CODEWITHSUNDEEP
javaaudiojavasound
Adam Pope
Adam Pope

Reputation: 3274

JavaSound writing to audio file with a stream

I'm attempting to create an audio filter using the JavaSound API to read and write the audio files. Currently my code is structured as follows:

        ByteArrayOutputStream b_out = new ByteArrayOutputStream();

        // Read a frame from the file.
        while (audioInputStream.read(audioBytes) != -1) {   
            //Do stuff here....
            b_out.write(outputvalue);
        }   

        // Hook output stream to output file
        ByteArrayInputStream b_in   = new ByteArrayInputStream(b_out.toByteArray());
        AudioInputStream     ais    = new AudioInputStream(b_in, format, length);
        AudioSystem.write(ais, inFileFormat.getType(), outputFile);

This reads the input file as a stream, processes it and writes it to a bytearrayoutputstream, but it waits until the entire file has been processed before writing to disk. Ideally, I would like it to write each sample to disk as it's processed. I've tried several combinations of stream constructs but can't find a way of doing it as AudioSystem.write() takes an input stream. Any ideas?

Upvotes: 2

Views: 8433

Answers (3)

Kanaris007
Kanaris007

Reputation: 314

It is possible to solve the issue if you reimplement AudioSystem.write method. It doesn't work with stream and WAVE format. You should read data from AudioInputStream, cache it in byte array, process the array and record to wave file. I would recommend you to check classes from the example: How to record audio to byte array

Upvotes: 0

eljenso
eljenso

Reputation: 17027

kasperjj's answer is right. You are probably working with WAV files. Look at this for the layout of a wave file. Note that the size of the entire WAV file is encoded in its header.

I don't know if this is applicable in your case, but to process WAV samples as you described, you can use a "regular" non-audio Java output stream. You could use a FileOutputStream for example to write them to a temp file, and after processing you can convert the temp file into a valid WAV file.

Upvotes: 2

kasperjj
kasperjj

Reputation: 3664

Some audio formats require metadata describing the length of the stream (or the number of chunks) in their header, thus making it impossible to start writing the data before the entire dataset is present. Inorder for the Java sound API to handle all formats with the same API, I suspect they have had to impose this limit on purpose.

There are however many audio formats that can easily be streamed. Many of them have open library implementations for java, so if you are willing to add an external lib it shouldn't be that hard to accomplish.

Upvotes: 1

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