rfc2035.java

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

package net.sf.fmj.media.codec.video.jpeg;



/**
 * Code from RFC 2035 - RTP Payload Format for JPEG Video.  See http://www.rfc-archive.org/getrfc.php?rfc=2035
 * Ported to Java from C by Ken Larson.
 * TODO: Obsoleted by RFC2435.  See http://rfc.sunsite.dk/rfc/rfc2435.html
 * 
 * @author Ken Larson
 *
 */
public class RFC2035
{
//	Appendix A
//
//	   The following code can be used to create a quantization table from a
//	   Q factor:

	// kenlars99: the sample code appears to have a mistake.  Several places on the
	// web refer to the q tables being in "zigzag" order.
	// http://www.obrador.com/essentialjpeg/headerinfo.htm
	// says "the quantization tables are stored in zigzag format".  The RFC does not say this, and the code
	// does not appear to do it.
	// Some LGPL code (JPEGVideoRTPSource.cpp) provides different tables, which we will use here:
	
//	 The default 'luma' and 'chroma' quantizer tables, in zigzag order:
	private static final int[] jpeg_luma_quantizer = new int[]{
	  // luma table:
	  16, 11, 12, 14, 12, 10, 16, 14,
	  13, 14, 18, 17, 16, 19, 24, 40,
	  26, 24, 22, 22, 24, 49, 35, 37,
	  29, 40, 58, 51, 61, 60, 57, 51,
	  56, 55, 64, 72, 92, 78, 64, 68,
	  87, 69, 55, 56, 80, 109, 81, 87,
	  95, 98, 103, 104, 103, 62, 77, 113,
	  121, 112, 100, 120, 92, 101, 103, 99,
	};
	private static final int[] jpeg_chroma_quantizer = new int[] {
	  // chroma table:
	  17, 18, 18, 24, 21, 24, 47, 26,
	  26, 47, 99, 66, 56, 66, 99, 99,
	  99, 99, 99, 99, 99, 99, 99, 99,
	  99, 99, 99, 99, 99, 99, 99, 99,
	  99, 99, 99, 99, 99, 99, 99, 99,
	  99, 99, 99, 99, 99, 99, 99, 99,
	  99, 99, 99, 99, 99, 99, 99, 99,
	  99, 99, 99, 99, 99, 99, 99, 99
	};
	
	// non-zigzagged versions:
//	/**
//	 * Table K.1 from JPEG spec.
//	 */
//	private static final int[] jpeg_luma_quantizer = new int[]{
//	        16, 11, 10, 16, 24, 40, 51, 61,
//	        12, 12, 14, 19, 26, 58, 60, 55,
//	        14, 13, 16, 24, 40, 57, 69, 56,
//	        14, 17, 22, 29, 51, 87, 80, 62,
//	        18, 22, 37, 56, 68, 109, 103, 77,
//	        24, 35, 55, 64, 81, 104, 113, 92,
//	        49, 64, 78, 87, 103, 121, 120, 101,
//	        72, 92, 95, 98, 112, 100, 103, 99
//	};
//
//	/**
//	 * Table K.2 from JPEG spec.
//	 */
//	private static final int[] jpeg_chroma_quantizer = new int[] {
//	        17, 18, 24, 47, 99, 99, 99, 99,
//	        18, 21, 26, 66, 99, 99, 99, 99,
//	        24, 26, 56, 99, 99, 99, 99, 99,
//	        47, 66, 99, 99, 99, 99, 99, 99,
//	        99, 99, 99, 99, 99, 99, 99, 99,
//	        99, 99, 99, 99, 99, 99, 99, 99,
//	        99, 99, 99, 99, 99, 99, 99, 99,
//	        99, 99, 99, 99, 99, 99, 99, 99
//	};


