private static string ReadTextField(StreamBuffer sb)
{
if (sb == null)
throw new ArgumentNullException("sb");
int size = sb.ReadInt16();
return sb.ReadString(size);
}
public void ReadInt16Test()
{
const short Value = 0x1234;
const short Expected = 0x1234;
StreamBuffer target = new StreamBuffer(BitConverter.GetBytes(Value)) { Position = 0 };
short actual = target.ReadInt16();
Assert.AreEqual(Expected, actual);
}
private static void ReadAudioMetaFields(StreamBuffer sb, MusicMatchTag tag)
{
if (sb == null)
throw new ArgumentNullException("sb");
// Single-line text fields
tag.SongTitle = ReadTextField(sb);
tag.AlbumTitle = ReadTextField(sb);
tag.ArtistName = ReadTextField(sb);
tag.Genre = ReadTextField(sb);
tag.Tempo = ReadTextField(sb);
tag.Mood = ReadTextField(sb);
tag.Situation = ReadTextField(sb);
tag.Preference = ReadTextField(sb);
// Non-text fields
tag.SongDuration = ReadTextField(sb);
tag.CreationDate = DateTime.FromOADate(sb.ReadDouble());
tag.PlayCounter = sb.ReadInt32();
tag.OriginalFilename = ReadTextField(sb);
tag.SerialNumber = ReadTextField(sb);
tag.TrackNumber = sb.ReadInt16();
// Multi-line text fields
tag.Notes = ReadTextField(sb);
tag.ArtistBio = ReadTextField(sb);
tag.Lyrics = ReadTextField(sb);
// Internet addresses
tag.ArtistUrl = ReadTextField(sb);
tag.BuyCdUrl = ReadTextField(sb);
tag.ArtistEmail = ReadTextField(sb);
}
////------------------------------------------------------------------------------------------------------------------------------
/// <summary>
/// Initializes a new instance of the <see cref="LameTag"/> class.
/// </summary>
/// <param name="firstFrameBuffer">The first frame buffer containing a <see cref="LameTag"/>.</param>
public LameTag(StreamBuffer firstFrameBuffer)
{
// string lameTag = "LAME"
firstFrameBuffer.ReadString(4);
float ver;
float.TryParse(firstFrameBuffer.ReadString(4), out ver);
Version = ver;
firstFrameBuffer.Seek(-8, SeekOrigin.Current);
if (Version < 3.90f)
{
// Initial LAME info, 20 bytes for LAME tag. for example, "LAME3.12 (beta 6)"
// LAME prior to 3.90 writes only a 20 byte encoder string.
EncoderVersion = firstFrameBuffer.ReadString(20);
}
else
{
EncoderVersion = firstFrameBuffer.ReadString(9);
// Revision Information Tag + VBR Info
int infoAndVbr = firstFrameBuffer.ReadByte();
// Revision information in 4 MSB
InfoTagRevision = infoAndVbr >> 4;
if (InfoTagRevision == Formats.InfoTagRevision.Reserved)
throw new ArgumentException("InfoTagRevision bit is set to reserved (0xF)");
// VBR info in 4 LSB
VbrMethod = infoAndVbr & 0x0F;
// lowpass information, multiply by 100 to get hz
LowpassFilterValue = firstFrameBuffer.ReadByte() * 100;
// Radio replay gain fields
// Peak signal amplitude
PeakSignalAmplitude = firstFrameBuffer.ReadFloat();
// Radio Replay Gain
RadioReplayGain = firstFrameBuffer.ReadInt16();
// Audiophile Replay Gain
AudiophileReplayGain = firstFrameBuffer.ReadInt16();
// Encoding Flags + ATH type
int encodingFlagsAndAthType = firstFrameBuffer.ReadByte();
// Encoding Flags in 4 MSB
EncodingFlags = encodingFlagsAndAthType >> 4;
// LAME ATH Type in 4 LSB
AthType = encodingFlagsAndAthType & 0x0F;
// If ABR, this will be the specified bitrate
// Otherwise (CBR/VBR), the minimal bitrate (255 means 255 or bigger)
BitRate = firstFrameBuffer.ReadByte();
// the 12 bit values (0-4095) of how many samples were added at start (encoder delay)
// in X and how many 0-samples were padded at the end in Y to complete the last frame.
EncoderDelays = firstFrameBuffer.ReadInt(3);
EncoderDelaySamples = EncoderDelays & 0xFFF;
EncoderDelayPaddingSamples = EncoderDelays >> 12;
////int numberSamplesInOriginalWav = frameCount
Misc = firstFrameBuffer.ReadByte();
// Any mp3 can be amplified by a factor 2 ^ ( x * 0.25) in a lossless manner by a tool like eg. mp3gain
// if done so, this 8-bit field can be used to log such transformation happened so that any given time it can be undone.
Mp3Gain = firstFrameBuffer.ReadByte();
// Preset and surround info
PresetSurroundInfo = firstFrameBuffer.ReadInt16();
// 32 bit integer filed containing the exact length in bytes of the mp3 file originally made by LAME excluded ID3 tag info at the end.
MusicLength = firstFrameBuffer.ReadBigEndianInt32();
// Contains a CRC-16 of the complete mp3 music data as made originally by LAME.
_musicCrc = (short)firstFrameBuffer.ReadBigEndianInt16();
// contains a CRC-16 of the first 190 bytes (0x00 - 0xBD) of the Info header frame.
// This field is calculated at the end, once all other fields are completed.
_infoTagCrc = (short)firstFrameBuffer.ReadBigEndianInt16();
}
}