blob: 397ebc27f01c846ff73d0f27cae8ca29c4aeb356 [file] [log] [blame]
// Copyright (c) 2012 The WebM project authors. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file in the root of the source
// tree. An additional intellectual property rights grant can be found
// in the file PATENTS. All contributing project authors may
// be found in the AUTHORS file in the root of the source tree.
#include "mkvparser/mkvparser.h"
#if defined(_MSC_VER) && _MSC_VER < 1800
#include <float.h> // _isnan() / _finite()
#define MSC_COMPAT
#endif
#include <cassert>
#include <cfloat>
#include <climits>
#include <cmath>
#include <cstring>
#include <memory>
#include <new>
#include "common/webmids.h"
namespace mkvparser {
const long long kStringElementSizeLimit = 20 * 1000 * 1000;
const float MasteringMetadata::kValueNotPresent = FLT_MAX;
const long long Colour::kValueNotPresent = LLONG_MAX;
const float Projection::kValueNotPresent = FLT_MAX;
#ifdef MSC_COMPAT
inline bool isnan(double val) { return !!_isnan(val); }
inline bool isinf(double val) { return !_finite(val); }
#else
inline bool isnan(double val) { return std::isnan(val); }
inline bool isinf(double val) { return std::isinf(val); }
#endif // MSC_COMPAT
template <typename Type>
Type* SafeArrayAlloc(unsigned long long num_elements, unsigned long long element_size) {
if (num_elements == 0 || element_size == 0) return NULL;
const size_t kMaxAllocSize = 0x80000000; // 2GiB
const unsigned long long num_bytes = num_elements * element_size;
if (element_size > (kMaxAllocSize / num_elements)) return NULL;
if (num_bytes != static_cast<size_t>(num_bytes)) return NULL;
return new (std::nothrow) Type[static_cast<size_t>(num_bytes)];
}
void GetVersion(int& major, int& minor, int& build, int& revision) {
major = 1;
minor = 0;
build = 0;
revision = 30;
}
long long ReadUInt(IMkvReader* pReader, long long pos, long& len) {
if (!pReader || pos < 0) return E_FILE_FORMAT_INVALID;
len = 1;
unsigned char b;
int status = pReader->Read(pos, 1, &b);
if (status < 0) // error or underflow
return status;
if (status > 0) // interpreted as "underflow"
return E_BUFFER_NOT_FULL;
if (b == 0) // we can't handle u-int values larger than 8 bytes
return E_FILE_FORMAT_INVALID;
unsigned char m = 0x80;
while (!(b & m)) {
m >>= 1;
++len;
}
long long result = b & (~m);
++pos;
for (int i = 1; i < len; ++i) {
status = pReader->Read(pos, 1, &b);
if (status < 0) {
len = 1;
return status;
}
if (status > 0) {
len = 1;
return E_BUFFER_NOT_FULL;
}
result <<= 8;
result |= b;
++pos;
}
return result;
}
// Reads an EBML ID and returns it.
// An ID must at least 1 byte long, cannot exceed 4, and its value must be
// greater than 0.
// See known EBML values and EBMLMaxIDLength:
// http://www.matroska.org/technical/specs/index.html
// Returns the ID, or a value less than 0 to report an error while reading the
// ID.
long long ReadID(IMkvReader* pReader, long long pos, long& len) {
if (pReader == NULL || pos < 0) return E_FILE_FORMAT_INVALID;
// Read the first byte. The length in bytes of the ID is determined by
// finding the first set bit in the first byte of the ID.
unsigned char temp_byte = 0;
int read_status = pReader->Read(pos, 1, &temp_byte);
if (read_status < 0)
return E_FILE_FORMAT_INVALID;
else if (read_status > 0) // No data to read.
return E_BUFFER_NOT_FULL;
if (temp_byte == 0) // ID length > 8 bytes; invalid file.
return E_FILE_FORMAT_INVALID;
int bit_pos = 0;
const int kMaxIdLengthInBytes = 4;
const int kCheckByte = 0x80;
// Find the first bit that's set.
bool found_bit = false;
for (; bit_pos < kMaxIdLengthInBytes; ++bit_pos) {
if ((kCheckByte >> bit_pos) & temp_byte) {
found_bit = true;
break;
}
}
if (!found_bit) {
// The value is too large to be a valid ID.
return E_FILE_FORMAT_INVALID;
}
// Read the remaining bytes of the ID (if any).
const int id_length = bit_pos + 1;
long long ebml_id = temp_byte;
for (int i = 1; i < id_length; ++i) {
ebml_id <<= 8;
read_status = pReader->Read(pos + i, 1, &temp_byte);
if (read_status < 0)
return E_FILE_FORMAT_INVALID;
else if (read_status > 0)
return E_BUFFER_NOT_FULL;
ebml_id |= temp_byte;
}
len = id_length;
return ebml_id;
}
long long GetUIntLength(IMkvReader* pReader, long long pos, long& len) {
if (!pReader || pos < 0) return E_FILE_FORMAT_INVALID;
long long total, available;
int status = pReader->Length(&total, &available);
if (status < 0 || (total >= 0 && available > total)) return E_FILE_FORMAT_INVALID;
len = 1;
if (pos >= available) return pos; // too few bytes available
unsigned char b;
status = pReader->Read(pos, 1, &b);
if (status != 0) return status;
if (b == 0) // we can't handle u-int values larger than 8 bytes
return E_FILE_FORMAT_INVALID;
unsigned char m = 0x80;
while (!(b & m)) {
m >>= 1;
++len;
}
return 0; // success
}
// TODO(vigneshv): This function assumes that unsigned values never have their
// high bit set.
long long UnserializeUInt(IMkvReader* pReader, long long pos, long long size) {
if (!pReader || pos < 0 || (size <= 0) || (size > 8)) return E_FILE_FORMAT_INVALID;
long long result = 0;
for (long long i = 0; i < size; ++i) {
unsigned char b;
const long status = pReader->Read(pos, 1, &b);
if (status < 0) return status;
result <<= 8;
result |= b;
++pos;
}
return result;
}
long UnserializeFloat(IMkvReader* pReader, long long pos, long long size_, double& result) {
if (!pReader || pos < 0 || ((size_ != 4) && (size_ != 8))) return E_FILE_FORMAT_INVALID;
const long size = static_cast<long>(size_);
unsigned char buf[8];
const int status = pReader->Read(pos, size, buf);
if (status < 0) // error
return status;
if (size == 4) {
union {
float f;
unsigned long ff;
};
ff = 0;
for (int i = 0;;) {
ff |= buf[i];
if (++i >= 4) break;
ff <<= 8;
}
result = f;
} else {
union {
double d;
unsigned long long dd;
};
dd = 0;
for (int i = 0;;) {
dd |= buf[i];
if (++i >= 8) break;
dd <<= 8;
}
result = d;
}
if (mkvparser::isinf(result) || mkvparser::isnan(result)) return E_FILE_FORMAT_INVALID;
return 0;
}
long UnserializeInt(IMkvReader* pReader, long long pos, long long size, long long& result_ref) {
if (!pReader || pos < 0 || size < 1 || size > 8) return E_FILE_FORMAT_INVALID;
signed char first_byte = 0;
const long status = pReader->Read(pos, 1, (unsigned char*)&first_byte);
if (status < 0) return status;
unsigned long long result = first_byte;
++pos;
for (long i = 1; i < size; ++i) {
unsigned char b;
const long status = pReader->Read(pos, 1, &b);
if (status < 0) return status;
result <<= 8;
result |= b;
++pos;
}
result_ref = static_cast<long long>(result);
return 0;
}
long UnserializeString(IMkvReader* pReader, long long pos, long long size, char*& str) {
delete[] str;
str = NULL;
if (size >= LONG_MAX || size < 0 || size > kStringElementSizeLimit) return E_FILE_FORMAT_INVALID;
// +1 for '\0' terminator
const long required_size = static_cast<long>(size) + 1;
str = SafeArrayAlloc<char>(1, required_size);
if (str == NULL) return E_FILE_FORMAT_INVALID;
unsigned char* const buf = reinterpret_cast<unsigned char*>(str);
const long status = pReader->Read(pos, static_cast<long>(size), buf);
if (status) {
delete[] str;
str = NULL;
return status;
}
str[required_size - 1] = '\0';
return 0;
}
long ParseElementHeader(IMkvReader* pReader, long long& pos, long long stop, long long& id, long long& size) {
if (stop >= 0 && pos >= stop) return E_FILE_FORMAT_INVALID;
long len;
id = ReadID(pReader, pos, len);
if (id < 0) return E_FILE_FORMAT_INVALID;
pos += len; // consume id
if (stop >= 0 && pos >= stop) return E_FILE_FORMAT_INVALID;
size = ReadUInt(pReader, pos, len);
if (size < 0 || len < 1 || len > 8) {
// Invalid: Negative payload size, negative or 0 length integer, or integer
// larger than 64 bits (libwebm cannot handle them).
