ref: 5232326716af469eafa6d98fba64f8154c69d9f8
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; }