FDK24/メディア/サウンド/WASAPI/Decoder.cs

   1 using System;
   2 using System.Collections.Generic;
   3 using System.Diagnostics;
   4 using System.Linq;
   5 using CSCore;
   6
   7 namespace FDK.メディア.サウンド.WASAPI
   8 {
   9         /// <summary>
  10         ///             指定されたメディアファイル（動画, 音楽）をデコードして、CSCore.IWaveStream オブジェクトを生成する。
  11         /// </summary>
  12         internal class Decoder : CSCore.IWaveSource
  13         {
  14                 /// <summary>
  15                 ///             シークは常にサポートする。
  16                 /// </summary>
  17                 public bool CanSeek => ( true );
  18
  19                 /// <summary>
  20                 ///             デコード後のオーディオデータの長さ[byte]。
  21                 /// </summary>
  22                 public long Length
  23                 {
  24                         get { return this._EncodedWaveData.Length; }
  25                 }
  26
  27                 /// <summary>
  28                 ///             現在の位置。
  29                 ///             先頭からのオフセット[byte]で表す。
  30                 /// </summary>
  31                 public long Position
  32                 {
  33                         get { return this._Position; }
  34                         set
  35                         {
  36                                 if( ( 0 > value ) || ( this.Length <= value ) )
  37                                         throw new ArgumentOutOfRangeException();
  38
  39                                 this._Position = value;
  40                         }
  41                 }
  42
  43                 /// <summary>
  44                 ///             デコード後のオーディオデータのフォーマット。
  45                 /// </summary>
  46                 public CSCore.WaveFormat WaveFormat
  47                 {
  48                         get;
  49                         protected set;
  50                 }
  51
  52                 /// <summary>
  53                 ///             メディアファイル（動画、音楽）をデコードする。
  54                 /// </summary>
  55                 /// <param name="path">メディアファイル（MediaFoundation でデコードできるもの）</param>
  56                 /// <param name="waveFormat">デコード先のフォーマット。</param>
  57                 public Decoder( string path, CSCore.WaveFormat waveFormat )
  58                 {
  59                         //if( ( waveFormat.WaveFormatTag != AudioEncoding.IeeeFloat ) &&
  60                         //      ( !CSCore.WaveFormatExtensible.SubTypeFromWaveFormat( waveFormat ).Equals( SharpDX.MediaFoundation.AudioFormatGuids.Float ) ) )
  61                         //{
  62                         //      throw new NotSupportedException( "IEEE Float 以外の形式のフォーマットはサポートしません。" );
  63                         //}
  64                         this.WaveFormat = waveFormat;
  65
  66                         this._初期化する( path );
  67                 }
  68
  69                 public void Dispose()
  70                 {
  71                         this._解放する();
  72                 }
  73
  74                 /// <summary>
  75                 ///             連続した要素を読み込み、this.Position を読み込んだ要素の数だけ進める。
  76                 /// </summary>
  77                 /// <param name="buffer">
  78                 ///             読み込んだ要素を格納するための配列。
  79                 ///             このメソッドから戻ると、buffer には offset ～ (offset + count - 1) の数の要素が格納されている。
  80                 /// </param>
  81                 /// <param name="offset">
  82                 ///             buffer に格納を始める位置。
  83                 /// </param>
  84                 /// <param name="count">
  85                 ///             読み込む最大の要素数。
  86                 /// </param>
  87                 /// <returns>
  88                 ///             buffer に読み込んだ要素の総数。
  89                 /// </returns>
  90                 public int Read( byte[] buffer, int offset, int count )
  91                 {
  92                         // 音がめちゃくちゃになるとうざいので、このメソッド内では例外を出さないこと。
  93
  94                         if( ( null == this._EncodedWaveData ) && ( null == buffer ) )
  95                                 return 0;
  96
  97                         // offset は、0～buffer.Length-1 に収める。
  98                         offset = Math.Max( 0, Math.Min( buffer.Length - 1, offset ) );
  99
 100                         // count は、_EncodeWaveData.Length-Position, buffer.Length-offset, count のうちの最小値とする。
 101                         count = Math.Min( Math.Min( this._EncodedWaveData.Length - (int) this._Position, count ), buffer.Length - offset );
 102
 103                         if( 0 < count )
 104                         {
 105                                 Array.Copy(
 106                                         sourceArray: this._EncodedWaveData,
 107                                         sourceIndex: this._Position,
 108                                         destinationArray: buffer,
 109                                         destinationIndex: offset,
 110                                         length: count );
