private static int CalSampleBit(BASS_CHANNELINFO_INTERNAL wavInfo, double durationSeconds, int dataLength, bool dataType)
{
int sampleBit = wavInfo.origres;
if (sampleBit == 0)
{
//1秒内播放的数据 sd=data.Length / durationSeconds=fs*chans*bits
sampleBit = (int)(dataLength / durationSeconds) / wavInfo.freq / wavInfo.chans * 8;
if (dataType)
{
sampleBit = sampleBit * 2;
}
if (sampleBit <= 8)
{
sampleBit = 8;
}
else if (sampleBit <= 16)
{
sampleBit = 16;
}
else if (sampleBit <= 24)
{
sampleBit = 24;
}
else
{
sampleBit = 32;
}
}
return(sampleBit);
}
/// <summary>
/// Retrieves information on a channel
/// </summary>
/// <param name="handle">The channel handle... a HCHANNEL, HMUSIC, HSTREAM, or HRECORD</param>
/// <returns>Pointer to structure to receive the channel information</returns>
public static BASS_CHANNELINFO_INTERNAL ChannelGetInfo(int handle)
{
BASS_CHANNELINFO_INTERNAL info = new BASS_CHANNELINFO_INTERNAL();
bool result = NativeMethods.BASS_ChannelGetInfo(handle, ref info);
if (!result)
{
throw new WavException(BassErrorCode.GetErrorInfo());
}
return(info);
}
/// <summary>
/// 获取解码后的线性short数据
/// </summary>
/// <returns>解码后的线性short数据</returns>
public static PcmDataInfo GetPcmDataShort(string filePath)
{
if (string.IsNullOrWhiteSpace(filePath))
{
throw new ArgumentNullException(nameof(filePath));
}
if (!File.Exists(filePath))
{
throw new FileNotFoundException("源文件不存在", filePath);
}
int handle = WavHelper.StreamCreateFile(filePath, 0, 0, BASSFlag.BASS_UNICODE | BASSFlag.BASS_STREAM_DECODE);
try
{
long byteLength = WavHelper.ChannelGetLength(handle, BASSMode.BASS_POS_BYTE);
double durationSeconds = WavHelper.ChannelBytes2Seconds(handle, byteLength);
int shortCount = (int)(byteLength);
short[] pcmData = new short[shortCount];
int count = WavHelper.ChannelGetData(handle, pcmData, shortCount);
//注:结果数据长度之所以除以2,是因为short=2byte,bass获取数据时必须使用字节长度,否则数据会少一半;
//但是使用字节长度获取数据后,后一半数据又全是0,需要截取掉
count = count / 2;
short[] pcmDataSrc = pcmData;
pcmData = new short[count];
Array.Copy(pcmDataSrc, pcmData, count);
BASS_CHANNELINFO_INTERNAL wavInfo = WavHelper.ChannelGetInfo(handle);
return(new PcmDataInfo(wavInfo, durationSeconds, pcmData));
}
finally
{
WavHelper.StreamFree(handle);
}
}
/// <summary>
/// Retrieves information on a channel
/// </summary>
/// <param name="handle">The channel handle... a HCHANNEL, HMUSIC, HSTREAM, or HRECORD</param>
/// <returns>If successful, TRUE is returned, else FALSE is returned. Use BASS_ErrorGetCode to get the error code</returns>
public static BASS_CHANNELINFO_INTERNAL BASS_ChannelGetInfo(int handle)
{
BASS_CHANNELINFO_INTERNAL info = new BASS_CHANNELINFO_INTERNAL();
bool result = false;
if (Environment.Is64BitProcess)
{
result = BassX64.BASS_ChannelGetInfo(handle, ref info);
}
else
{
result = BassX86.BASS_ChannelGetInfo(handle, ref info);
}
if (result)
{
return(info);
}
else
{
throw new ApplicationException("BASS_ChannelGetInfo Fail," + BassErrorCode.GetErrorInfo());
}
}
/// <summary>
/// 获取解码后的线性byte数据
/// </summary>
/// <returns>解码后的线性byte数据</returns>
public static PcmDataInfo GetPcmDataByte(string filePath)
{
if (string.IsNullOrWhiteSpace(filePath))
{
throw new ArgumentNullException(nameof(filePath));
}
if (!File.Exists(filePath))
{
throw new FileNotFoundException("源文件不存在", filePath);
}
int handle = WavHelper.StreamCreateFile(filePath, 0, 0, BASSFlag.BASS_UNICODE | BASSFlag.BASS_STREAM_DECODE);
try
{
long byteLength = WavHelper.ChannelGetLength(handle, BASSMode.BASS_POS_BYTE);
double durationSeconds = WavHelper.ChannelBytes2Seconds(handle, byteLength);
byte[] pcmData = new byte[byteLength];
int count = WavHelper.ChannelGetData(handle, pcmData, (int)byteLength);
if (count != byteLength)
{
WavLoger.OnRaiseLog(filePath, $"获取到文件长度:{byteLength},读取到数据长度:{count},二者不一致,根据实际读取进行拷贝");
byte[] pcmDataSrc = pcmData;
pcmData = new byte[count];
Array.Copy(pcmDataSrc, pcmData, pcmData.Length);
}
BASS_CHANNELINFO_INTERNAL wavInfo = WavHelper.ChannelGetInfo(handle);
return(new PcmDataInfo(wavInfo, durationSeconds, pcmData));
}
finally
{
WavHelper.StreamFree(handle);
}
}
public static extern bool BASS_ChannelGetInfo(int handle, [In, Out] ref BASS_CHANNELINFO_INTERNAL info);
/// <summary>
/// 构造函数
/// </summary>
/// <param name="wavInfo">音频数据信息</param>
/// <param name="durationSeconds">线性数据播放持续时长,单位/秒</param>
/// <param name="data">线性数据</param>
internal PcmDataInfo(BASS_CHANNELINFO_INTERNAL wavInfo, double durationSeconds, short[] data)
: this(wavInfo.chans, wavInfo.freq, CalSampleBit(wavInfo, durationSeconds, data.Length, true), durationSeconds, data)
{
}
