static int tzx_handle_direct(int16_t **buffer, const uint8_t *bytes, int pause, int data_size, int tstates, int bits_in_last_byte)
{
int size = 0;
int samples = tcycles_to_samplecount(tstates);
/* data */
for (int 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--)
{
if (byte & 0x80) wave_data = WAVE_HIGH;
else wave_data = WAVE_LOW;
tzx_output_wave(buffer, samples);
size += samples;
}
}
/* 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;
}
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;
}
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;
}
static int tzx_handle_generalized(int16_t **buffer, const uint8_t *bytes, int pause, int data_size, uint32_t totp, int npp, int asp, uint32_t totd, int npd, int asd )
{
int size = 0;
if (totp > 0)
{
// printf("pilot block table %04x\n", totp);
const uint8_t *symtable = bytes;
const uint8_t *table2 = symtable + (2 * npp + 1)*asp;
// the Pilot and sync data stream has an RLE encoding
for (int i = 0; i < totp; i+=3)
{
uint8_t symbol = table2[i + 0];
uint16_t repetitions = table2[i + 1] + (table2[i + 2] << 8);
//printf("symbol %02x repetitions %04x\n", symbol, repetitions); // does 1 mean repeat once, or that it only occurs once?
for (int j = 0; j < repetitions; j++)
{
size += tzx_handle_symbol(buffer, symtable, symbol, npp);
}
}
// advance to after this data
bytes += ((2 * npp + 1)*asp) + totp * 3;
}
if (totd > 0)
{
// printf("data block table %04x (has %0d symbols, max symbol length is %d)\n", totd, asd, npd);
const uint8_t *symtable = bytes;
const uint8_t *table2 = bytes + (2 * npd + 1)*asd;
int NB = ceil(compute_log2(asd)); // number of bits needed to represent each symbol
uint8_t stream_bit = 0;
uint32_t stream_byte = 0;
for (int i = 0; i < totd; i++)
{
uint8_t symbol = 0;
for (int j = 0; j < NB; j++)
{
symbol |= stream_get_bit(table2, stream_bit, stream_byte) << j;
}
size += tzx_handle_symbol(buffer, symtable, symbol, npd);
}
}
/* 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;
}
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;
}