	/**
	 * Call MakeTables with the Q factor and two int[64] return arrays
	 */
	private static void
	MakeTables(int q, byte[] /* u_char * */lum_q, byte[] /* u_char * */chr_q)
	{
	  int i;
	  int factor = q;

	  if (q < 1) factor = 1;
	  if (q > 99) factor = 99;
	  if (q < 50)
	    q = 5000 / factor;
	  else
	    q = 200 - factor*2;
	  
	  for (i=0; i < 64; i++) {
		    int lq = ( jpeg_luma_quantizer[i] * q + 50) / 100;
		    int cq = ( jpeg_chroma_quantizer[i] * q + 50) / 100;

		    /* Limit the quantizers to 1 <= q <= 255 */
		    if ( lq < 1) lq = 1;
		    else if ( lq > 255) lq = 255;
		    lum_q[i] = (byte) lq;

		    if ( cq < 1) cq = 1;
		    else if ( cq > 255) cq = 255;
		    chr_q[i] = (byte) cq;
		  }
		}

//		Appendix B
//
//		   The following routines can be used to create the JPEG marker segments
//		   corresponding to the table-specification data that is absent from the
//		   RTP/JPEG body.

		private static final byte /*u_char*/ lum_dc_codelens[] = {
		        0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0,
		};

		private static final byte /*u_char*/ lum_dc_symbols[] = {
		        0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
		};

		private static final byte /*u_char*/ lum_ac_codelens[] = {
		        0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, (byte) 0x7d,
		};

		private static final byte /*u_char*/ lum_ac_symbols[] = {
		        (byte) 0x01, (byte) 0x02, (byte) 0x03, (byte) 0x00, (byte) 0x04, (byte) 0x11, (byte) 0x05, (byte) 0x12,
		        (byte) 0x21, (byte) 0x31, (byte) 0x41, (byte) 0x06, (byte) 0x13, (byte) 0x51, (byte) 0x61, (byte) 0x07,
		        (byte) 0x22, (byte) 0x71, (byte) 0x14, (byte) 0x32, (byte) 0x81, (byte) 0x91, (byte) 0xa1, (byte) 0x08,
		        (byte) 0x23, (byte) 0x42, (byte) 0xb1, (byte) 0xc1, (byte) 0x15, (byte) 0x52, (byte) 0xd1, (byte) 0xf0,
		        (byte) 0x24, (byte) 0x33, (byte) 0x62, (byte) 0x72, (byte) 0x82, (byte) 0x09, (byte) 0x0a, (byte) 0x16,
		        (byte) 0x17, (byte) 0x18, (byte) 0x19, (byte) 0x1a, (byte) 0x25, (byte) 0x26, (byte) 0x27, (byte) 0x28,
		        (byte) 0x29, (byte) 0x2a, (byte) 0x34, (byte) 0x35, (byte) 0x36, (byte) 0x37, (byte) 0x38, (byte) 0x39,
		        (byte) 0x3a, (byte) 0x43, (byte) 0x44, (byte) 0x45, (byte) 0x46, (byte) 0x47, (byte) 0x48, (byte) 0x49,
		        (byte) 0x4a, (byte) 0x53, (byte) 0x54, (byte) 0x55, (byte) 0x56, (byte) 0x57, (byte) 0x58, (byte) 0x59,
		        (byte) 0x5a, (byte) 0x63, (byte) 0x64, (byte) 0x65, (byte) 0x66, (byte) 0x67, (byte) 0x68, (byte) 0x69,
		        (byte) 0x6a, (byte) 0x73, (byte) 0x74, (byte) 0x75, (byte) 0x76, (byte) 0x77, (byte) 0x78, (byte) 0x79,
		        (byte) 0x7a, (byte) 0x83, (byte) 0x84, (byte) 0x85, (byte) 0x86, (byte) 0x87, (byte) 0x88, (byte) 0x89,
		        (byte) 0x8a, (byte) 0x92, (byte) 0x93, (byte) 0x94, (byte) 0x95, (byte) 0x96, (byte) 0x97, (byte) 0x98,
		        (byte) 0x99, (byte) 0x9a, (byte) 0xa2, (byte) 0xa3, (byte) 0xa4, (byte) 0xa5, (byte) 0xa6, (byte) 0xa7,
		        (byte) 0xa8, (byte) 0xa9, (byte) 0xaa, (byte) 0xb2, (byte) 0xb3, (byte) 0xb4, (byte) 0xb5, (byte) 0xb6,
		        (byte) 0xb7, (byte) 0xb8, (byte) 0xb9, (byte) 0xba, (byte) 0xc2, (byte) 0xc3, (byte) 0xc4, (byte) 0xc5,
		        (byte) 0xc6, (byte) 0xc7, (byte) 0xc8, (byte) 0xc9, (byte) 0xca, (byte) 0xd2, (byte) 0xd3, (byte) 0xd4,
		        (byte) 0xd5, (byte) 0xd6, (byte) 0xd7, (byte) 0xd8, (byte) 0xd9, (byte) 0xda, (byte) 0xe1, (byte) 0xe2,
		        (byte) 0xe3, (byte) 0xe4, (byte) 0xe5, (byte) 0xe6, (byte) 0xe7, (byte) 0xe8, (byte) 0xe9, (byte) 0xea,
		        (byte) 0xf1, (byte) 0xf2, (byte) 0xf3, (byte) 0xf4, (byte) 0xf5, (byte) 0xf6, (byte) 0xf7, (byte) 0xf8,
		        (byte) 0xf9, (byte) 0xfa,
		};

