Beispiel #1
0
static int tzx_cas_handle_block( INT16 **buffer, const UINT8 *bytes, int pause, int data_size, int pilot, int pilot_length, int sync1, int sync2, int bit0, int bit1, int bits_in_last_byte ) {
	int pilot_samples = tcycles_to_samplecount( pilot );
	int sync1_samples = tcycles_to_samplecount( sync1 );
	int sync2_samples = tcycles_to_samplecount( sync2 );
	int bit0_samples = tcycles_to_samplecount( bit0 );
	int bit1_samples = tcycles_to_samplecount( bit1 );
	int data_index;
	int size = 0;

	logerror( "tzx_cas_block_size: pliot_length = %d, pilot_samples = %d, sync1_samples = %d, sync2_samples = %d, bit0_samples = %d, bit1_samples = %d\n", pilot_length, pilot_samples, sync1_samples, sync2_samples, bit0_samples, bit1_samples );

	/* PILOT */
	for( ; pilot_length > 0; pilot_length-- ) {
		tzx_output_wave( buffer, pilot_samples );
		size += pilot_samples;
		toggle_wave_data();
	}
	/* SYNC1 */
	if ( sync1_samples > 0 ) {
		tzx_output_wave( buffer, sync1_samples );
		size += sync1_samples;
		toggle_wave_data();
	}
	/* SYNC2 */
	if ( sync2_samples > 0 ) {
		tzx_output_wave( buffer, sync2_samples );
		size += sync2_samples;
		toggle_wave_data();
	}
	/* data */
	for( data_index = 0; data_index < data_size; data_index++ ) {
		UINT8	byte = bytes[data_index];
		int	bits_to_go = ( data_index == ( data_size - 1 ) ) ? bits_in_last_byte : 8;
		for( ; bits_to_go > 0; byte <<= 1, bits_to_go-- ) {
			int	bit_samples = ( byte & 0x80 ) ? bit1_samples : bit0_samples;
			tzx_output_wave( buffer, bit_samples );
			size += bit_samples;
			toggle_wave_data();
			tzx_output_wave( buffer, bit_samples );
			size += bit_samples;
			toggle_wave_data();
		}
	}
	/* pause */
	if ( pause > 0 ) {
		int start_pause_samples = millisec_to_samplecount( 1 );
		int rest_pause_samples = millisec_to_samplecount( pause - 1 );

		tzx_output_wave( buffer, start_pause_samples );
		size += start_pause_samples;
		wave_data = WAVE_LOW;
		tzx_output_wave( buffer, rest_pause_samples );
		size += rest_pause_samples;
	}
        return size;
}
Beispiel #2
0
static inline int tzx_handle_symbol(int16_t **buffer, const uint8_t *symtable, uint8_t symbol, int maxp)
{
	int size = 0;
	const uint8_t *cursymb = symtable + (2 * maxp + 1)*symbol;

	uint8_t starttype = cursymb[0];

	switch (starttype)
	{
	case 0x00:
		toggle_wave_data();
		break;

	case 0x01:
		// don't change
		break;

	case 0x02:
		// force low
		wave_data = WAVE_LOW;
		break;

	case 0x03:
		// force high
		wave_data = WAVE_HIGH;
		break;

	default:
		printf("SYMDEF invalid - bad starting polarity");
	}

	for (int i = 0; i < maxp; i++)
	{
		uint16_t pulse_length = cursymb[1 + (i*2)] | (cursymb[2 + (i*2)] << 8);

		// shorter lists can be terminated with a pulse_length of 0
		if (pulse_length != 0)
		{
			int samples = tcycles_to_samplecount(pulse_length);
			tzx_output_wave(buffer, samples);
			size += samples;
			toggle_wave_data();
		}
		else
		{
			toggle_wave_data();
			i = maxp;
			continue;
		}
	}

	return size;
}
Beispiel #3
0
static int tzx_cas_handle_block( int16_t **buffer, const uint8_t *bytes, int pause, int data_size, int pilot, int pilot_length, int sync1, int sync2, int bit0, int bit1, int bits_in_last_byte )
{
	int pilot_samples = tcycles_to_samplecount(pilot);
	int sync1_samples = tcycles_to_samplecount(sync1);
	int sync2_samples = tcycles_to_samplecount(sync2);
	int bit0_samples = tcycles_to_samplecount(bit0);
	int bit1_samples = tcycles_to_samplecount(bit1);
	int data_index;
	int size = 0;

	/* Uncomment this to include into error.log a fully detailed analysis of each block */
//  LOG_FORMATS("tzx_cas_block_size: pilot_length = %d, pilot_samples = %d, sync1_samples = %d, sync2_samples = %d, bit0_samples = %d, bit1_samples = %d\n", pilot_length, pilot_samples, sync1_samples, sync2_samples, bit0_samples, bit1_samples);

	/* PILOT */
	for ( ; pilot_length > 0; pilot_length--)
	{
		tzx_output_wave(buffer, pilot_samples);
		size += pilot_samples;
		toggle_wave_data();
	}
	/* SYNC1 */
	if (sync1_samples > 0)
	{
		tzx_output_wave(buffer, sync1_samples);
		size += sync1_samples;
		toggle_wave_data();
	}
	/* SYNC2 */
	if (sync2_samples > 0)
	{
		tzx_output_wave(buffer, sync2_samples);
		size += sync2_samples;
		toggle_wave_data();
	}
	/* data */
	for (data_index = 0; data_index < data_size; data_index++)
	{
		uint8_t byte = bytes[data_index];
		int bits_to_go = (data_index == (data_size - 1)) ? bits_in_last_byte : 8;

		for ( ; bits_to_go > 0; byte <<= 1, bits_to_go--)
		{
			int bit_samples = (byte & 0x80) ? bit1_samples : bit0_samples;
			tzx_output_wave(buffer, bit_samples);
			size += bit_samples;
			toggle_wave_data();
			tzx_output_wave(buffer, bit_samples);
			size += bit_samples;
			toggle_wave_data();
		}
	}
	/* pause */
	int start_pause_samples = millisec_to_samplecount(1);

	tzx_output_wave(buffer, start_pause_samples);
	size += start_pause_samples;

	if (pause > 0)
	{
		int rest_pause_samples = millisec_to_samplecount(pause - 1);

		wave_data = WAVE_LOW;
		tzx_output_wave(buffer, rest_pause_samples);
		size += rest_pause_samples;
	}
	return size;
}