public UInt64 IsFormat(StreamReader.IReader fileReader, UInt64 offset, UInt64 length)
{
if (fileReader.Read_16bitsBE(offset) != 0x8000)
{
return(0);
}
// Check encoding type ...
if (fileReader.Read_8Bits(offset + 4) != 3)
{
return(0);
}
// Check Frame Size ...
if (fileReader.Read_8Bits(offset + 5) != 18)
{
return(0);
}
// Check Bit per Samples ...
if (fileReader.Read_8Bits(offset + 6) != 4)
{
return(0);
}
// Check for channel count & sample rate
uint sampleRate = fileReader.Read_32bitsBE(offset + 0x08);
uint channelCount = fileReader.Read_8Bits(offset + 0x07);
if (((channelCount <= 0) || (channelCount > 8)) ||
((sampleRate < 11025) || (sampleRate > 48000)))
{
return(0);
}
// Search for the (c)CRI signature ...
UInt64 criOffset = fileReader.Read_16bitsBE(offset + 2);
if ((fileReader.Read_32bitsBE(offset + criOffset - 4) != 0x00002863) &&
(fileReader.Read_32bitsBE(offset + criOffset) != 0x29435249))
{
return(0);
}
// Find file length ...
UInt32 totalSamples = fileReader.Read_32bitsBE(offset + 0x0C);
UInt64 searchOffset = offset + (totalSamples * channelCount) / 32 * 18 + criOffset + 4;
while (fileReader.Read_16bitsBE(searchOffset) != 0x8001)
{
searchOffset++;
if (!fileReader.CanRead())
{
break;
}
}
UInt64 fileLength = (searchOffset - offset) + fileReader.Read_16bitsBE(searchOffset + 2) + 4;
return(fileLength);
}