bunzip2.c

这是一个SIGMA方案的PMP播放器的UCLINUX程序,可播放DVD,VCD,CD MP3...有很好的参考价值.

			if (! get_bits(s, &uc, 8)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			if (uc != 0x53) {
				retVal = BZ_DATA_ERROR;
				goto save_state_and_return;
			}

		case BZ_X_BLKHDR_6:
			s->state = BZ_X_BLKHDR_6;
			if (! get_bits(s, &uc, 8)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			if (uc != 0x59) {
				retVal = BZ_DATA_ERROR;
				goto save_state_and_return;
			}

		s->currBlockNo++;
		s->storedBlockCRC = 0;

		case BZ_X_BCRC_1:
			s->state = BZ_X_BCRC_1;
			if (! get_bits(s, &uc, 8)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			s->storedBlockCRC = (s->storedBlockCRC << 8) | ((unsigned int)uc);

		case BZ_X_BCRC_2:
			s->state = BZ_X_BCRC_2;
			if (! get_bits(s, &uc, 8)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			s->storedBlockCRC = (s->storedBlockCRC << 8) | ((unsigned int)uc);

		case BZ_X_BCRC_3:
			s->state = BZ_X_BCRC_3;
			if (! get_bits(s, &uc, 8)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			s->storedBlockCRC = (s->storedBlockCRC << 8) | ((unsigned int)uc);

		case BZ_X_BCRC_4:
			s->state = BZ_X_BCRC_4;
			if (! get_bits(s, &uc, 8)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			s->storedBlockCRC = (s->storedBlockCRC << 8) | ((unsigned int)uc);

		case BZ_X_RANDBIT:
			s->state = BZ_X_RANDBIT;
			{
				int tmp = s->blockRandomised;
				const int ret = get_bits(s, &tmp, 1);
				s->blockRandomised = tmp;
				if (! ret) {
					retVal = BZ_OK;
					goto save_state_and_return;
				}
			}

			s->origPtr = 0;

		case BZ_X_ORIGPTR_1:
			s->state = BZ_X_ORIGPTR_1;
			if (! get_bits(s, &uc, 8)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			s->origPtr = (s->origPtr << 8) | ((int)uc);

		case BZ_X_ORIGPTR_2:
			s->state = BZ_X_ORIGPTR_2;
			if (! get_bits(s, &uc, 8)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			s->origPtr = (s->origPtr << 8) | ((int)uc);

		case BZ_X_ORIGPTR_3:
			s->state = BZ_X_ORIGPTR_3;
			if (! get_bits(s, &uc, 8)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			s->origPtr = (s->origPtr << 8) | ((int)uc);

			if (s->origPtr < 0) {
				retVal = BZ_DATA_ERROR;
				goto save_state_and_return;
			}
			if (s->origPtr > 10 + 100000*s->blockSize100k) {
				retVal = BZ_DATA_ERROR;
				goto save_state_and_return;
			}

			/*--- Receive the mapping table ---*/
		case BZ_X_MAPPING_1:
			for (i = 0; i < 16; i++) {
				s->state = BZ_X_MAPPING_1;
				if (! get_bits(s, &uc, 1)) {
					retVal = BZ_OK;
					goto save_state_and_return;
				}
				if (uc == 1) {
					s->inUse16[i] = TRUE;
				} else {
					s->inUse16[i] = FALSE;
				}
			}

			for (i = 0; i < 256; i++) {
				s->inUse[i] = FALSE;
			}

			for (i = 0; i < 16; i++) {
				if (s->inUse16[i]) {
					for (j = 0; j < 16; j++) {
					case BZ_X_MAPPING_2:
						s->state = BZ_X_MAPPING_2;
						if (! get_bits(s, &uc, 1)) {
							retVal = BZ_OK;
							goto save_state_and_return;
						}
						if (uc == 1) {
							s->inUse[i * 16 + j] = TRUE;
						}
					}
				}
			}

			s->nInUse = 0;
			for (i = 0; i < 256; i++) {
				if (s->inUse[i]) {
					s->seqToUnseq[s->nInUse] = i;
					s->nInUse++;
				}
			}
			if (s->nInUse == 0) {
				retVal = BZ_DATA_ERROR;
				goto save_state_and_return;
			}
			alphaSize = s->nInUse+2;

