannot use OSLEC without DAHDI?
Sergey.
Regards, Steve
In VoIP you don't really have exactly 8000 samples per second. You might have 7999 in one direction and 8001 in the other. OSLEC can't tolerate that. It needs the two directions be using EXACTLY the same sample rate.
If TDM line and VoIP rate is not same then VoIP gateway is generating/dropping some part of PCM data. It similar to PDH device connected to SDH multiplexer and has not same clock source. Solution is elastic buffer. http://www.reeve.com/Documents/Synchronization.pdf The kernel is not a part of Freeswitch. The licencing of one piece of
software has not bearing on the licencing of some other piece of software it communicates with.
So after all OSLEC is not a part of FS. You do not compile OSLEC as part of the FS. OSLEC compiled as part of the Linux kernel. You just send the data or read data from the device driver, as well as you read or write data on the hard drive (or file system). After all, the FS does not ask the hard disk driver (or file system) under which it was written license. Why ask echo kernel device?
Sergey
On Sat, Apr 18, 2015 at 11:39 AM, Steve Underwood <steveu@coppice.org> wrote:
Could you help me understand that prevents the use echo cancellation in FS How would you expect to use echo cancellation in FS?
It could be useful with for example mod_portaudio, IMO Regards, Jalsot
Regards, Steve
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Tamas not only mod_portaudio. In my case used one leg terminated to FXS gateway, other leg terminated to PSTN via ISDN PRI/E1 gateway. Echo is observed for some calls. I think the echo is formed on the side of the subscriber connected to PSTN. I counted that the echo comes back with a delay of 44-64 ms or more (more detail http://www.adaptivedigital.com/product/echo_cancel/echo_explain.htm). Where: 1. 20-30 ms - packetization time on a-leg 2. ~1 ms - VoIP packet delivery 3. ~ 1 ms - PSTN network signal delivery 4. ~ 1 ms - PSTN network return signal delivery 5. 20-30 ms - packetization time on ISDN PRI gateway 6. ~1 ms - VoIP return RTP packet delivery If FS will apply echo canceller then is required compensate 22-32 ms echo for each leg. Sergey On Sun, Apr 19, 2015 at 9:11 AM, Tamas Jalsovszky <jalsot@gmail.com> wrote:
On Sat, Apr 18, 2015 at 11:39 AM, Steve Underwood <steveu@coppice.org> wrote:
Could you help me understand that prevents the use echo cancellation in FS How would you expect to use echo cancellation in FS?
It could be useful with for example mod_portaudio, IMO
Regards, Jalsot
Regards, Steve
_________________________________________________________________________ Professional FreeSWITCH Consulting Services: consulting@freeswitch.org http://www.freeswitchsolutions.com
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participants (4)
-
Nandy Dagondon
-
Sergey Safarov
-
Steve Underwood
-
Tamas Jalsovszky