// license:BSD-3-Clause // copyright-holders:Sandro Ronco /******************************************************************** Support for Videoton TVC .cas files http://tvc.homeserver.hu/html/konvertformatum.html ********************************************************************/ #include "tvc_cas.h" #define TVC64_BIT0_FREQ 1812 #define TVC64_BIT1_FREQ 2577 #define TVC64_PRE_FREQ 2128 #define TVC64_SYNC_FREQ 1359 #define WAVE_AMPLITUDE 0x3fffffff #define TVC64_HEADER_BYTES 0x90 #define TVC64_HEADER_BYTES 0x90 static void tvc64_emit_level(cassette_image *cass, double &time, int freq, int level) { double period = 1.0 / freq; cassette_put_sample(cass, 0, time, period, level * WAVE_AMPLITUDE); time += period; } static casserr_t tvc64_output_byte(cassette_image *cass, double &time, UINT8 byte) { for (int i=0; i<8; i++) { if ((byte>>i) & 0x01) { tvc64_emit_level(cass, time, TVC64_BIT1_FREQ*2, +1); tvc64_emit_level(cass, time, TVC64_BIT1_FREQ*2, -1); } else { tvc64_emit_level(cass, time, TVC64_BIT0_FREQ*2, +1); tvc64_emit_level(cass, time, TVC64_BIT0_FREQ*2, -1); } } return CASSETTE_ERROR_SUCCESS; } static int tvc64_output_predata(cassette_image *cass, double &time, int number) { for (int i=0; i>8) & 0xff); if (al & 0x80) crc ^= 0x0810; crc <<= 1; if (al & 0x80) crc += 1; } } return crc; } static casserr_t tvc64_cassette_load(cassette_image *cassette) { UINT8 tmp_buff[512]; int buff_idx = 0; double time = 0.0; UINT8 header[TVC64_HEADER_BYTES]; cassette_image_read(cassette, header, 0, TVC64_HEADER_BYTES); UINT16 cas_size = (header[0x83]<<8) | header[0x82]; // tape header tmp_buff[buff_idx++] = 0x00; tmp_buff[buff_idx++] = 0x6a; tmp_buff[buff_idx++] = 0xff; // head sector tmp_buff[buff_idx++] = 0x11; // not puffered tmp_buff[buff_idx++] = 0x00; // not write protected tmp_buff[buff_idx++] = 0x01; // 1 sector tmp_buff[buff_idx++] = 0x00; // sector number tmp_buff[buff_idx++] = 0x12; // head size tmp_buff[buff_idx++] = 0x01; // name size tmp_buff[buff_idx++] = ' '; // name tmp_buff[buff_idx++] = 0x00; tmp_buff[buff_idx++] = header[0x81]; // type tmp_buff[buff_idx++] = header[0x82]; // size LSB tmp_buff[buff_idx++] = header[0x83]; // size MSB tmp_buff[buff_idx++] = header[0x84]; // autostart // sector fill for (int i=0; i<10 ; i++) tmp_buff[buff_idx++] = 0x00; tmp_buff[buff_idx++] = 0x00; // file version tmp_buff[buff_idx++] = 0x00; // no last sector // updates the header CRC UINT16 crc = tvc64_calc_crc(tmp_buff, buff_idx); tmp_buff[buff_idx++] = crc & 0xff; tmp_buff[buff_idx++] = (crc>>8) & 0xff; // 2 sec silence tvc64_emit_level(cassette, time, 2, 0); // 10240 pre data cycles tvc64_output_predata(cassette, time, 10240); // 1 synchro cycle tvc64_emit_level(cassette, time, TVC64_SYNC_FREQ*2, +1); tvc64_emit_level(cassette, time, TVC64_SYNC_FREQ*2, -1); // header data for (int i=0; i 0 ? 1 : 0)); // number of sectors UINT8 sect_num = 1; int sector_num = cas_size / 256; for (int i=0; i<=sector_num; i++) { tmp_buff[buff_idx++] = sect_num++; // sector number // sector size if (i == sector_num) tmp_buff[buff_idx++] = cas_size % 256; else tmp_buff[buff_idx++] = 0x00; // sector data int sector_size = (i == sector_num) ? (cas_size % 256) : 256; for (int z=0; z < sector_size; z++) cassette_image_read(cassette, &tmp_buff[buff_idx++], TVC64_HEADER_BYTES + i*256 + z, 1); if (i == sector_num || ((i+1) == sector_num && (cas_size % 256 ) == 0)) tmp_buff[buff_idx++] = 0xff; // last sector else tmp_buff[buff_idx++] = 0x00; // no last sector // sector crc crc = tvc64_calc_crc(tmp_buff, buff_idx); tmp_buff[buff_idx++] = crc & 0xff; tmp_buff[buff_idx++] = (crc>>8) & 0xff; // output the sector for (int z=0; zbits_per_sample = 16; opts->channels = 1; opts->sample_frequency = 44100; return CASSETTE_ERROR_SUCCESS; } return CASSETTE_ERROR_INVALIDIMAGE; } static const struct CassetteFormat tvc64_cassette_image_format = { "cas", tvc64_cassette_identify, tvc64_cassette_load, NULL }; CASSETTE_FORMATLIST_START(tvc64_cassette_formats) CASSETTE_FORMAT(tvc64_cassette_image_format) CASSETTE_FORMATLIST_END