Background:
I started working out at the gym.
Currently, I'm working only on triceps.
I determine to myself some sets that I have to do every time I'm at the gym.
As you might know, the fitness appliance that works on triceps look like some iron rods connected to weights that I have to lift up.
So, I thought that I'll log it in my Android phone,
So I'll really know what I did and what I didn't.
So, I would have to create an .Xml file which record what I really did. But if I'll put the number manually, I'll lose all the point, So...
Question:
I need, somehow, to recognize the weights-unhand sound. When I unhand from the rod, the weight falling and making some sound (I guess you know the sound, like a small Boom).
Is there any way to recognize it?
You cannot expect the algorithm here, anyway I can help you get started.
Similar question here
You can start by recording your "small boom" sound. You can run FFT on these clips and extract the magnitude of the same. You can store this value as a hash and compare it with the live sound.
for additional details check here, here and here
Related
I am programming alarm clock for myself and i got that problem. I also want to use the solution of my problem to set specified(by me) loud of alarm and ringtone. Please, show the code, if possible?
A staple of programming is breaking down a requirement to it's very basic components. Imagine the alarm clock app you want to build as a big cube, made out of many smaller cubes. You need to break each one of them down into their atomic elements. Once you've done that, you'll have your answer.
For example, in your case, I would consider some of the following problems:
Running a background process, which would still be activated, after a user has minimized the app.
Playing a sound.
Taking priority of any other app, disregarding of the state of the phone(locked/unlocked) and displaying the 'Wake up' window.
Getting the date
Getting the time
I would then start searching SO/Google for answers to my specific questions. The Android website and academy is also an incredible resource for all things Android.
I hope this will be helpful to you.
I have searched for this online, but am still a bit confused (as I'm sure others will be if they think of something like this). I'd like to preface by saying that this is not for homework and/or profit.
I wanted to create an app that could listen to your microwave as you prepare popcorn. It would work by sounding an alarm when there's a certain time interval between pops (say 5-6 seconds). Again, this is simply a project to keep me occupied - not for a class.
Either way, I'm having trouble trying to figure out how to analyze the audio intake in real-time. That is, I need a way to log the time when a "pop" occurs. So that you guys don't think I didn't do any research into the matter, I've checked out this SO question and have extensively searched the AudioRecord function list.
I'm thinking that I will probably have to do something with one of the versions of read() and then compare the recorded audio every 2 seconds or so to the recorded audio of a "pop" (i.e. if 70% or more of the byte[] audioData array is the same as that of a popping sound, then log the time). Can anyone with Android audio input experience let me know if I'm at least on the right track? This is not a question of me wanting you to code anything for me, but a question as to whether I'm on the correct track, and, if not, which direction I should head instead.
I think I have an easier way.
You could use the MediaRecorder 's getMaxAmplitude method.
Anytime your recorder detects a big jump in amplitude, you have detected a corn pop!
Check out this code (ignore the playback part): Playing back sound coming from microphone in real-time
Basically the idea is that you will have to take the value of each 16-bit sample (which corresponds to the value of the wave at that time). Using the sampling rate, you can calculate the time between peaks in volume. I think that might accomplish what you want.
this may be a bit overkill, but there is a framework from MIT media labs called funf: http://code.google.com/p/funf-open-sensing-framework/
They already created classes for audio input and some analysis (FFT and the like), also saving to files or uploading is implemented as far as I've seen, and they handle most of the sensors available on the phone.
You can also get inspired from the code they wrote, which I think is pretty good.
I would like to listen to the mic (I guess using AudioRecord) and perform some action the very moment a person starts to speak. I know I can buffer audio with AudioRecord, but how do I analyze it ?
Well, the difficult part will be getting the phone to recognize that it's voice. You can set the voice recognition system as the input, instead of the mic, which might be able to do that. I don't think so though, because (I actually read all about this yesterday) the phone doesn't actually do the recognizing, it just opens up a live stream (like a phone call) to the Google servers, and they do the recognizing.
Also, the information that I have found so far points to the conclusion that Android does not support analysis of live audio from the mic. All these other apps that seem to be "live" are actually just taking a bunch of small samples and analyzing them really quickly so that they seem live. A 500 millisecond sample every 300 milliseconds seems to be common.
