customizemii-wiidb/CustomizeMii/MP3Info.cs

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2010-01-08 23:10:02 +01:00
/* This file is part of CustomizeMii
* Copyright (C) 2009 Leathl
*
* CustomizeMii is free software: you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published
* by the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* CustomizeMii is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
using System;
using System.Collections;
using System.IO;
class MP3Info
{
//Private Variables
private int fileSize;
private int headerPos;
private BitArray bitHeader;
private MpegVersion mpegVersion;
private MpegLayer mpegLayer;
private int bitrate;
private int frequency;
private bool paddingBit;
private int frameLength;
private int frameCount;
private double secLength;
private int waveSamples;
//Public Variables
public int FileSize { get { return fileSize; } }
public MpegVersion MPEGVersion { get { return mpegVersion; } }
public MpegLayer MPEGLayer { get { return mpegLayer; } }
public int Bitrate { get { return bitrate; } }
public int Frequency { get { return frequency; } }
public int FrameLength { get { return frameLength; } }
public int FrameCount { get { return frameCount; } }
public double Seconds { get { return secLength; } }
public int AudioSamples { get { return waveSamples; } }
//Public Functions
public MP3Info(string mp3File)
{
FileInfo fi = new FileInfo(mp3File);
this.fileSize = (int)fi.Length;
FileStream fs = fi.OpenRead();
fs.Seek(0, SeekOrigin.Begin);
this.headerPos = SearchHeader(fs);
byte[] header = new byte[4];
fs.Seek(this.headerPos, SeekOrigin.Begin);
fs.Read(header, 0, header.Length);
fs.Close();
GetHeaderBits(header);
LoadHeader();
}
public MP3Info(byte[] mp3Header)
{
GetHeaderBits(mp3Header);
LoadHeader();
}
//Private Functions
private void ShowHeader()
{
//For debugging
if (this.bitHeader != null)
{
string strBits = string.Empty;
foreach (bool x in this.bitHeader)
if (x) strBits += "1"; else strBits += "0";
for (int i = strBits.Length - 8; i >= 0; i -= 8)
strBits = strBits.Insert(i, " ");
System.Windows.Forms.MessageBox.Show(strBits);
}
}
private int SearchHeader(Stream fileStream)
{
int tmp;
while ((tmp = fileStream.ReadByte()) != -1)
{
if (tmp == 255)
{
tmp = fileStream.ReadByte();
BitArray tmpBits = new BitArray(new int[] { tmp });
if (tmpBits[7] && tmpBits[6] && tmpBits[5]) return (int)(fileStream.Position - 2);
}
}
throw new Exception("Frame Header couldn't be found!");
}
private void GetHeaderBits(byte[] fourBytes)
{
BitArray tmp = new BitArray(fourBytes);
this.bitHeader = new BitArray(4 * 8);
int count = 0;
for (int i = 0; i < 32; i += 8)
for (int j = 7; j >= 0; j--)
this.bitHeader[count++] = tmp[i + j];
}
private void LoadHeader()
{
GetVersion(this.bitHeader[11], this.bitHeader[12]);
if (this.mpegVersion == MpegVersion.Reserved) throw new NotSupportedException("Unsupported MPEG Version!");
GetLayer(this.bitHeader[13], this.bitHeader[14]);
if (this.mpegLayer == MpegLayer.Reserved) throw new NotSupportedException("Unsupported MPEG Layer!");
GetBitrate(this.bitHeader[16], this.bitHeader[17], this.bitHeader[18], this.bitHeader[19]);
if (this.bitrate == 0) throw new NotSupportedException("Unsupported Bitrate!");
GetFrequency(this.bitHeader[20], this.bitHeader[21]);
if (this.frequency == -1) throw new NotSupportedException("Unsupported Frequency");
this.paddingBit = this.bitHeader[22];
GetFrameLength();
GetFrameCount();
GetSeconds();
GetWaveSamples();
}
private void GetVersion(params bool[] twoBits)
{
if (twoBits[0] && twoBits[1]) this.mpegVersion = MpegVersion.MpegVersion1;
else if (twoBits[0] && !twoBits[1]) this.mpegVersion = MpegVersion.MpegVersion2;
else if (!twoBits[0] && twoBits[1]) this.mpegVersion = MpegVersion.Reserved;
else if (!twoBits[0] && !twoBits[1]) this.mpegVersion = MpegVersion.MpegVersion25;
}
private void GetLayer(params bool[] twoBits)
{
if (twoBits[0] && twoBits[1]) this.mpegLayer = MpegLayer.I;
else if (twoBits[0] && !twoBits[1]) this.mpegLayer = MpegLayer.II;
else if (!twoBits[0] && twoBits[1]) this.mpegLayer = MpegLayer.III;
else if (!twoBits[0] && !twoBits[1]) this.mpegLayer = MpegLayer.Reserved;
}
private void GetBitrate(params bool[] fourBits)
{
int[] bitrateTable = GetBitrateTable();
Array.Reverse(fourBits);
BitArray bArray = new BitArray(fourBits);
byte[] index = new byte[1];
bArray.CopyTo(index, 0);
this.bitrate = bitrateTable[index[0]];
}
private int[] GetBitrateTable()
{
if (this.mpegVersion == MpegVersion.MpegVersion1)
{
if (this.mpegLayer == MpegLayer.I) return new int[] { 0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, 0 };
if (this.mpegLayer == MpegLayer.II) return new int[] { 0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 0 };
if (this.mpegLayer == MpegLayer.III) return new int[] { 0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 0 };
}
else
{
if (this.mpegLayer == MpegLayer.I) return new int[] { 0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0 };
if (this.mpegLayer == MpegLayer.II ||
this.mpegLayer == MpegLayer.III) return new int[] { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0 };
}
throw new NotSupportedException("Unsupported MPEG Version or Layer!");
}
private void GetFrequency(params bool[] twoBits)
{
int[] frequencyTable = GetFrequencyTable();
Array.Reverse(twoBits);
BitArray bArray = new BitArray(twoBits);
byte[] index = new byte[1];
bArray.CopyTo(index, 0);
this.frequency = frequencyTable[index[0]];
}
private int[] GetFrequencyTable()
{
if (this.mpegVersion == MpegVersion.MpegVersion1)
return new int[] { 44100, 48000, 32000, -1 };
else if (this.mpegVersion == MpegVersion.MpegVersion2)
return new int[] { 22050, 24000, 16000, -1 };
else if (this.mpegVersion == MpegVersion.MpegVersion25)
return new int[] { 32000, 16000, 8000, -1 };
else
return new int[] { 0, 0, 0, -1 };
}
private void GetFrameLength()
{
double frmSize = (double)((this.mpegLayer == MpegLayer.I ? 12 : 144) * ((1000.0 * (float)this.bitrate / (float)this.frequency)));
this.frameLength = (int)Math.Ceiling(frmSize);
}
private void GetFrameCount()
{
this.frameCount = (this.fileSize - this.headerPos) / this.frameLength;
}
private void GetSeconds()
{
this.secLength = ((this.fileSize - this.headerPos) * 8.00) / (1000.00 * this.bitrate);
}
private void GetWaveSamples()
{
this.waveSamples = this.frameCount * 1125;
}
//Structs & Enums
public enum MpegVersion : int
{
Reserved = 0,
MpegVersion1 = 1,
MpegVersion25 = 2,
MpegVersion2 = 3
}
public enum MpegLayer : int
{
Reserved = 0,
I = 1,
II = 2,
III = 3
}
}