[Freeswitch-users] MP2

[Thomas Auge]

> The GPL licence rules out the use of MAD in FS.

Aren't MPL and GPL compatible these days?



>> On 03.01.2015 14:57, Steve Underwood wrote:
>>> Is there a standard set of test vectors for an MP2 decoder, and are they
>>> expected to give bit exact results?
>>>
>>> Steve
>>>
>>> On 01/04/2015 01:27 AM, Thomas Auge wrote:
>>>> A very interesting tech demo, but from his own readme, it might not be suitable for a freeswitch module:
>>>>
>>>>       - imprecise: due to the integer-only implementation, many rounding errors will
>>>>         occur; expect a 45-55 dB noise margin!
>>>>       - slow: it implements the synthesis process from the spec, which is very slow
>>>>         (82 multiplications, 1-2 divisions and countless shifts and additions per
>>>>         sample!)
>>>>       - not robust: it may easily crash on broken input data. Also, it ignores CRC
>>>>         values completely.
>>>>       - not thread-safe
>>>>
>>>> A bit of a bummer, because a lightweight decoder on top of twolame would have been nice.
>>>>
>>>>
>>>> On 03.01.2015 13:51, Steve Underwood wrote:
>>>>> I have no idea how well it works, but there is this MP2 decoder -
>>>>> http://keyj.emphy.de/kjmp2/
>>>>>
>>>>> On 01/03/2015 07:00 AM, Brian West wrote:
>>>>>> That looks like just the encoder, so we would need both the encoder
>>>>>> and decoder that takes signed linear.  I'll be on the look out for an
>>>>>> option too.
>>>>>>
>>>>>> On Fri, Jan 2, 2015 at 4:54 PM, Thomas Auge <auge at virtues.net
>>>>>> <mailto:auge at virtues.net>> wrote:
>>>>>>
>>>>>>          > G722 can be a native bearer capability on an ISDN b-channel but thats not widely used.  MP2 in your case is just
>>>>>>          > establishing a data channel be it via ISDN or IP.
>>>>>>
>>>>>>          Yup. I'm fairly certain that's what FreeTDM does for G722, else it
>>>>>>          wouldn't make much sense to have a codec
>>>>>>          configuration option. :)
>>>>>>
>>>>>>
>>>>>>          > Before proceeding I would seek out a license compatible
>>>>>>          encoder/decoder library that can be used, MP2 can mean so many
>>>>>>          > things their are multiple levels, options and details required
>>>>>>          to properly implement it.  I highly suspect its not an
>>>>>>          > afternoon event, I could be wrong if the right library is found
>>>>>>          thats license compatible.
>>>>>>
>>>>>>          There are a couple, T(w/o)oLame comes to mind.
>>>>>>          (http://www.twolame.org/ LGPL licensed) Any pointers as to which
>>>>>>          capabilities are needed in such a library? It seems the libraries
>>>>>>          are as outdated as the codec. :)
>>>>>>
>>>
>
>
> _________________________________________________________________________
> Professional FreeSWITCH Consulting Services:
> consulting at 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 at lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> http://www.freeswitch.org
>