javadecoder.java

FMJ（freedom media for java)是java视频开发的新选择

/*
 * SIP Communicator, the OpenSource Java VoIP and Instant Messaging client.
 *
 * Distributable under LGPL license.
 * See terms of license at gnu.org.
 */
package net.java.sip.communicator.impl.media.codec.audio.speex;

import java.io.*;
import javax.media.*;
import javax.media.format.*;

import org.xiph.speex.*;
import net.java.sip.communicator.impl.media.codec.*;

/**
 * Speex to PCM java decoder
 * @author Damian Minkov
 **/
public class JavaDecoder
    extends com.ibm.media.codec.audio.AudioCodec
{
    private Format lastFormat = null;
    private int numberOfChannels = 0;
    private SpeexDecoder decoder = null;

    public JavaDecoder()
    {
        inputFormats = new Format[]
            {
            new AudioFormat(
                Constants.SPEEX_RTP,
                8000,
                8,
                1,
                Format.NOT_SPECIFIED,
                Format.NOT_SPECIFIED
            )};

        supportedInputFormats = new AudioFormat[]
            {
            new AudioFormat(Constants.SPEEX_RTP,
                            8000,
                            8,
                            1,
                            Format.NOT_SPECIFIED,
                            Format.NOT_SPECIFIED)};

        defaultOutputFormats = new AudioFormat[]
            {
            new AudioFormat(AudioFormat.LINEAR)};

        PLUGIN_NAME = "Speex Decoder";
    }

    protected Format[] getMatchingOutputFormats(Format in)
    {
        AudioFormat af = (AudioFormat) in;

        supportedOutputFormats = new AudioFormat[]
            {
            new AudioFormat(
                AudioFormat.LINEAR,
                af.getSampleRate(),
                16,
                af.getChannels(),
                AudioFormat.LITTLE_ENDIAN, //isBigEndian(),
                AudioFormat.SIGNED //isSigned());
            )};

        return supportedOutputFormats;

    }


    public void open()
    {}

    public void close()
    {}

    private void initConverter(AudioFormat inFormat)
    {
        lastFormat = inFormat;

        numberOfChannels = inFormat.getChannels();

        decoder = new SpeexDecoder();

        decoder.init(0,
                     (int) ( (AudioFormat) inFormat).getSampleRate(),
                     inFormat.getChannels(),
                     false);
    }

    public int process(Buffer inputBuffer, Buffer outputBuffer)
    {
        if (!checkInputBuffer(inputBuffer))
        {
            return BUFFER_PROCESSED_FAILED;
        }

        if (isEOM(inputBuffer))
        {
            propagateEOM(outputBuffer);
            return BUFFER_PROCESSED_OK;
        }

        int channels = ( (AudioFormat) outputFormat).getChannels();

        byte[] inData = (byte[]) inputBuffer.getData();

        int inpLength = inputBuffer.getLength();

        int outLength = 0;

        int inOffset = inputBuffer.getOffset();
        int outOffset = outputBuffer.getOffset();

        Format newFormat = inputBuffer.getFormat();

        if (lastFormat != newFormat)
        {
            initConverter( (AudioFormat) newFormat);
        }

        try
        {
            decoder.processData(inData, inOffset, inpLength);
            outLength = decoder.getProcessedDataByteSize();

            byte[] outData = validateByteArraySize(outputBuffer, outLength);

            decoder.getProcessedData(outData, outOffset);
        }
        catch (StreamCorruptedException ex)
        {
            ex.printStackTrace();
        }

        updateOutput(outputBuffer, outputFormat, outLength, 0);

        return BUFFER_PROCESSED_OK;
    }

//    public java.lang.Object[] getControls()
//    {
//        if (controls == null)
//        {
//            controls = new Control[1];
//            controls[0] = new com.sun.media.controls.SilenceSuppressionAdapter(this, false, false);
//        }
//        return (Object[]) controls;
//    }

    static int SpeexSubModeSz[] =
        {
        0, 43, 119, 160,
        220, 300, 364, 492,
        79, 0, 0, 0,
        0, 0, 0, 0};
    static int SpeexInBandSz[] =
        {
        1, 1, 4, 4,
        4, 4, 4, 4,
        8, 8, 16, 16,
        32, 32, 64, 64};

    /**
     * Counts the samples in given data
     * @param data byte[]
     * @param len int
     * @return int
     */
    private static int speex_get_samples(byte[] data, int len)
    {
        int bit = 0;
        int cnt = 0;
        int off = 0;

        int c;

        //DEBU(G "speex_get_samples(%d)\n", len);
        while ((len * 8 - bit) >= 5) {
            /* skip wideband frames */
            off = speex_get_wb_sz_at(data, len, bit);
            if (off < 0)  {
                //DEBU(G "\tERROR reading wideband frames\n");
                break;
            }
            bit += off;

            if ((len * 8 - bit) < 5) {
                //DEBU(G "\tERROR not enough bits left after wb\n");
                break;
            }

            /* get control bits */
            c = get_n_bits_at(data, 5, bit);
            //DEBU(G "\tCONTROL: %d at %d\n", c, bit);
            bit += 5;

            if (c == 15) {
                //DEBU(G "\tTERMINATOR\n");
                break;
            } else if (c == 14) {
                /* in-band signal; next 4 bits contain signal id */
                c = get_n_bits_at(data, 4, bit);
                bit += 4;
                //DEBUG "\tIN-BAND %d bits\n", SpeexInBandSz[c]);
                bit += SpeexInBandSz[c];
            } else if (c == 13) {
                /* user in-band; next 5 bits contain msg len */
                c = get_n_bits_at(data, 5, bit);
                bit += 5;
                //DEBUG "\tUSER-BAND %d bytes\n", c);
                bit += c * 8;
            } else if (c > 8) {
                //DEBU(G "\tUNKNOWN sub-mode %d\n", c);
                break;
            } else {
                /* skip number bits for submode (less the 5 control bits) */
                //DEBU(G "\tSUBMODE %d %d bits\n", c, SpeexSubModeSz[c]);
                bit += SpeexSubModeSz[c] - 5;

                cnt += 160; /* new frame */
            }
        }
        //DEBU(G "\tSAMPLES: %d\n", cnt);
        return cnt;
    }

    private static int get_n_bits_at(byte[] data, int n, int bit)
    {
        int byteInt = bit / 8; /* byte containing first bit */
        int rem = 8 - (bit % 8); /* remaining bits in first byte */
        int ret = 0;

        if (n <= 0 || n > 8)
            return 0;

        if (rem < n)
        {
            ret = (data[byteInt] << (n - rem));
            ret |= (data[byteInt +1] >> (8 - n + rem));
        }
        else
        {
            ret = (data[byteInt] >> (rem - n));
        }

        return (ret & (0xff >> (8 - n)));
    }

    static int SpeexWBSubModeSz[] =
        {
        0, 36, 112, 192,
        352, 0, 0, 0};

    private static int speex_get_wb_sz_at(byte[] data, int len, int bit)
    {
        int off = bit;
        int c;

        /* skip up to two wideband frames */
        if ( ( (len * 8 - off) >= 5) &&
            get_n_bits_at(data, 1, off) != 0)
        {
            c = get_n_bits_at(data, 3, off + 1);
            off += SpeexWBSubModeSz[c];

            if ( ( (len * 8 - off) >= 5) &&
                get_n_bits_at(data, 1, off) != 0)
            {
                c = get_n_bits_at(data, 3, off + 1);
                off += SpeexWBSubModeSz[c];

                if ( ( (len * 8 - off) >= 5) &&
                    get_n_bits_at(data, 1, off) != 0)
                {
                    /* too many in a row */
                    //DEBU(G "\tCORRUPT too many wideband streams in a row\n");
                    return -1;
                }
            }

        }
        return off - bit;
    }
}