/// <summary>
/// The main conversion API. Calling this function sends an audio file to AT&T service for translation to text.
/// </summary>
/// <param name="attachment">Audio filename as it is stored on disk.</param>
/// <param name="speechContext">Speech content.</param>
/// <returns>Instance of <see cref="SpeechResponse"/> with sent speech response information.</returns>
/// <exception cref="System.ArgumentNullException">Throws an exception when attachment is null.</exception>
public async Task <SpeechResponse> SpeechToText(StorageFile attachment, XSpeechContext speechContext = XSpeechContext.Generic)
{
Argument.ExpectNotNull(() => attachment);
byte[] audioFileBytes = await BinaryFileUtils.ReadAllBytes(attachment);
var restEndPoint = new Uri(Settings.EndPoint, SendRelativeUrl);
var content = new ByteArrayContent(audioFileBytes);
string contentType = ContentTypeMapping.MapContentTypeFromExtension(attachment.FileType);
content.Headers.ContentType = new MediaTypeHeaderValue(contentType);
content.Headers.Add("X-SpeechContext", Enum.GetName(typeof(XSpeechContext), speechContext));
string strResponse = await SendContentRequest(HttpMethod.Post, restEndPoint.ToString(), content);
return(SpeechResponse.Parse(strResponse));
}
private static async Task <byte[]> EncodeBinaryContent(IEnumerable <Windows.Storage.StorageFile> attachments, string textContent, string timeStampStr)
{
var encoding = new UTF8Encoding();
byte[] buffer = null;
bool isFirstFile = true;
string currentFileName = String.Empty;
try
{
foreach (var fileName in attachments)
{
currentFileName = fileName.Name;
byte[] attachmentPrefixBytes = encoding.GetBytes(CreateAttachmentPrefix(isFirstFile, textContent, fileName.Path, timeStampStr));
byte[] fileBytes = await BinaryFileUtils.ReadAllBytes(fileName);
byte[] attachBuffer = BinaryFileUtils.CombineByteArrays(attachmentPrefixBytes, fileBytes);
if (isFirstFile)
{
buffer = attachBuffer;
}
else
{
buffer = BinaryFileUtils.CombineByteArrays(buffer, attachBuffer);
}
isFirstFile = false;
}
}
catch (FileNotFoundException ex)
{
throw new FileNotFoundException(string.Format("File '{0}' not found", currentFileName), ex);
}
return(BinaryFileUtils.CombineByteArrays(buffer, encoding.GetBytes("\r\n--" + timeStampStr + "--\r\n")));
}