Re: [Asterisk-Users] G729 vs. gsm
[EMAIL PROTECTED] wrote: On Sun, 29 May 2005, Steve Underwood wrote: It isn't a one way scale. Music on hold over G.729 is often unrecognisable. Over GSM 06.10 it is usually just poor. Is that a big issue for you, or totally irrelevant? GSM 06.10 and G.729 at 8kbps offer fairly similar quality for clean voice. GSM wins when there is background noise. G.729 wins on bit rate. One nice feature of GSM is that people are used to the way it sounds from their cellphones, they mentally tune the distortions out. Very few GSM phones/networks use the 06.10 codec any more. Its all half-rate, EFR and AMR these days. I think only phones more than 5 years old, or ancient cell sites, will be using 06.10, although all current phones still support it for compatibility. Regards, Steve ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
On Sun, 29 May 2005, Steve Underwood wrote: > It isn't a one way scale. Music on hold over G.729 is often > unrecognisable. Over GSM 06.10 it is usually just poor. Is that a big > issue for you, or totally irrelevant? GSM 06.10 and G.729 at 8kbps offer > fairly similar quality for clean voice. GSM wins when there is > background noise. G.729 wins on bit rate. One nice feature of GSM is that people are used to the way it sounds from their cellphones, they mentally tune the distortions out. Steve ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
We use g729 for everything, and it sounds great. Have no sound clips handy, but on decient equipment it works very very well. Preston Garrison direct: 877-748-4142 fax: 310-774-3901 cell: 623-748-4140 -Original Message- From: Marie <[EMAIL PROTECTED]> To: Asterisk Users Mailing List - Non-Commercial Discussion Sent: Sat, 28 May 2005 23:47:44 -0400 Subject: Re: [Asterisk-Users] G729 vs. gsm Anyone have the time and webspace to post a quick recording of a sample conversation in both codecs? If you want to get even more tricky, perhaps samples of music on hold in both as well? Or noisy environments? Obviously not very scientific and prone to a wide margin of error (background noise, etc) -- but I think if there was a comparison sound file posted on the Wiki or something it would help people feel better informed before jumping on the Digium licenses. Just a quick test for "humm, that doesn't sound too bad, maybe it's worth spending $10 for each license and fiddling with everything to give it a try". I can't be the only one that isn't quite sure where to place G729 on the scale of GSM - ULaw. ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
Marie wrote: Anyone have the time and webspace to post a quick recording of a sample conversation in both codecs? If you want to get even more tricky, perhaps samples of music on hold in both as well? Or noisy environments? This kind of quickie test is worthless. In doing serious codec evaluation we do things called MOS scores. They cost a fortune, as they involve lots of people over a long period. Basically they involve asking a large number of people to rate quality over a large number of varied voice samples. As an example of why a single test is useless, most codecs are better at coding male voices than female voices - i.e. they favour lower pitched voices. A couple of codecs are the other way around. If you ever tried the original US digital AMPS cellular system you will have heard this effect very clearly. The absolute meaningful comparison is with a few people having widely varying voices. Obviously not very scientific and prone to a wide margin of error (background noise, etc) -- but I think if there was a comparison sound file posted on the Wiki or something it would help people feel better informed before jumping on the Digium licenses. Even the MOS approach is not that scientific. Its still a subjective assessment, but at least it is averaged over a large number of people. A real problem with MOS, is how the layman is supposed to interpret the results. CD audio scores 5 - that is the maximum. G.711 gets about 4.5. The subjective assessment of most people is that is G.711 is quite a lot worse than CD audio. Actually, it is more than just subjective. The narrow bandwidth of G.711 looses the difference between, say, and "s" and an "f". All unvoiced sounds come out much the same over a normal PSTN phone. G.729 scores about 4. That might not sound too much lower than G.711. However, if you have worked with MOS you will know that 0.5 is actually rather a big drop. Subjective comments from people in the MOS tests says the difference is substantial. If people cannot actually tell the difference, this can be traced back to a problem with their