ref: 49f6ff11032df0d6696da8cf544d0292e185d00c
dir: /third_party/libwebm/mkvmuxerutil.cpp/
// 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 "mkvmuxerutil.hpp"
#ifdef __ANDROID__
#include <fcntl.h>
#endif
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <new>
#include "mkvwriter.hpp"
#include "webmids.hpp"
#ifdef _MSC_VER
// Disable MSVC warnings that suggest making code non-portable.
#pragma warning(disable : 4996)
#endif
namespace mkvmuxer {
namespace {
// Date elements are always 8 octets in size.
const int kDateElementSize = 8;
uint64 WriteBlock(IMkvWriter* writer, const Frame* const frame, int64 timecode,
uint64 timecode_scale) {
uint64 block_additional_elem_size = 0;
uint64 block_addid_elem_size = 0;
uint64 block_more_payload_size = 0;
uint64 block_more_elem_size = 0;
uint64 block_additions_payload_size = 0;
uint64 block_additions_elem_size = 0;
if (frame->additional()) {
block_additional_elem_size = EbmlElementSize(
kMkvBlockAdditional, frame->additional(), frame->additional_length());
block_addid_elem_size = EbmlElementSize(kMkvBlockAddID, frame->add_id());
block_more_payload_size =
block_addid_elem_size + block_additional_elem_size;
block_more_elem_size =
EbmlMasterElementSize(kMkvBlockMore, block_more_payload_size) +
block_more_payload_size;
block_additions_payload_size = block_more_elem_size;
block_additions_elem_size =
EbmlMasterElementSize(kMkvBlockAdditions,
block_additions_payload_size) +
block_additions_payload_size;
}
uint64 discard_padding_elem_size = 0;
if (frame->discard_padding() != 0) {
discard_padding_elem_size =
EbmlElementSize(kMkvDiscardPadding, frame->discard_padding());
}
const uint64 reference_block_timestamp =
frame->reference_block_timestamp() / timecode_scale;
uint64 reference_block_elem_size = 0;
if (!frame->is_key()) {
reference_block_elem_size =
EbmlElementSize(kMkvReferenceBlock, reference_block_timestamp);
}
const uint64 duration = frame->duration() / timecode_scale;
uint64 block_duration_elem_size = 0;
if (duration > 0)
block_duration_elem_size = EbmlElementSize(kMkvBlockDuration, duration);
const uint64 block_payload_size = 4 + frame->length();
const uint64 block_elem_size =
EbmlMasterElementSize(kMkvBlock, block_payload_size) + block_payload_size;
const uint64 block_group_payload_size =
block_elem_size + block_additions_elem_size + block_duration_elem_size +
discard_padding_elem_size + reference_block_elem_size;
if (!WriteEbmlMasterElement(writer, kMkvBlockGroup,
block_group_payload_size)) {
return 0;
}
if (!WriteEbmlMasterElement(writer, kMkvBlock, block_payload_size))
return 0;
if (WriteUInt(writer, frame->track_number()))
return 0;
if (SerializeInt(writer, timecode, 2))
return 0;
// For a Block, flags is always 0.
