search for: vocoder

Hi everyone, I?m a graduate student in a Brazilian Intitute of Technology, and I?m doing some academic research regarding secure voice transmission over phone lines. One of our reserach goals is to implement a hardware vocoder, with low bit rates, and a preferably free algorithm, to be used in this secure voice system. Actually, there is a functional system using a proprietary AMBE board (also a very expensive one) with a bit rate of 4800bps. When I found this project, I tought the vocoder hardware could be implemen...

Hello, I'm interested in a low rate vocoder to run on SA-1110 or XScale processor (for PDAs voice application). Is there a suitable speex vocoder for that? Thanks in advance, Eyal. ________________________________________________ Get your own "800" number Voicemail, fax, email, and a lot more http://www.ureach.com/reg/tag --- &g...

Hi, My name is Jean Quirion and I am a DSP engineer. Currently I am working on a project where it is desired to implement a VoIP solution over a GSM GPRS link. I would like to use Speex as the vocoder for this application. This application would require the Speex encoder/decoder and possibly the pre-processor to run on a low power fixed-point DSP such as a TI C55x. Thus, I am interested in getting involved in the fixed-point implementation of Speex. I feel I can contribute significantly to the...

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't have a direct connection with the signal....

...ke.ca> Date: Jul 22, 2005 1:02 AM Subject: Re: [Speex-dev] Fixed-point To: gue baja <gue_baja@yahoo.com> Cc: speex-dev@xiph.org Hi Baja, Here's a quick summary: In narrowband, the encoder and decoder are all ported to fixed-point for CBR between 4 kbps and 18.2 kbps. Only the 2 kbps (vocoder) and 24.6 kbps modes still have a few floats left. Most of wideband is also ported, but there are some float operations left. The packet loss concealment is also done, but not the VAD/VBR. The jitter buffer isn't converted, but there's not many float ops there in the first place. The prepro...

...sted, there are two Speex-related projects (below) and lots more in Xiph.Org in general (see http://wiki.xiph.org/index.php/Summer_of_Code). You can apply at http://groups.google.com/group/google-summer-of-code-announce/web/guide-to-the-gsoc-web-app-for-student-applicants Cheers, Jean-Marc *New vocoder for Speex* This is a real speech coding project! Speex currently has a very low bit-rate (2.15 kbps) mode that is implemented as a trivial vocoder. This mode has four "reserved" bits per frame, which means it would be possible to transmit more information. The idea of this project would...

...*** -And this is the basic seting of my two GrandStream SIP phones: ***************[1005]**************** IP Address:192.168.0.105 Subnet Mask:255.255.255.0 SIP Server: 192.168.0.103 Outbound Proxy:<empty> SIP User ID:1005 Authenticate ID:1005 Authenticate Password:123 Name:1005 Preferred Vocoder: choice 1: PCMU choice 2: PCMA choice 3: G723 choice 4: G729 choice 5: G726-32 choice 6: G728 G723 rate: 6.3kbps Silence Suppression:No Send DTMF:in-audio ***************[1004]**************** IP Address:192.168.0.104 Subnet Mask:255.255.255.0 SIP Server: 192.168.0.103 Outbound Proxy:<empty&g...

for the bits init I am using speex_bits_set_bit_buffer and I don't use the write to or read from because the data is already in the buffer I am reading from and I am writing to the final buffer so I don't need to move arrays around. what part is the vocoder part of the decode? Thanks for your help! -Mike >>> Jean-Marc Valin <jean-marc.valin@usherbrooke.ca> 08/06/07 7:00 PM >>> > I am aware that some of these functions are only not called because I > don't do a GET_ in the ctl functions or don't use ALLOC to in...

...ay, July 19, 2007 8:04 AM Subject: [Speex-dev] How Can I Get involved in Speex Fixed-PointDevelopment? Hi, My name is Jean Quirion and I am a DSP engineer. Currently I am working on a project where it is desired to implement a VoIP solution over a GSM GPRS link. I would like to use Speex as the vocoder for this application. This application would require the Speex encoder/decoder and possibly the pre-processor to run on a low power fixed-point DSP such as a TI C55x. Thus, I am interested in getting involved in the fixed-point implementation of Speex. I feel I can contribute significantly to the...