		/*--- Now the selectors ---*/
		case BZ_X_SELECTOR_1:
			s->state = BZ_X_SELECTOR_1;
			if (! get_bits(s, &nGroups, 3)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			if (nGroups < 2 || nGroups > 6) {
				retVal = BZ_DATA_ERROR;
				goto save_state_and_return;
			}

		case BZ_X_SELECTOR_2:
			s->state = BZ_X_SELECTOR_2;
			if (! get_bits(s, &nSelectors, 15)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			if (nSelectors < 1) {
				retVal = BZ_DATA_ERROR;
				goto save_state_and_return;
			}



			for (i = 0; i < nSelectors; i++) {
				j = 0;
				while (1) {
					case BZ_X_SELECTOR_3:
					s->state = BZ_X_SELECTOR_3;
					if (! get_bits(s, &uc, 1)) {
						retVal = BZ_OK;
						goto save_state_and_return;
					}
					if (uc == 0) {
						break;
					}
					j++;
					if (j >= nGroups) {
						retVal = BZ_DATA_ERROR;
						goto save_state_and_return;
					}
				}
				s->selectorMtf[i] = j;
			}

			/*--- Undo the MTF values for the selectors. ---*/
			{
				unsigned char pos[BZ_N_GROUPS], tmp, v;
				for (v = 0; v < nGroups; v++) {
					pos[v] = v;
				}
				for (i = 0; i < nSelectors; i++) {
					v = s->selectorMtf[i];
					tmp = pos[v];
					while (v > 0) {
						pos[v] = pos[v-1];
						v--;
					}
					pos[0] = tmp;
					s->selector[i] = tmp;
				}
			}

			/*--- Now the coding tables ---*/
			for (t = 0; t < nGroups; t++) {
			case BZ_X_CODING_1:
				s->state = BZ_X_CODING_1;
				if (! get_bits(s, &curr, 5)) {
					retVal = BZ_OK;
					goto save_state_and_return;
				}
			for (i = 0; i < alphaSize; i++) {
				while (TRUE) {
					if (curr < 1 || curr > 20) {
						retVal = BZ_DATA_ERROR;
						goto save_state_and_return;
					}

					case BZ_X_CODING_2:
						s->state = BZ_X_CODING_2;
						if (! get_bits(s, &uc, 1)) {
							retVal = BZ_OK;
							goto save_state_and_return;
						}
						if (uc == 0) {
							break;
						}

					case BZ_X_CODING_3:
						s->state = BZ_X_CODING_3;
						if (! get_bits(s, &uc, 1)) {
							retVal = BZ_OK;
							goto save_state_and_return;
						}
						if (uc == 0) {
							curr++;
						} else {
							curr--;
						}
				}
				s->len[t][i] = curr;
			}
		}

		/*--- Create the Huffman decoding tables ---*/
		for (t = 0; t < nGroups; t++) {
			minLen = 32;
			maxLen = 0;
			for (i = 0; i < alphaSize; i++) {
				if (s->len[t][i] > maxLen) {
					maxLen = s->len[t][i];
				}
				if (s->len[t][i] < minLen) {
					minLen = s->len[t][i];
				}
			}

			BZ2_hbCreateDecodeTables ( 
				&(s->limit[t][0]), 
				&(s->base[t][0]), 
				&(s->perm[t][0]), 
				&(s->len[t][0]),
				minLen, maxLen, alphaSize
				);


			s->minLens[t] = minLen;
		}

		/*--- Now the MTF values ---*/

		EOB      = s->nInUse+1;
		nblockMAX = 100000 * s->blockSize100k;
		groupNo  = -1;
		groupPos = 0;

		for (i = 0; i <= 255; i++) {
			s->unzftab[i] = 0;
		}
		/*-- MTF init --*/
		{
			int ii, jj, kk;
			kk = MTFA_SIZE-1;
			for (ii = 256 / MTFL_SIZE - 1; ii >= 0; ii--) {
				for (jj = MTFL_SIZE-1; jj >= 0; jj--) {
					s->mtfa[kk] = (unsigned char)(ii * MTFL_SIZE + jj);
					kk--;
				}
				s->mtfbase[ii] = kk + 1;
			}
		}
		/*-- end MTF init --*/

		nblock = 0;

		if (! get_mtf_val_init()) {
			goto save_state_and_return;
		}
		case BZ_X_MTF_1:
			s->state = BZ_X_MTF_1;
			if (! get_bits(s, &zvec, zn)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			while (1) {
				if (zn > 20 /* the longest code */) {
					retVal = BZ_DATA_ERROR;
					goto save_state_and_return;
				}
				if (zvec <= gLimit[zn]) {
					break;
				}
				zn++;