 111
 112                                 this._Position += count;
 113                         }
 114
 115                         return count;
 116                 }
 117
 118                 private SharpDX.MediaFoundation.MediaType _MediaType = null;
 119                 private byte[] _EncodedWaveData = null;
 120                 private long _Position = 0;
 121
 122                 private void _初期化する( string path )
 123                 {
 124                         try
 125                         {
 126                                 using( var sourceReader = new SharpDX.MediaFoundation.SourceReader( path ) )
 127                                 using( var waveStream = new System.IO.MemoryStream() )
 128                                 {
 129                                         #region " 最初のオーディオストリームを選択し、その他のすべてのストリームを非選択にする。"
 130                                         //----------------
 131                                         sourceReader.SetStreamSelection( SharpDX.MediaFoundation.SourceReaderIndex.AllStreams, false );
 132                                         sourceReader.SetStreamSelection( SharpDX.MediaFoundation.SourceReaderIndex.FirstAudioStream, true );
 133                                         //----------------
 134                                         #endregion
 135                                         #region " デコードフォーマットを持つ MediaType を作成し、SourceReader に登録する。"
 136                                         //----------------
 137                                         using( var partialMediaType = new SharpDX.MediaFoundation.MediaType() )
 138                                         {
 139                                                 // 部分メディアタイプを作成し、オーディオフォーマットを設定する。 （オーディオフォーマットは IEEE FLOAT で固定。）
 140                                                 partialMediaType.Set<Guid>( SharpDX.MediaFoundation.MediaTypeAttributeKeys.MajorType, SharpDX.MediaFoundation.MediaTypeGuids.Audio );
 141                                                 partialMediaType.Set<Guid>( SharpDX.MediaFoundation.MediaTypeAttributeKeys.Subtype, SharpDX.MediaFoundation.AudioFormatGuids.Float );
 142                                                 partialMediaType.Set<int>( SharpDX.MediaFoundation.MediaTypeAttributeKeys.AudioNumChannels, this.WaveFormat.Channels );
 143                                                 partialMediaType.Set<int>( SharpDX.MediaFoundation.MediaTypeAttributeKeys.AudioSamplesPerSecond, this.WaveFormat.SampleRate );
 144                                                 partialMediaType.Set<int>( SharpDX.MediaFoundation.MediaTypeAttributeKeys.AudioBlockAlignment, this.WaveFormat.BlockAlign );
 145                                                 partialMediaType.Set<int>( SharpDX.MediaFoundation.MediaTypeAttributeKeys.AudioAvgBytesPerSecond, this.WaveFormat.BytesPerSecond );
 146                                                 partialMediaType.Set<int>( SharpDX.MediaFoundation.MediaTypeAttributeKeys.AudioBitsPerSample, this.WaveFormat.BitsPerSample );
 147                                                 partialMediaType.Set<int>( SharpDX.MediaFoundation.MediaTypeAttributeKeys.AllSamplesIndependent, 1 ); // TRUE
 148
 149                                                 if( this.WaveFormat.WaveFormatTag == AudioEncoding.Extensible )
 150                                                 {
 151                                                         var wfmEx = this.WaveFormat as CSCore.WaveFormatExtensible;
 152                                                         partialMediaType.Set<int>( SharpDX.MediaFoundation.MediaTypeAttributeKeys.AudioChannelMask, (int) wfmEx.ChannelMask );
 153                                                         partialMediaType.Set<int>( SharpDX.MediaFoundation.MediaTypeAttributeKeys.AudioSamplesPerBlock, wfmEx.SamplesPerBlock );
 154                                                         partialMediaType.Set<int>( SharpDX.MediaFoundation.MediaTypeAttributeKeys.AudioValidBitsPerSample, wfmEx.ValidBitsPerSample );
 155                                                 }
 156
 157                                                 // 作成したメディアタイプを sourceReader にセットする。必要なデコーダが見つからなかったら、ここで例外が発生する。
 158                                                 sourceReader.SetCurrentMediaType( SharpDX.MediaFoundation.SourceReaderIndex.FirstAudioStream, partialMediaType );
 159
 160                                                 // 完成されたメディアタイプを取得する。
 161                                                 this._MediaType = sourceReader.GetCurrentMediaType( SharpDX.MediaFoundation.SourceReaderIndex.FirstAudioStream );
 162
 163                                                 // 最初のオーディオストリームが選択されていることを保証する。
 164                                                 sourceReader.SetStreamSelection( SharpDX.MediaFoundation.SourceReaderIndex.FirstAudioStream, true );
 165                                         }
