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-rw-r--r--src/lib/formats/x07_cas.cpp174
1 files changed, 174 insertions, 0 deletions
diff --git a/src/lib/formats/x07_cas.cpp b/src/lib/formats/x07_cas.cpp
new file mode 100644
index 00000000000..54f46acd488
--- /dev/null
+++ b/src/lib/formats/x07_cas.cpp
@@ -0,0 +1,174 @@
+// license:BSD-3-Clause
+// copyright-holders:Sandro Ronco
+/********************************************************************
+
+ Support for Canon X-07 cassette images
+
+********************************************************************/
+
+#include <assert.h>
+
+#include "x07_cas.h"
+
+#define WAVEENTRY_LOW -32768
+#define WAVEENTRY_HIGH 32767
+
+#define X07_WAV_FREQUENCY 4800
+#define X07_TIMER_FREQUENCY 1200
+#define X07_BIT_LENGTH (X07_WAV_FREQUENCY/X07_TIMER_FREQUENCY)
+#define X07_HEADER_BYTES 16
+
+// image size
+static int x07_image_size;
+
+static int x07_put_samples(INT16 *buffer, int sample_pos, int count, int level)
+{
+ if (buffer)
+ {
+ for (int i=0; i<count; i++)
+ buffer[sample_pos + i] = level;
+ }
+
+ return count;
+}
+
+static int x07_output_bit(INT16 *buffer, int sample_pos, UINT8 bit)
+{
+ int samples = 0;
+
+ if (bit)
+ {
+ samples += x07_put_samples(buffer, sample_pos + samples, X07_BIT_LENGTH/4, WAVEENTRY_HIGH);
+ samples += x07_put_samples(buffer, sample_pos + samples, X07_BIT_LENGTH/4, WAVEENTRY_LOW);
+ samples += x07_put_samples(buffer, sample_pos + samples, X07_BIT_LENGTH/4, WAVEENTRY_HIGH);
+ samples += x07_put_samples(buffer, sample_pos + samples, X07_BIT_LENGTH/4, WAVEENTRY_LOW);
+ }
+ else
+ {
+ samples += x07_put_samples(buffer, sample_pos + samples, X07_BIT_LENGTH/2, WAVEENTRY_HIGH);
+ samples += x07_put_samples(buffer, sample_pos + samples, X07_BIT_LENGTH/2, WAVEENTRY_LOW);
+ }
+
+ return samples;
+}
+
+static int x07_output_byte(INT16 *buffer, int sample_pos, UINT8 byte)
+{
+ int samples = 0;
+
+ /* start */
+ samples += x07_output_bit (buffer, sample_pos + samples, 0);
+
+ /* data */
+ for (int i=0; i<8; i++)
+ samples += x07_output_bit(buffer,sample_pos + samples, (byte>>i) & 0x01);
+
+ /* stop */
+ samples += x07_output_bit (buffer, sample_pos + samples, 1);
+ samples += x07_output_bit (buffer, sample_pos + samples, 1);
+ samples += x07_output_bit (buffer, sample_pos + samples, 1);
+
+ return samples;
+}
+
+static int x07_handle_cassette(INT16 *buffer, const UINT8 *bytes)
+{
+ int sample_count = 0;
+ int img_start = 0;
+
+ /* start */
+ for (int i=0; i<X07_WAV_FREQUENCY; i++)
+ sample_count += x07_output_bit(buffer, sample_count, 1);
+
+ /* header */
+ if (bytes[0] == 0xd3 && bytes[1] == 0xd3 && bytes[2] == 0xd3 && bytes[3] == 0xd3)
+ {
+ // valid header
+ for (int i=0; i<X07_HEADER_BYTES; i++)
+ sample_count += x07_output_byte(buffer, sample_count, bytes[i]);
+
+ img_start = X07_HEADER_BYTES;
+ }
+ else
+ {
+ // remove the NULL chars at start
+ while (!bytes[img_start])
+ img_start++;
+
+ // insert 0xd3 bytes
+ for (int i=0; i<10; i++)
+ sample_count += x07_output_byte(buffer, sample_count, 0xd3);
+
+ // fake filename
+ for (int i=0; i<6; i++)
+ sample_count += x07_output_byte(buffer, sample_count, 'A');
+ }
+
+ /* pause */
+ for (int i=0; i<X07_WAV_FREQUENCY/16; i++)
+ sample_count += x07_output_bit(buffer, sample_count, 1);
+
+ /* data */
+ for (int i=img_start; i<x07_image_size; i++)
+ sample_count += x07_output_byte(buffer, sample_count, bytes[i]);
+
+ /* end */
+ for (int i=0; i<X07_WAV_FREQUENCY/8; i++)
+ sample_count += x07_output_bit(buffer, sample_count, 1);
+
+ return sample_count;
+}
+
+
+/*******************************************************************
+ Generate samples for the tape image
+********************************************************************/
+
+static int x07_cassette_fill_wave(INT16 *buffer, int length, UINT8 *bytes)
+{
+ return x07_handle_cassette(buffer, bytes);
+}
+
+/*******************************************************************
+ Calculate the number of samples needed for this tape image
+********************************************************************/
+
+static int x07_cassette_calculate_size_in_samples(const UINT8 *bytes, int length)
+{
+ x07_image_size = length;
+
+ return x07_handle_cassette(NULL, bytes);
+}
+
+static const struct CassetteLegacyWaveFiller x07_legacy_fill_wave =
+{
+ x07_cassette_fill_wave, /* fill_wave */
+ -1, /* chunk_size */
+ 0, /* chunk_samples */
+ x07_cassette_calculate_size_in_samples, /* chunk_sample_calc */
+ X07_WAV_FREQUENCY, /* sample_frequency */
+ 0, /* header_samples */
+ 0 /* trailer_samples */
+};
+
+static casserr_t x07_cassette_identify(cassette_image *cassette, struct CassetteOptions *opts)
+{
+ return cassette_legacy_identify(cassette, opts, &x07_legacy_fill_wave);
+}
+
+static casserr_t x07_cassette_load(cassette_image *cassette)
+{
+ return cassette_legacy_construct(cassette, &x07_legacy_fill_wave);
+}
+
+static const struct CassetteFormat x07_cassette_image_format =
+{
+ "k7,lst,cas",
+ x07_cassette_identify,
+ x07_cassette_load,
+ NULL
+};
+
+CASSETTE_FORMATLIST_START(x07_cassette_formats)
+ CASSETTE_FORMAT(x07_cassette_image_format)
+CASSETTE_FORMATLIST_END