JAVA版MPEG播放器

import java.io.*; import java.net.*; import java.awt.*; import java.awt.image.*; import java.applet.*; /** * This class represents a buffered input stream which can read * variable length codes from MPEG-1 video streams. */ class BitInputStream { /** * MPEG video layers start codes */ public final static int SYNC_START_CODE = 0x000001; public final static int PIC_START_CODE = 0x00000100; public final static int SLICE_MIN_CODE = 0x00000101; public final static int SLICE_MAX_CODE = 0x000001af; public final static int USER_START_CODE = 0x000001b2; public final static int SEQ_START_CODE = 0x000001b3; public final static int EXT_START_CODE = 0x000001b5; public final static int SEQ_END_CODE = 0x000001b7; public final static int GOP_START_CODE = 0x000001b8; /** * The underlying input stream */ private InputStream stream; /** * The bit buffer variables */ private int bitbuffer, bitcount; /** * The 32 bit buffer variables */ private int buffer[], count, position; /** * Initializes the bit input stream object */ public BitInputStream(InputStream inputStream) { stream = inputStream; buffer = new int[1024]; bitbuffer = bitcount = 0; count = position = 0; } /** * Reads the next MPEG-1 layer start code */ public int getCode() throws IOException { alignBits(8); while (showBits(24) != SYNC_START_CODE) flushBits(8); return getBits(32); } /** * Shows the next MPEG-1 layer start code */ public int showCode() throws IOException { alignBits(8); while (showBits(24) != SYNC_START_CODE) flushBits(8); return showBits(32); } /** * Reads the next variable length code */ public int getBits(int nbits) throws IOException { int bits; if (nbits <= bitcount) { bits = bitbuffer >>> (32 - nbits); bitbuffer <<= nbits; bitcount -= nbits; } else { bits = bitbuffer >>> (32 - nbits); nbits -= bitcount; bitbuffer = get32Bits(); bits |= bitbuffer >>> (32 - nbits); bitbuffer <<= nbits; bitcount = 32 - nbits; } if (nbits >= 32) bitbuffer = 0; return bits; } /** * Shows the next variable length code */ public int showBits(int nbits) throws IOException { int bits = bitbuffer >>> (32 - nbits); if (nbits > bitcount) { bits |= show32Bits() >>> (32 + bitcount - nbits); } return bits; } /** * Flushes the current variable length code */ public void flushBits(int nbits) throws IOException { if (nbits <= bitcount) { bitbuffer <<= nbits; bitcount -= nbits; } else { nbits -= bitcount; bitbuffer = get32Bits() << nbits; bitcount = 32 - nbits; } } /** * Aligns the input stream pointer to a given boundary */ public void alignBits(int nbits) throws IOException { flushBits(bitcount % nbits); } /** * Reads the next 32-bit code from the buffered stream */ private int get32Bits() throws IOException { if (position >= count) { position = 0; for (count = 0; count < buffer.length; count++) buffer[count] = read32Bits(); } return buffer[position++]; } /** * Shows the next 32-bit code from the buffered stream */ private int show32Bits() throws IOException { if (position >= count) { position = 0; for (count = 0; count < buffer.length; count++) buffer[count] = read32Bits(); } return buffer[position]; } /** * Reads 32-bit big endian codes from the stream */ private int read32Bits() throws IOException { if (stream.available() <= 0) return SEQ_END_CODE; int a0 = stream.read() & 0xff; int a1 = stream.read() & 0xff; int a2 = stream.read() & 0xff; int a3 = stream.read() & 0xff; return (a0 << 24) + (a1 << 16) + (a2 << 8) + (a3 << 0); } } /** * Huffman VLC entropy decoder for MPEG-1 video streams. The tables * are from ISO/IEC 13818-2 DIS, Annex B, variable length code tables. */ class VLCInputStream extends BitInputStream { /** * Table B-1, variable length codes for macroblock address increments */ private final static byte MBAtable[][] = { // 00000011xxx { 33,11 }, { 32,11 }, { 31,11 }, { 30,11 }, { 29,11 }, { 28,11 }, { 27,11 }, { 26,11 }, // 0000010xxxx { 25,11 }, { 24,11 }, { 23,11 }, { 22,11 }, { 21,10 }, { 21,10 }, { 20,10 }, { 20,10 }, { 19,10 }, { 19,10 }, { 18,10 }, { 18,10 }, { 17,10 }, { 17,10 }, { 16,10 }, { 16,10 }, // 0000xxxx... { 0, 0 }, { 0, 0 }, { 0, 0 }, { 33,11 }, { 25,11 }, { 19,10 }, { 15, 8 }, { 14, 8 }, { 13, 8 }, { 12, 8 }, { 11, 8 }, { 10, 8 }, { 9, 7 }, { 9, 7 }, { 8, 7 }, { 8, 7 }, // 00xxx...... { 0, 0 }, { 13, 8 }, { 7, 5 }, { 6, 5 }, { 5, 4 }, { 5, 4 }, { 4, 4 }, { 4, 4 }, // xxx........ { 0, 0 }, { 5, 4 }, { 3, 3 }, { 2, 3 }, { 1, 1 }, { 1, 1 }, { 1, 1 }, { 1, 1 } }; /** * Table B-2, variable length codes for I-picture macroblock types */ private final static byte IMBtable[][] = { // xx { 0, 0 }, { 17,2 }, { 1,1 }, { 1,1 } }; /** * Table B-3, variable length codes for P-picture macroblock types */ private final static byte PMBtable[][] = { // 000xxx { 0,0 }, { 17,6 }, { 18,5 }, { 18,5 }, { 26,5 }, { 26,5 }, { 1,5 }, { 1,5 }, // xxx... { 0,0 }, { 8,3 }, { 2,2 }, { 2,2 }, { 10,1 }, { 10,1 }, { 10,1 }, { 10,1 } }; /** * Table B-4, variable length codes for B-picture macroblock types */ private final static byte BMBtable[][] = { // 00xxxx { 0,0 }, { 17,6 }, { 22,6 }, { 26,6 }, { 30,5 }, { 30,5 }, { 1,5 }, { 1,5 }, { 8,4 }, { 8,4 }, { 8,4 }, { 8,4 }, { 10,4 }, { 10,4 }, { 10,4 }, { 10,4 }, // xxx... { 0,0 }, { 8,4 }, { 4,3 }, { 6,3 }, { 12,2 }, { 12,2 }, { 14,2 }, { 14,2 }, }; /** * Table B-9, variable length codes for coded block patterns */ private final static byte CBPtable[][] = { // 000000xxx { 0,0 }, { 0,9 }, { 39,9 }, { 27,9 }, { 59,9 }, { 55,9 }, { 47,9 }, { 31,9 }, // 000xxxxx. { 0,0 }, { 39,9 }, { 59,9 }, { 47,9 }, { 58,8 }, { 54,8 }, { 46,8 }, { 30,8 }, { 57,8 }, { 53,8 }, { 45,8 }, { 29,8 }, { 38,8 }, { 26,8 }, { 37,8 }, { 25,8 }, { 43,8 }, { 23,8 }, { 51,8 }, { 15,8 }, { 42,8 }, { 22,8 }, { 50,8 }, { 14,8 }, { 41,8 }, { 21,8 }, { 49,8 }, { 13,8 }, { 35,8 }, { 19,8 }, { 11,8 }, { 7,8 }, // 001xxxx.. { 34,7 }, { 18,7 }, { 10,7 }, { 6,7 }, { 33,7 }, { 17,7 }, { 9,7 }, { 5,7 }, { 63,6 }, { 63,6 }, { 3,6 }, { 3,6 }, { 36,6 }, { 36,6 }, { 24,6 }, { 24,6 }, // xxxxx.... { 0,0 }, { 57,8 }, { 43,8 }, { 41,8 }, { 34,7 }, { 33,7 }, { 63,6 }, { 36,6 }, { 62,5 }, { 2,5 }, { 61,5 }, { 1,5 }, { 56,5 }, { 52,5 }, { 44,5 }, { 28,5 }, { 40,5 }, { 20,5 }, { 48,5 }, { 12,5 }, { 32,4 }, { 32,4 }, { 16,4 }, { 16,4 }, { 8,4 }, { 8,4 }, { 4,4 }, { 4,4 }, { 60,3 }, { 60,3 }, { 60,3 }, { 60,3 } }; /** * Table B-10, variable length codes for motion vector codes */ private final static byte MVtable[][] = { // 00000011xx { 16,10 }, { 15,10 }, { 14,10 }, { 13,10 }, // 0000010xxx { 12,10 }, { 11,10 }, { 10, 9 }, { 10, 9 }, { 9, 9 }, { 9, 9 }, { 8, 9 }, { 8, 9 }, // 000xxxx... { 0, 0 }, { 0, 0 }, { 12,10 }, { 7, 7 }, { 6, 7 }, { 5, 7 }, { 4, 6 }, { 4, 6 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, // xxx....... { 0, 0 }, { 2, 3 }, { 1, 2 }, { 1, 2 }, { 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 } }; /** * Table B-12, variable length codes for DC luminance sizes */ private final static byte DClumtable[][] = { // xxx...... { 1,2 }, { 1,2 }, { 2,2 }, { 2,2 }, { 0,3 }, { 3,3 }, { 4,3 }, { 5,4 }, // 111xxx... { 5,4 },