XAudio2 Learning Sample Rate Conversion

The wave file can be converted to sample rate using Ixaduio2submixvoice to meet the device's requirements for waveform audio sample rate. In XAudio2 learn three to get the audio output device information you can see that the audio playback device has its own support for playing the wave file format.

Take the 2-channel/44.1k sample-rate wave to 2-channel/48k wave as an example:

First of all, initialize the COM component;

HRESULT hr = CoInitializeEx (NULL, coinit_multithreaded);; /com Initialize if (FAILED (HR)) return 0;

Then, then create the IXAudio2 engine;

IXAudio2 *pengine = NULL; hr = Xaudio2create (&pengine);//Create Engine if (FAILED (HR)) return 0;

Then, create the main sound, and specify the number of channels is 2, the sampling rate is 48K;

WaveFormatEx waveformatex;//Sets the format of the main sound waveformatex.nchannels = 2;waveformatex.nsamplespersec = 48000; Waveformatex.wbitspersample = 32;waveformatex.navgbytespersec = 384000;waveformatex.nblockalign = 8; Waveformatex.wformattag = WAVE_FORMAT_PCM; Ixaudio2masteringvoice *pmastervoice = NULL; hr = Pengine->createmasteringvoice (&pmastervoice,waveformatex.nchannels,waveformatex.nsamplespersec);// Create a master sound, the default is to output the current speaker if (FAILED (HR)) return 0;

then, read the wave file and get the file format information;

Cwavefile Wavefile; hr = Wavefile.open (L "c:\\users\\xdd\\desktop\\ the time has gone. wav", NULL, Wavefile_read);//Load file if (FAILED (HR)) return 0; WaveFormatEx *waveformat = Wavefile.getformat ();//Get file format

then, create a Ixaudio2submixvoice object that specifies the number of channels to get the number of channels in the file format when created, the sample rate for the file's sample rate, and the output voice of the specified object as mastering voice:

Xaudio2_send_descriptor psend;psend.poutputvoice = pmastervoice;//Specify Output as mastering Voicepsend.flags = XAUDIO2_SEND_ Usefilter; Xaudio2_voice_sends psendlist;psendlist.psends = &psend;psendlist.sendcount = 1;IXAudio2SubmixVoice * Psubmixvoice = NULL;HR = Pengine->createsubmixvoice (&psubmixvoice, Waveformat->nchannels, waveFormat-> Nsamplespersec, 0, 0, &psendlist);//Specify Output as mastering Voiceif (FAILED (HR)) return 0;

In addition to specifying the output voice directly above on creation, you can also use the following method:

Psubmixvoice->setoutputvoices (&psendlist);

then, create the Ixaudio2sourcevoice object, create the format information using the obtained file, and specify the output voice for the Ixaduio2submixvoice object created above, Use Ixaudio2voicecallback callback at the same time for easy playback:

Psend.poutputvoice = psubmixvoice;//The specified output is submixvoicepsend.flags = Xaudio2_send_usefilter;psendlist.psends = & Psend;psendlist.sendcount = 1; Voicecallback Voicecallback; Ixaudio2sourcevoice *psourcevoice = Null;hr = Pengine->createsourcevoice (&psourcevoice, WaveFormat, 0, 1.0f, &voicecallback,&psendlist);//Create a source sound to submit data. Specify the output as Submixvoice if (FAILED (HR))

Then, read the wave audio data and use the Ixaudio2sourcevoice object to submit the data and start the playback:

DWORD size = Wavefile.getsize ();//Gets the size of the file BYTE *pdata = new byte[size];//request memory space for saving data hr = Wavefile.read (pData, size, &am p;size);//Read the file contents if (FAILED (HR)) return 0; Xaudio2_buffer buffer = {0};//will read the file data, assign the value Xaudio2_buffer buffer. audiobytes = size; Buffer.paudiodata = Pdata;buffer. Flags = Xaudio2_end_of_stream;  hr = Psourcevoice->submitsourcebuffer (&buffer);//Submit memory Data if (FAILED (HR)) return 0;  hr = Psourcevoice->start (0);//Start source Sound if (FAILED (HR)) return 0;

then, using the callback, wait for the playback to complete:

Xaudio2_voice_state state;psourcevoice->getstate (&state);//Gets the status while (state. buffersqueued) {WaitForSingleObject (voicecallback.hbufferendevent, INFINITE);p sourcevoice->getstate (& State);}

Finally, release the resources.

Pmastervoice->destroyvoice ();//Release Resources psubmixvoice->destroyvoice ();//Psourcevoice->destroyvoice ();//Release resources Pengine->release ();//Release Resource couninitialize ();//release resource delete []pdata;//release resource pData = NULL;

compile, run. Can hear a very clear sound.

SOURCE Download: http://download.csdn.net/detail/u011417605/9473537

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XAudio2 Learning Sample Rate Conversion