				case BZ_X_MTF_2:
					s->state = BZ_X_MTF_2;
					if (! get_bits(s, &zj, 1)) {
						retVal = BZ_OK;
						goto save_state_and_return;
					}
					zvec = (zvec << 1) | zj;
			}
			if (zvec - gBase[zn] < 0 || zvec - gBase[zn] >= BZ_MAX_ALPHA_SIZE) {
				retVal = BZ_DATA_ERROR;
				goto save_state_and_return;
			}
			nextSym = gPerm[zvec - gBase[zn]];

		while (1) {
			if (nextSym == EOB) {
				break;
			}

		if (nextSym == BZ_RUNA || nextSym == BZ_RUNB) {
			es = -1;
			N = 1;
			do {
				if (nextSym == BZ_RUNA) {
					es = es + (0+1) * N;
				} else {
					if (nextSym == BZ_RUNB) {
						es = es + (1+1) * N;
					}
				}
				N = N * 2;
				if (! get_mtf_val_init()) {
					goto save_state_and_return;
				}
				case BZ_X_MTF_3:
					s->state = BZ_X_MTF_3;
					if (! get_bits(s, &zvec, zn)) {
						retVal = BZ_OK;
						goto save_state_and_return;
					}
					while (1) {
						if (zn > 20 /* the longest code */) {
							retVal = BZ_DATA_ERROR;
							goto save_state_and_return;
						}
						if (zvec <= gLimit[zn]) {
							break;
						}
						zn++;

						case BZ_X_MTF_4:
							s->state = BZ_X_MTF_4;
							if (! get_bits(s, &zj, 1)) {
								retVal = BZ_OK;
								goto save_state_and_return;
							}
							zvec = (zvec << 1) | zj;
					}
					if (zvec - gBase[zn] < 0 || zvec - gBase[zn] >= BZ_MAX_ALPHA_SIZE) {
						retVal = BZ_DATA_ERROR;
						goto save_state_and_return;

					}
					nextSym = gPerm[zvec - gBase[zn]];
			}
			while (nextSym == BZ_RUNA || nextSym == BZ_RUNB);

			es++;
			uc = s->seqToUnseq[ s->mtfa[s->mtfbase[0]] ];
			s->unzftab[uc] += es;

			while (es > 0) {
				if (nblock >= nblockMAX) {
					retVal = BZ_DATA_ERROR;
					goto save_state_and_return;
				}
				s->tt[nblock] = (unsigned int)uc;
				nblock++;
				es--;
			}
			continue;
		} else {
			if (nblock >= nblockMAX) {
				retVal = BZ_DATA_ERROR;
				goto save_state_and_return;
			}
			/*-- uc = MTF ( nextSym-1 ) --*/
			{
				int ii, jj, kk, pp, lno, off;
				unsigned int nn;
				nn = (unsigned int)(nextSym - 1);

				if (nn < MTFL_SIZE) {
					/* avoid general-case expense */
					pp = s->mtfbase[0];
					uc = s->mtfa[pp+nn];
					while (nn > 3) {
						int z = pp+nn;
						s->mtfa[(z)  ] = s->mtfa[(z)-1];
						s->mtfa[(z)-1] = s->mtfa[(z)-2];
						s->mtfa[(z)-2] = s->mtfa[(z)-3];
						s->mtfa[(z)-3] = s->mtfa[(z)-4];
						nn -= 4;
					}
					while (nn > 0) { 
						s->mtfa[(pp+nn)] = s->mtfa[(pp+nn)-1]; nn--; 
					}
					s->mtfa[pp] = uc;
				} else { 
					/* general case */
					lno = nn / MTFL_SIZE;
					off = nn % MTFL_SIZE;
					pp = s->mtfbase[lno] + off;
					uc = s->mtfa[pp];
					while (pp > s->mtfbase[lno]) { 
						s->mtfa[pp] = s->mtfa[pp-1];
						pp--; 
					}
					s->mtfbase[lno]++;
					while (lno > 0) {
						s->mtfbase[lno]--;
						s->mtfa[s->mtfbase[lno]] = s->mtfa[s->mtfbase[lno-1] + MTFL_SIZE - 1];
						lno--;
					}
					s->mtfbase[0]--;
					s->mtfa[s->mtfbase[0]] = uc;
					if (s->mtfbase[0] == 0) {
						kk = MTFA_SIZE-1;
						for (ii = 256 / MTFL_SIZE-1; ii >= 0; ii--) {
							for (jj = MTFL_SIZE-1; jj >= 0; jj--) {
								s->mtfa[kk] = s->mtfa[s->mtfbase[ii] + jj];
								kk--;
							}
							s->mtfbase[ii] = kk + 1;
						}
					}
				}
			}
			/*-- end uc = MTF ( nextSym-1 ) --*/

