uint read(TagLib::File &file, uint limit)
{
ByteVector data = file.readBlock(std::min(m_size, limit));
uint count = data.size();
int index = data.find((char) 0);
if(index > -1) {
data.resize(index);
}
data.replace((char) 0xff, ' ');
value = data;
return count;
}
void IT::File::read(bool)
{
if(!isOpen())
return;
seek(0);
READ_ASSERT(readBlock(4) == "IMPM");
READ_STRING(d->tag.setTitle, 26);
seek(2, Current);
READ_U16L_AS(length);
READ_U16L_AS(instrumentCount);
READ_U16L_AS(sampleCount);
d->properties.setInstrumentCount(instrumentCount);
d->properties.setSampleCount(sampleCount);
READ_U16L(d->properties.setPatternCount);
READ_U16L(d->properties.setVersion);
READ_U16L(d->properties.setCompatibleVersion);
READ_U16L(d->properties.setFlags);
READ_U16L_AS(special);
d->properties.setSpecial(special);
READ_BYTE(d->properties.setGlobalVolume);
READ_BYTE(d->properties.setMixVolume);
READ_BYTE(d->properties.setBpmSpeed);
READ_BYTE(d->properties.setTempo);
READ_BYTE(d->properties.setPanningSeparation);
READ_BYTE(d->properties.setPitchWheelDepth);
// IT supports some kind of comment tag. Still, the
// sample/instrument names are abused as comments so
// I just add all together.
String message;
if(special & Properties::MessageAttached) {
READ_U16L_AS(messageLength);
READ_U32L_AS(messageOffset);
seek(messageOffset);
ByteVector messageBytes = readBlock(messageLength);
READ_ASSERT(messageBytes.size() == messageLength);
int index = messageBytes.find((char) 0);
if(index > -1)
messageBytes.resize(index, 0);
messageBytes.replace('\r', '\n');
message = messageBytes;
}
seek(64);
ByteVector pannings = readBlock(64);
ByteVector volumes = readBlock(64);
READ_ASSERT(pannings.size() == 64 && volumes.size() == 64);
int channels = 0;
for(int i = 0; i < 64; ++ i) {
// Strictly speaking an IT file has always 64 channels, but
// I don't count disabled and muted channels.
// But this always gives 64 channels for all my files anyway.
// Strangely VLC does report other values. I wonder how VLC
// gets it's values.
if((unsigned char) pannings[i] < 128 && volumes[i] > 0)
++channels;
}
d->properties.setChannels(channels);
// real length might be shorter because of skips and terminator
ushort realLength = 0;
for(ushort i = 0; i < length; ++ i) {
READ_BYTE_AS(order);
if(order == 255) break;
if(order != 254) ++ realLength;
}
d->properties.setLengthInPatterns(realLength);
StringList comment;
// Note: I found files that have nil characters somewhere
// in the instrument/sample names and more characters
// afterwards. The spec does not mention such a case.
// Currently I just discard anything after a nil, but
// e.g. VLC seems to interprete a nil as a space. I
// don't know what is the proper behaviour.
for(ushort i = 0; i < instrumentCount; ++ i) {
seek(192L + length + ((long)i << 2));
READ_U32L_AS(instrumentOffset);
seek(instrumentOffset);
ByteVector instrumentMagic = readBlock(4);
READ_ASSERT(instrumentMagic == "IMPI");
READ_STRING_AS(dosFileName, 13);
seek(15, Current);
READ_STRING_AS(instrumentName, 26);
comment.append(instrumentName);
}
for(ushort i = 0; i < sampleCount; ++ i) {
seek(192L + length + ((long)instrumentCount << 2) + ((long)i << 2));
READ_U32L_AS(sampleOffset);
seek(sampleOffset);
ByteVector sampleMagic = readBlock(4);
READ_ASSERT(sampleMagic == "IMPS");
READ_STRING_AS(dosFileName, 13);
READ_BYTE_AS(globalVolume);
READ_BYTE_AS(sampleFlags);
READ_BYTE_AS(sampleVolume);
READ_STRING_AS(sampleName, 26);
/*
READ_BYTE_AS(sampleCvt);
READ_BYTE_AS(samplePanning);
READ_U32L_AS(sampleLength);
READ_U32L_AS(loopStart);
READ_U32L_AS(loopStop);
READ_U32L_AS(c5speed);
READ_U32L_AS(sustainLoopStart);
READ_U32L_AS(sustainLoopEnd);
READ_U32L_AS(sampleDataOffset);
READ_BYTE_AS(vibratoSpeed);
READ_BYTE_AS(vibratoDepth);
READ_BYTE_AS(vibratoRate);
READ_BYTE_AS(vibratoType);
*/
comment.append(sampleName);
}
if(message.size() > 0)
comment.append(message);
d->tag.setComment(comment.toString("\n"));
d->tag.setTrackerName("Impulse Tracker");
}
