/* .APT tape images */ #include "formats/apf_apt.h" #define WAVEENTRY_LOW -32768 #define WAVEENTRY_HIGH 32767 #define WAVEENTRY_NULL 0 /* frequency of wave */ #define APF_WAV_FREQUENCY 11050 #define APF_APT_BIT_0_LENGTH ((int)(APF_WAV_FREQUENCY*0.0005)) #define APF_APT_BIT_1_LENGTH ((int)(APF_WAV_FREQUENCY*0.001)) struct apf_t { int cassette_length; }; static apf_t apf; /* 500 microsecond of bit 0 and 1000 microsecond of bit 1 */ static INT16 *apf_emit_level(INT16 *p, int count, INT16 wave_state) { int i; for (i=0; i>1), WAVEENTRY_HIGH); p = apf_emit_level(p, (APF_APT_BIT_1_LENGTH>>1), WAVEENTRY_LOW); } else { p = apf_emit_level(p, (APF_APT_BIT_0_LENGTH>>1), WAVEENTRY_HIGH); p = apf_emit_level(p, (APF_APT_BIT_0_LENGTH>>1), WAVEENTRY_LOW); } return p; } static int apf_get_bit_size_in_samples(UINT8 b) { if (b) { return APF_APT_BIT_1_LENGTH; } return APF_APT_BIT_0_LENGTH; } /*************************************************************************************/ /* each bit in the data represents a "1" or "0" waveform */ static int apf_cassette_calculate_size_in_samples(const UINT8 *bytes, int length) { unsigned i; int size; int b; UINT8 data; size = 0; apf.cassette_length = length; for (i=0; i>7) & 0x01); data = data<<1; } } return size; } /*************************************************************************************/ static int apf_cassette_fill_wave(INT16 *buffer, int length, UINT8 *bytes) { int i; INT16 *p; UINT8 data; int b; p = buffer; for (i=0; i>7) & 0x01); data = data<<1; } } return p - buffer; } static const struct CassetteLegacyWaveFiller apf_legacy_fill_wave = { apf_cassette_fill_wave, /* fill_wave */ -1, /* chunk_size */ 0, /* chunk_samples */ apf_cassette_calculate_size_in_samples, /* chunk_sample_calc */ APF_WAV_FREQUENCY, /* sample_frequency */ 0, /* header_samples */ 0 /* trailer_samples */ }; static casserr_t apf_apt_identify(cassette_image *cassette, struct CassetteOptions *opts) { return cassette_legacy_identify(cassette, opts, &apf_legacy_fill_wave); } static casserr_t apf_apt_load(cassette_image *cassette) { return cassette_legacy_construct(cassette, &apf_legacy_fill_wave); } static const struct CassetteFormat apf_apt_format = { "apt", apf_apt_identify, apf_apt_load, NULL }; CASSETTE_FORMATLIST_START(apf_cassette_formats) CASSETTE_FORMAT(apf_apt_format) CASSETTE_FORMATLIST_END