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-rw-r--r--trunk/src/lib/formats/pmd_cas.c214
1 files changed, 214 insertions, 0 deletions
diff --git a/trunk/src/lib/formats/pmd_cas.c b/trunk/src/lib/formats/pmd_cas.c
new file mode 100644
index 00000000000..78a793e48e2
--- /dev/null
+++ b/trunk/src/lib/formats/pmd_cas.c
@@ -0,0 +1,214 @@
+/********************************************************************
+
+ Support for PMD 85 cassette images
+
+ Supported formats:
+ - pmd: raw image
+ - ptp: PMD 85 tape package
+
+********************************************************************/
+
+#include "pmd_cas.h"
+
+#define WAVEENTRY_LOW -32768
+#define WAVEENTRY_HIGH 32767
+
+#define PMD85_WAV_FREQUENCY 7200
+#define PMD85_TIMER_FREQUENCY 1200
+#define PMD85_BIT_LENGTH (PMD85_WAV_FREQUENCY/PMD85_TIMER_FREQUENCY)
+#define PMD85_PILOT_BITS (PMD85_TIMER_FREQUENCY*3)
+#define PMD85_PAUSE_BITS (PMD85_TIMER_FREQUENCY/2)
+#define PMD85_HEADER_BYTES 63
+#define PMD85_BITS_PER_BYTE 11
+
+// image size
+static int pmd85_image_size;
+
+static int pmd85_emit_level(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 pmd85_output_bit(INT16 *buffer, int sample_pos, UINT8 bit)
+{
+ int samples = 0;
+
+ if (bit)
+ {
+ samples += pmd85_emit_level (buffer, sample_pos + samples, PMD85_BIT_LENGTH/2, WAVEENTRY_LOW);
+ samples += pmd85_emit_level (buffer, sample_pos + samples, PMD85_BIT_LENGTH/2, WAVEENTRY_HIGH);
+ }
+ else
+ {
+ samples += pmd85_emit_level (buffer, sample_pos + samples, PMD85_BIT_LENGTH/2, WAVEENTRY_HIGH);
+ samples += pmd85_emit_level (buffer, sample_pos + samples, PMD85_BIT_LENGTH/2, WAVEENTRY_LOW);
+ }
+
+ return samples;
+}
+
+static int pmd85_output_byte(INT16 *buffer, int sample_pos, UINT8 byte)
+{
+ int samples = 0;
+
+ /* start */
+ samples += pmd85_output_bit (buffer, sample_pos + samples, 0);
+
+ /* data */
+ for (int i=0; i<8; i++)
+ samples += pmd85_output_bit(buffer,sample_pos + samples, (byte>>i) & 0x01);
+
+ /* stop */
+ samples += pmd85_output_bit (buffer, sample_pos + samples, 1);
+ samples += pmd85_output_bit (buffer, sample_pos + samples, 1);
+
+ return samples;
+}
+
+static bool pmd85_is_header_block(const UINT8 *bytes)
+{
+ for (int i=0; i<0x10; i++)
+ {
+ if (bytes[i] != 0xff || bytes[i + 0x10] != 0x00 || bytes[i + 0x20] != 0x55)
+ return false;
+ }
+
+ return true;
+}
+
+static void pmd85_printf_image_info(const UINT8 *bytes, int sample_count)
+{
+#if 0
+ char track_name[9];
+ UINT32 sec = (UINT32)(sample_count/PMD85_WAV_FREQUENCY);
+ UINT16 addr = (bytes[0x33]<<8) | bytes[0x32];
+ strncpy(track_name, (char*)&bytes[0x36], 8);
+ track_name[8] = '\0';
+
+ printf("Block ID: %02d %s 0x%04x Tape pos: %02d:%02d\n", bytes[0x30], track_name, addr, sec/60, sec%60);
+#endif
+}
+
+static int pmd85_handle_cassette(INT16 *buffer, const UINT8 *bytes)
+{
+ int sample_count = 0;
+
+ if (pmd85_is_header_block(bytes))
+ {
+ // PMD file
+
+ /* pilot */
