We are developing a video chatting application on flex, it works well on Desktop systems and while running on a laptop the sound is loop backed and becomming a large noise, Please help me to fix the problem.
I can't speak to your problem from a coding from a coding standpoint. But, from a sound standpoint, feedback is created when the microphone picks up the sound coming out of the speaker that is amplifying the sound. So, kind of like this:
Speak into a Microphone
Your voice comes out of the speaker
The microphone picks uo your voice from the speaker
Your "speaker" voice is now coming out of the "speaker" a second time.
The microphone picks up the speaker noise, etc..
When setting up sound for live bands, it is best to get the microphone as far away from the monitors as possible. Some people even suggest making sure the "vocal" mic is perpendicular to the speaker.
I envision that here is nothing, codewise, you can do to solve this problem, if this is in fact your problem.
Try a headset mic on the laptop. Does that solve the problem?
Related
I'm trying to write an app that will be able to see when a lot of people are close inside a single area. I was thinking to use BLE. I don't have a good knowledge of this technology and I have a single, but big question. In modern days, how easy is it to see a BL device that is actually transmitting and discoverable in places like streets, etc...? It's my idea very dumb? Will my idea work with the spread of contact-tracing apps?? Thank you.
You can scan the Bluetooth frequency bands to detect devices that are advertising themselves, so yes, this is possible.
What might be more difficult is making sense of it all. If I run a Bluetooth scanner in my study, I get dozens of devices, most of which I have no idea what they are. A lot of them will probably belong to the people living next door; some advertise their name (Apple TV, for example), but most don't. If you look at the signal strength you can probably rule out a fair few devices that are too far away for your purposes.
I want to know if someone has a recording of someone else's voice, can they use that recording with Speaker Recognition API to pretend they are that person. I.e. can Speak Recognition API recognise if a voice is live or recorded?
Interesting question. I can't provide an answer specific to the Microsoft technology you mentioned, but I can make a few general remarks that might hold true nevertheless:
First, any technical system can only "listen" to a human voice through... a recording, since it doesn't have ears. So the real question is, can it distinguish between a live recording of a human voice and a pre-recorded recording of a human voice? Basically, that's something akin to a reversed Turing test where the machine tries to determine whether it's dealing with a machine, or a human.
Even if we ignore this very fundamental issue for a moment, I suspect that distinguishing between "live talk" and a "recording" might be difficult for any AI. This is easy for humans among other things because...
the reverb characteristics of what you hear often do not match the place that you are in; or
the sound isn't 3D enough; or
sound fidelity does not match what it should typically be for the sound transmission medium.
For those reasons distinguishing live & playback becomes harder over telecom (ever confused an answering machine with a real human?), but
if you know the person and/or the place they are supposedly in (typical background sounds) it's still easily possible.
An AI can't use these kinds of implicit knowledge of a person & their places.
One thing that an AI could do just like humans is try to interrupt the other party and see whether the other party stops talking to listen. If the other party doesn't react at all, it's perhaps a recording (the answering machine problem again). Though that's clearly not a foolproof test. We're back to in reverse Turing test waters.
P.S. if, in the course of trying to answer this question, you invent an acoustic, reversed version of ELIZA that tries to figure out whether her patient is human or not, I'm offering myself as a test subject. That would be a wickedly fun experiment.
yes, of course we can do it by Speaker Recognition API . i have done it already and its working fine . i used js to capture the live audio stream then send it to the speaker api with the help of custom webapi which i coded .
mainly it consist of 3 steps,
create a profile - which returns a unique profile ID.
Entroll - entroll / upload the audio to the profile ID , it stores your voice
sample permanently.
verify- verify your current audio with the samples you have saved before .
this is the main concept of the Speaker Recognition API , if you forward to look at the implementation i can help you .
https://westus.dev.cognitive.microsoft.com/docs/services/563309b6778daf02acc0a508/operations/563309b7778daf06340c9652
Speaker Recognition API currently does not differentiate between a live and a recorded audio, but the team is looking into that.
so basically I've been online trying to research this the whole day and I seem to only be able to come across specific setups that people have for their own specific needs rather than a generic list of hardware needed.
What I want to do firstly using my raspberry pi 2 running raspbian, and secondly a laptop running kali, is to be able to do penetration testing along with some extras.
What I Am looking for is a list of hardware that I need (other than the rpi2 for the first case and laptop for the second) that will enable me to sniff out WiFi signals, and attempt to get onto the network. I believe the general name for this is wardriving.
I know that I need a portable power supply for the rpi2, and a screen or some sort (I want a small screen that I can see the rpi gui desktop from. Not just terminal), so any suggestions of examples of those would be appreciated.
Where I get confused is about the WiFi antenna that I need. From what I understand is that it needs to be one that can monitor as well as connect to a WiFi, but I don't really know of any examples or of what the actual difference is between it and a normal usb WiFi stick.
I'm also not sure what else I need to have beyond that to successfully accomplish my stated goal.
Any further help would be greatly appreciated, and I think beneficial to anyone else who's looking to get started doing the same thing.
Any extra information would be good too what I mean is when I was doing my research I saw some people mentioning radio attachments, gps attachments, etc. But I'm not really sure if they're necessary to start or things that can be added further down the road with experience.
Thanks.
Ok so I seem to have found a good article that answers at least the general part of my question. It can be found here.
http://lewiscomputerhowto.blogspot.ca/2014/06/how-to-hack-wpawpa2-wi-fi-with-kali.html?m=1
It also gives tips on the process of pen testing.
