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mkvparser: create generic track objects

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Formerly, it was only possible to create instances of
the Track subclasses, VideoTrack and AudioTrack.  However,
we now populate WebM files with WebVTT metadata blocks,
so we must allow for a third kind of track object.

We now enable instances of type Track to be created,
by providing a new factory function, Track::Create, and
making all Track methods non-pure and with a generic
implementation.

Change-Id: I7d4c965eb566b9fc2f5ceefe1d43723cf8c1e5f0
This commit is contained in:
Matthew Heaney
2012-10-09 12:08:33 -07:00
parent cb8899a920
commit 2fc496a0d6
2 changed files with 183 additions and 96 deletions
Download Patch File Download Diff File Expand all files Collapse all files

266
mkvparser.cpp
View File

@@ -4760,6 +4760,35 @@ Track::~Track()
delete [] content_encoding_entries_;
}
long Track::Create(
Segment* pSegment,
const Info& info,
long long element_start,
long long element_size,
Track*& pResult)
{
if (pResult)
return -1;
Track* const pTrack = new (std::nothrow) Track(pSegment,
element_start,
element_size);
if (pTrack == NULL)
return -1; //generic error
const int status = info.Copy(pTrack->m_info);
if (status) // error
{
delete pTrack;
return status;
}
pResult = pTrack;
return 0; //success
}
Track::Info::Info():
nameAsUTF8(NULL),
codecId(NULL),
@@ -5098,6 +5127,31 @@ long Track::GetNext(
return 1;
}
bool Track::VetEntry(const BlockEntry* pBlockEntry) const
{
assert(pBlockEntry);
const Block* const pBlock = pBlockEntry->GetBlock();
assert(pBlock);
assert(pBlock->GetTrackNumber() == m_info.number);
// This function is used during a seek to determine whether the
// frame is a valid seek target. This default function simply
// returns true, which means all frames are valid seek targets.
// It gets overridden by the VideoTrack class, because only video
// keyframes can be used as seek target.
return true;
}
long Track::Seek(
long long /* time_ns */ ,
const BlockEntry*& pResult) const
{
// TODO(matthewjheaney): need to implement this?
pResult = NULL;
return -1; // generic error
}
const ContentEncoding*
Track::GetContentEncodingByIndex(unsigned long idx) const {
const ptrdiff_t count =
@@ -5221,15 +5275,15 @@ VideoTrack::VideoTrack(
long VideoTrack::Parse(
Segment* pSegment,
const Info& i,
long long elem_st,
long long elem_sz,
VideoTrack*& pTrack)
const Info& info,
long long element_start,
long long element_size,
VideoTrack*& pResult)
{
if (pTrack)
if (pResult)
return -1;
if (i.type != Track::kVideo)
if (info.type != Track::kVideo)
return -1;
long long width = 0;
@@ -5238,7 +5292,7 @@ long VideoTrack::Parse(
IMkvReader* const pReader = pSegment->m_pReader;
const Settings& s = i.settings;
const Settings& s = info.settings;
assert(s.start >= 0);
assert(s.size >= 0);
@@ -5296,36 +5350,35 @@ long VideoTrack::Parse(
assert(pos == stop);
pTrack = new (std::nothrow) VideoTrack(pSegment, elem_st, elem_sz);
VideoTrack* const pTrack = new (std::nothrow) VideoTrack(pSegment,
element_start,
element_size);
if (pTrack == NULL)
return -1; //generic error
const int status = i.Copy(pTrack->m_info);
const int status = info.Copy(pTrack->m_info);
if (status)
if (status) // error
{
delete pTrack;
return status;
}
pTrack->m_width = width;
pTrack->m_height = height;
pTrack->m_rate = rate;
pResult = pTrack;
return 0; //success
}
bool VideoTrack::VetEntry(const BlockEntry* pBlockEntry) const
{
assert(pBlockEntry);
const Block* const pBlock = pBlockEntry->GetBlock();
assert(pBlock);
assert(pBlock->GetTrackNumber() == m_info.number);
return pBlock->IsKey();
return Track::VetEntry(pBlockEntry) && pBlockEntry->GetBlock()->IsKey();
}
