I'd like to modify the audio input stream, the stream that would come
from my microphone.
I have looked through the java.sound package API, but did not entirely understand it,
nor how to modify direct sound input.
Does anyone here know how to do that, or know an API that is capable of doing it?
You want a mixture of things:
The Java Sound system: http://www.oracle.com/technetwork/java/index-139508.html
A trail for it: http://docs.oracle.com/javase/tutorial/sound/index.html
Using audio controls: http://docs.oracle.com/javase/1.5.0/docs/guide/sound/programmer_guide/chapter6.html (part of a wider set of documentation)
If you are able to give more information about what you want to do to the audio stream, it's likely we'll be able to give you more specific advice.
Related
I'm trying to record from the microphone to a wav file as per this example. At the same time, I need to be able to test for input level/volume and send an alert if it's too low. I've tried what's described in this link and seems to work ok.
The issue comes when trying to record and read bytes at the same time using one TargetDataLine (bytes read for monitoring are being skipped for recording and vice-versa.
Another thing is that these are long processes (hours probably) so memory usage should be considered.
How should I proceed here? Any way to clone TargetDataLine? Can I buffer a number of bytes while writing them with AudioSystem.write()? Is there any other way to write to a .wav file without filling the system memory?
Thanks!
If you are using a TargetDataLine for capturing audio similar to the example given in the Java Tutorials, then you have access to a byte array called "data". You can loop through this array to test the volume level before outputting it.
To do the volume testing, you will have to convert the bytes to some sort of sensible PCM data. For example, if the format is 16-bit stereo little-endian, you might take two bytes and assemble to either a signed short or a signed, normalized float, and then test.
I apologize for not looking more closely at your examples before posting my "solution".
I'm going to suggest that you extend InputStream, making a customized version that also performs the volume test. Override the 'read' method so that it obtains the byte that it returns from the code you have that tests the volume. You'll have to modify the volume-testing code to work on a per-byte basis and to pass through the required byte.
You should then be able to use this extended InputStream as an argument when you create the AudioInputStream for the output-to-wav stage.
I've used this approach to save audio successfully via two data sources: once from an array that is populated beforehand, once from a streaming audio mix passing through a "mixer" I wrote to combine audio data sources. The latter would be more like what you need to do. I haven't done it from a microphone source, though. But the same approach should work, as far as I can tell.
So, I went over the Java's sound tutorial and I did not find it all so helpful.
Anyways, what I understood from the tutorial for recording sound from a mic is this:
Although they do show how to get a target data line and so on, they do not tell how you can actually record sound [or maybe I didn't get it all well].
My understanding so far has been this:
Mixer can be your sound card or sound software drivers that can be used to process the sound, whether input or output
TargetDataLine is used when you want to output your sound into the computer. Like save it to the disk
Port is where your external devices like mic, etc are connected
Problems that remain
How do I select the proper mixer? Java's tut says that you get all the available mixers and query each one to see if it has what you want. That's quite vague for a beginner
How do I get the port on which my integrated mic is? Specifically, how do I get input from it into the mixer?
How do I output this to the disk?
Using the AudioSystem.getTargetDataLine(AudioFormat format) method you will get
... a target data line that can be used for recording audio data in the format specified by the AudioFormat object. The returned line will be provided by the default system mixer, or, if not possible, by any other mixer installed in the system that supports a matching TargetDataLine object.
See the accepted answer for Java Sound API - capturing microphone for an example of this.
If you want more control of which data line to use you can enumerate all the mixers and the data lines they support and pick the one you want. Here is some more information regarding how you would go about doing that: Java - recording from mixer
Once you've obtained the TargetDataLine you should open() it, and then call read() repeatedly to obtain data from that data line. The byte[] that you fill up with data with each call to read() can be written to disk e.g. through a FileOutputStream.
I have to do a library Magement System in Java Swing. I had done it well with all your supports. Thank you all. Now this s/w needs to identify book and students by barcode (1d). I couldn't get a perfect logic from any where. I have read in SO and other web. I got some logic. But the vision is not clear.
I know this.
bar-code scanner output to port - listen to key strock- need Interface
My doubt is
What the order of the logic flow. ?
do i have to add any lib/jar files to do it.
how to implement this?
I have read a focused text field is needed. How to know did the scanner end key stocks.
I am totally confused. Sorry for reading poor English. I will make up this
Advanced thanks for all your support .
Read the picture from the reader (depends on the hardware, you might need to use the proprietary API or whatever it requires)
Use a barcode reading library to 'parse' the picture. (like zxing, which maybe can access a camera?)
which will give you the number hidden in the barcode.
I'm developing applications for Android. I need to have some kind of audio mixing effect.
How can I combine 2 or more audio tracks into 1 audio track?
Or adding an audio track into a certain stream of an audio?
Can anyone give me samples where I can head start?
Maybe you could try to port this code to Android?
Mixing of multiple AudioInputStreams to one AudioInputStream.
This class takes a collection of AudioInputStreams and mixes
them together. Being a subclass of AudioInputStream itself,
reading from instances of this class behaves as if the mixdown
result of the input streams is read
.
I have to implement the LPC (linear predictive coding) Algorithm with Java and quiet frankly don't have a clue where to start. Could someone please point me into a right direction.. I can't. of course, use already implemented algorithms from the java sound api (if its provides a solution).
Java comes with an AudioInputStream.
You can get the inputStream by calling avax.sound.sampled.AudioSystem.getAudioInputStream(File f).
The AudioInputStream has a read() method which reads the data. Probably, you will want to read all the data, do something with it and store it back to a file...