hearing. G.723.1 scores about 3.8. Again, that might not sound too much worse than G.729, but it doesn't tell the whole story. Have you ever tried identifying speakers over G.723.1? It does a good job of avoiding robotic sound, but tends to make everyone sound alike. Issues like that can be important, but don't always get highlighted by MOS. One very bad thing about MOS, and most of the playoffs for standards bodies (e.g. picking the GSM codecs from amongst the submitted contenders) is these tests rarely introduce background noise, or anything other than a single human voice talking. Codecs in common use have not, therefore, been selected for any tolerance to what is commonly sent down a telephone line (this is a particular problem with cellular standards, as these phones are heavily used in noisy places). For VoIP users, there is also the problem that few people perform any meaningful assessments of how badly packet loss degrades things. This varies quite a lot between codecs. G.729 and G.723.1 are rather bad at tolerating packet loss. Just a quick test for "humm, that doesn't sound too bad, maybe it's worth spending $10 for each license and fiddling with everything to give it a try". I can't be the only one that isn't quite sure where to place G729 on the scale of GSM - ULaw. It isn't a one way scale. Music on hold over G.729 is often unrecognisable. Over GSM 06.10 it is usually just poor. Is that a big issue for you, or totally irrelevant? GSM 06.10 and G.729 at 8kbps offer fairly similar quality for clean voice. GSM wins when there is background noise. G.729 wins on bit rate. The real world gets so complicated. :-) Regards, Steve ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
Anyone have the time and webspace to post a quick recording of a sample conversation in both codecs? If you want to get even more tricky, perhaps samples of music on hold in both as well? Or noisy environments? Obviously not very scientific and prone to a wide margin of error (background noise, etc) -- but I think if there was a comparison sound file posted on the Wiki or something it would help people feel better informed before jumping on the Digium licenses. Just a quick test for "humm, that doesn't sound too bad, maybe it's worth spending $10 for each license and fiddling with everything to give it a try". I can't be the only one that isn't quite sure where to place G729 on the scale of GSM - ULaw. ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
Tim Pushor wrote: Its obvious that Steve never looses, even when he's wrong, so arguing about it to him won't get anywhere. I have been known to loose arguments. Not too many, but some. :-) As for g729, I was pleasantly surprised by the quality. I fully agree. I may be old fashioned, but the purpose of my phone system is to communicate voice with other people, mostly in a business environment (low background noise). MY perception is that it works very well, much better than I had anticipated. In fact, it allowed me to drop a nice IP phone at one of my customers premises that have a less than stellar internet connection (ulaw was stutter city), with no outbound shaping. I fully agree. I don't care about what anyone else says, I am impressed with g729 and if it weren't for 1) the cost of transcoding and 2) the lack of g729 on FreeBSD I'd be using it more. I fully agree. Just my (humble) $0.02 CDN Now tell me what relevance any of what you said has to the issue at hand. People come here looking for advice. How good is it? What are the pitfalls? Telling them G.729 is as good as G.711 is just plain stupid. They want a meaningful comparison - do I loose a little, or do I loose a lot? Tim Regards, Steve ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
On Saturday 28 May 2005 00:53, Tim Pushor wrote: > Its obvious that Steve never looses, even when he's wrong, so arguing > about it to him won't get anywhere. It's obvious to anyone who's been doing this for any amount of time that he's not wrong here. But hey -- don't let reality get in the way of your statements. > As for g729, I was pleasantly surprised by the quality. As am I. It's great for a single voice in a relatively quiet environment. That's exactly what it was *designed* for and, as Steve points out, it works very well for its intended purpose. > I don't care about what anyone else says, I am impressed with g729 and > if it weren't for 1) the cost of transcoding and 2) the lack of g729 on > FreeBSD I'd be using it more. I use it too. Hell I bet Steve uses it where he needs it. Nobody said it was crap. -A. ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
