VAS/AMR codec fine tuning problem for GPRS/EDGE network

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Hi,

Well, as remote specifies mode-set param, the local encoder must obey
it, rfc4867 sec 8.1:
"... If mode-set is specified, it MUST be abided, ...."

Regarding jitter buffer, I think we'll always need it for
'normalizing' jitter and clock drift, so instead of omitting it,
perhaps it's better to improve it and share the good result to the
community :)

BR,
nanang


2010/2/1 cq_wei <cq_wei at 126.com>:
> naning,
> It does not sound change anything. The 200 OK message have SDP setting
> modeset=1 which means 5150bps is always selected,
> so the fix for ticket #1028 does not change anything. For ticket #969, Would
> passthrough codec using jitter buffer of pjmedia? I suppose we should
> minimize jitter buffer for passthrough codec and let the rtp packet
> passthrough to VAS directly!
>
> I have merge both fix but the voice quality still have gap with Nokia's own
> implementation.
>
> Anyway thanks for help. I will dive deeper into code to trace the problem.
>
>
>
>> >Message: 1 >Date: Fri, 29 Jan 2010 19:45:53 +0700
>> > >From: Nanang Izzuddin <nanang@xxxxxxxxx>
>> > >To: pjsip list <pjsip at lists.pjsip.org>
>> > >Subject: Re: VAS/AMR codec fine tuning problem for GPRS/EDGE >
>> > network >Message-ID: >
>> > <f8a01ced1001290445w129d3374x4e3ad1225dbd3f6d at mail.gmail.com>
>> > >Content-Type: text/plain; charset=GB2312 > >Hi, >
>> > >Please update your source from SVN trunk, in case you haven't. There
>> > >was a bug in VAS wrapper regarding bitrate setting, so AMR always
>> > >worked on 4750bps bitrate regardless the setting. This has been fixed
>> > >in changeset 3078 (of ticket #1028). Also, there has been a work on
>> > >jitter buffer for low bandwidth network, please see ticket #969. >
>> > >We'll be glad to hear any feedbacks. > >BR, >nanang > >
>> > >2010/1/29 cq_wei <cq_wei at 126.com>: >> Hi all, >>
>> > >> Anybody know if there is more params to adjust? I am building an user agent
>> > >> on symbian platform using VAS/AMR codec, it works but the voice quality is
>> > >> poor. In order to fine tuning I have change the following things >>
>> > >> 1)       Default codec , I have changed the definition for AMR's codec_desc
>> > >> in passthrough codec.c. the default mode and frame per packet have been
>> > >> adjusted (I just change them same as nokia's own PoC client). >>
>> > >> 2)       Media_cfg. Using default configuration. default param is most
>> > >> suitable for VAS/AMR passthrough codec, right? >>
>> > >> Still the quality is uncomparable with Nokia's own client (NOKIA PTT
>> > >> client). The delay is longer (Nokia's is 1 second around while mine is 2
>> > >> seconds around) and jitter is obvious. The network is GRPS/EDGE. >>
>> > >> Is there any more params I can adjust to improve voice quality? >>
>
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