Luckily, on the side of my programming job, I'm also a sound technician, so I can tell you that (if you were willing to put in the work) there is a way to detect actual voice as opposed to just sound. Every voice is split into a few distinct ratios of frequencies which all combine to make the voice we hear, and every voice's ratios remains pretty constant, while each individual voice's ratios are different (which is why voice-based passwords work). So, if you were able to take a sample, break it up into frequencies of about 10hz each, and watch for the amplitude of each, and when you got a frequency/amplitude pattern that looked similar to a voice instead of just "white noise", you'd be in business. DOING that however, doesn't seem like it'd be easy at all. Something similar has been done before with the app called SpectralView, which displays the audio spectrum all broken up.
Also, as you can see by using the Voice Search, a voice also fluctuates a lot in how loud it is. You could look for that, but it wouldn't be as reliable.
In conclusion, how do you analyze it? Well, you would have to look for a pattern in the frequencies that looks like a voice. How do you do that? Well, to be honest, I don't know for sure. Sorry.
I noticed that Flash allows you to insert cue's into a video file (flv). Is something like this possible on Android? I have a video that runs locally in my Android app and I would like to insert cues into the video which will give me callbacks when a certain portion of the video has been reached. If this is not possible, are there any other methods to do something similar? I have to be pretty precise with where the cue is located.
Thanks
Note:
I just found this same question on stackoverflow. Can anyone verify that this is still the case? (That it is not possible, only by polling the video continually). I did know of this way, but it's not the most accurate way if you need to be precise and stich dynamic pieces of video together seamlessly.
Android VideoView - Detect point of time in video
I´m working on this as well and a kind of cue/action scripts. For tutorials, instruction video I need to keep track of current position to serve for example questions and navigation menus appropriate for that point in time. Easy when it´s sufficient to act in response to user input but otherwise firing up a thread to poll at some decent interval is the thing. Accuracy might be acceptable and can be calibrated by sensing actual position.
I'm trying to build a gadget that detects pistol shots using Android. It's a part of a training aid for pistol shooters that tells how the shots are distributed in time and I use a HTC Tattoo for testing.
I use the MediaRecorder and its getMaxAmplitude method to get the highest amplitude during the last 1/100 s but it does not work as expected; speech gives me values from getMaxAmplitude in the range from 0 to about 25000 while the pistol shots (or shouting!) only reaches about 15000. With a sampling frequency of 8kHz there should be some samples with considerably high level.
Anyone who knows how these things work? Are there filters that are applied before registering the max amplitude. If so, is it hardware or software?
Thanks,
/George
It seems there's an AGC (Automatic Gain Control) filter in place. You should also be able to identify the shot by its frequency characteristics. I would expect it to show up across most of the audible spectrum, but get a spectrum analyzer (there are a few on the app market, like SpectralView) and try identifying the event by its frequency "signature" and amplitude. If you clap your hands what do you get for max amplitude? You could also try covering the phone with something to muffle the sound like a few layers of cloth
It seems like AGC is in the media recorder. When I use AudioRecord I can detect shots using the amplitude even though it sometimes reacts on sounds other than shots. This is not a problem since the shooter usually doesn't make any other noise while shooting.
But I will do some FFT too to get it perfect :-)
Sounds like you figured out your agc problem. One further suggestion: I'm not sure the FFT is the right tool for the job. You might have better detection and lower CPU use with a sliding power estimator.
e.g.
signal => square => moving average => peak detection
All of the above can be implemented very efficiently using fixed point math, which fits well with mobile android platforms.
You can find more info by searching for "Parseval's Theorem" and "CIC filter" (cascaded integrator comb)
Sorry for the late response; I didn't see this question until I started searching for a different problem...
I have started an application to do what I think you're attempting. It's an audio-based lap timer (button to start/stop recording, and loud audio noises for lap setting). It' not finished, but might provide you with a decent base to get started.
Right now, it allows you to monitor the signal volume coming from the mic, and set the ambient noise amount. It's also using the new BSD license, so feel free to check out the code here: http://code.google.com/p/audio-timer/. It's set up to use the 1.5 API to include as many devices as possible.
It's not finished, in that it has two main issues:
The audio capture doesn't currently work for emulated devices because of the unsupported frequency requested
The timer functionality doesn't work yet - was focusing on getting the audio capture first.
I'm looking into the frequency support, but Android doesn't seem to have a way to find out which frequencies are supported without trial and error per-device.
I also have on my local dev machine some extra code to create a layout for the listview items to display "lap" information. Got sidetracked by the frequency problem though. But since the display and audio capture are pretty much done, using the system time to fill in the display values for timing information should be relatively straightforward, and then it shouldn't be too difficult to add the ability to export the data table to a CSV on the SD card.
Let me know if you want to join this project, or if you have any questions.