On Saturday 28 May 2005 12:34, Rusty Shackleford wrote: > > This is meaningless drivel. > > Hardly. Each conversion introduces the equivalent of "gen loss". Two > such conversions are easily encountered, especially when dealing with a > third-party network, and will produce (in MY subjective opinion) > positively crappy sound. Actually Steve's right on this one -- converting to or from ulaw is not costing you any quality. recoding to g729 or any other compressed codec is. You can convert between ulaw and alaw 1 times and it'll sound exactly the same as the original 8000Hz 16-bit sample because... well... it is. > Yes, and your guidance is oh-so-meaningful. > Prove you're right. I'm solidly behind Steve here; sip to sip you're gonna be converting to slinear at both ends just to get the sound into your ears and from your mouth so there'll always be at least two conversions. gsm and g729 sound pretty damn good for their bitrates; that's why people use them. But to say they sound identical to g711 is ... well, just plain wrong. -A. ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
Well shame on me. There they are, plain as day. I stumbled upon some posts in the FreeBSD mailing list complaining about the lack of the g729 codec on FreeBSD, and assumed that was still the case. Thanks for pointing that out, Tim snacktime wrote: city), with no outbound shaping. I don't care about what anyone else says, I am impressed with g729 and if it weren't for 1) the cost of transcoding and 2) the lack of g729 on FreeBSD I'd be using it more. The digium g729 codec works fine on Freebsd 5.X. Chris ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
city), with no outbound shaping. > > I don't care about what anyone else says, I am impressed with g729 and > if it weren't for 1) the cost of transcoding and 2) the lack of g729 on > FreeBSD I'd be using it more. The digium g729 codec works fine on Freebsd 5.X. Chris ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
Its obvious that Steve never looses, even when he's wrong, so arguing about it to him won't get anywhere. As for g729, I was pleasantly surprised by the quality. I may be old fashioned, but the purpose of my phone system is to communicate voice with other people, mostly in a business environment (low background noise). MY perception is that it works very well, much better than I had anticipated. In fact, it allowed me to drop a nice IP phone at one of my customers premises that have a less than stellar internet connection (ulaw was stutter city), with no outbound shaping. I don't care about what anyone else says, I am impressed with g729 and if it weren't for 1) the cost of transcoding and 2) the lack of g729 on FreeBSD I'd be using it more. Just my (humble) $0.02 CDN Tim Rusty Shackleford wrote: -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Steve Underwood Sent: Friday, May 27, 2005 6:40 PM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: Re: [Asterisk-Users] G729 vs. gsm Well, it does to anyone without hearing damage. It sounds very obviously different. Different, yes, but to what degree is an entirely subjective judgement. Ergo, your judgement of "...very obviously different..." is valid only for you. Please do not get me wrong that G711u sounds better through the PSTN. Thats a given! You can't convert G729 up and down to G711 and expect the sound quality to be there. This is meaningless drivel. Hardly. Each conversion introduces the equivalent of "gen loss". Two such conversions are easily encountered, especially when dealing with a third-party network, and will produce (in MY subjective opinion) positively crappy sound. Since it doesn't correlate with the impression of even the developers of G.729, it *is* bad information. Realistic people know G.729 will be worse. What they need is meaningful guidance as to just how much. Yes, and your guidance is oh-so-meaningful. ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] G729 vs. gsm
> -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > Steve Underwood > Sent: Friday, May 27, 2005 6:40 PM > To: Asterisk Users Mailing List - Non-Commercial Discussion > Subject: Re: [Asterisk-Users] G729 vs. gsm > Well, it does to anyone without hearing damage. It sounds > very obviously different. Different, yes, but to what degree is an entirely subjective judgement. Ergo, your judgement of "...very obviously different..." is valid only for you. > > Please do not get me wrong that G711u sounds better through the PSTN. > > Thats a given! You can't convert G729 up and down to G711 and expect > > the sound quality to be there. > This is meaningless drivel. Hardly. Each conversion introduces the equivalent of "gen loss". Two such conversions are easily encountered, especially when dealing with a third-party network, and will produce (in MY subjective opinion) positively crappy sound. > Since it doesn't correlate with the impression of even the > developers of > G.729, it *is* bad information. Realistic people know G.729 will be > worse. What they need is meaningful guidance as to just how much. Yes, and your guidance is oh-so-meaningful. -- Internal Virus Database is out-of-date. Checked by AVG Anti-Virus. Version: 7.0.322 / Virus Database: 266.11.14 - Release Date: 05/20/2005 ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