long VideoTrack::Seek(
long long time_ns,
const BlockEntry*& pResult) const
@@ -5459,20 +5512,20 @@ AudioTrack::AudioTrack(
long AudioTrack::Parse(
Segment* pSegment,
const Info& i,
long long elem_st,
long long elem_sz,
AudioTrack*& pTrack)
const Info& info,
long long element_start,
long long element_size,
AudioTrack*& pResult)
{
if (pTrack)
if (pResult)
return -1;
if (i.type != Track::kAudio)
if (info.type != Track::kAudio)
return -1;
IMkvReader* const pReader = pSegment->m_pReader;
const Settings& s = i.settings;
const Settings& s = info.settings;
assert(s.start >= 0);
assert(s.size >= 0);
@@ -5481,7 +5534,7 @@ long AudioTrack::Parse(
const long long stop = pos + s.size;
double rate = 8000.0;
double rate = 8000.0; // MKV default
long long channels = 1;
long long bit_depth = 0;
@@ -5530,36 +5583,30 @@ long AudioTrack::Parse(
assert(pos == stop);
pTrack = new (std::nothrow) AudioTrack(pSegment, elem_st, elem_sz);
AudioTrack* const pTrack = new (std::nothrow) AudioTrack(pSegment,
element_start,
element_size);
if (pTrack == NULL)
return -1; //generic error
const int status = i.Copy(pTrack->m_info);
const int status = info.Copy(pTrack->m_info);
if (status)
{
delete pTrack;
return status;
}
pTrack->m_rate = rate;
pTrack->m_channels = channels;
pTrack->m_bitDepth = bit_depth;
pResult = pTrack;
return 0; //success
}
bool AudioTrack::VetEntry(const BlockEntry* pBlockEntry) const
{
assert(pBlockEntry);
const Block* const pBlock = pBlockEntry->GetBlock();
assert(pBlock);
assert(pBlock->GetTrackNumber() == m_info.number);
return true;
}
long AudioTrack::Seek(
long long time_ns,
const BlockEntry*& pResult) const
@@ -5791,11 +5838,11 @@ unsigned long Tracks::GetTracksCount() const
long Tracks::ParseTrackEntry(
long long track_start,
long long track_size,
long long elem_st,
long long elem_sz,
Track*& pTrack) const
long long element_start,
long long element_size,
Track*& pResult) const
{
if (pTrack)
if (pResult)
return -1;
IMkvReader* const pReader = m_pSegment->m_pReader;
@@ -5803,11 +5850,11 @@ long Tracks::ParseTrackEntry(
long long pos = track_start;
const long long track_stop = track_start + track_size;
Track::Info i;
Track::Info info;
i.type = 0;
i.number = 0;
i.uid = 0;
info.type = 0;
info.number = 0;
info.uid = 0;
Track::Settings v;
v.start = -1;
@@ -5868,7 +5915,7 @@ long Tracks::ParseTrackEntry(
if ((size <= 0) || (size > 8))
return E_FILE_FORMAT_INVALID;
i.uid = 0;
info.uid = 0;
long long pos_ = start;
const long long pos_end = start + size;
@@ -5882,8 +5929,8 @@ long Tracks::ParseTrackEntry(
if (status)
return status;
i.uid <<= 8;
i.uid |= b;
info.uid <<= 8;
info.uid |= b;
++pos_;
}
@@ -5895,7 +5942,7 @@ long Tracks::ParseTrackEntry(
if ((num <= 0) || (num > 127))
return E_FILE_FORMAT_INVALID;
i.number = static_cast<long>(num);
info.number = static_cast<long>(num);
}
else if (id == 0x03) //Track Type
{
@@ -5904,7 +5951,7 @@ long Tracks::ParseTrackEntry(
if ((type <= 0) || (type > 254))
return E_FILE_FORMAT_INVALID;
i.type = static_cast<long>(type);
info.type = static_cast<long>(type);
}
else if (id == 0x136E) //Track Name
{
@@ -5912,7 +5959,7 @@ long Tracks::ParseTrackEntry(
pReader,
pos,
size,
i.nameAsUTF8);
info.nameAsUTF8);
if (status)
return status;
@@ -5923,7 +5970,7 @@ long Tracks::ParseTrackEntry(
pReader,
pos,
size,
i.codecId);
info.codecId);
if (status)
return status;
@@ -5937,9 +5984,9 @@ long Tracks::ParseTrackEntry(
}
else if (id == 0x23A2) //Codec Private
{
delete[] i.codecPrivate;
i.codecPrivate = NULL;
i.codecPrivateSize = 0;
delete[] info.codecPrivate;
info.codecPrivate = NULL;
info.codecPrivateSize = 0;
if (size <= 0)
return E_FILE_FORMAT_INVALID;
@@ -5961,8 +6008,8 @@ long Tracks::ParseTrackEntry(
return status;
}
i.codecPrivate = buf;
i.codecPrivateSize = buflen;