		private static final byte /*u_char*/ chm_dc_codelens[] = {
		        0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
		};

		private static final byte /*u_char*/ chm_dc_symbols[] = {
		        0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
		};

		private static final byte /*u_char*/ chm_ac_codelens[] = {
		        0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, (byte) 0x77,
		};

		private static final byte /*u_char*/ chm_ac_symbols[] = {
		        (byte) 0x00, (byte) 0x01, (byte) 0x02, (byte) 0x03, (byte) 0x11, (byte) 0x04, (byte) 0x05, (byte) 0x21,
		        (byte) 0x31, (byte) 0x06, (byte) 0x12, (byte) 0x41, (byte) 0x51, (byte) 0x07, (byte) 0x61, (byte) 0x71,
		        (byte) 0x13, (byte) 0x22, (byte) 0x32, (byte) 0x81, (byte) 0x08, (byte) 0x14, (byte) 0x42, (byte) 0x91,
		        (byte) 0xa1, (byte) 0xb1, (byte) 0xc1, (byte) 0x09, (byte) 0x23, (byte) 0x33, (byte) 0x52, (byte) 0xf0,
		        (byte) 0x15, (byte) 0x62, (byte) 0x72, (byte) 0xd1, (byte) 0x0a, (byte) 0x16, (byte) 0x24, (byte) 0x34,
		        (byte) 0xe1, (byte) 0x25, (byte) 0xf1, (byte) 0x17, (byte) 0x18, (byte) 0x19, (byte) 0x1a, (byte) 0x26,
		        (byte) 0x27, (byte) 0x28, (byte) 0x29, (byte) 0x2a, (byte) 0x35, (byte) 0x36, (byte) 0x37, (byte) 0x38,
		        (byte) 0x39, (byte) 0x3a, (byte) 0x43, (byte) 0x44, (byte) 0x45, (byte) 0x46, (byte) 0x47, (byte) 0x48,
		        (byte) 0x49, (byte) 0x4a, (byte) 0x53, (byte) 0x54, (byte) 0x55, (byte) 0x56, (byte) 0x57, (byte) 0x58,
		        (byte) 0x59, (byte) 0x5a, (byte) 0x63, (byte) 0x64, (byte) 0x65, (byte) 0x66, (byte) 0x67, (byte) 0x68,
		        (byte) 0x69, (byte) 0x6a, (byte) 0x73, (byte) 0x74, (byte) 0x75, (byte) 0x76, (byte) 0x77, (byte) 0x78,
		        (byte) 0x79, (byte) 0x7a, (byte) 0x82, (byte) 0x83, (byte) 0x84, (byte) 0x85, (byte) 0x86, (byte) 0x87,
		        (byte) 0x88, (byte) 0x89, (byte) 0x8a, (byte) 0x92, (byte) 0x93, (byte) 0x94, (byte) 0x95, (byte) 0x96,
		        (byte) 0x97, (byte) 0x98, (byte) 0x99, (byte) 0x9a, (byte) 0xa2, (byte) 0xa3, (byte) 0xa4, (byte) 0xa5,
		        (byte) 0xa6, (byte) 0xa7, (byte) 0xa8, (byte) 0xa9, (byte) 0xaa, (byte) 0xb2, (byte) 0xb3, (byte) 0xb4,
		        (byte) 0xb5, (byte) 0xb6, (byte) 0xb7, (byte) 0xb8, (byte) 0xb9, (byte) 0xba, (byte) 0xc2, (byte) 0xc3,
		        (byte) 0xc4, (byte) 0xc5, (byte) 0xc6, (byte) 0xc7, (byte) 0xc8, (byte) 0xc9, (byte) 0xca, (byte) 0xd2,
		        (byte) 0xd3, (byte) 0xd4, (byte) 0xd5, (byte) 0xd6, (byte) 0xd7, (byte) 0xd8, (byte) 0xd9, (byte) 0xda,
		        (byte) 0xe2, (byte) 0xe3, (byte) 0xe4, (byte) 0xe5, (byte) 0xe6, (byte) 0xe7, (byte) 0xe8, (byte) 0xe9,
		        (byte) 0xea, (byte) 0xf2, (byte) 0xf3, (byte) 0xf4, (byte) 0xf5, (byte) 0xf6, (byte) 0xf7, (byte) 0xf8,
		        (byte) 0xf9, (byte) 0xfa,
		};