return E_FILE_FORMAT_INVALID;
}
// Avoid rolling over pos when very close to LLONG_MAX.
const unsigned long long rollover_check = static_cast<unsigned long long>(pos) + len;
if (rollover_check > LLONG_MAX) return E_FILE_FORMAT_INVALID;
pos += len; // consume length of size
// pos now designates payload
if (stop >= 0 && pos > stop) return E_FILE_FORMAT_INVALID;
return 0; // success
}
bool Match(IMkvReader* pReader, long long& pos, unsigned long expected_id, long long& val) {
if (!pReader || pos < 0) return false;
long long total = 0;
long long available = 0;
const long status = pReader->Length(&total, &available);
if (status < 0 || (total >= 0 && available > total)) return false;
long len = 0;
const long long id = ReadID(pReader, pos, len);
if (id < 0 || (available - pos) > len) return false;
if (static_cast<unsigned long>(id) != expected_id) return false;
pos += len; // consume id
const long long size = ReadUInt(pReader, pos, len);
if (size < 0 || size > 8 || len < 1 || len > 8 || (available - pos) > len) return false;
pos += len; // consume length of size of payload
val = UnserializeUInt(pReader, pos, size);
if (val < 0) return false;
pos += size; // consume size of payload
return true;
}
bool Match(IMkvReader* pReader, long long& pos, unsigned long expected_id, unsigned char*& buf, size_t& buflen) {
if (!pReader || pos < 0) return false;
long long total = 0;
long long available = 0;
long status = pReader->Length(&total, &available);
if (status < 0 || (total >= 0 && available > total)) return false;
long len = 0;
const long long id = ReadID(pReader, pos, len);
if (id < 0 || (available - pos) > len) return false;
if (static_cast<unsigned long>(id) != expected_id) return false;
pos += len; // consume id
const long long size = ReadUInt(pReader, pos, len);
if (size < 0 || len <= 0 || len > 8 || (available - pos) > len) return false;
unsigned long long rollover_check = static_cast<unsigned long long>(pos) + len;
if (rollover_check > LLONG_MAX) return false;
pos += len; // consume length of size of payload
rollover_check = static_cast<unsigned long long>(pos) + size;
if (rollover_check > LLONG_MAX) return false;
if ((pos + size) > available) return false;
if (size >= LONG_MAX) return false;
const long buflen_ = static_cast<long>(size);
buf = SafeArrayAlloc<unsigned char>(1, buflen_);
if (!buf) return false;
status = pReader->Read(pos, buflen_, buf);
if (status != 0) return false;
buflen = buflen_;
pos += size; // consume size of payload
return true;
}
EBMLHeader::EBMLHeader() : m_docType(NULL) { Init(); }
EBMLHeader::~EBMLHeader() { delete[] m_docType; }
void EBMLHeader::Init() {
m_version = 1;
m_readVersion = 1;
m_maxIdLength = 4;
m_maxSizeLength = 8;
if (m_docType) {
delete[] m_docType;
m_docType = NULL;
}
m_docTypeVersion = 1;
m_docTypeReadVersion = 1;
}
long long EBMLHeader::Parse(IMkvReader* pReader, long long& pos) {
if (!pReader) return E_FILE_FORMAT_INVALID;
long long total, available;
long status = pReader->Length(&total, &available);
if (status < 0) // error
return status;
pos = 0;
// Scan until we find what looks like the first byte of the EBML header.
const long long kMaxScanBytes = (available >= 1024) ? 1024 : available;
const unsigned char kEbmlByte0 = 0x1A;
unsigned char scan_byte = 0;
while (pos < kMaxScanBytes) {
status = pReader->Read(pos, 1, &scan_byte);
if (status < 0) // error
return status;
else if (status > 0)
return E_BUFFER_NOT_FULL;
if (scan_byte == kEbmlByte0) break;
++pos;
}
long len = 0;
const long long ebml_id = ReadID(pReader, pos, len);
if (ebml_id == E_BUFFER_NOT_FULL) return E_BUFFER_NOT_FULL;
if (len != 4 || ebml_id != libwebm::kMkvEBML) return E_FILE_FORMAT_INVALID;
// Move read pos forward to the EBML header size field.
pos += 4;
// Read length of size field.
long long result = GetUIntLength(pReader, pos, len);
if (result < 0) // error
return E_FILE_FORMAT_INVALID;
else if (result > 0) // need more data
return E_BUFFER_NOT_FULL;
if (len < 1 || len > 8) return E_FILE_FORMAT_INVALID;
if ((total >= 0) && ((total - pos) < len)) return E_FILE_FORMAT_INVALID;
if ((available - pos) < len) return pos + len; // try again later
// Read the EBML header size.
result = ReadUInt(pReader, pos, len);
if (result < 0) // error
return result;
pos += len; // consume size field
// pos now designates start of payload
if ((total >= 0) && ((total - pos) < result)) return E_FILE_FORMAT_INVALID;
if ((available - pos) < result) return pos + result;
const long long end = pos + result;
Init();
while (pos < end) {
long long id, size;
status = ParseElementHeader(pReader, pos, end, id, size);
if (status < 0) // error
return status;
if (size == 0) return E_FILE_FORMAT_INVALID;
if (id == libwebm::kMkvEBMLVersion) {
m_version = UnserializeUInt(pReader, pos, size);
if (m_version <= 0) return E_FILE_FORMAT_INVALID;
} else if (id == libwebm::kMkvEBMLReadVersion) {
m_readVersion = UnserializeUInt(pReader, pos, size);
if (m_readVersion <= 0) return E_FILE_FORMAT_INVALID;
} else if (id == libwebm::kMkvEBMLMaxIDLength) {
m_maxIdLength = UnserializeUInt(pReader, pos, size);
if (m_maxIdLength <= 0) return E_FILE_FORMAT_INVALID;
} else if (id == libwebm::kMkvEBMLMaxSizeLength) {
m_maxSizeLength = UnserializeUInt(pReader, pos, size);
if (m_maxSizeLength <= 0) return E_FILE_FORMAT_INVALID;
} else if (id == libwebm::kMkvDocType) {
if (m_docType) return E_FILE_FORMAT_INVALID;
status = UnserializeString(pReader, pos, size, m_docType);
if (status) // error
return status;
} else if (id == libwebm::kMkvDocTypeVersion) {
m_docTypeVersion = UnserializeUInt(pReader, pos, size);
if (m_docTypeVersion <= 0) return E_FILE_FORMAT_INVALID;
} else if (id == libwebm::kMkvDocTypeReadVersion) {
m_docTypeReadVersion = UnserializeUInt(pReader, pos, size);
if (m_docTypeReadVersion <= 0) return E_FILE_FORMAT_INVALID;
}
pos += size;
}
if (pos != end) return E_FILE_FORMAT_INVALID;
// Make sure DocType, DocTypeReadVersion, and DocTypeVersion are valid.
if (m_docType == NULL || m_docTypeReadVersion <= 0 || m_docTypeVersion <= 0) return E_FILE_FORMAT_INVALID;
// Make sure EBMLMaxIDLength and EBMLMaxSizeLength are valid.