 166                                         //----------------
 167                                         #endregion
 168                                         #region " sourceReader からサンプルを取得してデコードし、waveStream へ書き込んだのち、byte[] _EncodedWaveData へ出力する。"
 169                                         //-----------------
 170                                         using( var pcmWriter = new System.IO.BinaryWriter( waveStream ) )
 171                                         {
 172                                                 while( true )
 173                                                 {
 174                                                         // 次のサンプルを読み込む。
 175                                                         int dwActualStreamIndexRef = 0;
 176                                                         var dwStreamFlagsRef = SharpDX.MediaFoundation.SourceReaderFlags.None;
 177                                                         Int64 llTimestampRef = 0;
 178                                                         using( var sample = sourceReader.ReadSample(
 179                                                                 SharpDX.MediaFoundation.SourceReaderIndex.FirstAudioStream,
 180                                                                 SharpDX.MediaFoundation.SourceReaderControlFlags.None,
 181                                                                 out dwActualStreamIndexRef,
 182                                                                 out dwStreamFlagsRef,
 183                                                                 out llTimestampRef ) )
 184                                                         {
 185                                                                 if( null == sample )
 186                                                                         break;      // EndOfStream やエラーのときも null になる。
 187
 188                                                                 // sample をロックし、オーディオデータへのポインタを取得する。
 189                                                                 int cbMaxLengthRef = 0;
 190                                                                 int cbCurrentLengthRef = 0;
 191                                                                 using( var mediaBuffer = sample.ConvertToContiguousBuffer() )
 192                                                                 {
 193                                                                         // オーディオデータをメモリストリームに書き込む。
 194                                                                         var audioData = mediaBuffer.Lock( out cbMaxLengthRef, out cbCurrentLengthRef );
 195                                                                         try
 196                                                                         {
 197                                                                                 byte[] dstData = new byte[ cbCurrentLengthRef ];
 198                                                                                 System.Runtime.InteropServices.Marshal.Copy( audioData, dstData, 0, cbCurrentLengthRef );
 199                                                                                 pcmWriter.Write( dstData, 0, cbCurrentLengthRef );
 200                                                                         }
 201                                                                         finally
 202                                                                         {
 203                                                                                 mediaBuffer.Unlock();
 204                                                                         }
 205                                                                 }
 206                                                         }
 207                                                 }
 208
 209                                                 // ストリームの内容を byte 配列に出力。
 210                                                 this._EncodedWaveData = waveStream.ToArray();
 211                                         }
 212                                         //-----------------
 213                                         #endregion
 214                                 }
 215                         }
 216                         catch
 217                         {
 218                                 this._EncodedWaveData = new byte[] { };
 219                         }
 220
 221                         this._Position = 0;
 222                 }
 223
 224                 private void _解放する()
 225                 {
 226                         FDK.Utilities.解放する( ref this._MediaType );
 227                 }
 228
 229                 #region " Win32 "
 230                 //----------------
 231                 private const int MF_E_INVALIDMEDIATYPE = unchecked((int) 0xC00D36B4);
 232                 //----------------
 233                 #endregion
 234         }
 235 }