/// <summary>Getthe first wave audio stream</summary>
/// <returns>AudioStream object for the stream</returns>
public AudioStream GetWaveStream()
{
IntPtr aviStream;
int result = Avi.AVIFileGetStream(
aviFile,
out aviStream,
Avi.streamtypeAUDIO, 0);
if(result != 0){
throw new Exception("Exception in AVIFileGetStream: "+result.ToString());
}
AudioStream stream = new AudioStream(aviFile, aviStream);
streams.Add(stream);
return stream;
}
/// <summary>Add an existing wave audio stream to the file</summary>
/// <param name="newStream">The stream to add</param>
/// <param name="startAtFrameIndex">
/// The index of the video frame at which the sound is going to start.
/// '0' inserts the sound at the beginning of the video.
/// </param>
public void AddAudioStream(AudioStream newStream, int startAtFrameIndex)
{
Avi.AVISTREAMINFO streamInfo = new Avi.AVISTREAMINFO();
Avi.PCMWAVEFORMAT streamFormat = new Avi.PCMWAVEFORMAT();
int streamLength = 0;
IntPtr rawData = newStream.GetStreamData(ref streamInfo, ref streamFormat, ref streamLength);
IntPtr waveData = rawData;
if (startAtFrameIndex > 0) {
//not supported
//streamInfo.dwStart = startAtFrameIndex;
double framesPerSecond = GetVideoStream().FrameRate;
double samplesPerSecond = newStream.CountSamplesPerSecond;
double startAtSecond = startAtFrameIndex / framesPerSecond;
int startAtSample = (int)(samplesPerSecond * startAtSecond);
waveData = InsertSilence(startAtSample - 1, waveData, streamLength, ref streamInfo);
}
IntPtr aviStream;
int result = Avi.AVIFileCreateStream(aviFile, out aviStream, ref streamInfo);
if(result != 0){
throw new Exception("Exception in AVIFileCreateStream: "+result.ToString());
}
result = Avi.AVIStreamSetFormat(aviStream, 0, ref streamFormat, Marshal.SizeOf(streamFormat));
if(result != 0){
throw new Exception("Exception in AVIStreamSetFormat: "+result.ToString());
}
result = Avi.AVIStreamWrite(aviStream, 0, streamLength, waveData, streamLength, Avi.AVIIF_KEYFRAME, 0, 0);
if(result != 0){
throw new Exception("Exception in AVIStreamWrite: "+result.ToString());
}
result = Avi.AVIStreamRelease(aviStream);
if(result != 0){
throw new Exception("Exception in AVIStreamRelease: "+result.ToString());
}
Marshal.FreeHGlobal(waveData);
}