Function gmext_write_sequence

src/Engine/GMCat.cpp:159–287

};

static int gmext_write_sequence (std::vector<unsigned char> &midi,
	const struct gmstream *stream, unsigned int channel,
	const struct seq *seq, struct output_status *status)
{
	const unsigned char *data = seq->data;
	unsigned int left = seq->size;

	unsigned char cmd = -1;

	while (left) {

		// read delta
		unsigned int ndelta = 0;

		for (int i=0; ; ) {
			unsigned char c = *data++;
			left--;
			ndelta += c & 0x7F;
			if (!(c & 0x80))
				break;
			if ((++i == 4) || !left)
				return -1;
			ndelta <<= 7;
		}

		status->delta += ndelta;

		// read cmd byte
		if (!left)
			return -1;

		if (*data & 0x80) {
			// actual cmd byte
			cmd = *data++;
			left--;
			switch (cmd) {
				case 0xFF:	  // end track
				case 0xFD:	  // end subsequence
					return 0;
				case 0xFE:	  // insert subsequence
					if (!left--)
						return -1;
					if (*data >= stream->nsubs)
						// invalid subsequence
						return -1;
					if (gmext_write_sequence(midi,
						stream, channel,
						&stream->subs[*data++], status)
							== -1)
						return -1;
					cmd = 0;
					continue;
				default:
					cmd &= 0xF0;
			}
		} else if (cmd == 0)
			return -1;	  // invalid running mode