Concatenating WAV files in Java

Question

Here is my code that concatenates four wav files and produces wavAppended.wav. This concatenated file nicely plays in Windows Media Player. But through the PlaySound class, only

Answer 1

In above given example you need to use the SequenceInputStream then it will work fine. please find my code below to join two files.

import java.io.File;
import java.io.IOException;
import java.io.SequenceInputStream;

import javax.sound.sampled.AudioFileFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;

public class JoinWav{

        public static void main(String... args) throws Exception{
                String wav_1 = "1497434542598100215.wav";
                String wav_2 = "104860397153760.wav";
                AudioInputStream stream_1 = AudioSystem.getAudioInputStream(new File(wav_1));
                AudioInputStream stream_2 = AudioSystem.getAudioInputStream(new File(wav_2));
                System.out.println("Info : Format ["+stream_1.getFormat()+"] Frame Length ["+stream_1.getFrameLength()+"]");
                AudioInputStream stream_join = new AudioInputStream(new SequenceInputStream(stream_1,stream_2),stream_1.getFormat(),stream_1.getFrameLength()+stream_2.getFrameLength());
                AudioSystem.write(stream_join,AudioFileFormat.Type.WAVE,new File("join.wav"));
        }

}

Answer 2

WAV files don't work that way -- you can't just throw multiple files together (same as you can't concatenate JPEG images, for instance), as there's a header on the data, and there are multiple different formats the data may be in. I'm surprised that the file loads at all.

Answer 3

To get you started with the WAV processing you may have a look at my small project. It can copy and paste WAV files together based on an time index file. The project should contain all the Java WAV processing you need (using javax.sound.sampled). The Butcher implementation and Composer contain the actual processing.

The idea is simple: take input audio files and create a index of words contained in these files. The index entry is the word, start time and end time. When a new sentence is created it will be stitched together with single words taken from the index.

The AudioInputStream is the main class to interact with the Java Sound API. You read audio data from it. If you create audio data you do this by creating a AudioInputStream the AudioSystem can read from. The actual encoding is done by the AudioSystem implementation depending on the output audio format.

The Butcher class is the one concerned with audio files. It can read and write audio files and create AudioInputStreams from an input byte array. The other interesting think the Butcher can is cutting samples from a AudioInputStream. The AudioInputStream consists of frames that represent the samples of the PCM signal. Frames have a length of multiple bytes. To cut a valid range of frames from the AudioInputStream one has to take the frame size into account. The start and end time in milliseconds have to be translated to start byte and end bytes of the start frame and end frame. (The start and end data is stored as timestamps to keep them independent from the underlying encoding of the file used.)

The Composer creates the output file. For a given sentence it takes the audio data for each word from the input files, concatenates the audio data and writes the result to disk.

In the end you'll need some understanding of the PCM and the WAV format. The Java sound API does not abstract that away.