if (m_maxIdLength <= 0 || m_maxIdLength > 4 || m_maxSizeLength <= 0 || m_maxSizeLength > 8)
return E_FILE_FORMAT_INVALID;
return 0;
}
Segment::Segment(IMkvReader* pReader, long long elem_start,
// long long elem_size,
long long start, long long size)
: m_pReader(pReader),
m_element_start(elem_start),
// m_element_size(elem_size),
m_start(start),
m_size(size),
m_pos(start),
m_pUnknownSize(0),
m_pSeekHead(NULL),
m_pInfo(NULL),
m_pTracks(NULL),
m_pCues(NULL),
m_pChapters(NULL),
m_pTags(NULL),
m_clusters(NULL),
m_clusterCount(0),
m_clusterPreloadCount(0),
m_clusterSize(0) {}
Segment::~Segment() {
const long count = m_clusterCount + m_clusterPreloadCount;
Cluster** i = m_clusters;
Cluster** j = m_clusters + count;
while (i != j) {
Cluster* const p = *i++;
delete p;
}
delete[] m_clusters;
delete m_pTracks;
delete m_pInfo;
delete m_pCues;
delete m_pChapters;
delete m_pTags;
delete m_pSeekHead;
}
long long Segment::CreateInstance(IMkvReader* pReader, long long pos, Segment*& pSegment) {
if (pReader == NULL || pos < 0) return E_PARSE_FAILED;
pSegment = NULL;
long long total, available;
const long status = pReader->Length(&total, &available);
if (status < 0) // error
return status;
if (available < 0) return -1;
if ((total >= 0) && (available > total)) return -1;
// I would assume that in practice this loop would execute
// exactly once, but we allow for other elements (e.g. Void)
// to immediately follow the EBML header. This is fine for
// the source filter case (since the entire file is available),
// but in the splitter case over a network we should probably
// just give up early. We could for example decide only to
// execute this loop a maximum of, say, 10 times.
// TODO:
// There is an implied "give up early" by only parsing up
// to the available limit. We do do that, but only if the
// total file size is unknown. We could decide to always
// use what's available as our limit (irrespective of whether
// we happen to know the total file length). This would have
// as its sense "parse this much of the file before giving up",
// which a slightly different sense from "try to parse up to
// 10 EMBL elements before giving up".
for (;;) {
if ((total >= 0) && (pos >= total)) return E_FILE_FORMAT_INVALID;
// Read ID
long len;
long long result = GetUIntLength(pReader, pos, len);
if (result) // error, or too few available bytes
return result;
if ((total >= 0) && ((pos + len) > total)) return E_FILE_FORMAT_INVALID;
if ((pos + len) > available) return pos + len;
const long long idpos = pos;
const long long id = ReadID(pReader, pos, len);
if (id < 0) return E_FILE_FORMAT_INVALID;
pos += len; // consume ID
// Read Size
result = GetUIntLength(pReader, pos, len);
if (result) // error, or too few available bytes
return result;
if ((total >= 0) && ((pos + len) > total)) return E_FILE_FORMAT_INVALID;
if ((pos + len) > available) return pos + len;
long long size = ReadUInt(pReader, pos, len);
if (size < 0) // error
return size;
pos += len; // consume length of size of element
// Pos now points to start of payload
// Handle "unknown size" for live streaming of webm files.
const long long unknown_size = (1LL << (7 * len)) - 1;
if (id == libwebm::kMkvSegment) {
if (size == unknown_size)
size = -1;
else if (total < 0)
size = -1;
else if ((pos + size) > total)
size = -1;
pSegment = new (std::nothrow) Segment(pReader, idpos, pos, size);
if (pSegment == NULL) return E_PARSE_FAILED;
return 0; // success
}
if (size == unknown_size) return E_FILE_FORMAT_INVALID;
if ((total >= 0) && ((pos + size) > total)) return E_FILE_FORMAT_INVALID;
if ((pos + size) > available) return pos + size;
pos += size; // consume payload
}
}
long long Segment::ParseHeaders() {
// Outermost (level 0) segment object has been constructed,
// and pos designates start of payload. We need to find the
// inner (level 1) elements.
long long total, available;
const int status = m_pReader->Length(&total, &available);
if (status < 0) // error
return status;
if (total > 0 && available > total) return E_FILE_FORMAT_INVALID;
const long long segment_stop = (m_size < 0) ? -1 : m_start + m_size;
if ((segment_stop >= 0 && total >= 0 && segment_stop > total) || (segment_stop >= 0 && m_pos > segment_stop)) {
return E_FILE_FORMAT_INVALID;
}
for (;;) {
if ((total >= 0) && (m_pos >= total)) break;
if ((segment_stop >= 0) && (m_pos >= segment_stop)) break;
long long pos = m_pos;
const long long element_start = pos;
// Avoid rolling over pos when very close to LLONG_MAX.
unsigned long long rollover_check = pos + 1ULL;
if (rollover_check > LLONG_MAX) return E_FILE_FORMAT_INVALID;
if ((pos + 1) > available) return (pos + 1);
long len;
long long result = GetUIntLength(m_pReader, pos, len);
if (result < 0) // error
return result;
if (result > 0) {
// MkvReader doesn't have enough data to satisfy this read attempt.
return (pos + 1);
}
if ((segment_stop >= 0) && ((pos + len) > segment_stop)) return E_FILE_FORMAT_INVALID;
if ((pos + len) > available) return pos + len;
const long long idpos = pos;
const long long id = ReadID(m_pReader, idpos, len);
if (id < 0) return E_FILE_FORMAT_INVALID;
if (id == libwebm::kMkvCluster) break;
pos += len; // consume ID
if ((pos + 1) > available) return (pos + 1);
// Read Size
result = GetUIntLength(m_pReader, pos, len);
if (result < 0) // error
return result;
if (result > 0) {
// MkvReader doesn't have enough data to satisfy this read attempt.
return (pos + 1);
}
if ((segment_stop >= 0) && ((pos + len) > segment_stop)) return E_FILE_FORMAT_INVALID;
if ((pos + len) > available) return pos + len;
const long long size = ReadUInt(m_pReader, pos, len);
if (size < 0 || len < 1 || len > 8) {
// TODO(tomfinegan): ReadUInt should return an error when len is < 1 or
// len > 8 is true instead of checking this _everywhere_.
return size;
}
pos += len; // consume length of size of element
// Avoid rolling over pos when very close to LLONG_MAX.
rollover_check = static_cast<unsigned long long>(pos) + size;
if (rollover_check > LLONG_MAX) return E_FILE_FORMAT_INVALID;
const long long element_size = size + pos - element_start;
// Pos now points to start of payload
if ((segment_stop >= 0) && ((pos + size) > segment_stop)) return E_FILE_FORMAT_INVALID;
// We read EBML elements either in total or nothing at all.