I was wondering if the developers were using anything to "objectively" test the quality of the speex vocoder. For instance PSQM or one of the many derivatives. Mean Opinion Scoring seems an expensive route. Is there some open source software to use for this? <p>--- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this lis...

Is there any place where I can see a summary of what is being done and what is still pending with the fixed point version of the libraries? I have some experience with vocoders and fairly good experience with de-jitters and suchs. I may be able to help. Thanks Baja

...9, 2007 8:04 AM Subject: [Speex-dev] How Can I Get involved in Speex Fixed-PointDevelopment? Hi, My name is Jean Quirion and I am a DSP engineer. Currently I am working on a project where it is desired to implement a VoIP solution over a GSM GPRS link. I would like to use Speex as the vocoder for this application. This application would require the Speex encoder/decoder and possibly the pre-processor to run on a low power fixed-point DSP such as a TI C55x. Thus, I am interested in getting involved in the fixed-point implementation of Speex. I feel I can contribute significant...

...r-speex-dev@xiph.org]On > Behalf Of Jean-Marc Valin > Sent: Tuesday, February 25, 2003 7:24 PM > To: speex > Subject: Re: [speex-dev] Quality > > > > I was wondering if the developers were using anything to > "objectively" test > > the quality of the speex vocoder. For instance PSQM or one of the many > > derivatives. Mean Opinion Scoring seems an expensive route. > > > > Is there some open source software to use for this? > > Well, I haven't found and open-source perceptual testing software, so > I've relied so far mostl...

...The wideband indeed goes away with DISABLE_WIDEBAND but that's about all. Due to extensive use of function pointers very little unused stuff beyond wideband goes away when unused. For starter, I would like DISABLE_VBR analogous to DISABLE_WIDEBAND. After that, it's probably possible to put vocoder under conditional compilation the stuff that is used only in vocoder modes. It seems that modes 3 to 7 are too similar to each other to save significant amount of code by eliminating some of them, but I have a feeling that generic mechanism for picking only those modes needed (either through con...

I've noticed that the nb decoder uses floating point in several places even when using FIXED_POINT. I don't have to deal with lost packets, so I'm mainly interested in innov_gain and pgain in no transmission mode (nb_celp.c around line 1272) and g and exci in vocoder mode (around line 1557). Is there a reason that these places must use floating point, or would it be possible to make them use fixed point? -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 2363 bytes Desc: smime...

...e: [Speex-dev] Fixed-point > To: gue baja < gue_baja@yahoo.com> > Cc: speex-dev@xiph.org > > Hi Baja, > > Here's a quick summary: > In narrowband, the encoder and decoder are all ported to fixed-point > for > CBR between 4 kbps and 18.2 kbps. Only the 2 kbps (vocoder) and 24.6 > kbps modes still have a few floats left. Most of wideband is also > ported, but there are some float operations left. The packet loss > concealment is also done, but not the VAD/VBR. The jitter buffer > isn't > converted, but there's not many float ops there in t...

...lh host=dynamic canreinvite=no The phone as the default config on it. If I use the phone to call a Zap interface (a tdm card) the voice sounds all choppy. If I use the phone to call a x100p card, it does not dial what I dial (no DTMF) I don't know what else to try.....should I change the vocoder (it is on PCMU at the momemnt) I am using the phone on a LAN so bandwidth is not an issue. Any Help would be great, Michael

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

...playback. Bill 2010/10/19 Jean-Marc Valin <Jean-Marc.Valin at usherbrooke.ca>: > 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't have a direct > connection with...

I'm trying to get ChansSpy to work. It works, in the pass/fail sense, but it is difficult to understand the various speakers. I can hear users on our end just fine, but the other end sounds like their going through a vocoder, if I can understand them at all. Otherwise it is just garbled. We are using the following setup: all of our phones are SIP phones; for our outgoing calls we make use of a voice PRI, but for incoming calls (and failover in case the PRI goes down) we use an IAX2 provider. Hearing our internal SIP us...