mpegformatconversionprovider.java

java处理声音文件

	private static final boolean	t = true;
	private static final boolean	f = false;

	/*
	 *	One row for each source format.
	 */
	private static final boolean[][]	CONVERSIONS =
	{
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,t,t,f,f,f,f, f,f,f,f,f,f},	// 0
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,t,t,f,f, f,f,f,f,f,f},	// 1
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,t,t, f,f,f,f,f,f},	// 2
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, t,t,f,f,f,f},	// 3
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,t,t,f,f},	// 4
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,t,t},	// 5

		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,t,t,f,f,f,f, f,f,f,f,f,f},	// 6
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,t,t,f,f, f,f,f,f,f,f},	// 7
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,t,t, f,f,f,f,f,f},	// 8
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, t,t,f,f,f,f},	// 9
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,t,t,f,f},	// 10
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,t,t},	// 11

		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,t,t,f,f,f,f, f,f,f,f,f,f},	// 12
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,t,t,f,f, f,f,f,f,f,f},	// 13
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,t,t, f,f,f,f,f,f},	// 14
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, t,t,f,f,f,f},	// 15
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,t,t,f,f},	// 16
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,t,t},	// 17

		{f,f,f,f,f,f,f,f,f,f, f,f,t,t,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 18
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,t,t,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 19 
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,t,t,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 20
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,t,t, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 21
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, t,t,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 22
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,t,t,f,f,f,f,f,f, f,f,f,f,f,f},	// 23

		{f,f,f,f,f,f,f,f,f,f, f,f,t,t,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 24
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,t,t,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 25
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,t,t,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 26
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,t,t, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 27
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, t,t,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 28
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,t,t,f,f,f,f,f,f, f,f,f,f,f,f},	// 29

		{f,f,f,f,f,f,f,f,f,f, f,f,t,t,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 30
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,t,t,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 31
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,t,t,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 32
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,t,t, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 33
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, t,t,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 34
		{f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,t,t,f,f,f,f,f,f, f,f,f,f,f,f},	// 35

		{t,t,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 36
		{f,f,t,t,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 37
		{f,f,f,f,t,t,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 38
		{f,f,f,f,f,f,t,t,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 39
		{f,f,f,f,f,f,f,f,t,t, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 40
		{f,f,f,f,f,f,f,f,f,f, t,t,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 41

		{t,t,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 42
		{f,f,t,t,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 43
		{f,f,f,f,t,t,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 44
		{f,f,f,f,f,f,t,t,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 45
		{f,f,f,f,f,f,f,f,t,t, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 46
		{f,f,f,f,f,f,f,f,f,f, t,t,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 47

		{t,t,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 48
		{f,f,t,t,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 49
		{f,f,f,f,t,t,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 50
		{f,f,f,f,f,f,t,t,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 51
		{f,f,f,f,f,f,f,f,t,t, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 52
		{f,f,f,f,f,f,f,f,f,f, t,t,f,f,f,f,f,f,f,f, f,f,f,f,f,f,f,f,f,f, f,f,f,f,f,f},	// 53

	};



	/**	Constructor.
	 */
	public MpegFormatConversionProvider()
	{
		super(Arrays.asList(INPUT_FORMATS),
		      Arrays.asList(OUTPUT_FORMATS),
		      CONVERSIONS);
	}



	public AudioInputStream getAudioInputStream(AudioFormat targetFormat, AudioInputStream audioInputStream)
	{
		if (isConversionSupported(targetFormat,
					  audioInputStream.getFormat()))
		{
			return new DecodedMpegAudioInputStream(
				targetFormat,
				audioInputStream);
		}
		else
		{
			throw new IllegalArgumentException("conversion not supported");
		}
	}



	public static class DecodedMpegAudioInputStream
		extends		TAsynchronousFilteredAudioInputStream
	{
		private InputStream		m_encodedStream;
		private Bitstream		m_bitstream;
		private Decoder			m_decoder;
		private DMAISObuffer		m_oBuffer;



		public DecodedMpegAudioInputStream(AudioFormat outputFormat, AudioInputStream inputStream)
		{
			// TODO: try to find out length (possible?)
			super(outputFormat, -1);
			m_encodedStream = inputStream;
			m_bitstream = new Bitstream(inputStream);
			m_decoder = new Decoder(null);
			m_oBuffer = new DMAISObuffer(outputFormat.getChannels());
			m_decoder.setOutputBuffer(m_oBuffer);
		}



		public void execute()
		{
			try
			{
				Header	header = m_bitstream.readFrame();
				if (header == null)
				{
					if (TDebug.TraceAudioConverter)
					{
						TDebug.out("header is null (end of mpeg stream)");
					}
					m_circularBuffer.close();
					return;
				}
				Obuffer	decoderOutput = m_decoder.decodeFrame(header, m_bitstream);
				m_bitstream.closeFrame();
				m_circularBuffer.write(m_oBuffer.getBuffer(), 0, m_oBuffer.getCurrentBufferSize());
				m_oBuffer.reset();
			}
			catch (BitstreamException e)
			{
				if (TDebug.TraceAudioConverter)
				{
					TDebug.out(e);
				}
			}
			catch (DecoderException e)
			{
				if (TDebug.TraceAudioConverter)
				{
					TDebug.out(e);
				}
			}
		}



		private boolean isBigEndian()
		{
			return getFormat().isBigEndian();
		}



		public void close()
			throws	IOException
		{
			super.close();
			m_encodedStream.close();
		}



		private class DMAISObuffer
			extends		Obuffer
		{
			private int			m_nChannels;
			private byte[]			m_abBuffer;
			private int[]			m_anBufferPointers;
			private boolean			m_bIsBigEndian;



			public DMAISObuffer(int	nChannels)
			{
				m_nChannels = nChannels;
				m_abBuffer = new byte[OBUFFERSIZE * nChannels];
				m_anBufferPointers = new int[nChannels];
				reset();
				m_bIsBigEndian = DecodedMpegAudioInputStream.this.isBigEndian();
			}



			public void append(int nChannel, short sValue)
			{
				byte	bFirstByte;
				byte	bSecondByte;
				if (m_bIsBigEndian)
				{
					bFirstByte = (byte) ((sValue >>> 8) & 0xFF);
					bSecondByte = (byte) (sValue & 0xFF);
				}
				else	// little endian
				{
					bFirstByte = (byte) (sValue & 0xFF);
					bSecondByte = (byte) ((sValue >>> 8) & 0xFF);
				}
				m_abBuffer[m_anBufferPointers[nChannel]] = bFirstByte;
				m_abBuffer[m_anBufferPointers[nChannel] + 1] = bSecondByte;
				m_anBufferPointers[nChannel] += m_nChannels * 2;
			}


			public void set_stop_flag()
			{
			}



			public void close()
			{
			}



			public void write_buffer(int nValue)
			{
			}



			public void clear_buffer()
			{
			}



			public byte[] getBuffer()
			{
				return m_abBuffer;
			}



			public int getCurrentBufferSize()
			{
				return m_anBufferPointers[0];
			}



			public void reset()
			{
				for (int i = 0; i < m_nChannels; i++)
				{
					/*	Points to byte location,
					 *	implicitely assuming 16 bit
					 *	samples.
					 */
					m_anBufferPointers[i] = i * 2;
				}
			}


			
		}
	}
}



/*** MpegFormatConversionProvider.java ***/