Sind die SpeakProgressEventArgs des SpeechSynthesizer ungenau?

Question

Mit der System.Speech.Synthesis.SpeechSynthesizer-Klasse in .NET 3.5 scheint die AudioPosition-Eigenschaft des SpeakProgressEventArgs ungenau zu sein.

Der folgende Code erzeugt die folgende Ausgabe:

Code:

using System; 
using System.Speech.Synthesis; 
using System.Threading; 

namespace SpeechTest 
{ 
    class Program 
    { 
     static ManualResetEvent speechDoneEvent = new ManualResetEvent(false); 

     static void Main(string[] args) 
     { 
      SpeechSynthesizer synthesizer = new SpeechSynthesizer(); 

      synthesizer.SpeakProgress += new EventHandler<SpeakProgressEventArgs>(synthesizer_SpeakProgress); 

      synthesizer.SpeakCompleted += new EventHandler<SpeakCompletedEventArgs>(synthesizer_SpeakCompleted); 

      synthesizer.SetOutputToWaveFile("Test.wav"); 

      synthesizer.SpeakAsync("This holiday season, support the music you love by shopping at Made in Washington, online and at one of five local stores. Made in Washington chocolates, bountiful gift baskets and ornaments are the perfect holiday gifts for family, friends and co-workers."); 

      speechDoneEvent.WaitOne(); 
     } 

     static void synthesizer_SpeakCompleted(object sender, SpeakCompletedEventArgs e) 
     { 
      speechDoneEvent.Set(); 
     } 

     static void synthesizer_SpeakProgress(object sender, SpeakProgressEventArgs e) 
     { 
      Console.WriteLine("SpeakProgress: AudioPosition=" + e.AudioPosition + ",\tCharacterPosition=" + e.CharacterPosition + ",\tCharacterCount=" + e.CharacterCount + ",\tText=" + e.Text); 
     } 
    } 
} 

Ausgang:

