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Finally the libffmpeg part compiles (almost) without Qt
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@ChristianFeldmann
ChristianFeldmann committed Oct 5, 2023
1 parent 70580b2 commit 22b7863
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Showing 4 changed files with 34 additions and 341 deletions.
134 changes: 0 additions & 134 deletions YUViewLib/externalLibs/LibFFmpeg++/wrappers/AVPacketWrapper.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -31,104 +31,10 @@
*/

#include "AVPacketWrapper.h"
#include <parser/common/SubByteReaderLogging.h>
#include <stdexcept>

namespace LibFFmpeg
{

namespace
{

bool checkForRawNALFormat(QByteArray &data, bool threeByteStartCode)
{
if (threeByteStartCode && data.length() > 3 && data.at(0) == (char)0 && data.at(1) == (char)0 &&
data.at(2) == (char)1)
return true;
if (!threeByteStartCode && data.length() > 4 && data.at(0) == (char)0 && data.at(1) == (char)0 &&
data.at(2) == (char)0 && data.at(3) == (char)1)
return true;
return false;
}

bool checkForMp4Format(QByteArray &data)
{
// Check the ISO mp4 format: Parse the whole data and check if the size bytes per Unit are
// correct.
uint64_t posInData = 0;
while (posInData + 4 <= uint64_t(data.length()))
{
auto firstBytes = data.mid(posInData, 4);

unsigned size = (unsigned char)firstBytes.at(3);
size += (unsigned char)firstBytes.at(2) << 8;
size += (unsigned char)firstBytes.at(1) << 16;
size += (unsigned char)firstBytes.at(0) << 24;
posInData += 4;

if (size > 1'000'000'000)
// A Nal with more then 1GB? This is probably an error.
return false;
if (posInData + size > uint64_t(data.length()))
// Not enough data in the input array to read NAL unit.
return false;
posInData += size;
}
return true;
}

bool checkForObuFormat(QByteArray &data)
{
// TODO: We already have an implementation of this in the parser
// That should also be used here so we only have one place where we parse OBUs.
try
{
size_t posInData = 0;
while (posInData + 2 <= size_t(data.length()))
{
parser::reader::SubByteReaderLogging reader(
parser::reader::SubByteReaderLogging::convertToByteVector(data), nullptr, "", posInData);

QString bitsRead;
auto forbiddenBit = reader.readFlag("obu_forbidden_bit");
if (forbiddenBit)
return false;
auto obu_type = reader.readBits("obu_type", 4);
if (obu_type == 0 || (obu_type >= 9 && obu_type <= 14))
// RESERVED obu types should not occur (highly unlikely)
return false;
auto obu_extension_flag = reader.readFlag("obu_extension_flag");
auto obu_has_size_field = reader.readFlag("obu_has_size_field");
reader.readFlag("obu_reserved_1bit", parser::reader::Options().withCheckEqualTo(1));

if (obu_extension_flag)
{
reader.readBits("temporal_id", 3);
reader.readBits("spatial_id", 2);
reader.readBits(
"extension_header_reserved_3bits", 3, parser::reader::Options().withCheckEqualTo(0));
}
size_t obu_size;
if (obu_has_size_field)
{
obu_size = reader.readLEB128("obu_size");
}
else
{
obu_size = (size_t(data.size()) - posInData) - 1 - (obu_extension_flag ? 1 : 0);
}
posInData += obu_size + reader.nrBytesRead();
}
}
catch (...)
{
return false;
}
return true;
}

} // namespace

AVPacketWrapper::AVPacketWrapper(AVPacket *packet, const LibraryVersions &libraryVersions)
{
assert(packet != nullptr);
Expand Down Expand Up @@ -317,46 +223,6 @@ int AVPacketWrapper::getDataSize()
return this->size;
}

PacketType AVPacketWrapper::getPacketType() const
{
return this->packetType;
}

void AVPacketWrapper::setPacketType(PacketType packetType)
{
this->packetType = packetType;
}

PacketDataFormat AVPacketWrapper::guessDataFormatFromData()
{
if (this->packetFormat != PacketDataFormat::Unknown)
return this->packetFormat;

auto avpacketData = QByteArray::fromRawData((const char *)(getData()), getDataSize());
if (avpacketData.length() < 4)
{
this->packetFormat = PacketDataFormat::Unknown;
return this->packetFormat;
}

// AVPacket data can be in one of two formats:
// 1: The raw annexB format with start codes (0x00000001 or 0x000001)
// 2: ISO/IEC 14496-15 mp4 format: The first 4 bytes determine the size of the NAL unit followed
// by the payload We will try to guess the format of the data from the data in this AVPacket. This
// should always work unless a format is used which we did not encounter so far (which is not
// listed above) Also I think this should be identical for all packets in a bitstream.
if (checkForRawNALFormat(avpacketData, false))
this->packetFormat = PacketDataFormat::RawNAL;
else if (checkForMp4Format(avpacketData))
this->packetFormat = PacketDataFormat::MP4;
else if (checkForObuFormat(avpacketData))
this->packetFormat = PacketDataFormat::OBU;
else if (checkForRawNALFormat(avpacketData, true))
this->packetFormat = PacketDataFormat::RawNAL;

return this->packetFormat;
}

void AVPacketWrapper::update()
{
if (this->pkt == nullptr)
Expand Down
37 changes: 3 additions & 34 deletions YUViewLib/externalLibs/LibFFmpeg++/wrappers/AVPacketWrapper.h
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Original file line number Diff line number Diff line change
Expand Up @@ -37,27 +37,6 @@
namespace LibFFmpeg
{

// AVPacket data can be in one of two formats:
// 1: The raw annexB format with start codes (0x00000001 or 0x000001)
// 2: ISO/IEC 14496-15 mp4 format: The first 4 bytes determine the size of the NAL unit followed by
// the payload
enum class PacketDataFormat
{
Unknown,
RawNAL,
MP4,
OBU
};

enum class PacketType
{
VIDEO,
AUDIO,
SUBTITLE_DVB,
SUBTITLE_608,
OTHER
};

// AVPacket is part of avcodec. The definition is different for different major versions of avcodec.
// These are the version independent functions to retrive data from AVPacket.
// The size of this struct is part of the public API and must be correct
Expand Down Expand Up @@ -139,13 +118,6 @@ class AVPacketWrapper
uint8_t * getData();
int getDataSize();

// This info is set externally (in FileSourceFFmpegFile) based on the stream info
PacketType getPacketType() const;
void setPacketType(PacketType packetType);

// Guess the format. The actual guessing is only performed if the packetFormat is not set yet.
PacketDataFormat guessDataFormatFromData();

explicit operator bool() const { return this->pkt != nullptr; };

private:
Expand All @@ -164,11 +136,8 @@ class AVPacketWrapper
int64_t duration{};
int64_t pos{};

PacketType packetType{};

AVPacket * pkt{};
LibraryVersions libraryVersions{};
PacketDataFormat packetFormat{PacketDataFormat::Unknown};
AVPacket * pkt{};
LibraryVersions libraryVersions{};
};

} // namespace LibFFmpeg
} // namespace LibFFmpeg
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