+ for (int i=0; i<PMD85_PILOT_BITS; i++)
+ sample_count += pmd85_output_bit(buffer, sample_count, 1);
+
+ if (!buffer)
+ pmd85_printf_image_info(bytes, sample_count);
+
+ /* header */
+ for (int i=0; i<PMD85_HEADER_BYTES; i++)
+ sample_count += pmd85_output_byte(buffer, sample_count, bytes[i]);
+
+ /* pause */
+ for (int i=0; i<PMD85_PAUSE_BITS; i++)
+ sample_count += pmd85_output_bit(buffer, sample_count, 1);
+
+ /* data */
+ for (int i=PMD85_HEADER_BYTES; i<pmd85_image_size; i++)
+ sample_count += pmd85_output_byte(buffer, sample_count, bytes[i]);
+ }
+ else
+ {
+ // PTP file
+
+ /* pilot */
+ for (int i=0; i<PMD85_PILOT_BITS; i++)
+ sample_count += pmd85_output_bit(buffer, sample_count, 1);
+
+ int data_pos = 0;
+ while (data_pos < pmd85_image_size)
+ {
+ UINT16 block_size = (bytes[data_pos + 1]<<8) | bytes[data_pos];
+ int pause_len = PMD85_PAUSE_BITS;
+
+ data_pos += 2;
+
+ if (pmd85_is_header_block(bytes + data_pos))
+ {
+ if (!buffer)
+ pmd85_printf_image_info(bytes + data_pos, sample_count);
+
+ pause_len *= 2;
+ }
+
+ for (int i=0; i<pause_len; i++)
+ sample_count += pmd85_output_bit(buffer, sample_count, 1);
+
+ for (int i=0; i<block_size; i++)
+ sample_count += pmd85_output_byte(buffer, sample_count, bytes[data_pos + i]);
+
+ data_pos += block_size;
+ }
+ }
+
+ return sample_count;
+}
+
+
+/*******************************************************************
+ Generate samples for the tape image
+********************************************************************/
+
+static int pmd85_cassette_fill_wave(INT16 *buffer, int length, UINT8 *bytes)
+{
+ return pmd85_handle_cassette(buffer, bytes);
+}
+
+/*******************************************************************
+ Calculate the number of samples needed for this tape image
+********************************************************************/
+
+static int pmd85_cassette_calculate_size_in_samples(const UINT8 *bytes, int length)
+{
+ pmd85_image_size = length;
+
+ return pmd85_handle_cassette(NULL, bytes);
+}
+
+static const struct CassetteLegacyWaveFiller pmd85_legacy_fill_wave =
+{
+ pmd85_cassette_fill_wave, /* fill_wave */
+ -1, /* chunk_size */
+ 0, /* chunk_samples */
+ pmd85_cassette_calculate_size_in_samples, /* chunk_sample_calc */
+ PMD85_WAV_FREQUENCY, /* sample_frequency */
+ 0, /* header_samples */
+ 0 /* trailer_samples */
+};
+
+static casserr_t pmd85_cassette_identify(cassette_image *cassette, struct CassetteOptions *opts)
+{
+ return cassette_legacy_identify(cassette, opts, &pmd85_legacy_fill_wave);
+}
+
+static casserr_t pmd85_cassette_load(cassette_image *cassette)
+{
+ return cassette_legacy_construct(cassette, &pmd85_legacy_fill_wave);
+}
+
+static const struct CassetteFormat pmd85_cassette_image_format =
+{
+ "pmd,tap,ptp",
+ pmd85_cassette_identify,
+ pmd85_cassette_load,
+ NULL
+};
+
+CASSETTE_FORMATLIST_START(pmd85_cassette_formats)
+ CASSETTE_FORMAT(pmd85_cassette_image_format)
+CASSETTE_FORMATLIST_END