diff options
Diffstat (limited to 'tutorials/sndkit/dsp/str/strplay.c')
| -rw-r--r-- | tutorials/sndkit/dsp/str/strplay.c | 575 |
1 files changed, 575 insertions, 0 deletions
diff --git a/tutorials/sndkit/dsp/str/strplay.c b/tutorials/sndkit/dsp/str/strplay.c new file mode 100644 index 0000000..82a3cda --- /dev/null +++ b/tutorials/sndkit/dsp/str/strplay.c @@ -0,0 +1,575 @@ +#include <stdio.h> +#include <unistd.h> +#include <stdlib.h> +#ifdef __STDC__ +#include <string.h> +#else /* __STDC__ */ +#include <strings.h> +#endif /* __STDC__ */ +#include <sys/types.h> + +#include <sys/soundcard.h> +#include "str.h" + +extern int audio; +extern unsigned char *audiobuf; +extern int abuf_ptr; +extern int abuf_size; + +extern char *command; +extern int quiet_mode, verbose_mode; +extern int mute[4]; +extern int dsp_stereo; +extern int dsp_samplesize; +extern long dsp_speed; + +extern FILE *fp; + +static int VSYNC; /* number of sample bytes to output in 1/50 sec */ + +static int notes, channel, vsync, bytes, pat_num; /* loop variables */ +static int note, pat; +static int end_pattern; + +/* song data and parameters */ +static int speed; +static char songlength, songrepeat, tune[128]; +static int nvoices; +static Voice voices[32]; +static char num_patterns; +static Pattern patterns[128]; +static Channel ch[4]; + +/* table for generating pitches */ +static int step_table[1024]; + +/* sine wave table for the vibrato effect */ +static int sin_table[] = { + 0x00, 0x18, 0x31, 0x4A, 0x61, 0x78, 0x8D, 0xA1, + 0xB4, 0xC5, 0xD4, 0xE0, 0xEB, 0xF4, 0xFA, 0xFD, + 0xFF, 0xFD, 0xFA, 0xF4, 0xEB, 0xE0, 0xD4, 0xC5, + 0xB4, 0xA1, 0x8D, 0x78, 0x61, 0x4A, 0x31, 0x18 +}; + +/* period table for notes C0-B2, used for arpeggio effect */ +static int periods[] = { + 0x358, 0x328, 0x2FA, 0x2D0, 0x2A6, 0x280, + 0x25C, 0x23A, 0x21A, 0x1FC, 0x1E0, 0x1C5, + 0x1AC, 0x194, 0x17D, 0x168, 0x153, 0x140, + 0x12E, 0x11D, 0x10D, 0x0FE, 0x0F0, 0x0E2, + 0x0D6, 0x0CA, 0x0BE, 0x0B4, 0x0AA, 0x0A0, + 0x097, 0x08F, 0x087, 0x07F, 0x078, 0x071 +}; + +/* skip n bytes of file f - stdin has no fseek */ +void +byteskip (f, n) + FILE *f; + int n; +{ + while (n--) + fgetc (f); +} + +/* get string of length <len> from file f */ +char * +getstring (f, len) + FILE *f; + int len; +{ + static char s[256]; + int i; + + for (i = 0; i < len; i++) + { + if ((s[i] = fgetc (f)) == '\1') + s[i] = '\0'; /* bug fix for some few modules */ + if (s[i] < 32 && s[i]) + { + fprintf (stderr, "This is not a string. Wrong format?\n"); + exit (EXIT_FAILURE); + } + } + s[len] = '\0'; + + return s; +} + +void +audioput (c) + int c; +{ + audiobuf[abuf_ptr++] = c; + if (abuf_ptr >= ABUF_SIZE) + { +#if 0 + int count; + + if (ioctl (audio, SNDCTL_DSP_GETODELAY, &count) == -1) + perror ("GETODELAY"); + printf ("%6d\n", count); +#endif + if (write (audio, audiobuf, abuf_ptr) == -1) + { + perror ("audio_write"); + exit (EXIT_FAILURE); + } + abuf_ptr = 0; + } +} + +void +audioput16 (c) + int c; +{ + audiobuf[abuf_ptr++] = c & 0xFF; + audiobuf[abuf_ptr++] = c >> 8; + if ((abuf_ptr + 1) >= ABUF_SIZE) + { + if (write (audio, audiobuf, abuf_ptr) == -1) + { + perror ("audio_write"); + exit (EXIT_FAILURE); + } + abuf_ptr = 0; + } +} + +void +play_song () +{ + int i; + + /* set up pitch table: + * 3576872 is the base clock frequency of the Amiga's Paula chip, + * the pitch i is the number of cycles between outputting two samples. + * => i / 3576872 is the delay between two bytes + * => our_freq * i / 3576872 is our delay. + * The 65536 are just there for accuracy of integer operations (<< 16). + */ + step_table[0] = 0; + for (i = 1; i < 1024; i++) + step_table[i] = (int) (((3575872.0 / dsp_speed) / i) * 65536.0); + + /* VSYNC is the number of bytes in 1/50 sec + * computed as freq * (1 / 50). + */ + VSYNC = (dsp_speed + 25) / 50; /* with round */ + + /* read song name */ + if (quiet_mode) + byteskip (fp, 20); + else + printf ("Module : %s\n\n", getstring (fp, 20)); + + /* determine number of voices from command name */ + nvoices = strstr (command, "15") == NULL ? 