if ((pos + size) > available) return pos + size;
if (id == libwebm::kMkvInfo) {
if (m_pInfo) return E_FILE_FORMAT_INVALID;
m_pInfo = new (std::nothrow) SegmentInfo(this, pos, size, element_start, element_size);
if (m_pInfo == NULL) return -1;
const long status = m_pInfo->Parse();
if (status) return status;
} else if (id == libwebm::kMkvTracks) {
if (m_pTracks) return E_FILE_FORMAT_INVALID;
m_pTracks = new (std::nothrow) Tracks(this, pos, size, element_start, element_size);
if (m_pTracks == NULL) return -1;
const long status = m_pTracks->Parse();
if (status) return status;
} else if (id == libwebm::kMkvCues) {
if (m_pCues == NULL) {
m_pCues = new (std::nothrow) Cues(this, pos, size, element_start, element_size);
if (m_pCues == NULL) return -1;
}
} else if (id == libwebm::kMkvSeekHead) {
if (m_pSeekHead == NULL) {
m_pSeekHead = new (std::nothrow) SeekHead(this, pos, size, element_start, element_size);
if (m_pSeekHead == NULL) return -1;
const long status = m_pSeekHead->Parse();
if (status) return status;
}
} else if (id == libwebm::kMkvChapters) {
if (m_pChapters == NULL) {
m_pChapters = new (std::nothrow) Chapters(this, pos, size, element_start, element_size);
if (m_pChapters == NULL) return -1;
const long status = m_pChapters->Parse();
if (status) return status;
}
} else if (id == libwebm::kMkvTags) {
if (m_pTags == NULL) {
m_pTags = new (std::nothrow) Tags(this, pos, size, element_start, element_size);
if (m_pTags == NULL) return -1;
const long status = m_pTags->Parse();
if (status) return status;
}
}
m_pos = pos + size; // consume payload
}
if (segment_stop >= 0 && m_pos > segment_stop) return E_FILE_FORMAT_INVALID;
if (m_pInfo == NULL) // TODO: liberalize this behavior
return E_FILE_FORMAT_INVALID;
if (m_pTracks == NULL) return E_FILE_FORMAT_INVALID;
return 0; // success
}
long Segment::LoadCluster(long long& pos, long& len) {
for (;;) {
const long result = DoLoadCluster(pos, len);
if (result <= 1) return result;
}
}
long Segment::DoLoadCluster(long long& pos, long& len) {
if (m_pos < 0) return DoLoadClusterUnknownSize(pos, len);
long long total, avail;
long status = m_pReader->Length(&total, &avail);
if (status < 0) // error
return status;
if (total >= 0 && avail > total) return E_FILE_FORMAT_INVALID;
const long long segment_stop = (m_size < 0) ? -1 : m_start + m_size;
long long cluster_off = -1; // offset relative to start of segment
long long cluster_size = -1; // size of cluster payload
for (;;) {
if ((total >= 0) && (m_pos >= total)) return 1; // no more clusters
if ((segment_stop >= 0) && (m_pos >= segment_stop)) return 1; // no more clusters
pos = m_pos;
// Read ID
if ((pos + 1) > avail) {
len = 1;
return E_BUFFER_NOT_FULL;
}
long long result = GetUIntLength(m_pReader, pos, len);
if (result < 0) // error
return static_cast<long>(result);
if (result > 0) return E_BUFFER_NOT_FULL;
if ((segment_stop >= 0) && ((pos + len) > segment_stop)) return E_FILE_FORMAT_INVALID;
if ((pos + len) > avail) return E_BUFFER_NOT_FULL;
const long long idpos = pos;
const long long id = ReadID(m_pReader, idpos, len);
if (id < 0) return E_FILE_FORMAT_INVALID;
pos += len; // consume ID
// Read Size
if ((pos + 1) > avail) {
len = 1;
return E_BUFFER_NOT_FULL;
}
result = GetUIntLength(m_pReader, pos, len);
if (result < 0) // error
return static_cast<long>(result);
if (result > 0) return E_BUFFER_NOT_FULL;
if ((segment_stop >= 0) && ((pos + len) > segment_stop)) return E_FILE_FORMAT_INVALID;
if ((pos + len) > avail) return E_BUFFER_NOT_FULL;
const long long size = ReadUInt(m_pReader, pos, len);
if (size < 0) // error
return static_cast<long>(size);
pos += len; // consume length of size of element
// pos now points to start of payload
if (size == 0) {
// Missing element payload: move on.
m_pos = pos;
continue;
}
const long long unknown_size = (1LL << (7 * len)) - 1;
if ((segment_stop >= 0) && (size != unknown_size) && ((pos + size) > segment_stop)) {
return E_FILE_FORMAT_INVALID;
}
if (id == libwebm::kMkvCues) {
if (size == unknown_size) {
// Cues element of unknown size: Not supported.
return E_FILE_FORMAT_INVALID;
}
if (m_pCues == NULL) {
const long long element_size = (pos - idpos) + size;
m_pCues = new (std::nothrow) Cues(this, pos, size, idpos, element_size);
if (m_pCues == NULL) return -1;
}
m_pos = pos + size; // consume payload
continue;
}
if (id != libwebm::kMkvCluster) {
// Besides the Segment, Libwebm allows only cluster elements of unknown
// size. Fail the parse upon encountering a non-cluster element reporting
// unknown size.
if (size == unknown_size) return E_FILE_FORMAT_INVALID;
m_pos = pos + size; // consume payload
continue;
}
// We have a cluster.
cluster_off = idpos - m_start; // relative pos
if (size != unknown_size) cluster_size = size;
break;
}
if (cluster_off < 0) {
// No cluster, die.
return E_FILE_FORMAT_INVALID;
}
long long pos_;
long len_;
status = Cluster::HasBlockEntries(this, cluster_off, pos_, len_);
if (status < 0) { // error, or underflow
pos = pos_;
len = len_;
return status;
}
// status == 0 means "no block entries found"
// status > 0 means "found at least one block entry"
// TODO:
// The issue here is that the segment increments its own
// pos ptr past the most recent cluster parsed, and then
// starts from there to parse the next cluster. If we
// don't know the size of the current cluster, then we
// must either parse its payload (as we do below), looking
// for the cluster (or cues) ID to terminate the parse.
// This isn't really what we want: rather, we really need
// a way to create the curr cluster object immediately.
// The pity is that cluster::parse can determine its own
// boundary, and we largely duplicate that same logic here.
//
// Maybe we need to get rid of our look-ahead preloading
// in source::parse???
//
// As we're parsing the blocks in the curr cluster
//(in cluster::parse), we should have some way to signal
// to the segment that we have determined the boundary,
// so it can adjust its own segment::m_pos member.
//
// The problem is that we're asserting in asyncreadinit,
// because we adjust the pos down to the curr seek pos,
// and the resulting adjusted len is > 2GB. I'm suspicious
// that this is even correct, but even if it is, we can't
// be loading that much data in the cache anyway.
const long idx = m_clusterCount;
if (m_clusterPreloadCount > 0) {
if (idx >= m_clusterSize) return E_FILE_FORMAT_INVALID;
Cluster* const pCluster = m_clusters[idx];
if (pCluster == NULL || pCluster->m_index >= 0) return E_FILE_FORMAT_INVALID;
const long long off = pCluster->GetPosition();
if (off < 0) return E_FILE_FORMAT_INVALID;
if (off == cluster_off) { // preloaded already
if (status == 0) // no entries found
return E_FILE_FORMAT_INVALID;
if (cluster_size >= 0)
pos += cluster_size;
else {
const long long element_size = pCluster->GetElementSize();
if (element_size <= 0) return E_FILE_FORMAT_INVALID; // TODO: handle this case
pos = pCluster->m_element_start + element_size;
}
pCluster->m_index = idx; // move from preloaded to loaded
++m_clusterCount;
--m_clusterPreloadCount;
m_pos = pos; // consume payload
if (segment_stop >= 0 && m_pos > segment_stop) return E_FILE_FORMAT_INVALID;
return 0; // success
}
}
if (status == 0) { // no entries found
if (cluster_size >= 0) pos += cluster_size;
if ((total >= 0) && (pos >= total)) {
m_pos = total;
return 1; // no more clusters
}
if ((segment_stop >= 0) && (pos >= segment_stop)) {
m_pos = segment_stop;
return 1; // no more clusters
}
m_pos = pos;
return 2; // try again
}
// status > 0 means we have an entry
Cluster* const pCluster = Cluster::Create(this, idx, cluster_off);
if (pCluster == NULL) return -1;
if (!AppendCluster(pCluster)) {
delete pCluster;
return -1;
}
if (cluster_size >= 0) {
pos += cluster_size;
m_pos = pos;
if (segment_stop > 0 && m_pos > segment_stop) return E_FILE_FORMAT_INVALID;
return 0;
}
m_pUnknownSize = pCluster;
m_pos = -pos;
return 0; // partial success, since we have a new cluster
// status == 0 means "no block entries found"
// pos designates start of payload
// m_pos has NOT been adjusted yet (in case we need to come back here)
}
long Segment::DoLoadClusterUnknownSize(long long& pos, long& len) {
if (m_pos >= 0 || m_pUnknownSize == NULL) return E_PARSE_FAILED;
const long status = m_pUnknownSize->Parse(pos, len);
if (status < 0) // error or underflow
return status;
if (status == 0) // parsed a block
return 2; // continue parsing
const long long start = m_pUnknownSize->m_element_start;
const long long size = m_pUnknownSize->GetElementSize();
if (size < 0) return E_FILE_FORMAT_INVALID;
pos = start + size;
m_pos = pos;
m_pUnknownSize = 0;
return 2; // continue parsing
}
bool Segment::AppendCluster(Cluster* pCluster) {
if (pCluster == NULL || pCluster->m_index < 0) return false;
const long count = m_clusterCount + m_clusterPreloadCount;
long& size = m_clusterSize;
const long idx = pCluster->m_index;
if (size < count || idx != m_clusterCount) return false;
if (count >= size) {
const long n = (size <= 0) ? 2048 : 2 * size;
Cluster** const qq = new (std::nothrow) Cluster*[n];
if (qq == NULL) return false;
Cluster** q = qq;
Cluster** p = m_clusters;
Cluster** const pp = p + count;
while (p != pp) *q++ = *p++;
delete[] m_clusters;
m_clusters = qq;
size = n;
}
if (m_clusterPreloadCount > 0) {
Cluster** const p = m_clusters + m_clusterCount;
if (*p == NULL || (*p)->m_index >= 0) return false;
Cluster** q = p + m_clusterPreloadCount;
if (q >= (m_clusters + size)) return false;
for (;;) {
Cluster** const qq = q - 1;
if ((*qq)->m_index >= 0) return false;
*q = *qq;
q = qq;
if (q == p) break;
}
}
m_clusters[idx] = pCluster;
++m_clusterCount;
return true;
}
bool Segment::PreloadCluster(Cluster* pCluster, ptrdiff_t idx) {
if (pCluster == NULL || pCluster->m_index >= 0 || idx < m_clusterCount) return false;
const long count = m_clusterCount + m_clusterPreloadCount;
long& size = m_clusterSize;
if (size < count) return false;
if (count >= size) {
const long n = (size <= 0) ? 2048 : 2 * size;
Cluster** const qq = new (std::nothrow) Cluster*[n];
if (qq == NULL) return false;
Cluster** q = qq;
Cluster** p = m_clusters;
Cluster** const pp = p + count;
while (p != pp) *q++ = *p++;
delete[] m_clusters;
m_clusters = qq;
size = n;
}
if (m_clusters == NULL) return false;
Cluster** const p = m_clusters + idx;
Cluster** q = m_clusters + count;
if (q < p || q >= (m_clusters + size)) return false;
while (q > p) {
Cluster** const qq = q - 1;
if ((*qq)->m_index >= 0) return false;
*q = *qq;
q = qq;
}
m_clusters[idx] = pCluster;
++m_clusterPreloadCount;
return true;
}
long Segment::Load() {
if (m_clusters != NULL || m_clusterSize != 0 || m_clusterCount != 0) return E_PARSE_FAILED;
// Outermost (level 0) segment object has been constructed,
// and pos designates start of payload. We need to find the
// inner (level 1) elements.