I've ripped open an old Pentium desktop. The main board is a Zida 5svx. I got to know from the manual (which i downloaded from the internet) the location of the ROM chip on the board, and took it out. It was mentioned in the manual that the chip was a Flash EEPROM.
Now, what I am interested in is this: Is there a way to erase the ROM and flash it with, say a C program to blink an LED (i know this might put you into a fit of laughter, but read on all the same), or control a motor?
I also want to know if I can construct a mega-sized micro-controller with the left-over Pentium, some MBs of RAM, and this ROM.
Any suggestions?
P.S: I know that such a uC will require appropriate power supply setup and things.
The key is in getting and deeply studying the manufacturer's datasheets for each device you remove and wish to reuse. I am supposing that since you asked the question that you did that you are not a professional electrical engineer - that's OK, but you will need to do hours, days, or weeks of study to truly understand the datasheets well enough to successfully reuse your motherboard chips because they are written for professional engineers with years of experience, and unfortunately they were not written to be understood by hobbyists. If you can succeed in acquiring and thoroughly understanding all of the datasheets (and the related user's guides as well for the more complex chips) then you have made it to the point where you might be able to start a custom design based on your recovered parts, on paper at least. In order to test your design and insure that each part of it is working will require at least an oscilloscope and volt meter - and the knowledge of how to use them. An understanding of basic electronics is essential, you will not succeed without it. Very good soldering/rework/assembly skills will be required as well if you hope to have your design truly work - you can do everything else right and it can still fail if your skills in this area are lacking. There is simply not enough time for me to advise you on everything you will need to know - but if you are motivated, dedicated, and you don't give up when setbacks and roadblocks occur (and trust me, they occur all too frequently for even the best engineers and best designs) - meaning that you are not easily frustrated when things don't work - then you have a chance at success. I wish you all the best, and try to have fun while doing it (important in case fun is all you ever get out of your project). :)
I would like to solder a microcontroller, control buttons and an DVI/HDMI output and program this in a way, that I can store images on it and let them display as a dia-show via the outputs.
It doesn't have to have a lot of storage capacity, 128Mb would be enough.
but I don't know how to start, because I haven't done anything like this before.
My aim is to present some important images to friends by just taking this hardware, connecting it to a TV screen and showing these photos. If should be able to switch the photos manually (using a button) or automatically in a dia-show.
It should support several TV resolutions and it should be connectable to my PC (USB prefered), so that I can upload and delete photos.
So where to start and how to do that?
Thank you in advance, Andreas
If your aim is just to show some photos, there are assuredly simpler and more cost effective ways to do so; devices exist which do more or less exactly what you are proposing.
If your aim is to learn about microcontrollers and this is a project your are taking up to further that, I would recommend looking into the Arduino: http://www.arduino.cc/ or a similar kit based micro, and growing your project from that.
Microcontroller + low level language will be a huge pain to work with, particularly if you wish to handle various file formats and screen resolutions. Get a full-blown computer with an OS instead - something like http://en.wikipedia.org/wiki/PC/104
If your goal is purely to be able to display photos then I would recommend using a digital camera with video out capabilities.
If your aim is to learn about electronics and microcontrollers I would start with a good book and an Arduino board. Note that writing microcontroller code to handle file systems, image formats and video output is non-trivial. Simpler projects may be a better starting point as they are more accessible resulting in quicker progress, less frustration and more motivation!
The engineering field is a interesting field. You can start with the web site "www.microchip.com". You will need a high end device consider the PIC32MX795L512, there is a nice starter kit for it, "Ethernet Starter Kit" http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=2615&dDocName=en545713. This kit has the on board debugger & programmer to do all the hard work.
You get sample projects with the package, you can program using ansi c programming.
IDE : MPLAB which is free, and the C32 compiler has a student/lite version.
Arduino also has a board with the same device.
I personally like "www.techtoys.com.hk", they have device compatible with Microchip boards like techtoys.com.hk/PIC_boards/PIC32STK%20SSD1963%20EVK/PIC32STK%20SSD1963%20EVK%20R1A.htm, or this techtoys.com.hk/PIC_boards/PIC2432EVK-RD4/PIC2432%20EVK%20RD4.htm where this board you will need a debugger/programmer like the low cost PIC Kit 3 "microchip.com/pickit3".
The trouble is you need to write the HDMI video library yourself, there are some VGA libraries available but they are only black and white and very hard to get color with these analog images. The rest of the libraries are already there, USB MSD(flash drive), SD Card, pictures (jpg) etc.
microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=2680&dDocName=en547784
Feel free to contact me if you need some help, I might be able to help with the HDMI library.
It's a lot of fun to play with these toys.
Regards
Lucas
B-Eng Digital Engineering.
imlucanio#yahoo.com (no spamming)
Remember to add the http and www to the web links.
It sounds like you want an iPod. That is a dead simple thing to work with and it does everything you want. Otherwise, very complicated. I'd suggest the BeagleBoard and embedded Linux. Yes, it warrants that level of complexity.
The options for small microcontrollers just aren't there. The Arduino is very popular and yes, you can interface an SD card to it. That'd be your storage. Yes, you can put a digital potentiometer on it, that can be your interface. I've seen some video overlays that do simple text, but never any JPEG display (too much processing required). And certainly no 24 bit color (so that the output would actually look good) - that would take WAY too many pins to do correctly (and the Arduino doesn't have a D/A converter! You'd have to rig something up that would suck). And even then, all of the options for TV out weren't HDMI, but RCA (the old red/white/yellow cables).
So in short, no. Get a computer. That's what can do the job.