Clue or clueless? Your call. Steve Underwood wrote: Michael D Schelin wrote: Steve, you should really test the Codec and have G729 running as a pure IP to IP call you can not hear the difference on good networks! Well, it does to anyone without hearing damage. It sounds very obviously different. Please do not get me wrong that G711u sounds better through the PSTN. Thats a given! You can't convert G729 up and down to G711 and expect the sound quality to be there. I'm a carrier and have tested G711 and G729 and have found that they both sound great through dedicated hardware. This is meaningless drivel. Asterisk's colors the G729 a little. Also my The only time when Asterisk colours G.729 is when there is packet loss. Asterisk isn't handling that well. hearing is fine. Please do not put down the comments of others in this forum. I'm stating my comments from my real world trials and this is not bad information. Since it doesn't correlate with the impression of even the developers of G.729, it *is* bad information. Realistic people know G.729 will be worse. What they need is meaningful guidance as to just how much. The man must compare codecs on his own and see what works for him. For me we've stuck with G711u because it's best through the PSTN. If I was running a pure IP to IP system I would use G729, Iblc, or GSM. In a sane world pure IP to IP systems would't use G.711, G,729, iLBC, or GSM. They would be usign a wideband codec, as Skype does. Look at the favourable impression people have of that. Next time, its probably better to argue with someone who hasn't spent time in speech codec development. We tend to have a clue what we are talking about. :-) Regards, Steve ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
Michael D Schelin wrote: Steve, you should really test the Codec and have G729 running as a pure IP to IP call you can not hear the difference on good networks! Well, it does to anyone without hearing damage. It sounds very obviously different. Please do not get me wrong that G711u sounds better through the PSTN. Thats a given! You can't convert G729 up and down to G711 and expect the sound quality to be there. I'm a carrier and have tested G711 and G729 and have found that they both sound great through dedicated hardware. This is meaningless drivel. Asterisk's colors the G729 a little. Also my The only time when Asterisk colours G.729 is when there is packet loss. Asterisk isn't handling that well. hearing is fine. Please do not put down the comments of others in this forum. I'm stating my comments from my real world trials and this is not bad information. Since it doesn't correlate with the impression of even the developers of G.729, it *is* bad information. Realistic people know G.729 will be worse. What they need is meaningful guidance as to just how much. The man must compare codecs on his own and see what works for him. For me we've stuck with G711u because it's best through the PSTN. If I was running a pure IP to IP system I would use G729, Iblc, or GSM. In a sane world pure IP to IP systems would't use G.711, G,729, iLBC, or GSM. They would be usign a wideband codec, as Skype does. Look at the favourable impression people have of that. Next time, its probably better to argue with someone who hasn't spent time in speech codec development. We tend to have a clue what we are talking about. :-) Regards, Steve ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] G729 vs. gsm