const long long header_status = ParseHeaders();
if (header_status < 0) // error
return static_cast<long>(header_status);
if (header_status > 0) // underflow
return E_BUFFER_NOT_FULL;
if (m_pInfo == NULL || m_pTracks == NULL) return E_FILE_FORMAT_INVALID;
for (;;) {
const long status = LoadCluster();
if (status < 0) // error
return status;
if (status >= 1) // no more clusters
return 0;
}
}
SeekHead::Entry::Entry() : id(0), pos(0), element_start(0), element_size(0) {}
SeekHead::SeekHead(Segment* pSegment, long long start, long long size_, long long element_start, long long element_size)
: m_pSegment(pSegment),
m_start(start),
m_size(size_),
m_element_start(element_start),
m_element_size(element_size),
m_entries(0),
m_entry_count(0),
m_void_elements(0),
m_void_element_count(0) {}
SeekHead::~SeekHead() {
delete[] m_entries;
delete[] m_void_elements;
}
long SeekHead::Parse() {
IMkvReader* const pReader = m_pSegment->m_pReader;
long long pos = m_start;
const long long stop = m_start + m_size;
// first count the seek head entries
int entry_count = 0;
int void_element_count = 0;
while (pos < stop) {
long long id, size;
const long status = ParseElementHeader(pReader, pos, stop, id, size);
if (status < 0) // error
return status;
if (id == libwebm::kMkvSeek)
++entry_count;
else if (id == libwebm::kMkvVoid)
++void_element_count;
pos += size; // consume payload
if (pos > stop) return E_FILE_FORMAT_INVALID;
}
if (pos != stop) return E_FILE_FORMAT_INVALID;
if (entry_count > 0) {
m_entries = new (std::nothrow) Entry[entry_count];
if (m_entries == NULL) return -1;
}
if (void_element_count > 0) {
m_void_elements = new (std::nothrow) VoidElement[void_element_count];
if (m_void_elements == NULL) return -1;
}
// now parse the entries and void elements
Entry* pEntry = m_entries;
VoidElement* pVoidElement = m_void_elements;
pos = m_start;
while (pos < stop) {
const long long idpos = pos;
long long id, size;
const long status = ParseElementHeader(pReader, pos, stop, id, size);
if (status < 0) // error
return status;
if (id == libwebm::kMkvSeek && entry_count > 0) {
if (ParseEntry(pReader, pos, size, pEntry)) {
Entry& e = *pEntry++;
e.element_start = idpos;
e.element_size = (pos + size) - idpos;
}
} else if (id == libwebm::kMkvVoid && void_element_count > 0) {
VoidElement& e = *pVoidElement++;
e.element_start = idpos;
e.element_size = (pos + size) - idpos;
}
pos += size; // consume payload
if (pos > stop) return E_FILE_FORMAT_INVALID;
}
if (pos != stop) return E_FILE_FORMAT_INVALID;
ptrdiff_t count_ = ptrdiff_t(pEntry - m_entries);
assert(count_ >= 0);
assert(count_ <= entry_count);
m_entry_count = static_cast<int>(count_);
count_ = ptrdiff_t(pVoidElement - m_void_elements);
assert(count_ >= 0);
assert(count_ <= void_element_count);
m_void_element_count = static_cast<int>(count_);
return 0;
}
int SeekHead::GetCount() const { return m_entry_count; }
const SeekHead::Entry* SeekHead::GetEntry(int idx) const {
if (idx < 0) return 0;
if (idx >= m_entry_count) return 0;
return m_entries + idx;
}
int SeekHead::GetVoidElementCount() const { return m_void_element_count; }
const SeekHead::VoidElement* SeekHead::GetVoidElement(int idx) const {
if (idx < 0) return 0;
if (idx >= m_void_element_count) return 0;
return m_void_elements + idx;
}
long Segment::ParseCues(long long off, long long& pos, long& len) {
if (m_pCues) return 0; // success
if (off < 0) return -1;
long long total, avail;
const int status = m_pReader->Length(&total, &avail);
if (status < 0) // error
return status;
assert((total < 0) || (avail <= total));
pos = m_start + off;
if ((total < 0) || (pos >= total)) return 1; // don't bother parsing cues
const long long element_start = pos;
const long long segment_stop = (m_size < 0) ? -1 : m_start + m_size;
if ((pos + 1) > avail) {
len = 1;
return E_BUFFER_NOT_FULL;
}
long long result = GetUIntLength(m_pReader, pos, len);
if (result < 0) // error
return static_cast<long>(result);
if (result > 0) // underflow (weird)
{
len = 1;
return E_BUFFER_NOT_FULL;
}
if ((segment_stop >= 0) && ((pos + len) > segment_stop)) return E_FILE_FORMAT_INVALID;
if ((pos + len) > avail) return E_BUFFER_NOT_FULL;
const long long idpos = pos;
const long long id = ReadID(m_pReader, idpos, len);
if (id != libwebm::kMkvCues) return E_FILE_FORMAT_INVALID;
pos += len; // consume ID
assert((segment_stop < 0) || (pos <= segment_stop));
// Read Size
if ((pos + 1) > avail) {
len = 1;
return E_BUFFER_NOT_FULL;
}
result = GetUIntLength(m_pReader, pos, len);
if (result < 0) // error
return static_cast<long>(result);
if (result > 0) // underflow (weird)
{
len = 1;
return E_BUFFER_NOT_FULL;
}
if ((segment_stop >= 0) && ((pos + len) > segment_stop)) return E_FILE_FORMAT_INVALID;
if ((pos + len) > avail) return E_BUFFER_NOT_FULL;
const long long size = ReadUInt(m_pReader, pos, len);
if (size < 0) // error
return static_cast<long>(size);
if (size == 0) // weird, although technically not illegal
return 1; // done
pos += len; // consume length of size of element
assert((segment_stop < 0) || (pos <= segment_stop));
// Pos now points to start of payload
const long long element_stop = pos + size;
if ((segment_stop >= 0) && (element_stop > segment_stop)) return E_FILE_FORMAT_INVALID;
if ((total >= 0) && (element_stop > total)) return 1; // don't bother parsing anymore
len = static_cast<long>(size);
if (element_stop > avail) return E_BUFFER_NOT_FULL;
const long long element_size = element_stop - element_start;
m_pCues = new (std::nothrow) Cues(this, pos, size, element_start, element_size);
if (m_pCues == NULL) return -1;
return 0; // success
}
bool SeekHead::ParseEntry(IMkvReader* pReader, long long start, long long size_, Entry* pEntry) {
if (size_ <= 0) return false;
long long pos = start;
const long long stop = start + size_;
long len;
// parse the container for the level-1 element ID
const long long seekIdId = ReadID(pReader, pos, len);
if (seekIdId < 0) return false;
if (seekIdId != libwebm::kMkvSeekID) return false;
if ((pos + len) > stop) return false;
pos += len; // consume SeekID id
const long long seekIdSize = ReadUInt(pReader, pos, len);
if (seekIdSize <= 0) return false;
if ((pos + len) > stop) return false;
pos += len; // consume size of field
if ((pos + seekIdSize) > stop) return false;
pEntry->id = ReadID(pReader, pos, len); // payload
if (pEntry->id <= 0) return false;
if (len != seekIdSize) return false;
pos += seekIdSize; // consume SeekID payload
const long long seekPosId = ReadID(pReader, pos, len);
if (seekPosId != libwebm::kMkvSeekPosition) return false;
if ((pos + len) > stop) return false;
pos += len; // consume id
const long long seekPosSize = ReadUInt(pReader, pos, len);
if (seekPosSize <= 0) return false;
if ((pos + len) > stop) return false;
pos += len; // consume size
if ((pos + seekPosSize) > stop) return false;
pEntry->pos = UnserializeUInt(pReader, pos, seekPosSize);
if (pEntry->pos < 0) return false;
pos += seekPosSize; // consume payload
if (pos != stop) return false;
return true;
}
Cues::Cues(Segment* pSegment, long long start_, long long size_, long long element_start, long long element_size)
: m_pSegment(pSegment),
m_start(start_),
m_size(size_),
m_element_start(element_start),
m_element_size(element_size),
m_cue_points(NULL),
m_count(0),
m_preload_count(0),
m_pos(start_) {}
Cues::~Cues() {
const long n = m_count + m_preload_count;
CuePoint** p = m_cue_points;
CuePoint** const q = p + n;
while (p != q) {
CuePoint* const pCP = *p++;
assert(pCP);
delete pCP;
}
delete[] m_cue_points;
}
long Cues::GetCount() const {
if (m_cue_points == NULL) return -1;
return m_count; // TODO: really ignore preload count?
