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"); }