search for: melp

Has anyone needed a coded that Asterisk does not natively support, such as MELPe or CVSD? If so, did you find a pure software solution and provided that as an addition to Asterisk? Was that solution successful? Has using an I/F card with a DSP proved to be the better solutions? We are beginners with Asterisk so any help/advice on how to best implement non-native Codecs into As...

You're asking the wrong question. The question is not "why does it would bad with Speex?", but "why does it sound good with LPC10 and MELP?". And the answer is that both are vocoders. Try dropping frames/subframes with anything else (Vorbis, MP3, G.729, u-law, ...) and it'll sound terrible as well. The only reason it sounds good with vocoders is because the codec parameters are in fact synthesizer parameters that don&...

...ke to know how well Speex handles multiple input streams. More specifically, if i have 4 streams that are playing at "the same time", how well does the CODEC handle switching from one stream to the next to process the audio. The reason i ask is this....My project up until now uses the MELP CODEC which didn't specifically have the ability to handle multiple streams. I'd give the CODEC a packet to process from Stream #1, then i'd give it a packet from Stream #2 and just keep cycling through my different input streams. The problem was that MELP used a lot of global varia...

Hi, Jean-Marc, and thanks for the quick reply. Let me just say I'm a huge fan of speex, and the work you've done. I actually barely understand what I'm reading so far in the source code and documentation, just enough to understand just how cool the algorithms are. LPC10 and MELP allow me to speed up speech with a simple hack on the decoder frame size. Playing fewer samples per frame speeds up the speech, without effecting the excitation. It works well, but not as well as I would like. I've attached a sample of a female voice sped up with MELPe. I fully understand b...

...a bandwidth of about 1.9 to 2.4 KHz round about. The shorter the bandwith the more a signal can reach. So I started wondering if it is maybe possible to compress a voice signal down to a bandwith of 1000 KHz which would be a PSK 1000 mode with a fully open Codec? The only thing I found so far is MELP (800 Bit/s), but, according to Wikipedia, it has some Patent rights so it can't be used freely. The only melp code I found so far available for download only has some Microsoft Developer Studio build information. So far, speex has a bandwith of 2150 Bits/s. Which is almost below the 2kBit...

...ining excellent quality. To date, I've been playing with low bit rate LPC coding, and it works, which is very cool. However, the quality of the voices I speed up are too low. The blind will hate me if try to switch them over to these low quality voices. I've tried both basic LPC-10, and MELPe. Next, I want to try modifying Speex to see if it can generate higher quality voice at high speed. Do you think this will this be a difficult or easy project? Do you think speex can be modified to generate very high quality voice at high speed? By high speed, I mean voice starting at about 2.5...

...ity is very poor. ?This is where it gets harder for > me, as the quality is impacted by so many parts of the code. ?Can > anyone guess which part of the decoder is leading to such poor quality > when I cut the frame size in half? ?This hack works very well in > LPC10, and fairly well in MELPe. > > I've attached two outputs from speex: the decoded playback at normal > speed, and the 2X speed version. > > Thanks, > Bill >

...it gets harder for >>> me, as the quality is impacted by so many parts of the code. ?Can >>> anyone guess which part of the decoder is leading to such poor quality >>> when I cut the frame size in half? ?This hack works very well in >>> LPC10, and fairly well in MELPe. >>> >>> I've attached two outputs from speex: the decoded playback at normal >>> speed, and the 2X speed version. >>> >>> Thanks, >>> Bill >>> >> _______________________________________________ >> Speex-dev mailing lis...

.... However, the quality is very poor. This is where it gets harder for me, as the quality is impacted by so many parts of the code. Can anyone guess which part of the decoder is leading to such poor quality when I cut the frame size in half? This hack works very well in LPC10, and fairly well in MELPe. I've attached two outputs from speex: the decoded playback at normal speed, and the 2X speed version. Thanks, Bill -------------- next part -------------- A non-text attachment was scrubbed... Name: 1x.ogg Type: audio/ogg Size: 48563 bytes Desc: not available Url : http://lists.xiph.org/pip...

.... This is where it gets harder for >> me, as the quality is impacted by so many parts of the code. Can >> anyone guess which part of the decoder is leading to such poor quality >> when I cut the frame size in half? This hack works very well in >> LPC10, and fairly well in MELPe. >> >> I've attached two outputs from speex: the decoded playback at normal >> speed, and the 2X speed version. >> >> Thanks, >> Bill >> > _______________________________________________ > Speex-dev mailing list > Speex-dev at xiph.org > ht...

We have Asterisk1.8.11 and can not move to a newer version right now. But when we run Asterisk as a service, the -r option does not result in giving the CLI prompt? Did the option to get the CLI change? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.digium.com/pipermail/asterisk-users/attachments/20130722/903d1851/attachment.htm>

...the US and some of the rules relating to amateur > satellite communications can be read to preclude the use of existing > proprietary algorithms. > > At present the low-bit rate algorithms known to be best suited to > amateur communications in the HF and VHF regions are AMBE and MELP, both > of which are seriously encumbered. An open source solution suited to > the peculiarities of this market would be welcomed and it is easy to > demonstrate that a chip based implementation would find a place in a > number of amateur digital voice devices. > > I will pr...

Hi, We would like to announce the first release of the Speex project. Speex (http://speex.sourceforge.net) is an open-source (LGPL), patent-free compression format allowing an alternative to expensive proprietary codecs. Unlike Ogg Vorbis which compresses general audio, Speex is designed especially for speech. For that reason, Speex is meant to be a complement to Vorbis. Since it is specialized