SpeakProgress: AudioPosition=00:00:00.0043750, CharacterPosition=0, CharacterCount=4,  Text=This 
SpeakProgress: AudioPosition=00:00:00.2925625, CharacterPosition=5, CharacterCount=7,  Text=holiday 
SpeakProgress: AudioPosition=00:00:00.9086250, CharacterPosition=13, CharacterCount=6,  Text=season 
SpeakProgress: AudioPosition=00:00:01.9421250, CharacterPosition=21, CharacterCount=7,  Text=support 
SpeakProgress: AudioPosition=00:00:02.5621250, CharacterPosition=29, CharacterCount=3,  Text=the 
SpeakProgress: AudioPosition=00:00:02.6760625, CharacterPosition=33, CharacterCount=5,  Text=music 
SpeakProgress: AudioPosition=00:00:03.2648125, CharacterPosition=39, CharacterCount=3,  Text=you 
SpeakProgress: AudioPosition=00:00:03.5199375, CharacterPosition=43, CharacterCount=4,  Text=love 
SpeakProgress: AudioPosition=00:00:03.8435625, CharacterPosition=48, CharacterCount=2,  Text=by 
SpeakProgress: AudioPosition=00:00:04.0701875, CharacterPosition=51, CharacterCount=8,  Text=shopping 
SpeakProgress: AudioPosition=00:00:04.6840625, CharacterPosition=60, CharacterCount=2,  Text=at 
SpeakProgress: AudioPosition=00:00:04.8036250, CharacterPosition=63, CharacterCount=4,  Text=Made 
SpeakProgress: AudioPosition=00:00:05.0698125, CharacterPosition=68, CharacterCount=2,  Text=in 
SpeakProgress: AudioPosition=00:00:05.2521250, CharacterPosition=71, CharacterCount=10,  Text=Washington 
SpeakProgress: AudioPosition=00:00:06.2961875, CharacterPosition=83, CharacterCount=6,  Text=online 
SpeakProgress: AudioPosition=00:00:07.0540625, CharacterPosition=90, CharacterCount=3,  Text=and 
SpeakProgress: AudioPosition=00:00:07.3331250, CharacterPosition=94, CharacterCount=2,  Text=at 
SpeakProgress: AudioPosition=00:00:07.6818750, CharacterPosition=97, CharacterCount=3,  Text=one 
SpeakProgress: AudioPosition=00:00:08.0598750, CharacterPosition=101, CharacterCount=2,  Text=of 
SpeakProgress: AudioPosition=00:00:08.2163750, CharacterPosition=104, CharacterCount=4,  Text=five 
SpeakProgress: AudioPosition=00:00:08.5971875, CharacterPosition=109, CharacterCount=5,  Text=local 
SpeakProgress: AudioPosition=00:00:09.0243750, CharacterPosition=115, CharacterCount=6,  Text=stores 
SpeakProgress: AudioPosition=00:00:10.5325625, CharacterPosition=123, CharacterCount=4,  Text=Made 
SpeakProgress: AudioPosition=00:00:10.7700625, CharacterPosition=128, CharacterCount=2,  Text=in 
SpeakProgress: AudioPosition=00:00:10.9377500, CharacterPosition=131, CharacterCount=10,  Text=Washington 
SpeakProgress: AudioPosition=00:00:11.6708125, CharacterPosition=142, CharacterCount=10,  Text=chocolates 
SpeakProgress: AudioPosition=00:00:12.9798750, CharacterPosition=154, CharacterCount=9,  Text=bountiful 
SpeakProgress: AudioPosition=00:00:13.6303125, CharacterPosition=164, CharacterCount=4,  Text=gift 
SpeakProgress: AudioPosition=00:00:14.0959375, CharacterPosition=169, CharacterCount=7,  Text=baskets 
SpeakProgress: AudioPosition=00:00:14.7848125, CharacterPosition=177, CharacterCount=3,  Text=and 
SpeakProgress: AudioPosition=00:00:15.0507500, CharacterPosition=181, CharacterCount=9,  Text=ornaments 
SpeakProgress: AudioPosition=00:00:15.7195000, CharacterPosition=191, CharacterCount=3,  Text=are 
SpeakProgress: AudioPosition=00:00:15.9872500, CharacterPosition=195, CharacterCount=3,  Text=the 
SpeakProgress: AudioPosition=00:00:16.1488750, CharacterPosition=199, CharacterCount=7,  Text=perfect 
SpeakProgress: AudioPosition=00:00:16.7275000, CharacterPosition=207, CharacterCount=7,  Text=holiday 
SpeakProgress: AudioPosition=00:00:17.3336875, CharacterPosition=215, CharacterCount=5,  Text=gifts 
SpeakProgress: AudioPosition=00:00:17.9813125, CharacterPosition=221, CharacterCount=3,  Text=for 
SpeakProgress: AudioPosition=00:00:18.2216875, CharacterPosition=225, CharacterCount=6,  Text=family 
SpeakProgress: AudioPosition=00:00:19.0973750, CharacterPosition=233, CharacterCount=7,  Text=friends 
SpeakProgress: AudioPosition=00:00:19.7726250, CharacterPosition=241, CharacterCount=3,  Text=and 
SpeakProgress: AudioPosition=00:00:19.9655625, CharacterPosition=245, CharacterCount=10,  Text=co-workers 
SpeakProgress: AudioPosition=00:00:20.2518750, CharacterPosition=245, CharacterCount=10,  Text=co-workers 

jedoch die Dauer der .wav-Datei erzeugt wird, ist 15,69 Sekunden. Das gleiche Verhalten tritt auf, wenn Sie einen Stream oder NULL ausgeben.

Die documentation für die Eigenschaft sagt, die Eigenschaft ist "Ein TimeSpan-Objekt, das die Zeitposition des Ereignisses im Audio-Ausgangsstrom darstellt".

Sollte es eine genaue Zeit sein, die die Zeit angibt, zu der das Wort in der Ausgabedatei gestartet oder beendet wurde, oder interpretiere ich es falsch?

Answer 1

Die audioPosition hängt von der ausgewählten Stimme des Sprachsynthesizers ab. Für einige Microsoft-Stimmen wie Anna, Zira, David, Hazel, wie ich erfahren habe, ist das unterstützte Audioformat ein PCM mit 16000 Hz. So kann die folgende Lösung die auido Position korrigieren:

var format = 
new System.Speech.AudioFormat.SpeechAudioFormatInfo(EncodingFormat.Pcm, 
                16000, 16, 1, 32000, 2, null); 
synthesizer.SetOutputToWaveFile("Test.wav", format); 

, wenn Sie merken, das Standard-Abtastrate der SetOutputToWaveFile ist 22050, und das Verhältnis der korrekten Zeit (15,69) auf die Zeit gezeigt durch AudipPosition (20.25) ist etwa 0,77. Wenn Sie dieses Verhältnis mit 22050 multiplizieren, erhalten Sie etwa 16000, was die korrekte Abtastrate ist.