92 lines
3.4 KiB
C++
92 lines
3.4 KiB
C++
#include "./mpegaudioframestream.h"
|
|
|
|
#include "../exceptions.h"
|
|
#include "../mediaformat.h"
|
|
|
|
#include <c++utilities/conversion/stringbuilder.h>
|
|
|
|
#include <sstream>
|
|
|
|
using namespace std;
|
|
using namespace CppUtilities;
|
|
|
|
namespace TagParser {
|
|
|
|
/*!
|
|
* \class TagParser::MpegAudioFrameStream
|
|
* \brief Implementation of TagParser::AbstractTrack MPEG audio streams.
|
|
*/
|
|
|
|
/*!
|
|
* \brief Adds the information from the specified \a frame to the specified \a track.
|
|
*/
|
|
void MpegAudioFrameStream::addInfo(const MpegAudioFrame &frame, AbstractTrack &track)
|
|
{
|
|
track.m_version = frame.mpegVersion();
|
|
track.m_format = MediaFormat(GeneralMediaFormat::Mpeg1Audio, static_cast<unsigned char>(frame.layer()));
|
|
track.m_channelCount = frame.channelMode() == MpegChannelMode::SingleChannel ? 1 : 2;
|
|
track.m_channelConfig = static_cast<std::uint8_t>(frame.channelMode());
|
|
track.m_samplingFrequency = frame.samplingFrequency();
|
|
}
|
|
|
|
void MpegAudioFrameStream::internalParseHeader(Diagnostics &diag, AbortableProgressFeedback &progress)
|
|
{
|
|
CPP_UTILITIES_UNUSED(progress)
|
|
|
|
static const string context("parsing MPEG audio frame header");
|
|
if (!m_istream) {
|
|
throw NoDataFoundException();
|
|
}
|
|
// parse frames until the first valid, non-empty frame is reached
|
|
m_istream->seekg(static_cast<std::streamoff>(m_startOffset), ios_base::beg);
|
|
for (size_t invalidByteskipped = 0; m_frames.size() < 200 && invalidByteskipped <= 0x600u;) {
|
|
MpegAudioFrame &frame = invalidByteskipped > 0 ? m_frames.back() : m_frames.emplace_back();
|
|
try {
|
|
frame.parseHeader(m_reader, diag);
|
|
} catch (const InvalidDataException &) {
|
|
if (++invalidByteskipped > 1) {
|
|
diag.pop_back();
|
|
}
|
|
m_istream->seekg(-3, ios_base::cur);
|
|
continue;
|
|
}
|
|
if (invalidByteskipped > 1) {
|
|
diag.emplace_back(DiagLevel::Critical, argsToString("The next ", invalidByteskipped, " bytes are junk as well."), context);
|
|
}
|
|
if (!frame.size()) {
|
|
continue; // likely just junk, check further frames
|
|
}
|
|
invalidByteskipped = 0;
|
|
if (frame.isProtectedByCrc()) {
|
|
m_istream->seekg(2, ios_base::cur);
|
|
}
|
|
break;
|
|
}
|
|
if (!m_frames.back().isValid()) {
|
|
return;
|
|
}
|
|
const MpegAudioFrame &frame = m_frames.back();
|
|
addInfo(frame, *this);
|
|
if (frame.isXingBytesfieldPresent()) {
|
|
const auto xingSize = frame.xingBytesfield();
|
|
if (!m_size) {
|
|
m_size = xingSize;
|
|
} else if (xingSize != m_size) {
|
|
diag.emplace_back(DiagLevel::Warning,
|
|
argsToString("Real size of MPEG audio frames (", m_size, " byte) is not in accordance with value provided by Xing header (", xingSize,
|
|
" byte). The real size will be used."),
|
|
context);
|
|
}
|
|
}
|
|
if (frame.isXingFramefieldPresent()) {
|
|
const auto duration = static_cast<double>(frame.xingFrameCount() * frame.sampleCount()) / static_cast<double>(frame.samplingFrequency());
|
|
m_bitrate = static_cast<double>(m_size) / duration / 125.0;
|
|
m_duration = TimeSpan::fromSeconds(duration);
|
|
} else {
|
|
m_bitrate = frame.bitrate();
|
|
m_duration = TimeSpan::fromSeconds(static_cast<double>(m_size) / (m_bytesPerSecond = static_cast<std::uint32_t>(m_bitrate * 125)));
|
|
}
|
|
}
|
|
|
|
} // namespace TagParser
|