AudioSystem.java 文件源码

/**
 * Obtains an audio input stream of the indicated encoding, by converting
 * the provided audio input stream.
 *
 * @param  targetEncoding the desired encoding after conversion
 * @param  sourceStream the stream to be converted
 * @return an audio input stream of the indicated encoding
 * @throws IllegalArgumentException if the conversion is not supported
 * @throws NullPointerException if {@code targetEncoding} or
 *         {@code sourceStream} are {@code null}
 * @see #getTargetEncodings(AudioFormat.Encoding)
 * @see #getTargetEncodings(AudioFormat)
 * @see #isConversionSupported(AudioFormat.Encoding, AudioFormat)
 * @see #getAudioInputStream(AudioFormat, AudioInputStream)
 */
public static AudioInputStream getAudioInputStream(AudioFormat.Encoding targetEncoding,
                                                   AudioInputStream sourceStream) {
    Objects.requireNonNull(targetEncoding);
    Objects.requireNonNull(sourceStream);
    if (sourceStream.getFormat().getEncoding().equals(targetEncoding)) {
        return sourceStream;
    }

    List<FormatConversionProvider> codecs = getFormatConversionProviders();

    for(int i = 0; i < codecs.size(); i++) {
        FormatConversionProvider codec = codecs.get(i);
        if( codec.isConversionSupported( targetEncoding, sourceStream.getFormat() ) ) {
            return codec.getAudioInputStream( targetEncoding, sourceStream );
        }
    }
    // we ran out of options, throw an exception
    throw new IllegalArgumentException("Unsupported conversion: " + targetEncoding + " from " + sourceStream.getFormat());
}