We too are a carrier / clec and our lucent iMerge for the PTSN is all g711-ulaw -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Michael D Schelin Sent: Friday, May 27, 2005 3:07 PM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: Re: [Asterisk-Users] G729 vs. gsm Steve, you should really test the Codec and have G729 running as a pure IP to IP call you can not hear the difference on good networks! Please do not get me wrong that G711u sounds better through the PSTN. Thats a given! You can't convert G729 up and down to G711 and expect the sound quality to be there. I'm a carrier and have tested G711 and G729 and have found that they both sound great through dedicated hardware. Asterisk's colors the G729 a little. Also my hearing is fine. Please do not put down the comments of others in this forum. I'm stating my comments from my real world trials and this is not bad information. The man must compare codecs on his own and see what works for him. For me we've stuck with G711u because it's best through the PSTN. If I was running a pure IP to IP system I would use G729, Iblc, or GSM. Mike Steve Underwood wrote: > Michael D Schelin wrote: > >> I have used G729 and it sounds almost as good as G711U. The problem is >> the way Asterisk uses it. It does not sound robotic and it's not >> suppose to sound that way. Most Carriers want the calls to be in >> g711u so thats why I use G711u otherwise I want to save money on >> bandwidth. G729 on Asterisk adds latency. this could be one of your >> problems. Also you will not get music on hold to play well with G729. > > > G.729 doesn't sound that bad. However, if you find it hard to tell G.729 > from G.711, I think you should have your hearing checked. :-) It really > doesn't help people to assess what is right for them, if other people > make these exaggerated and unreasonable claims. Even the people > promoting G.729 give it a MOS far below G.711. You are certainly right > about music on hold, but even voice plus a little background noise can > sound bloody awful through G.729. Its performance is *very* dependant on > compressing just a single human voice. > > Regards, > Steve > > ___ > Asterisk-Users mailing list > Asterisk-Users@lists.digium.com > http://lists.digium.com/mailman/listinfo/asterisk-users > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users > > ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
Steve, you should really test the Codec and have G729 running as a pure IP to IP call you can not hear the difference on good networks! Please do not get me wrong that G711u sounds better through the PSTN. Thats a given! You can't convert G729 up and down to G711 and expect the sound quality to be there. I'm a carrier and have tested G711 and G729 and have found that they both sound great through dedicated hardware. Asterisk's colors the G729 a little. Also my hearing is fine. Please do not put down the comments of others in this forum. I'm stating my comments from my real world trials and this is not bad information. The man must compare codecs on his own and see what works for him. For me we've stuck with G711u because it's best through the PSTN. If I was running a pure IP to IP system I would use G729, Iblc, or GSM. Mike Steve Underwood wrote: Michael D Schelin wrote: I have used G729 and it sounds almost as good as G711U. The problem is the way Asterisk uses it. It does not sound robotic and it's not suppose to sound that way. Most Carriers want the calls to be in g711u so thats why I use G711u otherwise I want to save money on bandwidth. G729 on Asterisk adds latency. this could be one of your problems. Also you will not get music on hold to play well with G729. G.729 doesn't sound that bad. However, if you find it hard to tell G.729 from G.711, I think you should have your hearing checked. :-) It really doesn't help people to assess what is right for them, if other people make these exaggerated and unreasonable claims. Even the people promoting G.729 give it a MOS far below G.711. You are certainly right about music on hold, but even voice plus a little background noise can sound bloody awful through G.729. Its performance is *very* dependant on compressing just a single human voice. Regards, Steve ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
On May 27, 2005 01:27 pm, Michael D Schelin wrote: > I have used G729 and it sounds almost as good as G711U. The problem is > the way Asterisk uses it. It does not sound robotic and it's not suppose > to sound that way. Most Carriers want the calls to be in g711u so > thats why I use G711u otherwise I want to save money on bandwidth. G729 > on Asterisk adds latency. this could be one of your problems. Also you > will not get music on hold to play well with G729. Latency is increased any time you have to take time to mangle bits. This means going from any codec to any other codec. Of course, some codecs take more time to mangle the bits than others, and this is the case with any decent-sounding compressed codec such as gsm or g729 or even ilbc or speex. If the latency's too high, get a more powerful system. The codecs are all coded fairly well so there's not much to be gained by trying to reimplement the codec. Also g729 sounds nothing like toll quality; the compressed codecs are able to compress so well by throwing away large chunks of the already limited trunk bandwidth. As a result, music sounds like crap on most compressed codecs. Personally I find gsm plays on hold music quite well (obviously not amazingly well and nowhere near as good as ulaw), but yes g729 mangles it pretty well. :-) It's not an Asterisk problem, and it's not a g729 problem. Hell, it's not even an implmentation issue. It's the nature of the beast. -A. ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