if (SerializeInt(writer, 0, 1))
return 0;
if (writer->Write(frame->frame(), static_cast<uint32>(frame->length())))
return 0;
if (frame->additional()) {
if (!WriteEbmlMasterElement(writer, kMkvBlockAdditions,
block_additions_payload_size)) {
return 0;
}
if (!WriteEbmlMasterElement(writer, kMkvBlockMore, block_more_payload_size))
return 0;
if (!WriteEbmlElement(writer, kMkvBlockAddID, frame->add_id()))
return 0;
if (!WriteEbmlElement(writer, kMkvBlockAdditional, frame->additional(),
frame->additional_length())) {
return 0;
}
}
if (frame->discard_padding() != 0 &&
!WriteEbmlElement(writer, kMkvDiscardPadding, frame->discard_padding())) {
return false;
}
if (!frame->is_key() &&
!WriteEbmlElement(writer, kMkvReferenceBlock,
reference_block_timestamp)) {
return false;
}
if (duration > 0 && !WriteEbmlElement(writer, kMkvBlockDuration, duration)) {
return false;
}
return EbmlMasterElementSize(kMkvBlockGroup, block_group_payload_size) +
block_group_payload_size;
}
uint64 WriteSimpleBlock(IMkvWriter* writer, const Frame* const frame,
int64 timecode) {
if (WriteID(writer, kMkvSimpleBlock))
return 0;
const int32 size = static_cast<int32>(frame->length()) + 4;
if (WriteUInt(writer, size))
return 0;
if (WriteUInt(writer, static_cast<uint64>(frame->track_number())))
return 0;
if (SerializeInt(writer, timecode, 2))
return 0;
uint64 flags = 0;
if (frame->is_key())
flags |= 0x80;
if (SerializeInt(writer, flags, 1))
return 0;
if (writer->Write(frame->frame(), static_cast<uint32>(frame->length())))
return 0;
return GetUIntSize(kMkvSimpleBlock) + GetCodedUIntSize(size) + 4 +
frame->length();
}
} // namespace
int32 GetCodedUIntSize(uint64 value) {
if (value < 0x000000000000007FULL)
return 1;
else if (value < 0x0000000000003FFFULL)
return 2;
else if (value < 0x00000000001FFFFFULL)
return 3;
else if (value < 0x000000000FFFFFFFULL)
return 4;
else if (value < 0x00000007FFFFFFFFULL)
return 5;
else if (value < 0x000003FFFFFFFFFFULL)
return 6;
else if (value < 0x0001FFFFFFFFFFFFULL)
return 7;
return 8;
}
int32 GetUIntSize(uint64 value) {
if (value < 0x0000000000000100ULL)
return 1;
else if (value < 0x0000000000010000ULL)
return 2;
else if (value < 0x0000000001000000ULL)
return 3;
else if (value < 0x0000000100000000ULL)
return 4;
else if (value < 0x0000010000000000ULL)
return 5;
else if (value < 0x0001000000000000ULL)
return 6;
else if (value < 0x0100000000000000ULL)
return 7;
return 8;
}
int32 GetIntSize(int64 value) {
// Doubling the requested value ensures positive values with their high bit
// set are written with 0-padding to avoid flipping the signedness.
const uint64 v = (value < 0) ? value ^ -1LL : value;
return GetUIntSize(2 * v);
}
uint64 EbmlMasterElementSize(uint64 type, uint64 value) {
// Size of EBML ID
int32 ebml_size = GetUIntSize(type);
// Datasize
ebml_size += GetCodedUIntSize(value);
return ebml_size;
}
uint64 EbmlElementSize(uint64 type, int64 value) {
// Size of EBML ID
int32 ebml_size = GetUIntSize(type);
// Datasize
ebml_size += GetIntSize(value);
// Size of Datasize
ebml_size++;
return ebml_size;
}
uint64 EbmlElementSize(uint64 type, uint64 value) {
// Size of EBML ID
int32 ebml_size = GetUIntSize(type);
// Datasize
ebml_size += GetUIntSize(value);
// Size of Datasize
ebml_size++;
return ebml_size;
}
uint64 EbmlElementSize(uint64 type, float /* value */) {
// Size of EBML ID
uint64 ebml_size = GetUIntSize(type);
// Datasize
ebml_size += sizeof(float);
// Size of Datasize