}
bool Cues::DoneParsing() const {
const long long stop = m_start + m_size;
return (m_pos >= stop);
}
bool Cues::Init() const {
if (m_cue_points) return true;
if (m_count != 0 || m_preload_count != 0) return false;
IMkvReader* const pReader = m_pSegment->m_pReader;
const long long stop = m_start + m_size;
long long pos = m_start;
long cue_points_size = 0;
while (pos < stop) {
const long long idpos = pos;
long len;
const long long id = ReadID(pReader, pos, len);
if (id < 0 || (pos + len) > stop) {
return false;
}
pos += len; // consume ID
const long long size = ReadUInt(pReader, pos, len);
if (size < 0 || (pos + len > stop)) {
return false;
}
pos += len; // consume Size field
if (pos + size > stop) {
return false;
}
if (id == libwebm::kMkvCuePoint) {
if (!PreloadCuePoint(cue_points_size, idpos)) return false;
}
pos += size; // skip payload
}
return true;
}
bool Cues::PreloadCuePoint(long& cue_points_size, long long pos) const {
if (m_count != 0) return false;
if (m_preload_count >= cue_points_size) {
const long n = (cue_points_size <= 0) ? 2048 : 2 * cue_points_size;
CuePoint** const qq = new (std::nothrow) CuePoint*[n];
if (qq == NULL) return false;
CuePoint** q = qq; // beginning of target
CuePoint** p = m_cue_points; // beginning of source
CuePoint** const pp = p + m_preload_count; // end of source
while (p != pp) *q++ = *p++;
delete[] m_cue_points;
m_cue_points = qq;
cue_points_size = n;
}
CuePoint* const pCP = new (std::nothrow) CuePoint(m_preload_count, pos);
if (pCP == NULL) return false;
m_cue_points[m_preload_count++] = pCP;
return true;
}
bool Cues::LoadCuePoint() const {
const long long stop = m_start + m_size;
if (m_pos >= stop) return false; // nothing else to do
if (!Init()) {
m_pos = stop;
return false;
}
IMkvReader* const pReader = m_pSegment->m_pReader;
while (m_pos < stop) {
const long long idpos = m_pos;
long len;
const long long id = ReadID(pReader, m_pos, len);
if (id < 0 || (m_pos + len) > stop) return false;
m_pos += len; // consume ID
const long long size = ReadUInt(pReader, m_pos, len);
if (size < 0 || (m_pos + len) > stop) return false;
m_pos += len; // consume Size field
if ((m_pos + size) > stop) return false;
if (id != libwebm::kMkvCuePoint) {
m_pos += size; // consume payload
if (m_pos > stop) return false;
continue;
}
if (m_preload_count < 1) return false;
CuePoint* const pCP = m_cue_points[m_count];
if (!pCP || (pCP->GetTimeCode() < 0 && (-pCP->GetTimeCode() != idpos))) return false;
if (!pCP->Load(pReader)) {
m_pos = stop;
return false;
}
++m_count;
--m_preload_count;
m_pos += size; // consume payload
if (m_pos > stop) return false;
return true; // yes, we loaded a cue point
}
return false; // no, we did not load a cue point
}
bool Cues::Find(long long time_ns, const Track* pTrack, const CuePoint*& pCP,
const CuePoint::TrackPosition*& pTP) const {
if (time_ns < 0 || pTrack == NULL || m_cue_points == NULL || m_count == 0) return false;
CuePoint** const ii = m_cue_points;
CuePoint** i = ii;
CuePoint** const jj = ii + m_count;
CuePoint** j = jj;
pCP = *i;
if (pCP == NULL) return false;
if (time_ns <= pCP->GetTime(m_pSegment)) {
pTP = pCP->Find(pTrack);
return (pTP != NULL);
}
while (i < j) {
// INVARIANT:
//[ii, i) <= time_ns
//[i, j) ?
//[j, jj) > time_ns
CuePoint** const k = i + (j - i) / 2;
if (k >= jj) return false;
CuePoint* const pCP = *k;
if (pCP == NULL) return false;
const long long t = pCP->GetTime(m_pSegment);
if (t <= time_ns)
i = k + 1;
else
j = k;
if (i > j) return false;
}
if (i != j || i > jj || i <= ii) return false;
pCP = *--i;
if (pCP == NULL || pCP->GetTime(m_pSegment) > time_ns) return false;
// TODO: here and elsewhere, it's probably not correct to search
// for the cue point with this time, and then search for a matching
// track. In principle, the matching track could be on some earlier
// cue point, and with our current algorithm, we'd miss it. To make
// this bullet-proof, we'd need to create a secondary structure,
// with a list of cue points that apply to a track, and then search
// that track-based structure for a matching cue point.
pTP = pCP->Find(pTrack);
return (pTP != NULL);
}
const CuePoint* Cues::GetFirst() const {
if (m_cue_points == NULL || m_count == 0) return NULL;
CuePoint* const* const pp = m_cue_points;
if (pp == NULL) return NULL;
CuePoint* const pCP = pp[0];
if (pCP == NULL || pCP->GetTimeCode() < 0) return NULL;
return pCP;
}
const CuePoint* Cues::GetLast() const {
if (m_cue_points == NULL || m_count <= 0) return NULL;
const long index = m_count - 1;
CuePoint* const* const pp = m_cue_points;
if (pp == NULL) return NULL;
CuePoint* const pCP = pp[index];
if (pCP == NULL || pCP->GetTimeCode() < 0) return NULL;
return pCP;
}
const CuePoint* Cues::GetNext(const CuePoint* pCurr) const {
if (pCurr == NULL || pCurr->GetTimeCode() < 0 || m_cue_points == NULL || m_count < 1) {
return NULL;
}
long index = pCurr->m_index;
if (index >= m_count) return NULL;
CuePoint* const* const pp = m_cue_points;
if (pp == NULL || pp[index] != pCurr) return NULL;
++index;
if (index >= m_count) return NULL;
CuePoint* const pNext = pp[index];
if (pNext == NULL || pNext->GetTimeCode() < 0) return NULL;
return pNext;
}
const BlockEntry* Cues::GetBlock(const CuePoint* pCP, const CuePoint::TrackPosition* pTP) const {
if (pCP == NULL || pTP == NULL) return NULL;
return m_pSegment->GetBlock(*pCP, *pTP);
}
const BlockEntry* Segment::GetBlock(const CuePoint& cp, const CuePoint::TrackPosition& tp) {
Cluster** const ii = m_clusters;
Cluster** i = ii;
const long count = m_clusterCount + m_clusterPreloadCount;
Cluster** const jj = ii + count;
Cluster** j = jj;
while (i < j) {
// INVARIANT:
//[ii, i) < pTP->m_pos
//[i, j) ?
