Java Page.serialno方法代码示例

import com.jcraft.jogg.Page; //导入方法依赖的package包/类
/**
 * Bisect forward serial number.
 * @param begin beginning
 * @param searched searched
 * @param end end
 * @param currentno current number
 * @param m member
 * @return success flag OV_*
 */
int bisectForwardSerialno(long begin, long searched, long end,
		int currentno, int m) {
	long endsearched = end;
	long next = end;
	Page page = new Page();
	int ret;

	while (searched < endsearched) {
		long bisect;
		if (endsearched - searched < CHUNKSIZE) {
			bisect = searched;
		} else {
			bisect = (searched + endsearched) / 2;
		}

		seekHelper(bisect);
		ret = getNextPage(page, -1);
		if (ret == OV_EREAD) {
			return OV_EREAD;
		}
		if (ret < 0 || page.serialno() != currentno) {
			endsearched = bisect;
			if (ret >= 0) {
				next = ret;
			}
		} else {
			searched = ret + page.headerLen + page.bodyLen;
		}
	}
	seekHelper(next);
	ret = getNextPage(page, -1);
	if (ret == OV_EREAD) {
		return OV_EREAD;
	}

	if (searched >= end || ret == -1) {
		links = m + 1;
		offsets = new long[m + 2];
		offsets[m + 1] = searched;
	} else {
		ret = bisectForwardSerialno(next, offset, end, page.serialno(),
				m + 1);
		if (ret == OV_EREAD) {
			return OV_EREAD;
		}
	}
	offsets[m] = begin;
	return 0;
}
 

import com.jcraft.jogg.Page; //导入方法依赖的package包/类
/**
 * Uses the local ogg_stream storage in vf; this is important for
 * non-streaming input sources.
 * @param vi the info block
 * @param vc comment block
 * @param serialno serial numbers
 * @param ogPtr ogg pointer page
 * @return success codes OV_*
 */
int fetchHeaders(Info vi, Comment vc, int[] serialno, Page ogPtr) {
	Page og = new Page();
	Packet op = new Packet();
	int ret;

	if (ogPtr == null) {
		ret = getNextPage(og, CHUNKSIZE);
		if (ret == OV_EREAD) {
			return OV_EREAD;
		}
		if (ret < 0) {
			return OV_ENOTVORBIS;
		}
		ogPtr = og;
	}

	if (serialno != null) {
		serialno[0] = ogPtr.serialno();
	}

	os.init(ogPtr.serialno());

	// extract the initial header from the first page and verify that the
	// Ogg bitstream is in fact Vorbis data

	vi.init();
	vc.init();

	int i = 0;
	while (i < 3) {
		os.pagein(ogPtr);
		while (i < 3) {
			int result = os.packetout(op);
			if (result == 0) {
				break;
			}
			if (result == -1) {
				vi.clear();
				vc.clear();
				os.clear();
				return -1;
			}
			if (vi.synthesisHeaderin(vc, op) != 0) {
				vi.clear();
				vc.clear();
				os.clear();
				return -1;
			}
			i++;
		}
		if (i < 3) {
			if (getNextPage(ogPtr, 1) < 0) {
				vi.clear();
				vc.clear();
				os.clear();
				return -1;
			}
		}
	}
	return 0;
}
 

import com.jcraft.jogg.Page; //导入方法依赖的package包/类
/**
 * Last step of the OggVorbis_File initialization; get all the
 * vorbis_info structs and PCM positions. Only called by the seekable
 * initialization (local stream storage is hacked slightly; pay
 * attention to how that's done)
 * @param firstInfo first info
 * @param firstComment first comment
 * @param dataoffset data offset
 * @throws JOrbisException if an error occurs
 */
void prefetchAllHeaders(Info firstInfo, Comment firstComment, int dataoffset)
		throws JOrbisException {
	Page og = new Page();
	int ret;

	vi = new Info[links];
	vc = new Comment[links];
	dataoffsets = new long[links];
	pcmlengths = new long[links];
	serialnos = new int[links];

	for (int i = 0; i < links; i++) {
		if (firstInfo != null && firstComment != null && i == 0) {
			// we already grabbed the initial header earlier. This just
			// saves the waste of grabbing it again
			vi[i] = firstInfo;
			vc[i] = firstComment;
			dataoffsets[i] = dataoffset;
		} else {
			// seek to the location of the initial header
			seekHelper(offsets[i]); // !!!
			vi[i] = new Info();
			vc[i] = new Comment();
			if (fetchHeaders(vi[i], vc[i], null, null) == -1) {
				dataoffsets[i] = -1;
			} else {
				dataoffsets[i] = offset;
				os.clear();
			}
		}

		// get the serial number and PCM length of this link. To do this,
		// get the last page of the stream
		long end = offsets[i + 1]; // !!!
		seekHelper(end);

		while (true) {
			ret = getPrevPage(og);
			if (ret == -1) {
				// this should not be possible
				vi[i].clear();
				vc[i].clear();
				break;
			}
			if (og.granulepos() != -1) {
				serialnos[i] = og.serialno();
				pcmlengths[i] = og.granulepos();
				break;
			}
		}
	}
}
 

import com.jcraft.jogg.Page; //导入方法依赖的package包/类
/**
 * Open seekable.
 * @return success value
 * @throws JOrbisException if an error occurs
 */
int openSeekable() throws JOrbisException {
	Info initialInfo = new Info();
	Comment initialComment = new Comment();
	int serialno;
	long end;
	int ret;
	int dataoffset;
	Page og = new Page();
	// is this even vorbis...?
	int[] foo = new int[1];
	ret = fetchHeaders(initialInfo, initialComment, foo, null);
	serialno = foo[0];
	dataoffset = (int) offset; // !!
	os.clear();
	if (ret == -1) {
		return (-1);
	}
	if (ret < 0) {
		return (ret);
	}
	// we can seek, so set out learning all about this file
	seekable = true;
	fseek(datasource, 0, SEEK_END);
	offset = ftell(datasource);
	end = offset;
	// We get the offset for the last page of the physical bitstream.
	// Most OggVorbis files will contain a single logical bitstream
	end = getPrevPage(og);
	// moer than one logical bitstream?
	if (og.serialno() != serialno) {
		// Chained bitstream. Bisect-search each logical bitstream
		// section. Do so based on serial number only
		if (bisectForwardSerialno(0, 0, end + 1, serialno, 0) < 0) {
			clear();
			return OV_EREAD;
		}
	} else {
		// Only one logical bitstream
		if (bisectForwardSerialno(0, end, end + 1, serialno, 0) < 0) {
			clear();
			return OV_EREAD;
		}
	}
	prefetchAllHeaders(initialInfo, initialComment, dataoffset);
	return 0;
}