Michael D Schelin wrote: I have used G729 and it sounds almost as good as G711U. The problem is the way Asterisk uses it. It does not sound robotic and it's not suppose to sound that way. Most Carriers want the calls to be in g711u so thats why I use G711u otherwise I want to save money on bandwidth. G729 on Asterisk adds latency. this could be one of your problems. Also you will not get music on hold to play well with G729. G.729 doesn't sound that bad. However, if you find it hard to tell G.729 from G.711, I think you should have your hearing checked. :-) It really doesn't help people to assess what is right for them, if other people make these exaggerated and unreasonable claims. Even the people promoting G.729 give it a MOS far below G.711. You are certainly right about music on hold, but even voice plus a little background noise can sound bloody awful through G.729. Its performance is *very* dependant on compressing just a single human voice. Regards, Steve ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
I have used G729 and it sounds almost as good as G711U. The problem is the way Asterisk uses it. It does not sound robotic and it's not suppose to sound that way. Most Carriers want the calls to be in g711u so thats why I use G711u otherwise I want to save money on bandwidth. G729 on Asterisk adds latency. this could be one of your problems. Also you will not get music on hold to play well with G729. Andrew Kohlsmith wrote: On May 27, 2005 06:12 am, chawki hammoud wrote: I installed G729 from Diguim and I was expecting the sound quality on my i686 machine to be better than gsm. Compared to gsm, G729 sounds closer and a little robotic. Is this what is supposed to be or am I missing something? It sounded more or less the same to me, perhaps with GSM being a little more human (I can easily listen to music on hold with GSM). I am interested in G729 because the internet in my country is very expensive and I want to save every bit possible. I want to use G729 because it takes less bandwidth for each additional call between two IAX servers than other codecs. Make sure you use IAX2 trunking then. It can give you very large bandwidth savings when you have multiple audio streams between two servers since the UDP overhead is not repeated for every call. -A. ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
chawki hammoud wrote: I installed G729 from Diguim and I was expecting the sound quality on my i686 machine to be better than gsm. Compared to gsm, G729 sounds closer and a little robotic. Is this what is supposed to be or am I missing something? I am interested in G729 because the internet in my country is very expensive and I want to save every bit possible. I want to use G729 because it takes less bandwidth for each additional call between two IAX servers than other codecs. Why did you expect it to sound better? Its a "high quality for 8kbps" codec. By absolute standards it sucks. GSM is less sophisticated, but running at 13.2kbps it can get away with that, and still sound as good. In fact, if there is lots of background noise GSM sounds rather better. Regards, Steve ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] G729 vs. gsm
On May 27, 2005 06:12 am, chawki hammoud wrote: > I installed G729 from Diguim and I was expecting the > sound quality on my i686 machine to be better than > gsm. Compared to gsm, G729 sounds closer and a little > robotic. Is this what is supposed to be or am I > missing something? It sounded more or less the same to me, perhaps with GSM being a little more human (I can easily listen to music on hold with GSM). > I am interested in G729 because the internet in my > country is very expensive and I want to save every bit > possible. I want to use G729 because it takes less > bandwidth for each additional call between two IAX > servers than other codecs. Make sure you use IAX2 trunking then. It can give you very large bandwidth savings when you have multiple audio streams between two servers since the UDP overhead is not repeated for every call. -A. ___ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
