private AudioHeader(uint flags, long streamLength, TagLib.Mpeg.XingHeader xingHeader, TagLib.Mpeg.VBRIHeader vbriHeader)
{
this.flags = flags;
this.stream_length = streamLength;
this.xing_header = xingHeader;
this.vbri_header = vbriHeader;
this.duration = TimeSpan.Zero;
}
private AudioHeader(ByteVector data, TagLib.File file, long position)
{
this.duration = TimeSpan.Zero;
this.stream_length = 0L;
if (data.Count < 4)
{
throw new CorruptFileException("Insufficient header length.");
}
if (data[0] != 0xff)
{
throw new CorruptFileException("First byte did not match MPEG synch.");
}
if (((data[1] & 230) <= 0xe0) || ((data[1] & 0x18) == 8))
{
throw new CorruptFileException("Second byte did not match MPEG synch.");
}
this.flags = data.ToUInt();
if (((this.flags >> 12) & 15) == 15)
{
throw new CorruptFileException("Header uses invalid bitrate index.");
}
if (((this.flags >> 10) & 3) == 3)
{
throw new CorruptFileException("Invalid sample rate.");
}
this.xing_header = TagLib.Mpeg.XingHeader.Unknown;
this.vbri_header = TagLib.Mpeg.VBRIHeader.Unknown;
file.Seek(position + TagLib.Mpeg.XingHeader.XingHeaderOffset(this.Version, this.ChannelMode));
ByteVector vector = file.ReadBlock(0x10);
if ((vector.Count == 0x10) && vector.StartsWith(TagLib.Mpeg.XingHeader.FileIdentifier))
{
this.xing_header = new TagLib.Mpeg.XingHeader(vector);
}
if (!this.xing_header.Present)
{
file.Seek(position + TagLib.Mpeg.VBRIHeader.VBRIHeaderOffset());
ByteVector vector2 = file.ReadBlock(0x18);
if ((vector2.Count == 0x18) && vector2.StartsWith(TagLib.Mpeg.VBRIHeader.FileIdentifier))
{
this.vbri_header = new TagLib.Mpeg.VBRIHeader(vector2);
}
}
}
//Additional info here http://gabriel.mp3-tech.org/mp3infotag.html
//https://www.codeproject.com/Articles/8295/MPEG-Audio-Frame-Header
/// <summary>See if the mp3 file is encoded using VBR. Not sure what to do with ABR...
/// </summary>
private bool IsVBR()
{
bool bVBR = false;
if (currentFile.MimeType != "taglib/mp3")
{
return(false);
}
foreach (ICodec codec in currentFile.Properties.Codecs)
{
TagLib.Mpeg.AudioHeader header = (TagLib.Mpeg.AudioHeader)codec;
// if (header == null)
// return;
if (header.XingHeader.Present)
{
currentFile.Mode = TagLib.File.AccessMode.Read;
long XingHeader = currentFile.Find(TagLib.Mpeg.XingHeader.FileIdentifier);
long Offset = TagLib.Mpeg.XingHeader.XingHeaderOffset(header.Version, header.ChannelMode);
TagLib.Mpeg.XingHeader xing_header = TagLib.Mpeg.XingHeader.Unknown;
currentFile.Seek(XingHeader);// + Offset);
ByteVector xing_data = currentFile.ReadBlock(16);
if (xing_data.Count == 16 && xing_data.StartsWith(
TagLib.Mpeg.XingHeader.FileIdentifier))
{
xing_header = new TagLib.Mpeg.XingHeader(xing_data);
}
int Flags = BitConverter.ToInt32(xing_data.Take(8).ToArray().Reverse().ToArray(), 0);
bool FramesPresent = (Flags & 0x0001) > 0;
bool BytesPresent = (Flags & 0x0002) > 0;
bool TOCPresent = (Flags & 0x0004) > 0;
bool QualityPresent = (Flags & 0x0008) > 0;
long LameHeader = currentFile.Find(LAME_Identifier);
if (QualityPresent)
{
//Header offset + 8 (XING + flags) + Frames, Bytes and TOC if available
currentFile.Seek(XingHeader + 8 + 4 * (FramesPresent ? 1 : 0) + 4 * (BytesPresent ? 1 : 0) + 100 * (TOCPresent ? 1 : 0));
ByteVector Quality_data = currentFile.ReadBlock(4);
int VBRQuality = BitConverter.ToInt32(Quality_data.ToArray().Reverse().ToArray(), 0);
bVBR = true;
}
currentFile.Mode = TagLib.File.AccessMode.Closed;
// if (xing_header.Present)
// return false;
// var vector = new TagLib.ByteVector();
// TagLib.ByteVector xing = header.;
/* CODE HERE */
/* TagLib.File ref(fileName);
* TagLib.Mpeg.File *file = dynamic_cast<TagLib.Mpeg.File *>(ref file());
*
* if(!file)
* return;
*
* TagLib.Mpeg.Properties *properties = file->audioProperties();
* const TagLib::MPEG::XingHeader *xingHeader = properties->xingHeader();
*
* if(!xingHeader)
* return;
*/
}
if (header.VBRIHeader.Present)
{
/* CODE HERE */
}
}
return(bVBR);
}
