1 /***************************************************************************
2 copyright : (C) 2002 - 2008 by Scott Wheeler
3 email : wheeler@kde.org
4 ***************************************************************************/
6 /***************************************************************************
7 * This library is free software; you can redistribute it and/or modify *
8 * it under the terms of the GNU Lesser General Public License version *
9 * 2.1 as published by the Free Software Foundation. *
11 * This library is distributed in the hope that it will be useful, but *
12 * WITHOUT ANY WARRANTY; without even the implied warranty of *
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
14 * Lesser General Public License for more details. *
16 * You should have received a copy of the GNU Lesser General Public *
17 * License along with this library; if not, write to the Free Software *
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 *
21 * Alternatively, this file is available under the Mozilla Public *
22 * License Version 1.1. You may obtain a copy of the License at *
23 * http://www.mozilla.org/MPL/ *
24 ***************************************************************************/
34 #include "oggpageheader.h"
37 using namespace TagLib;
39 class Ogg::PageHeader::PageHeaderPrivate
42 PageHeaderPrivate(File *f, long pageOffset) :
44 fileOffset(pageOffset),
46 firstPacketContinued(false),
47 lastPacketCompleted(false),
48 firstPageOfStream(false),
49 lastPageOfStream(false),
50 absoluteGranularPosition(0),
51 streamSerialNumber(0),
52 pageSequenceNumber(-1),
60 List<int> packetSizes;
61 bool firstPacketContinued;
62 bool lastPacketCompleted;
63 bool firstPageOfStream;
64 bool lastPageOfStream;
65 long long absoluteGranularPosition;
66 uint streamSerialNumber;
67 int pageSequenceNumber;
72 ////////////////////////////////////////////////////////////////////////////////
74 ////////////////////////////////////////////////////////////////////////////////
76 Ogg::PageHeader::PageHeader(Ogg::File *file, long pageOffset)
78 d = new PageHeaderPrivate(file, pageOffset);
79 if(file && pageOffset >= 0)
83 Ogg::PageHeader::~PageHeader()
88 bool Ogg::PageHeader::isValid() const
93 List<int> Ogg::PageHeader::packetSizes() const
95 return d->packetSizes;
98 void Ogg::PageHeader::setPacketSizes(const List<int> &sizes)
100 d->packetSizes = sizes;
103 bool Ogg::PageHeader::firstPacketContinued() const
105 return d->firstPacketContinued;
108 void Ogg::PageHeader::setFirstPacketContinued(bool continued)
110 d->firstPacketContinued = continued;
113 bool Ogg::PageHeader::lastPacketCompleted() const
115 return d->lastPacketCompleted;
118 void Ogg::PageHeader::setLastPacketCompleted(bool completed)
120 d->lastPacketCompleted = completed;
123 bool Ogg::PageHeader::firstPageOfStream() const
125 return d->firstPageOfStream;
128 void Ogg::PageHeader::setFirstPageOfStream(bool first)
130 d->firstPageOfStream = first;
133 bool Ogg::PageHeader::lastPageOfStream() const
135 return d->lastPageOfStream;
138 void Ogg::PageHeader::setLastPageOfStream(bool last)
140 d->lastPageOfStream = last;
143 long long Ogg::PageHeader::absoluteGranularPosition() const
145 return d->absoluteGranularPosition;
148 void Ogg::PageHeader::setAbsoluteGranularPosition(long long agp)
150 d->absoluteGranularPosition = agp;
153 int Ogg::PageHeader::pageSequenceNumber() const
155 return d->pageSequenceNumber;
158 void Ogg::PageHeader::setPageSequenceNumber(int sequenceNumber)
160 d->pageSequenceNumber = sequenceNumber;
163 TagLib::uint Ogg::PageHeader::streamSerialNumber() const
165 return d->streamSerialNumber;
168 void Ogg::PageHeader::setStreamSerialNumber(uint n)
170 d->streamSerialNumber = n;
173 int Ogg::PageHeader::size() const
178 int Ogg::PageHeader::dataSize() const
183 ByteVector Ogg::PageHeader::render() const
191 // stream structure version
193 data.append(char(0));
197 std::bitset<8> flags;
198 flags[0] = d->firstPacketContinued;
199 flags[1] = d->pageSequenceNumber == 0;
200 flags[2] = d->lastPageOfStream;
202 data.append(char(flags.to_ulong()));
204 // absolute granular position
206 data.append(ByteVector::fromLongLong(d->absoluteGranularPosition, false));
208 // stream serial number
210 data.append(ByteVector::fromUInt(d->streamSerialNumber, false));
212 // page sequence number
214 data.append(ByteVector::fromUInt(d->pageSequenceNumber, false));
216 // checksum -- this is left empty and should be filled in by the Ogg::Page
219 data.append(ByteVector(4, 0));
221 // page segment count and page segment table
223 ByteVector pageSegments = lacingValues();
225 data.append(char(uchar(pageSegments.size())));
226 data.append(pageSegments);
231 ////////////////////////////////////////////////////////////////////////////////
233 ////////////////////////////////////////////////////////////////////////////////
235 void Ogg::PageHeader::read()
237 d->file->seek(d->fileOffset);
239 // An Ogg page header is at least 27 bytes, so we'll go ahead and read that
240 // much and then get the rest when we're ready for it.
242 ByteVector data = d->file->readBlock(27);
244 // Sanity check -- make sure that we were in fact able to read as much data as
245 // we asked for and that the page begins with "OggS".
247 if(data.size() != 27 || !data.startsWith("OggS")) {
248 debug("Ogg::PageHeader::read() -- error reading page header");
252 std::bitset<8> flags(data[5]);
254 d->firstPacketContinued = flags.test(0);
255 d->firstPageOfStream = flags.test(1);
256 d->lastPageOfStream = flags.test(2);
258 d->absoluteGranularPosition = data.mid(6, 8).toLongLong(false);
259 d->streamSerialNumber = data.mid(14, 4).toUInt(false);
260 d->pageSequenceNumber = data.mid(18, 4).toUInt(false);
262 // Byte number 27 is the number of page segments, which is the only variable
263 // length portion of the page header. After reading the number of page
264 // segments we'll then read in the corresponding data for this count.
266 int pageSegmentCount = uchar(data[26]);
268 ByteVector pageSegments = d->file->readBlock(pageSegmentCount);
270 // Another sanity check.
272 if(pageSegmentCount < 1 || int(pageSegments.size()) != pageSegmentCount)
275 // The base size of an Ogg page 27 bytes plus the number of lacing values.
277 d->size = 27 + pageSegmentCount;
281 for(int i = 0; i < pageSegmentCount; i++) {
282 d->dataSize += uchar(pageSegments[i]);
283 packetSize += uchar(pageSegments[i]);
285 if(uchar(pageSegments[i]) < 255) {
286 d->packetSizes.append(packetSize);
292 d->packetSizes.append(packetSize);
293 d->lastPacketCompleted = false;
296 d->lastPacketCompleted = true;
301 ByteVector Ogg::PageHeader::lacingValues() const
305 List<int> sizes = d->packetSizes;
306 for(List<int>::ConstIterator it = sizes.begin(); it != sizes.end(); ++it) {
308 // The size of a packet in an Ogg page is indicated by a series of "lacing
309 // values" where the sum of the values is the packet size in bytes. Each of
310 // these values is a byte. A value of less than 255 (0xff) indicates the end
313 div_t n = div(*it, 255);
315 for(int i = 0; i < n.quot; i++)
316 data.append(char(uchar(255)));
318 if(it != --sizes.end() || d->lastPacketCompleted)
319 data.append(char(uchar(n.rem)));