dtmf detection

Background System Structure Extension 1026 and extension 1027 are used in the existing telephone system, and an asterisk is implemented under extension 1026 and extension 1027. A: In the 1027 system, ext. B: 1011 in the 1026 system, ext. 1012 is now called B through a. Because the language menu is implemented in the 1026 system, first, you can use the 91026 incoming call 1026 system (with an external dialing 9), and then enter 1012 according to the prompt. The existing vswitch does not sup

Pjsip source code is relatively powerful. Let's talk about what DTMF is? Dual-Tone Multi-frequency DTMF (Dual Tone Multi frequency), dual-Tone Multi-frequency, composed of high frequency groups and low frequency groups, each of which contains four frequencies. A high-frequency signal and a low-frequency signal are combined to form a combined signal, representing a number. The

This item is the starting point for accurate identification of DTMF signals. After detecting this item, the DTMF decoder is triggered to decode the received data and wait until the corresponding dial key value is reached.1. analysis of input signal features: the signal is the circuit noise in the DTMF signal plus the channel. Now, preliminary analysis shows that

DTMF encoding transmitted by rfc2833 in Voice Transmission 2007-03-23 11:13:48 The class is defined as follows: # If! Defined (afx_head_2833_h000093b5c358_6f19_475b_a49f_13bfcc9dfe1c00000000ded _)# DefineAfx_head_2833_h000093b5c358_6f19_475b_a49f_13bfcc9dfe1c00000000ded _ # If _ msc_ver> 1000# Pragma once# Endif // _ msc_ver> 1000 Class chead_2833{Public:Bool dispelhead (char *Cvalue );Int btodd (char * cvalue );Char * dtob (intNvalue );Che

This article from csdn ucser, http://blog.csdn.net/perfectpdl reprinted to indicate the source, thank you! DTMF is called multi-tone dual-join, also called secondary dialing. There are three methods for VoIP to carry DTMF: inband, RFC 2833 (the latest RFC is 4733, which is referenced in IMS), and SIP info. The inband mode transfers the buffer generated by keys to the audio RTP stream, instead of definin

++) {unsigned char*p= (unsigned char*) img->imagedata+h*img->widthstep;for (int w=0;wwidth;w++) {unsigned int t=0;t+=*p++;tt+=*p++;tt+=*p++;Imginput.push_back (t);}}Sal. Getsaliencymap (Imginput, Img->width, Img->height, imgsal);Vector to Iplimageint index=0;iplimage* imgout=cvcreateimage (Cvgetsize (IMG), ipl_depth_64f, 1);for (int h=0;hheight;h++) {Double*p= (double*) (imgout->imagedata+h*imgout->widthstep);for (int w=0;wwidth;w++) {*p++=imgsal[index++];}}Name.append (". saliency.jpg");Cvsavei

This is an introduction to the face detection of technology from the view of the article: "2016 ACM MM unitbox:an Advanced Object Detection Network". The code should not be put out, but the implementation is relatively simple. (Interrupt a sentence, the paper said speed can reach 12fps, I'm a little panic, we look at science does not) —————————— split line —————————— Introduction Target

Estimating the distribution of P (x)--Density estimationWe have a sample of M, each sample has n eigenvalues, each of which obeys different Gaussian distributions, and the formula in the assumption that each feature is independent, the effect of the formula is good, regardless of whether each feature is independent. The formula for the multiplication is expressed as shown.Estimating The distribution of P (x) is called the density estimation problem (density estimation)Anomaly

Original URL: Http://www.cnblogs.com/laiqun/p/6501865.html The task of image target detection has made great progress in the past three years, and the detection performance has been significantly improved. But in video surveillance, vehicle-assisted driving and other fields, video-based target detection has a wider range of needs. Because of the problems such a

"Reprint" ILSVRC2016 Target Detection task review: Video target detection (VID) Reproduced from: http://geek.csdn.net/news/detail/133792The task of image target detection has made great progress in the past three years, and the detection performance has been greatly improved. But in the field of video surveillance, veh

DDoS attacks are essentially time-series data, and the data characteristics of t+1 moments are strongly correlated with T-moments, so it is necessary to use HMM or CRF for detection! --and a sentence of the word segmentation algorithm CRF no difference!Note: Traditional DDoS detection is directly based on the IP data sent traffic to identify, through the hardware firewall. Big data scenarios are done for sl

first, the paper Articles in the review category: [1] D. Geronimo, and A. M.lopez. vision-based pedestrian Protection Systems for Intelligent vehicles, book, 2014. [2] P.dollar, C. Wojek,b Schiele, et al pedestrian detection:an evaluation of the state of the art [J]. IEEE transactions on Patternanalysis andmachine Intelligence, 2012, 34 (4): 743-761. [3] Cogs Zhi, Li Shaozi, Chen Shuyuan, etc. Survey of pedestrian detection technology [J]. Journal of

The Windows Phone operating system can take actions to reduce power consumption on the device when it detects that the user or the current application is in an idle state. depending on the type of application you are creating, you may need to disable idle detection for users or applications. this topic explains how to modify the operating system's idle behavior. Important Note: This Windows Phone feature has certification requi

Example: Cocos2d-x physical engine: collision detection, cocos2d-x Collision DetectionCollision detection is an important purpose of using the physical engine. Using the physical engine can perform precise collision detection, and the execution efficiency is also high.Use the event dispatch mechanism in Cocos2d-x 3.x to manage collision events, and EventListenerP

In his blog Featuredetectionisnotbrowserdetection of the same name, NCZ describes a popular technology that has been used in front-end development-detection of users' browser platforms, and details historical development and advantages and disadvantages of various methods. I have roughly translated some articles and may have some misunderstandings. please correct me. It is worth noting that the comments are also worth reading. Feature

I have roughly translated some Article , Which may be incorrect. please correct me. It is worth noting that the comments are also worth reading. Feature Detection At first, front-end engineers opposed browser detection. They thought the User-Agent sniffing method was very bad because it was not a future-oriented method.Code, Cannot adapt to the new version of the browser. A better way is to use feature