		/**
		 * @return new offset in p.
		 */
		private static int /* u_char * */
		MakeQuantHeader(byte[] /* u_char * */p, int i, byte[] /* u_char * */qt, int tableNo)
		{
				p[i++] = (byte) 0xff;
		        p[i++] = (byte) 0xdb;            /* DQT */
		        p[i++] = (byte) 0;               /* length msb */
		        p[i++] = (byte) 67;              /* length lsb */
		        p[i++] = (byte) tableNo;
		        System.arraycopy(qt, 0, p, i, 64);
		        i += 64;
		        return i;
		}

		/**
		 * @return new offset in p.
		 */
		private static int /* u_char * */
		MakeHuffmanHeader(byte[] /* u_char * */p, int i, byte[] /* u_char * */codelens, int ncodes, byte[] /* u_char * */symbols,
		                  int nsymbols, int tableNo, int tableClass)
		{
				p[i++] = (byte) 0xff;
		        p[i++] = (byte) 0xc4;            /* DHT */
		        p[i++] = (byte) 0;               /* length msb */
		        p[i++] = (byte) (3 + ncodes + nsymbols); /* length lsb */
		        p[i++] = (byte)  (tableClass << 4 | tableNo);
		        System.arraycopy(codelens, 0, p, i, ncodes);
		        i += ncodes;
		        System.arraycopy(symbols, 0, p, i, nsymbols);
		        i += nsymbols;
		        return i;
		}

		/**
		 * Given an RTP/JPEG type code, q factor, width, and height,
		 * generate a frame and scan headers that can be prepended
		 * to the RTP/JPEG data payload to produce a JPEG compressed
		 * image in interchange format (except for possible trailing
		 * garbage and absence of an EOI marker to terminate the scan).
		 * @param i starting offset
		 * @param includeSOI - kenlars99 - not in original RFC sample code, allows us to control whether
		 * to include the initial SOI marker (0xFFD8).  Turn this off if there are other headers before these,
		 * such as the JFIF header.  If false, caller is responsible for the initial SOI marker.
		 */
		public static int MakeHeaders(boolean includeSOI, byte[] /* u_char * */p, int i, int type, int q, int w, int h)
		{
			//    byte[] /* u_char * */start = p;
			byte[] /*u_char*/ lqt = new byte[64];
			byte[] /*u_char*/ cqt = new byte[64];