//[j, jj) > pTP->m_pos
Cluster** const k = i + (j - i) / 2;
assert(k < jj);
Cluster* const pCluster = *k;
assert(pCluster);
// const long long pos_ = pCluster->m_pos;
// assert(pos_);
// const long long pos = pos_ * ((pos_ < 0) ? -1 : 1);
const long long pos = pCluster->GetPosition();
assert(pos >= 0);
if (pos < tp.m_pos)
i = k + 1;
else if (pos > tp.m_pos)
j = k;
else
return pCluster->GetEntry(cp, tp);
}
assert(i == j);
// assert(Cluster::HasBlockEntries(this, tp.m_pos));
Cluster* const pCluster = Cluster::Create(this, -1, tp.m_pos); //, -1);
if (pCluster == NULL) return NULL;
const ptrdiff_t idx = i - m_clusters;
if (!PreloadCluster(pCluster, idx)) {
delete pCluster;
return NULL;
}
assert(m_clusters);
assert(m_clusterPreloadCount > 0);
assert(m_clusters[idx] == pCluster);
return pCluster->GetEntry(cp, tp);
}
const Cluster* Segment::FindOrPreloadCluster(long long requested_pos) {
if (requested_pos < 0) return 0;
Cluster** const ii = m_clusters;
Cluster** i = ii;
const long count = m_clusterCount + m_clusterPreloadCount;
Cluster** const jj = ii + count;
Cluster** j = jj;
while (i < j) {
// INVARIANT:
//[ii, i) < pTP->m_pos
//[i, j) ?
//[j, jj) > pTP->m_pos
Cluster** const k = i + (j - i) / 2;
assert(k < jj);
Cluster* const pCluster = *k;
assert(pCluster);
// const long long pos_ = pCluster->m_pos;
// assert(pos_);
// const long long pos = pos_ * ((pos_ < 0) ? -1 : 1);
const long long pos = pCluster->GetPosition();
assert(pos >= 0);
if (pos < requested_pos)
i = k + 1;
else if (pos > requested_pos)
j = k;
else
return pCluster;
}
assert(i == j);
// assert(Cluster::HasBlockEntries(this, tp.m_pos));
Cluster* const pCluster = Cluster::Create(this, -1, requested_pos);
if (pCluster == NULL) return NULL;
const ptrdiff_t idx = i - m_clusters;
if (!PreloadCluster(pCluster, idx)) {
delete pCluster;
return NULL;
}
assert(m_clusters);
assert(m_clusterPreloadCount > 0);
assert(m_clusters[idx] == pCluster);
return pCluster;
}
CuePoint::CuePoint(long idx, long long pos)
: m_element_start(0),
m_element_size(0),
m_index(idx),
m_timecode(-1 * pos),
m_track_positions(NULL),
m_track_positions_count(0) {
assert(pos > 0);
}
CuePoint::~CuePoint() { delete[] m_track_positions; }
bool CuePoint::Load(IMkvReader* pReader) {
// odbgstream os;
// os << "CuePoint::Load(begin): timecode=" << m_timecode << endl;
if (m_timecode >= 0) // already loaded
return true;
assert(m_track_positions == NULL);
assert(m_track_positions_count == 0);
long long pos_ = -m_timecode;
const long long element_start = pos_;
long long stop;
{
long len;
const long long id = ReadID(pReader, pos_, len);
if (id != libwebm::kMkvCuePoint) return false;
pos_ += len; // consume ID
const long long size = ReadUInt(pReader, pos_, len);
assert(size >= 0);
pos_ += len; // consume Size field
// pos_ now points to start of payload
stop = pos_ + size;
}
const long long element_size = stop - element_start;
long long pos = pos_;
// First count number of track positions
while (pos < stop) {
long len;
const long long id = ReadID(pReader, pos, len);
if ((id < 0) || (pos + len > stop)) {
return false;
}
pos += len; // consume ID
const long long size = ReadUInt(pReader, pos, len);
if ((size < 0) || (pos + len > stop)) {
return false;
}
pos += len; // consume Size field
if ((pos + size) > stop) {
return false;
}
if (id == libwebm::kMkvCueTime)
m_timecode = UnserializeUInt(pReader, pos, size);
else if (id == libwebm::kMkvCueTrackPositions)
++m_track_positions_count;
pos += size; // consume payload
}
if (m_timecode < 0 || m_track_positions_count <= 0) {
return false;
}
// os << "CuePoint::Load(cont'd): idpos=" << idpos
// << " timecode=" << m_timecode
// << endl;
m_track_positions = new (std::nothrow) TrackPosition[m_track_positions_count];
if (m_track_positions == NULL) return false;
// Now parse track positions
TrackPosition* p = m_track_positions;
pos = pos_;
while (pos < stop) {
long len;
const long long id = ReadID(pReader, pos, len);
if (id < 0 || (pos + len) > stop) return false;
pos += len; // consume ID
const long long size = ReadUInt(pReader, pos, len);
assert(size >= 0);
assert((pos + len) <= stop);
pos += len; // consume Size field
assert((pos + size) <= stop);
if (id == libwebm::kMkvCueTrackPositions) {
TrackPosition& tp = *p++;
if (!tp.Parse(pReader, pos, size)) {
return false;
}
}
pos += size; // consume payload
if (pos > stop) return false;
}
assert(size_t(p - m_track_positions) == m_track_positions_count);
m_element_start = element_start;
m_element_size = element_size;
return true;
}
bool CuePoint::TrackPosition::Parse(IMkvReader* pReader, long long start_, long long size_) {
const long long stop = start_ + size_;
long long pos = start_;
m_track = -1;
m_pos = -1;
m_block = 1; // default
while (pos < stop) {
long len;
const long long id = ReadID(pReader, pos, len);
if ((id < 0) || ((pos + len) > stop)) {
return false;
}
pos += len; // consume ID
const long long size = ReadUInt(pReader, pos, len);
if ((size < 0) || ((pos + len) > stop)) {
return false;
}
pos += len; // consume Size field
if ((pos + size) > stop) {
return false;
}
if (id == libwebm::kMkvCueTrack)
m_track = UnserializeUInt(pReader, pos, size);
else if (id == libwebm::kMkvCueClusterPosition)
m_pos = UnserializeUInt(pReader, pos, size);
else if (id == libwebm::kMkvCueBlockNumber)
m_block = UnserializeUInt(pReader, pos, size);
pos += size; // consume payload
}
if ((m_pos < 0) || (m_track <= 0)) {
return false;
}
return true;
}
const CuePoint::TrackPosition* CuePoint::Find(const Track* pTrack) const {
if (pTrack == NULL) {
return NULL;
}
const long long n = pTrack->GetNumber();
const TrackPosition* i = m_track_positions;
const TrackPosition* const j = i + m_track_positions_count;
while (i != j) {
const TrackPosition& p = *i++;
if (p.m_track == n) return &p;
}
return NULL; // no matching track number found
}
long long CuePoint::GetTimeCode() const { return m_timecode; }
long long CuePoint::GetTime(const Segment* pSegment) const {
assert(pSegment);
assert(m_timecode >= 0);
const SegmentInfo* const pInfo = pSegment->GetInfo();
assert(pInfo);
const long long scale = pInfo->GetTimeCodeScale();
assert(scale >= 1);
const long long time = scale * m_timecode;
return time;
}
bool Segment::DoneParsing() const {
if (m_size < 0) {
long long total, avail;
const int status = m_pReader->Length(&total, &avail);
if (status < 0) // error
return true; // must assume done
if (total < 0) return false; // assume live stream
return (m_pos >= total);
}
const long long stop = m_start + m_size;
return (m_pos >= stop);
}
const Cluster* Segment::GetFirst() const {
if ((m_clusters == NULL) || (m_clusterCount <= 0)) return &m_eos;
Cluster* const pCluster = m_clusters[0];
assert(pCluster);
return pCluster;
}
const Cluster* Segment::GetLast() const {
if ((m_clusters == NULL) || (m_clusterCount <= 0)) return &m_eos;
const long idx = m_clusterCount - 1;
Cluster* const pCluster = m_clusters[idx];
assert(pCluster);
return pCluster;
}
