/// <summary>
/// Loads the .ts file with the given URI and extracts the audio.
/// </summary>
/// <param name="tsFileUri">The .ts file URI.</param>
/// <returns>Loaded and processed media segment content.</returns>
public async Task <MediaSegmentContent> LoadTsFileAndExtractAudioAsync(Uri tsFileUri)
{
if (string.IsNullOrWhiteSpace(tsFileUri.ToString()))
{
throw new ArgumentNullException("TS file URI missing");
}
byte[] contentAsByteArray = null;
using (HttpClient httpClient = new HttpClient())
{
using (HttpResponseMessage httpResponseMessage = await httpClient.GetAsync(tsFileUri))
{
using (HttpContent httpContent = httpResponseMessage.Content)
{
contentAsByteArray = await httpContent.ReadAsByteArrayAsync();
}
}
}
MediaSegmentContent mediaSegmentContent = new MediaSegmentContent()
{
FullContent = contentAsByteArray
};
MemoryStream contentAsMemoryStream = new MemoryStream(contentAsByteArray);
using (WaveStream pcmStream =
WaveFormatConversionStream.CreatePcmStream(
new StreamMediaFoundationReader(contentAsMemoryStream)))
{
// TODO: Read in chunks if the length is long
WaveStream blockAlignReductionStream = new BlockAlignReductionStream(pcmStream);
mediaSegmentContent.Audio = new AudioSample(blockAlignReductionStream);
}
System.Diagnostics.Debug.WriteLine($"Extracted: {mediaSegmentContent.Audio}");
return(mediaSegmentContent);
}
/// <summary>
/// Processes the stream with the given URI:
/// Extracts the audio and does the audio transcription.
/// Once the processing is complete, MediaSegmentProcessed event,
/// including the processed content, is fired.
/// </summary>
/// <param name="streamUri">The stream URI.</param>
public async Task ProcessStreamAsync(Uri streamUri)
{
MediaSegmentContent mediaSegmentContent = null;
try
{
mediaSegmentContent = await LoadTsFileAndExtractAudioAsync(streamUri);
}
catch (Exception e)
{
System.Diagnostics.Debug.WriteLine($"Failed to extract audio: {e.Message}");
}
if (!string.IsNullOrWhiteSpace(_bingSpeechToTextApiSubscriptionKey) &&
mediaSegmentContent.Audio != null)
{
string transcription = string.Empty;
DetailedSpeechRecognition detailedSpeechRecognition = null;
try
{
transcription = new Transcriber(_bingSpeechToTextApiSubscriptionKey).Transcribe(mediaSegmentContent.Audio);
detailedSpeechRecognition = JsonConvert.DeserializeObject <DetailedSpeechRecognition>(transcription);
}
catch (Exception e)
{
System.Diagnostics.Debug.WriteLine($"Failed to transcribe audio/deserialize transcription: {e.Message}");
}
mediaSegmentContent.TranscriptionResult = transcription;
mediaSegmentContent.Transcription = detailedSpeechRecognition;
}
// Notify
MediaSegmentProcessed?.Invoke(this, mediaSegmentContent);
}