ebml_size++;
return ebml_size;
}
uint64 EbmlElementSize(uint64 type, const char* value) {
if (!value)
return 0;
// Size of EBML ID
uint64 ebml_size = GetUIntSize(type);
// Datasize
ebml_size += strlen(value);
// Size of Datasize
ebml_size++;
return ebml_size;
}
uint64 EbmlElementSize(uint64 type, const uint8* value, uint64 size) {
if (!value)
return 0;
// Size of EBML ID
uint64 ebml_size = GetUIntSize(type);
// Datasize
ebml_size += size;
// Size of Datasize
ebml_size += GetCodedUIntSize(size);
return ebml_size;
}
uint64 EbmlDateElementSize(uint64 type) {
// Size of EBML ID
uint64 ebml_size = GetUIntSize(type);
// Datasize
ebml_size += kDateElementSize;
// Size of Datasize
ebml_size++;
return ebml_size;
}
int32 SerializeInt(IMkvWriter* writer, int64 value, int32 size) {
if (!writer || size < 1 || size > 8)
return -1;
for (int32 i = 1; i <= size; ++i) {
const int32 byte_count = size - i;
const int32 bit_count = byte_count * 8;
const int64 bb = value >> bit_count;
const uint8 b = static_cast<uint8>(bb);
const int32 status = writer->Write(&b, 1);
if (status < 0)
return status;
}
return 0;
}
int32 SerializeFloat(IMkvWriter* writer, float f) {
if (!writer)
return -1;
assert(sizeof(uint32) == sizeof(float));
// This union is merely used to avoid a reinterpret_cast from float& to
// uint32& which will result in violation of strict aliasing.
union U32 {
uint32 u32;
float f;
} value;
value.f = f;
for (int32 i = 1; i <= 4; ++i) {
const int32 byte_count = 4 - i;
const int32 bit_count = byte_count * 8;
const uint8 byte = static_cast<uint8>(value.u32 >> bit_count);
const int32 status = writer->Write(&byte, 1);
if (status < 0)
return status;
}
return 0;
}
int32 WriteUInt(IMkvWriter* writer, uint64 value) {
if (!writer)
return -1;
int32 size = GetCodedUIntSize(value);
return WriteUIntSize(writer, value, size);
}
int32 WriteUIntSize(IMkvWriter* writer, uint64 value, int32 size) {
if (!writer || size < 0 || size > 8)
return -1;
if (size > 0) {
const uint64 bit = 1LL << (size * 7);
if (value > (bit - 2))
return -1;
value |= bit;
} else {
size = 1;
int64 bit;
for (;;) {
bit = 1LL << (size * 7);
const uint64 max = bit - 2;
if (value <= max)
break;
++size;
}
if (size > 8)
return false;
value |= bit;
}
return SerializeInt(writer, value, size);
}
int32 WriteID(IMkvWriter* writer, uint64 type) {
if (!writer)
return -1;
writer->ElementStartNotify(type, writer->Position());
const int32 size = GetUIntSize(type);
return SerializeInt(writer, type, size);
}
bool WriteEbmlMasterElement(IMkvWriter* writer, uint64 type, uint64 size) {
if (!writer)
return false;
if (WriteID(writer, type))
return false;
if (WriteUInt(writer, size))
return false;
return true;
}
bool WriteEbmlElement(IMkvWriter* writer, uint64 type, uint64 value) {
if (!writer)
return false;
if (WriteID(writer, type))
return false;
const uint64 size = GetUIntSize(value);
if (WriteUInt(writer, size))
return false;
if (SerializeInt(writer, value, static_cast<int32>(size)))
return false;
return true;
}
bool WriteEbmlElement(IMkvWriter* writer, uint64 type, int64 value) {
if (!writer)
return false;
if (WriteID(writer, type))
return 0;
const uint64 size = GetIntSize(value);
if (WriteUInt(writer, size))
return false;
if (SerializeInt(writer, value, static_cast<int32>(size)))
return false;
return true;
}
bool WriteEbmlElement(IMkvWriter* writer, uint64 type, float value) {
if (!writer)
return false;
if (WriteID(writer, type))
return false;
if (WriteUInt(writer, 4))
return false;
if (SerializeFloat(writer, value))
return false;
return true;
}
bool WriteEbmlElement(IMkvWriter* writer, uint64 type, const char* value) {
if (!writer || !value)
return false;
if (WriteID(writer, type))
return false;
const uint64 length = strlen(value);
if (WriteUInt(writer, length))
return false;
if (writer->Write(value, static_cast<const uint32>(length)))
return false;
return true;
}
bool WriteEbmlElement(IMkvWriter* writer, uint64 type, const uint8* value,
uint64 size) {
if (!writer || !value || size < 1)
return false;
if (WriteID(writer, type))
return false;
if (WriteUInt(writer, size))
return false;
if (writer->Write(value, static_cast<uint32>(size)))
return false;
return true;
}
bool WriteEbmlDateElement(IMkvWriter* writer, uint64 type, int64 value) {
if (!writer)
return false;
if (WriteID(writer, type))
return false;
if (WriteUInt(writer, kDateElementSize))
return false;
if (SerializeInt(writer, value, kDateElementSize))
return false;
return true;
}
uint64 WriteFrame(IMkvWriter* writer, const Frame* const frame,
Cluster* cluster) {
if (!writer || !frame || !frame->IsValid() || !cluster ||
!cluster->timecode_scale())
return 0;
// Technically the timecode for a block can be less than the
// timecode for the cluster itself (remember that block timecode
// is a signed, 16-bit integer). However, as a simplification we
// only permit non-negative cluster-relative timecodes for blocks.
const int64 relative_timecode = cluster->GetRelativeTimecode(
frame->timestamp() / cluster->timecode_scale());
if (relative_timecode < 0 || relative_timecode > kMaxBlockTimecode)
return 0;
return frame->CanBeSimpleBlock() ?
WriteSimpleBlock(writer, frame, relative_timecode) :
WriteBlock(writer, frame, relative_timecode,
cluster->timecode_scale());
}
uint64 WriteVoidElement(IMkvWriter* writer, uint64 size) {
if (!writer)
return false;
// Subtract one for the void ID and the coded size.
uint64 void_entry_size = size - 1 - GetCodedUIntSize(size - 1);
uint64 void_size =
EbmlMasterElementSize(kMkvVoid, void_entry_size) + void_entry_size;
if (void_size != size)
return 0;
const int64 payload_position = writer->Position();
if (payload_position < 0)
return 0;
if (WriteID(writer, kMkvVoid))
return 0;
if (WriteUInt(writer, void_entry_size))
return 0;
const uint8 value = 0;
for (int32 i = 0; i < static_cast<int32>(void_entry_size); ++i) {
if (writer->Write(&value, 1))
return 0;
}
const int64 stop_position = writer->Position();
if (stop_position < 0 ||
stop_position - payload_position != static_cast<int64>(void_size))
return 0;
return void_size;
}
void GetVersion(int32* major, int32* minor, int32* build, int32* revision) {
*major = 0;
*minor = 2;
*build = 1;
*revision = 0;
}
} // namespace mkvmuxer
mkvmuxer::uint64 mkvmuxer::MakeUID(unsigned int* seed) {
uint64 uid = 0;
#ifdef __MINGW32__
srand(*seed);
#endif
for (int i = 0; i < 7; ++i) { // avoid problems with 8-byte values
uid <<= 8;
// TODO(fgalligan): Move random number generation to platform specific code.
#ifdef _MSC_VER
(void)seed;
const int32 nn = rand();
#elif __ANDROID__
int32 temp_num = 1;
int fd = open("/dev/urandom", O_RDONLY);
if (fd != -1) {
read(fd, &temp_num, sizeof(int32));
close(fd);
}
const int32 nn = temp_num;
#elif defined __MINGW32__
const int32 nn = rand();
#else
const int32 nn = rand_r(seed);
#endif
const int32 n = 0xFF & (nn >> 4); // throw away low-order bits
uid |= n;
}
return uid;
}