		        /* convert from blocks to pixels */
		        w <<= 3;
		        h <<= 3;

		        MakeTables(q, lqt, cqt);

		        if (includeSOI)
		        {
			        p[i++] = (byte) 0xff;
			        p[i++] = (byte) 0xd8;            /* SOI */
		        }
		        i = MakeQuantHeader(p, i, lqt, 0);

		        i = MakeQuantHeader(p, i, cqt, 1);

		        i = MakeHuffmanHeader(p, i, lum_dc_codelens,
		                              lum_dc_codelens.length,
		                              lum_dc_symbols,
		                              lum_dc_symbols.length, 0, 0);
		        i = MakeHuffmanHeader(p, i, lum_ac_codelens,
		                              lum_ac_codelens.length,
		                              lum_ac_symbols,
		                              lum_ac_symbols.length, 0, 1);
		        i = MakeHuffmanHeader(p, i, chm_dc_codelens,
		                              chm_dc_codelens.length,
		                              chm_dc_symbols,
		                              chm_dc_symbols.length, 1, 0);
		        i = MakeHuffmanHeader(p, i, chm_ac_codelens,
		                              chm_ac_codelens.length,
		                              chm_ac_symbols,
		                              chm_ac_symbols.length, 1, 1);

		        p[i++] = (byte) 0xff;
		        p[i++] = (byte) 0xc0;            /* SOF */
		        p[i++] = (byte) 0;               /* length msb */
		        p[i++] = (byte) 17;              /* length lsb */
		        p[i++] = (byte) 8;               /* 8-bit precision */
		        p[i++] = (byte) (h >> 8);          /* height msb */
		        p[i++] = (byte) h;               /* height lsb */
		        p[i++] = (byte) (w >> 8);          /* width msb */
		        p[i++] = (byte) w;               /* wudth lsb */
		        p[i++] = (byte) 3;               /* number of components */
		        p[i++] = (byte) 0;               /* comp 0 */
		        if (type == 0)
		                p[i++] = (byte) 0x21;    /* hsamp = 2, vsamp = 1 */
		        else
		                p[i++] = (byte) 0x22;    /* hsamp = 2, vsamp = 2 */
		        p[i++] = (byte) 0;               /* quant table 0 */
		        p[i++] = (byte) 1;               /* comp 1 */
		        p[i++] = (byte) 0x11;            /* hsamp = 1, vsamp = 1 */
		        p[i++] = (byte) 1;               /* quant table 1 */
		        p[i++] = (byte) 2;               /* comp 2 */
		        p[i++] = (byte) 0x11;            /* hsamp = 1, vsamp = 1 */
		        p[i++] = (byte) 1;               /* quant table 1 */

		        p[i++] = (byte) 0xff;
		        p[i++] = (byte) 0xda;            /* SOS */
		        p[i++] = (byte) 0;               /* length msb */
		        p[i++] = (byte) 12;              /* length lsb */
		        p[i++] = (byte) 3;               /* 3 components */
		        p[i++] = (byte) 0;               /* comp 0 */

		        p[i++] = (byte) 0;               /* huffman table 0 */
		        p[i++] = (byte) 1;               /* comp 1 */
		        p[i++] = (byte) 0x11;            /* huffman table 1 */
		        p[i++] = (byte) 2;               /* comp 2 */
		        p[i++] = (byte) 0x11;            /* huffman table 1 */
		        p[i++] = (byte) 0;               /* first DCT coeff */
		        p[i++] = (byte) 63;              /* last DCT coeff */
		        p[i++] = (byte) 0;               /* sucessive approx. */

		        return i;
		};




}