info.codecPrivate = buf;
info.codecPrivateSize = buflen;
}
else if (id == 0x058688) //Codec Name
{
@@ -5970,7 +6017,7 @@ long Tracks::ParseTrackEntry(
pReader,
pos,
size,
i.codecNameAsUTF8);
info.codecNameAsUTF8);
if (status)
return status;
@@ -5982,29 +6029,18 @@ long Tracks::ParseTrackEntry(
assert(pos == track_stop);
if (i.number <= 0) //not specified
if (info.number <= 0) //not specified
return E_FILE_FORMAT_INVALID;
if (GetTrackByNumber(i.number))
if (GetTrackByNumber(info.number))
return E_FILE_FORMAT_INVALID;
if (i.type <= 0) //not specified
if (info.type <= 0) //not specified
return E_FILE_FORMAT_INVALID;
if ((i.type != Track::kVideo) && (i.type != Track::kAudio))
{
//TODO(matthewjheaney): go ahead and create a "generic" track
//object, so that GetTrackByXXX always returns something, even
//if the object it returns has a type that is not kVideo or kAudio.
info.lacing = (lacing > 0) ? true : false;
return 0; //no error
}
i.lacing = (lacing > 0) ? true : false;
long status;
if (i.type == Track::kVideo)
if (info.type == Track::kVideo)
{
if (v.start < 0)
return E_FILE_FORMAT_INVALID;
@@ -6012,38 +6048,82 @@ long Tracks::ParseTrackEntry(
if (a.start >= 0)
return E_FILE_FORMAT_INVALID;
i.settings = v;
info.settings = v;
VideoTrack* p = NULL;
VideoTrack* pTrack = NULL;
status = VideoTrack::Parse(m_pSegment, i, elem_st, elem_sz, p);
pTrack = p;
const long status = VideoTrack::Parse(m_pSegment,
info,
element_start,
element_size,
pTrack);
if (status)
return status;
pResult = pTrack;
assert(pResult);
if (e.start >= 0)
pResult->ParseContentEncodingsEntry(e.start, e.size);
}
else
else if (info.type == Track::kAudio)
{
assert(i.type == Track::kAudio);
if (a.start < 0)
return E_FILE_FORMAT_INVALID;
if (v.start >= 0)
return E_FILE_FORMAT_INVALID;
i.settings = a;
info.settings = a;
AudioTrack* p = NULL;
AudioTrack* pTrack = NULL;
status = AudioTrack::Parse(m_pSegment, i, elem_st, elem_sz, p);
pTrack = p;
const long status = AudioTrack::Parse(m_pSegment,
info,
element_start,
element_size,
pTrack);
if (status)
return status;
pResult = pTrack;
assert(pResult);
if (e.start >= 0)
pResult->ParseContentEncodingsEntry(e.start, e.size);
}
else
{
// neither video nor audio - probably metadata
if (status)
return status;
if (a.start >= 0)
return E_FILE_FORMAT_INVALID;
assert(pTrack);
if (v.start >= 0)
return E_FILE_FORMAT_INVALID;
if (e.start >= 0)
pTrack->ParseContentEncodingsEntry(e.start, e.size);
if (e.start >= 0)
return E_FILE_FORMAT_INVALID;
info.settings.start = -1;
info.settings.size = 0;
Track* pTrack = NULL;
const long status = Track::Create(m_pSegment,
info,
element_start,
element_size,
pTrack);
if (status)
return status;
pResult = pTrack;
assert(pResult);
}
return 0; //success
}

13
mkvparser.hpp
View File

@@ -315,6 +315,14 @@ class Track
Track& operator=(const Track&);
public:
class Info;
static long Create(
Segment*,
const Info&,
long long element_start,
long long element_size,
Track*&);
enum Type { kVideo = 1, kAudio = 2 };
Segment* const m_pSegment;
@@ -366,8 +374,8 @@ public:
long GetFirst(const BlockEntry*&) const;
long GetNext(const BlockEntry* pCurr, const BlockEntry*& pNext) const;
virtual bool VetEntry(const BlockEntry*) const = 0;
virtual long Seek(long long time_ns, const BlockEntry*&) const = 0;
virtual bool VetEntry(const BlockEntry*) const;
virtual long Seek(long long time_ns, const BlockEntry*&) const;
const ContentEncoding* GetContentEncodingByIndex(unsigned long idx) const;
unsigned long GetContentEncodingCount() const;
@@ -452,7 +460,6 @@ public:
double GetSamplingRate() const;
long long GetChannels() const;
long long GetBitDepth() const;
bool VetEntry(const BlockEntry*) const;
long Seek(long long time_ns, const BlockEntry*&) const;
private: