ref: a1088e0b5f275612ae973d70b46ed949eede68c0
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>
#ifdef _MSC_VER
#define _CRT_RAND_S
#endif
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <new>
#include "mkvwriter.hpp"
#include "webmids.hpp"
namespace mkvmuxer {
namespace {
// Date elements are always 8 octets in size.
const int kDateElementSize = 8;
} // 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;
}
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) {
return EbmlElementSize(type, static_cast<uint64>(value));
}
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, int64 value) {
// 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, 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 WriteSimpleBlock(IMkvWriter* writer, const uint8* data, uint64 length,
uint64 track_number, int64 timecode, uint64 is_key) {
if (!writer)
return false;
if (!data || length < 1)
return false;
// Here we only permit track number values to be no greater than
// 126, which the largest value we can store having a Matroska
// integer representation of only 1 byte.
if (track_number < 1 || track_number > 126)
return false;
// Technically the timestamp for a block can be less than the
// timestamp for the cluster itself (remember that block timestamp
// is a signed, 16-bit integer). However, as a simplification we
// only permit non-negative cluster-relative timestamps for blocks.
if (timecode < 0 || timecode > kMaxBlockTimecode)
return false;
if (WriteID(writer, kMkvSimpleBlock))
return 0;
const int32 size = static_cast<int32>(length) + 4;
if (WriteUInt(writer, size))
return 0;
if (WriteUInt(writer, static_cast<uint64>(track_number)))
return 0;
if (SerializeInt(writer, timecode, 2))
return 0;
uint64 flags = 0;
if (is_key)
flags |= 0x80;
if (SerializeInt(writer, flags, 1))
return 0;
if (writer->Write(data, static_cast<uint32>(length)))
return 0;
const uint64 element_size =
GetUIntSize(kMkvSimpleBlock) + GetCodedUIntSize(size) + 4 + length;
return element_size;
}
// We must write the metadata (key)frame as a BlockGroup element,
// because we need to specify a duration for the frame. The
// BlockGroup element comprises the frame itself and its duration,
// and is laid out as follows:
//
// BlockGroup tag
// BlockGroup size
// Block tag
// Block size
// (the frame is the block payload)
// Duration tag
// Duration size
// (duration payload)
//
uint64 WriteMetadataBlock(IMkvWriter* writer, const uint8* data, uint64 length,
uint64 track_number, int64 timecode,
uint64 duration) {
// We don't backtrack when writing to the stream, so we must
// pre-compute the BlockGroup size, by summing the sizes of each
// sub-element (the block and the duration).
// We use a single byte for the track number of the block, which
// means the block header is exactly 4 bytes.
// TODO(matthewjheaney): use EbmlMasterElementSize and WriteEbmlMasterElement
const uint64 block_payload_size = 4 + length;
const int32 block_size = GetCodedUIntSize(block_payload_size);
const uint64 block_elem_size = 1 + block_size + block_payload_size;
const int32 duration_payload_size = GetUIntSize(duration);
const int32 duration_size = GetCodedUIntSize(duration_payload_size);
const uint64 duration_elem_size = 1 + duration_size + duration_payload_size;
const uint64 blockg_payload_size = block_elem_size + duration_elem_size;
const int32 blockg_size = GetCodedUIntSize(blockg_payload_size);
const uint64 blockg_elem_size = 1 + blockg_size + blockg_payload_size;
if (WriteID(writer, kMkvBlockGroup)) // 1-byte ID size
return 0;
if (WriteUInt(writer, blockg_payload_size))
return 0;
// Write Block element
if (WriteID(writer, kMkvBlock)) // 1-byte ID size
return 0;
if (WriteUInt(writer, block_payload_size))
return 0;
// Byte 1 of 4
if (WriteUInt(writer, track_number))
return 0;
// Bytes 2 & 3 of 4
if (SerializeInt(writer, timecode, 2))
return 0;
// Byte 4 of 4
const uint64 flags = 0;
if (SerializeInt(writer, flags, 1))
return 0;
// Now write the actual frame (of metadata)
if (writer->Write(data, static_cast<uint32>(length)))
return 0;
// Write Duration element
if (WriteID(writer, kMkvBlockDuration)) // 1-byte ID size
return 0;
if (WriteUInt(writer, duration_payload_size))
return 0;
if (SerializeInt(writer, duration, duration_payload_size))
return 0;
// Note that we don't write a reference time as part of the block
// group; no reference time(s) indicates that this block is a
// keyframe. (Unlike the case for a SimpleBlock element, the header
// bits of the Block sub-element of a BlockGroup element do not
// indicate keyframe status. The keyframe status is inferred from
// the absence of reference time sub-elements.)
return blockg_elem_size;
}
// Writes a WebM BlockGroup with BlockAdditional data. The structure is as
// follows:
// Indentation shows sub-levels
// BlockGroup
// Block
// Data
// BlockAdditions
// BlockMore
// BlockAddID
// 1 (Denotes Alpha)
// BlockAdditional
// Data
uint64 WriteBlockWithAdditional(IMkvWriter* writer, const uint8* data,
uint64 length, const uint8* additional,
uint64 additional_length, uint64 add_id,
uint64 track_number, int64 timecode,
uint64 is_key) {
if (!data || !additional || length < 1 || additional_length < 1)
return 0;
const uint64 block_payload_size = 4 + length;
const uint64 block_elem_size =
EbmlMasterElementSize(kMkvBlock, block_payload_size) + block_payload_size;
const uint64 block_additional_elem_size =
EbmlElementSize(kMkvBlockAdditional, additional, additional_length);
const uint64 block_addid_elem_size = EbmlElementSize(kMkvBlockAddID, add_id);
const uint64 block_more_payload_size =
block_addid_elem_size + block_additional_elem_size;
const uint64 block_more_elem_size =
EbmlMasterElementSize(kMkvBlockMore, block_more_payload_size) +
block_more_payload_size;
const uint64 block_additions_payload_size = block_more_elem_size;
const uint64 block_additions_elem_size =
EbmlMasterElementSize(kMkvBlockAdditions, block_additions_payload_size) +
block_additions_payload_size;
const uint64 block_group_payload_size =
block_elem_size + block_additions_elem_size;
const uint64 block_group_elem_size =
EbmlMasterElementSize(kMkvBlockGroup, block_group_payload_size) +
block_group_payload_size;
if (!WriteEbmlMasterElement(writer, kMkvBlockGroup, block_group_payload_size))
return 0;
if (!WriteEbmlMasterElement(writer, kMkvBlock, block_payload_size))
return 0;
if (WriteUInt(writer, track_number))
return 0;
if (SerializeInt(writer, timecode, 2))
return 0;
uint64 flags = 0;
if (is_key)
flags |= 0x80;
if (SerializeInt(writer, flags, 1))
return 0;
if (writer->Write(data, static_cast<uint32>(length)))
return 0;
if (!WriteEbmlMasterElement(writer, kMkvBlockAdditions,
block_additions_payload_size))
return 0;
if (!WriteEbmlMasterElement(writer, kMkvBlockMore, block_more_payload_size))
return 0;
if (!WriteEbmlElement(writer, kMkvBlockAddID, add_id))
return 0;
if (!WriteEbmlElement(writer, kMkvBlockAdditional, additional,
additional_length))
return 0;
return block_group_elem_size;
}
// Writes a WebM BlockGroup with DiscardPadding. The structure is as follows:
// Indentation shows sub-levels
// BlockGroup
// Block
// Data
// DiscardPadding
uint64 WriteBlockWithDiscardPadding(IMkvWriter* writer, const uint8* data,
uint64 length, int64 discard_padding,
uint64 track_number, int64 timecode,
uint64 is_key) {
if (!data || length < 1 || discard_padding <= 0)
return 0;
const uint64 block_payload_size = 4 + length;
const uint64 block_elem_size =
EbmlMasterElementSize(kMkvBlock, block_payload_size) + block_payload_size;
const uint64 discard_padding_elem_size =
EbmlElementSize(kMkvDiscardPadding, discard_padding);
const uint64 block_group_payload_size =
block_elem_size + discard_padding_elem_size;
const uint64 block_group_elem_size =
EbmlMasterElementSize(kMkvBlockGroup, block_group_payload_size) +
block_group_payload_size;
if (!WriteEbmlMasterElement(writer, kMkvBlockGroup, block_group_payload_size))
return 0;
if (!WriteEbmlMasterElement(writer, kMkvBlock, block_payload_size))
return 0;
if (WriteUInt(writer, track_number))
return 0;
if (SerializeInt(writer, timecode, 2))
return 0;
uint64 flags = 0;
if (is_key)
flags |= 0x80;
if (SerializeInt(writer, flags, 1))
return 0;
if (writer->Write(data, static_cast<uint32>(length)))
return 0;
if (WriteID(writer, kMkvDiscardPadding))
return 0;
const uint64 size = GetUIntSize(discard_padding);
if (WriteUInt(writer, size))
return false;
if (SerializeInt(writer, discard_padding, static_cast<int32>(size)))
return false;
return block_group_elem_size;
}
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;
unsigned int random_value;
const errno_t e = rand_s(&random_value);
(void)e;
const int32 nn = random_value;
#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;
}