FileDocCategorySizeDatePackage
NativeDecoder.javaAPI DocJMF 2.1.1e7214Mon May 12 12:21:02 BST 2003com.ibm.media.codec.audio.mpega

NativeDecoder

public class NativeDecoder extends com.ibm.media.codec.audio.AudioCodec
GSM to PCM java decoder
author
Shay Ben-David bendavid@haifa.vnet.ibm.com

Fields Summary
public static final String
a_copyright_notice
Licensed Materials - Property of IBM

"Restricted Materials of IBM"

5746-SM2

(c) Copyright IBM Corporation 1997,1998 All Rights Reserved

US Government Users Restricted Rights - Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corporation.
static final int
MAX_MPEG_STREAM_FRAME_SIZE
static final int
MAX_PCM_FRAME_SIZE
static final int
INTERNAL_BUFFER_LEN
static final int
DECODE_ONE_FRAME_ONLY
static final int
DECODE_MANY_FRAMES
static final int
MPEG_CD_QUALITY
static final int
MPEG_HIGH_QUALITY
static final int
MPEG_MEDIUM_QUALITY
static final int
MPEG_NOERROR
static final int
MPEG_ERROR
private int
mpegAudioQuality
private int
one_frame_flag
private long[]
pdata
private int[]
samp_freq
private int[]
stereo
private int[]
in_bytes_read
private int[]
num_samples_done
private byte[]
internalBuffer
private int
internalBufferDataLen
Constructors Summary
public NativeDecoder()



    ////////////////////////////////////////////////////////////////////////////
    // Methods
      
       	supportedInputFormats = new AudioFormat[] { new AudioFormat(AudioFormat.MPEG)   };
        defaultOutputFormats  = new AudioFormat[] { new AudioFormat(AudioFormat.LINEAR) };
        PLUGIN_NAME="MPEG Decoder";
    
Methods Summary
public voidclose()

        mpeg_terminate (pdata[0]);
    
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;
    
private static native intmpeg_audio_decode(long pdata, byte[] in_buf_byte, int in_buf_offset, int in_buf_len, byte[] out_buf_byte, int out_buf_offset, int out_buf_len, int one_frame_flag, int[] num_samples_done, int[] in_bytes_read, int[] samp_freq, int[] stereo)

private static native intmpeg_initialization(long[] pdata, int mpeg_quality)

private static native intmpeg_terminate(long pdata)

public voidopen()

        try {
	    JMFSecurityManager.loadLibrary("jmutil");
	    JMFSecurityManager.loadLibrary("jmmpega");
            internalBufferDataLen = 0;
            mpeg_initialization(pdata,mpegAudioQuality);
            return;

	} catch (Throwable t) {
            System.out.println("Unable to load "+PLUGIN_NAME+"\n"+t);

	}
        throw new ResourceUnavailableException("Unable to load "+PLUGIN_NAME);
    
public intprocess(Buffer inputBuffer, Buffer outputBuffer)

     if (!checkInputBuffer(inputBuffer) ) {
        return BUFFER_PROCESSED_FAILED;
     }

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

     int inpLength=inputBuffer.getLength();
     int outLength=44100*40;  /* default output is 1 second of 44.1Khz stereo */ // *40 is arbitray
     int rc, returnResult = 0;
     byte[] inpData = (byte[]) inputBuffer.getData();
     byte[] outData = validateByteArraySize(outputBuffer, outLength);

     /* fill input data */
     if (INTERNAL_BUFFER_LEN - internalBufferDataLen > inpLength) {
         System.arraycopy(inpData, inputBuffer.getOffset(),
                          internalBuffer, internalBufferDataLen, inpLength);
         internalBufferDataLen += inpLength;
     } else {
         returnResult |= INPUT_BUFFER_NOT_CONSUMED;
     }

     /* decode */
     rc = mpeg_audio_decode (pdata[0],
                             internalBuffer, 0, internalBufferDataLen ,
                             outData, 0, outData.length,
                             one_frame_flag, num_samples_done,
                             in_bytes_read, samp_freq, stereo);
     if (rc != MPEG_NOERROR) {
         // System.out.println("MPEG Audio decoder error");
         return (returnResult | BUFFER_PROCESSED_FAILED);
     }

     /* if read too much, due to incomplete frame, do not crash */
     if (in_bytes_read[0] > internalBufferDataLen) {
         //if (in_bytes_read[0]-10 > internalBufferDataLen) {    // few bytes can be over-read in the dll in end-of-stream...
         //    System.out.println("PROBLEM in Mpeg Audio Decoder: too many bytes have been decoded");
         //}
         in_bytes_read[0] = internalBufferDataLen;
     }

     /* meanwhile, always shift data to buf start (not so efficient...) */
     System.arraycopy(internalBuffer, in_bytes_read[0],
                      internalBuffer, 0,
		      internalBufferDataLen - in_bytes_read[0]);

     /* update */
     internalBufferDataLen -= in_bytes_read[0];
     outLength = num_samples_done[0] << 1; // number of bytes
     if (outLength > 0) {
         updateOutput(outputBuffer, outputFormat, outLength, 0);
     } else {
         returnResult |= OUTPUT_BUFFER_NOT_FILLED;
     }

     return (returnResult | BUFFER_PROCESSED_OK);
   
public voidreset()

        close();
        try {
            open();
        } catch (Exception e) {
        }