			s->unzftab[s->seqToUnseq[uc]]++;
			s->tt[nblock]   = (unsigned int)(s->seqToUnseq[uc]);
			nblock++;

			if (! get_mtf_val_init()) {
				goto save_state_and_return;
			}
			case BZ_X_MTF_5:
				s->state = BZ_X_MTF_5;
				if (! get_bits(s, &zvec, zn)) {
					retVal = BZ_OK;
					goto save_state_and_return;
				}
				while (1) {
					if (zn > 20 /* the longest code */) {
						retVal = BZ_DATA_ERROR;
						goto save_state_and_return;
					}
					if (zvec <= gLimit[zn]) {
						break;
					}
					zn++;

					case BZ_X_MTF_6:
						s->state = BZ_X_MTF_6;
						if (! get_bits(s, &zj, 1)) {
							retVal = BZ_OK;
							goto save_state_and_return;
						}
						zvec = (zvec << 1) | zj;
				}
			if (zvec - gBase[zn] < 0 || zvec - gBase[zn] >= BZ_MAX_ALPHA_SIZE) {
				retVal = BZ_DATA_ERROR;
				goto save_state_and_return;
			}
			nextSym = gPerm[zvec - gBase[zn]];
			continue;
		}
	}

	/* Now we know what nblock is, we can do a better sanity
		check on s->origPtr.
	*/
	if (s->origPtr < 0 || s->origPtr >= nblock) {
		retVal = BZ_DATA_ERROR;
		goto save_state_and_return;
	}
	s->state_out_len = 0;
	s->state_out_ch  = 0;
	s->calculatedBlockCRC = 0xffffffffL;
	s->state = BZ_X_OUTPUT;

	/*-- Set up cftab to facilitate generation of T^(-1) --*/
	s->cftab[0] = 0;
	for (i = 1; i <= 256; i++) {
		s->cftab[i] = s->unzftab[i-1];
	}
	for (i = 1; i <= 256; i++) {
		s->cftab[i] += s->cftab[i-1];
	}

	/*-- compute the T^(-1) vector --*/
	for (i = 0; i < nblock; i++) {
		uc = (unsigned char)(s->tt[i] & 0xff);
		s->tt[s->cftab[uc]] |= (i << 8);
		s->cftab[uc]++;
	}

	s->tPos = s->tt[s->origPtr] >> 8;
	s->nblock_used = 0;
	if (s->blockRandomised) {
		s->rNToGo = 0;
		s->rTPos  = 0;
		s->k0 = bz_get_fast(s);

		s->nblock_used++;
		bz_rand_udp_mask(s);
		s->k0 ^= ((s->rNToGo == 1) ? 1 : 0);
	} else {
		s->k0 = bz_get_fast(s);
		s->nblock_used++;
	}

		retVal = BZ_OK;
		goto save_state_and_return;

endhdr_2:
		case BZ_X_ENDHDR_2:
			s->state = BZ_X_ENDHDR_2;
			if (! get_bits(s, &uc, 8)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			if (uc != 0x72) {
				retVal = BZ_DATA_ERROR;
				goto save_state_and_return;
			}

		case BZ_X_ENDHDR_3:
			s->state = BZ_X_ENDHDR_3;
			if (! get_bits(s, &uc, 8)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			if (uc != 0x45) {
				retVal = BZ_DATA_ERROR;
				goto save_state_and_return;
			}

		case BZ_X_ENDHDR_4:
			s->state = BZ_X_ENDHDR_4;
			if (! get_bits(s, &uc, 8)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			if (uc != 0x38) {
				retVal = BZ_DATA_ERROR;
				goto save_state_and_return;
			}

		case BZ_X_ENDHDR_5:
			s->state = BZ_X_ENDHDR_5;
			if (! get_bits(s, &uc, 8)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			if (uc != 0x50) {
				retVal = BZ_DATA_ERROR;
				goto save_state_and_return;
			}

		case BZ_X_ENDHDR_6:
			s->state = BZ_X_ENDHDR_6;
			if (! get_bits(s, &uc, 8)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			if (uc != 0x90) {
				retVal = BZ_DATA_ERROR;
				goto save_state_and_return;
			}
			s->storedCombinedCRC = 0;

		case BZ_X_CCRC_1:
			s->state = BZ_X_CCRC_1;
			if (! get_bits(s, &uc, 8)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((unsigned int)uc);
		case BZ_X_CCRC_2:
			s->state = BZ_X_CCRC_2;
			if (! get_bits(s, &uc, 8)) {
				retVal = BZ_OK;
				goto save_state_and_return;
			}
			s->storedCombinedCRC = (s->storedCombinedCRC << 8) | ((unsigned int)uc);