Audio converting with Xuggler

Question

I\'m trying to convert aac/wav/wma audio files to mp3 with Xuggler in Java.

Unfortunately, I have a big loss of quality. My input file size is about 7MB and my output fi

Answer 1

Be carefull when you have a mp3 with cover (png) you could end up with errors because you are trying to send video png stream to audio stream.. By using ISamples and reading packet with if ( packet.getStreamIndex( ) == audioStreamId ) {} gives a better control over the stream that you use. check my full code:

private static void streamToSource( OutputStream source, Path path ) throws IOException {

    byte[] buffer = new byte[4096];
    PipedInputStream pis = new PipedInputStream( );
    PipedOutputStream pos = new PipedOutputStream( pis );
    convertToMP3Xuggler( path, pos );

    System.out.println( "start streaming" );
    int nRead = 0;
    while ( ( nRead = pis.read( buffer ) ) != -1 ) {
        source.write( buffer,0 , nRead );
    }
    pis.close( );

    System.out.println( "end : " + path );

}

private static void convertToMP3Xuggler( Path path, PipedOutputStream pos ) throws FileNotFoundException {

    // create a media reader
    // final IMediaReader mediaReader = ToolFactory.makeReader( XugglerIO.map( new FileInputStream( path.toFile( ) ) ) );

    // create a media writer
    // IMediaWriter mediaWriter = ToolFactory.makeWriter( XugglerIO.map( XugglerIO.generateUniqueName( os, ".mp3" ), os ), mediaReader );
    IMediaWriter mediaWriter = ToolFactory.makeWriter( XugglerIO.map( pos ) );
    // manually set the container format (because it can't detect it by filename anymore)


    IContainerFormat containerFormat = IContainerFormat.make( );
    containerFormat.setOutputFormat( "mp3", null, "audio/mp3" );
    mediaWriter.getContainer( ).setFormat( containerFormat );

    System.out.println( "file = " + path.toFile( ).toString( ) );

    IContainer audioContainer = IContainer.make( );
    audioContainer.open( path.toFile( ).toString( ), IContainer.Type.READ, null );

    System.out.println( "streams= " + audioContainer.getNumStreams( ) );
    System.out.println( "# Duration (ms): " + ( ( audioContainer.getDuration( ) == Global.NO_PTS ) ? "unknown" : "" + audioContainer.getDuration( ) / 1000 ) );
    System.out.println( "# File size (bytes): " + audioContainer.getFileSize( ) );
    System.out.println( "# Bit rate: " + audioContainer.getBitRate( ) );
    int audioStreamId = -1;


    for ( int i = 0; i < audioContainer.getNumStreams( ); i++ ) {
        // Find the stream object
        IStream stream = audioContainer.getStream( i );
        // Get the pre-configured decoder that can decode this stream;
        IStreamCoder coder = stream.getStreamCoder( );
        if ( coder.getCodecType( ) == ICodec.Type.CODEC_TYPE_AUDIO ) {
            audioStreamId = i;
            break;
        }
    }
    if ( audioStreamId < 0 ) {
        throw new IllegalArgumentException( "cannot find audio stream in the current file : " + path.toString( ) );
    }
    System.out.println( "found audio stream = " + audioStreamId );

    IStreamCoder coderAudio = audioContainer.getStream( audioStreamId ).getStreamCoder( );

    if ( coderAudio.open( null, null ) < 0 ) {
        throw new RuntimeException( "Cant open audio coder" );
    }
    coderAudio.setSampleFormat( IAudioSamples.Format.FMT_S16 );

    System.out.println( "bitrate from reading = " + audioContainer.getBitRate( ) );
    System.out.println( "bitrate from reading = " + coderAudio.getBitRate( ) );

    int streamIndex = mediaWriter.addAudioStream( 0, 0, coderAudio.getChannels( ), coderAudio.getSampleRate( ) );
    IStreamCoder writerCoder = mediaWriter.getContainer( ).getStream( streamIndex ).getStreamCoder( );
    writerCoder.setFlag( IStreamCoder.Flags.FLAG_QSCALE, false );
    writerCoder.setBitRate( BITRATE * 1000 );
    writerCoder.setBitRateTolerance( 0 );
    System.out.println( "bitrate for output = " + writerCoder.getBitRate( ) );

    IPacket packet = IPacket.make( );

    runInThread( path, pos, mediaWriter, audioContainer, audioStreamId, coderAudio, streamIndex, packet );

}

private static void runInThread( Path path, PipedOutputStream pos, IMediaWriter mediaWriter, IContainer audioContainer, int audioStreamId, IStreamCoder coderAudio, int streamIndex, IPacket packet ) {

    new Thread( ) {
        @Override
        public void run( ) {

            while ( audioContainer.readNextPacket( packet ) >= 0 ) {
                /*
                 * Now we have a packet, let's see if it belongs to our audio stream
                 */
                if ( packet.getStreamIndex( ) == audioStreamId ) {
                    /*
                     * We allocate a set of samples with the same number of channels as the
                     * coder tells us is in this buffer.
                     * We also pass in a buffer size (4096 in our example), although Xuggler
                     * will probably allocate more space than just the 4096 (it's not important why).
                     */

                    IAudioSamples samples = IAudioSamples.make( 4096, coderAudio.getChannels( ), IAudioSamples.Format.FMT_S16 );

                    /*
                     * A packet can actually contain multiple sets of samples (or frames of samples
                     * in audio-decoding speak). So, we may need to call decode audio multiple
                     * times at different offsets in the packet's data. We capture that here.
                     */
                    int offset = 0;

                    /*
                     * Keep going until we've processed all data
                     */

                    while ( offset < packet.getSize( ) ) {
                        int bytesDecoded = coderAudio.decodeAudio( samples, packet, offset );
                        if ( bytesDecoded < 0 ) {
                            System.out.println( "decode error in : " + path + " bytesDecoded =" + bytesDecoded + " offset=" + offset + " packet=" + packet );
                            break;
                            //                                throw new RuntimeException( "got error decoding audio in: " + path );
                        }

                        offset += bytesDecoded;

                        //                            System.out.println( "pktSize = " + packet.getSize( ) + "  offset = " + offset + " samplesComplete = " + samples.isComplete( ) );

                        /*
                         * Some decoder will consume data in a packet, but will not be able to construct
                         * a full set of samples yet. Therefore you should always check if you
                         * got a complete set of samples from the decoder
                         */
                        if ( samples.isComplete( ) ) {
                            mediaWriter.encodeAudio( streamIndex, samples );
                        }
                    }
                }
            }
            coderAudio.close( );
            audioContainer.close( );
            mediaWriter.close( );
            try {
                pos.close( );
            } catch ( IOException e ) {
                e.printStackTrace( );
            }
        }

    }.start( );
}