unsigned long Segment::GetCount() const { return m_clusterCount; }
const Cluster* Segment::GetNext(const Cluster* pCurr) {
assert(pCurr);
assert(pCurr != &m_eos);
assert(m_clusters);
long idx = pCurr->m_index;
if (idx >= 0) {
assert(m_clusterCount > 0);
assert(idx < m_clusterCount);
assert(pCurr == m_clusters[idx]);
++idx;
if (idx >= m_clusterCount) return &m_eos; // caller will LoadCluster as desired
Cluster* const pNext = m_clusters[idx];
assert(pNext);
assert(pNext->m_index >= 0);
assert(pNext->m_index == idx);
return pNext;
}
assert(m_clusterPreloadCount > 0);
long long pos = pCurr->m_element_start;
assert(m_size >= 0); // TODO
const long long stop = m_start + m_size; // end of segment
{
long len;
long long result = GetUIntLength(m_pReader, pos, len);
assert(result == 0);
assert((pos + len) <= stop); // TODO
if (result != 0) return NULL;
const long long id = ReadID(m_pReader, pos, len);
if (id != libwebm::kMkvCluster) return NULL;
pos += len; // consume ID
// Read Size
result = GetUIntLength(m_pReader, pos, len);
assert(result == 0); // TODO
assert((pos + len) <= stop); // TODO
const long long size = ReadUInt(m_pReader, pos, len);
assert(size > 0); // TODO
// assert((pCurr->m_size <= 0) || (pCurr->m_size == size));
pos += len; // consume length of size of element
assert((pos + size) <= stop); // TODO
// Pos now points to start of payload
pos += size; // consume payload
}
long long off_next = 0;
while (pos < stop) {
long len;
long long result = GetUIntLength(m_pReader, pos, len);
assert(result == 0);
assert((pos + len) <= stop); // TODO
if (result != 0) return NULL;
const long long idpos = pos; // pos of next (potential) cluster
const long long id = ReadID(m_pReader, idpos, len);
if (id < 0) return NULL;
pos += len; // consume ID
// Read Size
result = GetUIntLength(m_pReader, pos, len);
assert(result == 0); // TODO
assert((pos + len) <= stop); // TODO
const long long size = ReadUInt(m_pReader, pos, len);
assert(size >= 0); // TODO
pos += len; // consume length of size of element
assert((pos + size) <= stop); // TODO
// Pos now points to start of payload
if (size == 0) // weird
continue;
if (id == libwebm::kMkvCluster) {
const long long off_next_ = idpos - m_start;
long long pos_;
long len_;
const long status = Cluster::HasBlockEntries(this, off_next_, pos_, len_);
assert(status >= 0);
if (status > 0) {
off_next = off_next_;
break;
}
}
pos += size; // consume payload
}
if (off_next <= 0) return 0;
Cluster** const ii = m_clusters + m_clusterCount;
Cluster** i = ii;
Cluster** const jj = ii + m_clusterPreloadCount;
Cluster** j = jj;
while (i < j) {
// INVARIANT:
//[0, i) < pos_next
//[i, j) ?
//[j, jj) > pos_next
Cluster** const k = i + (j - i) / 2;
assert(k < jj);
Cluster* const pNext = *k;
assert(pNext);
assert(pNext->m_index < 0);
// const long long pos_ = pNext->m_pos;
// assert(pos_);
// pos = pos_ * ((pos_ < 0) ? -1 : 1);
pos = pNext->GetPosition();
if (pos < off_next)
i = k + 1;
else if (pos > off_next)
j = k;
else
return pNext;
}
assert(i == j);
Cluster* const pNext = Cluster::Create(this, -1, off_next);
if (pNext == NULL) return NULL;
const ptrdiff_t idx_next = i - m_clusters; // insertion position
if (!PreloadCluster(pNext, idx_next)) {
delete pNext;
return NULL;
}
assert(m_clusters);
assert(idx_next < m_clusterSize);
assert(m_clusters[idx_next] == pNext);
return pNext;
}
long Segment::ParseNext(const Cluster* pCurr, const Cluster*& pResult, long long& pos, long& len) {
assert(pCurr);
assert(!pCurr->EOS());
assert(m_clusters);
pResult = 0;
if (pCurr->m_index >= 0) { // loaded (not merely preloaded)
assert(m_clusters[pCurr->m_index] == pCurr);
const long next_idx = pCurr->m_index + 1;
if (next_idx < m_clusterCount) {
pResult = m_clusters[next_idx];
return 0; // success
}
// curr cluster is last among loaded
const long result = LoadCluster(pos, len);
if (result < 0) // error or underflow
return result;
if (result > 0) // no more clusters
{
// pResult = &m_eos;
return 1;
}
pResult = GetLast();
return 0; // success
}
assert(m_pos > 0);
long long total, avail;
long status = m_pReader->Length(&total, &avail);
if (status < 0) // error
return status;
assert((total < 0) || (avail <= total));
const long long segment_stop = (m_size < 0) ? -1 : m_start + m_size;
// interrogate curr cluster
pos = pCurr->m_element_start;
if (pCurr->m_element_size >= 0)
pos += pCurr->m_element_size;
else {
if ((pos + 1) > avail) {
len = 1;
return E_BUFFER_NOT_FULL;
}
long long result = GetUIntLength(m_pReader, pos, len);
if (result < 0) // error
return static_cast<long>(result);
if (result > 0) // weird
return E_BUFFER_NOT_FULL;
if ((segment_stop >= 0) && ((pos + len) > segment_stop)) return E_FILE_FORMAT_INVALID;
if ((pos + len) > avail) return E_BUFFER_NOT_FULL;
const long long id = ReadUInt(m_pReader, pos, len);
if (id != libwebm::kMkvCluster) return -1;
pos += len; // consume ID
// Read Size
if ((pos + 1) > avail) {
len = 1;
return E_BUFFER_NOT_FULL;
}
result = GetUIntLength(m_pReader, pos, len);
if (result < 0) // error
return static_cast<long>(result);
if (result > 0) // weird
return E_BUFFER_NOT_FULL;
if ((segment_stop >= 0) && ((pos + len) > segment_stop)) return E_FILE_FORMAT_INVALID;
if ((pos + len) > avail) return E_BUFFER_NOT_FULL;
const long long size = ReadUInt(m_pReader, pos, len);
if (size < 0) // error
return static_cast<long>(size);
pos += len; // consume size field
const long long unknown_size = (1LL << (7 * len)) - 1;
if (size == unknown_size) // TODO: should never happen
return E_FILE_FORMAT_INVALID; // TODO: resolve this
// assert((pCurr->m_size <= 0) || (pCurr->m_size == size));
if ((segment_stop >= 0) && ((pos + size) > segment_stop)) return E_FILE_FORMAT_INVALID;
// Pos now points to start of payload
pos += size; // consume payload (that is, the current cluster)
if (segment_stop >= 0 && pos > segment_stop) return E_FILE_FORMAT_INVALID;
// By consuming the payload, we are assuming that the curr
// cluster isn't interesting. That is, we don't bother checking
// whether the payload of the curr cluster is less than what
// happens to be available (obtained via IMkvReader::Length).
// Presumably the caller has already dispensed with the current
// cluster, and really does want the next cluster.
}
// pos now points to just beyond the last fully-loaded cluster
for (;;) {
const long status = DoParseNext(pResult, pos, len);
if (status <= 1) return status;
}
}
long Segment::DoParseNext(const Cluster*& pResult, long long& pos, long& len) {
long long total, avail;
long status = m_pReader->Length(&total, &avail);
if (status < 0) // error
return status;
assert((total < 0) || (avail <= total));
const long long segment_stop = (m_size < 0) ? -1 : m_start + m_size;
// Parse next cluster. This is strictly a parsing activity.
// Creation of a new cluster object happens later, after the
// parsing is done.
long long off_next = 0;
long long cluster_size = -1;
for (;;) {
if ((total >= 0) && (pos >= total)) return 1; // EOF