Windows8 音频播放

#include "AudioFile.h" AudioFile::AudioFile(String^ filename) : m_file(NULL), m_filename(filename), m_soundFormat(nullptr), m_soundData(nullptr) { } AudioFile::~AudioFile() { if (NULL != m_file) { CloseHandle(m_file); m_file = NULL; } } Platform::Array<byte>^ AudioFile::getSoundData() { GetData(); return m_soundData; } Platform::Array<byte>^ AudioFile::getSoundFormat() { GetData(); return m_soundFormat; } void AudioFile::GetData() { if (NULL == m_file && m_filename != nullptr) { try { if (0 == openFile(m_filename)) { uint64 fileSize = getFileSize(); if (fileSize > 0) { // Locate, read and validate the RIFF chunk uint64 riffLoc = FindChunk(FOURCC_RIFF_TAG, 0, fileSize); // Read beyond the riff header. ChunkHeader chunkHeader; ReadHeader(riffLoc, chunkHeader); uint32 tag = 0; Platform::Array<byte>^ riffData = Read(sizeof(tag)); tag = *reinterpret_cast<uint32*>(riffData->Data); if (tag != FOURCC_WAVE_FILE_TAG) { // Only support .wav files throw ref new Platform::FailureException(); } uint64 riffChildrenStart = riffLoc + sizeof(chunkHeader) + sizeof(tag); uint64 riffChildrenEnd = riffLoc + sizeof(chunkHeader) + chunkHeader.size; // Find, read and validate the format chunk (a child within the RIFF chunk) uint64 formatLoc = FindChunk(FOURCC_FORMAT_TAG, riffChildrenStart, riffChildrenEnd); ReadHeader(formatLoc, chunkHeader); m_soundFormat = Read(chunkHeader.size); WAVEFORMATEX* format = reinterpret_cast<WAVEFORMATEX*>(m_soundFormat->Data); if (format->wFormatTag != WAVE_FORMAT_PCM && format->wFormatTag != WAVE_FORMAT_ADPCM) { // This is not PCM or ADPCM, which is all we support throw ref new Platform::FailureException(); } // Locate, the PCM data in the data chunk uint64 dataChunkStart = FindChunk(FOURCC_DATA_TAG, riffChildrenStart, riffChildrenEnd); ReadHeader(dataChunkStart, chunkHeader); // Now read the PCM data and setup the buffer m_soundData = Read(chunkHeader.size); } } } catch (Platform::Exception^ e) { CloseHandle(m_file); m_file = NULL; } } } int AudioFile::openFile(String^ filename) { Platform::String^ fullPath = Windows::ApplicationModel::Package::Current->InstalledLocation->Path; fullPath += filename; m_file = ::CreateFile2( fullPath->Data(), GENERIC_READ, FILE_SHARE_READ, OPEN_EXISTING, nullptr ); if (m_file == INVALID_HANDLE_VALUE) { return -1; } return 0; } uint64 AudioFile::getFileSize() { FILE_STANDARD_INFO fileStandardInfo = { 0 }; BOOL result = ::GetFileInformationByHandleEx( m_file, FileStandardInfo, &fileStandardInfo, sizeof(fileStandardInfo) ); if ((result == 0) || (fileStandardInfo.AllocationSize.QuadPart < 0)) { return 0; } return fileStandardInfo.AllocationSize.QuadPart; } void AudioFile::SeekAbsolute(uint64 position) { if (position < 0) { throw ref new Platform::FailureException(); } LARGE_INTEGER pos; pos.QuadPart = position; BOOL result = ::SetFilePointerEx(m_file, pos, nullptr, FILE_BEGIN); if (result == 0) { throw ref new Platform::FailureException(); } } void AudioFile::SeekRelative(int64 offset) { LARGE_INTEGER position; position.QuadPart = offset; BOOL result = ::SetFilePointerEx(m_file, position, nullptr, FILE_CURRENT); if (result == 0) { throw ref new Platform::FailureException(); } } Platform::Array<byte>^ AudioFile::Read(_In_ size_t bytesToRead) { Platform::Array<byte>^ fileData = ref new Platform::Array<byte>(static_cast<unsigned int>(bytesToRead)); if (!ReadFile( m_file, fileData->Data, fileData->Length, nullptr, nullptr )) { throw ref new Platform::FailureException(); } return fileData; } uint64 AudioFile::FindChunk(uint32 tag, uint64 startLoc, uint64 endLoc) { // Move to start of search SeekAbsolute(startLoc); uint64 newLoc = startLoc; while (endLoc > (newLoc + sizeof(ChunkHeader))) { Platform::Array<byte>^ headerBytes = Read(sizeof(ChunkHeader)); ChunkHeader* header = reinterpret_cast<ChunkHeader*>(headerBytes->Data); if (header->tag == tag) { // Found the requested tag return newLoc; } SeekRelative(static_cast<int64>(header->size)); newLoc += header->size + sizeof(*header); } return -1; } void AudioFile::ReadHeader(uint64 loc, ChunkHeader& header) { // Move to read location SeekAbsolute(loc); Platform::Array<byte>^ headerBytes = Read(sizeof(ChunkHeader)); header = *reinterpret_cast<ChunkHeader*>(headerBytes->Data); }