31 : 15; + + /* read in the sample information tables */ + voices[0].length = 0; + for (i = 1; i <= nvoices; i++) + { + /* sample name */ + if (quiet_mode) + byteskip (fp, 22); + else if (nvoices == 15) + printf ("%6d : %s\n", i, getstring (fp, 22)); + else + { + printf ("%6d : %22s", i, getstring (fp, 22)); + if (!(i & 1)) + printf ("\n"); + } + /* the sample length and repeat data are stored as numbers of words, + * we want the number of bytes << 16. + */ + voices[i].length = (fgetc (fp) << 25) | (fgetc (fp) << 17); + fgetc (fp); + if ((voices[i].volume = fgetc (fp)) > 64) + voices[i].volume = 64; + voices[i].rep_start = (fgetc (fp) << 25) | (fgetc (fp) << 17); + voices[i].rep_end = (fgetc (fp) << 25) | (fgetc (fp) << 17); + if (voices[i].rep_end <= 4 << 16) + voices[i].rep_end = 0; + else + { + voices[i].rep_end += voices[i].rep_start; + if (voices[i].rep_end > voices[i].length) + voices[i].rep_end = voices[i].length; + } + } + + /* read sequence data: length and repeat position */ + songlength = fgetc (fp); + songrepeat = fgetc (fp); + if (songrepeat > songlength) /* this is often buggy in modules */ + songrepeat = 0; + + /* read in the sequence and determine the number of patterns + * by looking for the highest pattern number. + */ + num_patterns = 0; + for (i = 0; i < 128; i++) + { + tune[i] = fgetc (fp); + if (tune[i] > num_patterns) + num_patterns = tune[i]; + } + num_patterns++; /* pattern numbers begin at 0 */ + + /* skip over sig in new modules (usually M.K.). + * note: this sig could be used for determining whether the module + * is of an old type (15 samples max) or new (up to 31 samples) + */ + if (nvoices == 31) + byteskip (fp, 4); + + /* read in the patterns. + * Each pattern consists of 64 lines, + * each containing data for the four voices. + */ + for (pat_num = 0; pat_num < num_patterns; pat_num++) + for (notes = 0; notes < 64; notes++) + for (channel = 0; channel < 4; channel++) + { + note = (fgetc (fp) << 8) | fgetc (fp); + patterns[pat_num].sample[notes][channel] = (note >> 8) & 0x10; + patterns[pat_num].period[notes][channel] = MIN (note & 0xFFF, 1023); + note = (fgetc (fp) << 8) | fgetc (fp); + patterns[pat_num].sample[notes][channel] |= note >> 12; + patterns[pat_num].effect[notes][channel] = (note >> 8) & 0xF; + patterns[pat_num].params[notes][channel] = note & 0xFF; + } + + /* store each sample as an array of char */ + for (i = 1; i <= nvoices; i++) + if (voices[i].length) + { + if ((voices[i].info = malloc (voices[i].length >> 16)) == NULL) + { + fprintf (stderr, "%s: can't allocate memory\n", command); + exit (EXIT_FAILURE); + } + fread (voices[i].info, 1, voices[i].length >> 16, fp); + if (voices[i].rep_end) + voices[i].length = voices[i].rep_end; + voices[i].rep_start -= voices[i].length; + } + + /* initialize global and channel replay data */ + speed = 6; + for (i = 0; i < 4; i++) + { + ch[i].pointer = 0; + ch[i].step = 0; + ch[i].volume = 0; + ch[i].pitch = 0; + } + + if (!quiet_mode) + if (verbose_mode) + printf ("\n"); + else + { + printf ("\nPosition (%d):", songlength); + fflush (stdout); + } + + + /*******************************/ + /* Here begins the replay part */ + /*******************************/ + + for (pat_num = 0; pat_num < songlength; pat_num++) + { + pat = tune[pat_num]; + + if (!quiet_mode) + if (verbose_mode) + printf (" --------------+--------------+--------------+-----" + "--------- %02X (%02X) = %02X\n", pat_num, + songlength, pat); + else + { + printf ("\r\t\t%3d", pat_num); + fflush (stdout); + } + + end_pattern = FALSE; + for (notes = 0; notes < 64; notes++) + { + int samp, pitch, cmd, para; + Channel *curch; + + if (!quiet_mode && verbose_mode) + printf ("%02X ", notes); + + curch = ch; + for (channel = 0; channel < 4; channel++, curch++) + { + samp = patterns[pat].sample[notes][channel]; + pitch = patterns[pat].period[notes][channel]; + cmd = patterns[pat].effect[notes][channel]; + para = patterns[pat].params[notes][channel]; + + if (verbose_mode && !quiet_mode) + if (pitch) + printf (" %03X %2X %X%02X%s", pitch, samp, cmd, para, + channel == 3 ? "\n" : " |"); + else + printf (" --- %2X %X%02X%s", samp, cmd, para, + channel == 3 ? "\n" : " |"); + + if (mute[channel]) + { + if (cmd == 0x0B || cmd == 0x0D || cmd == 0x0F) + switch (cmd) + { + case 0xB: /* Pattern jump */ + end_pattern = TRUE; + pat_num = (para & 0xF) + (10 * (para >> 4)); + break; + case 0xD: /* Pattern break */ + end_pattern = TRUE; + break; + case 0xF: /* Set speed */ + speed = para; + break; + } + continue; + } + + /* if a sample number is given, it is loaded and the note + * is restarted + */ + if (samp) + { + curch->samp = samp; + /* load new instrument */ + curch->volume = voices[samp].volume; + } + + if (samp || (pitch && cmd != 3)) + { + if (pitch) + curch->pitch = curch->arp[0] = pitch; + curch->pointer = 0; + curch->viboffs = 0; + } + + /* by default there is no effect */ + curch->doarp = FALSE; + curch->doslide = FALSE; + curch->doporta = FALSE; + curch->dovib = FALSE; + curch->doslidevol = FALSE; + + switch (cmd) + { /* Do effects */ + case 0: /* Arpeggio */ + if (para) + { + for (i = 0; i < 36 && periods[i] > curch->arp[0]; i++); + if (i + (para >> 4) < 36 && i + (para & 0xF) < 36) + { + curch->doarp = TRUE; + curch->arp[0] = periods[i]; + curch->arp[1] = periods[i + (para >> 4)]; + curch->arp[2] = periods[i + (para & 0xF)]; + } + } + break; + case 1: /* Portamento up */ + curch->doslide = TRUE; + if (para) + curch->slide = -para; + break; + case 2: /* Portamento down */ + curch->doslide = TRUE; + if (para) + curch->slide = para; + break; + case 3: /* Note portamento */ + curch->doporta = TRUE; + if (para) + curch->portarate = para; + if (pitch) + curch->pitchgoal = pitch; + break; + case 4: /* Vibrato */ + curch->dovib = TRUE; + if (para) + { + curch->vibspeed = (para >> 2) & 0x3C; + curch->vibamp = para & 0xF; + } + break; + case 0xA: /* Volume slide */ + curch->doslidevol = TRUE; + if (para) + { + if (!(para & 0xF0)) + curch->volslide = -para; + else + curch->volslide = (para >> 4); + } + break; + case 0xB: /* Pattern jump */ + end_pattern = TRUE; + pat_num = (para & 0xF) + (10 * (para >> 4)); + break; + case 0xC: /* Set volume */ + curch->volume = MIN (para, 64); + break; + case 0xD: /* Pattern break */ + end_pattern = TRUE; + break; + case 0xF: /* Set speed */ + speed = para; + break; + default: + /* printf(" [%d][%d] ", cmd, para); */ + break; + } + } + + { + register Channel *curch; + register Voice *curv; + + for (vsync = 0; vsync < speed; vsync++) + { + + ch[0].step = step_table[ch[0].pitch]; + ch[1].step = step_table[ch[1].pitch]; + ch[2].step = step_table[ch[2].pitch]; + ch[3].step = step_table[ch[3].pitch]; + + for (bytes = 0; bytes < VSYNC; bytes++) + { + int byte[2] = { 0, 0 }; + + curch = ch; + for (channel = 0; channel < 4; channel++, curch++) + { + if (!curch->samp || mute[channel]) + continue; + + curv = &voices[(int) curch->samp]; + + /* test for end of sample */ + if (curch->pointer >= curv->length) + if (!curv->rep_end) + continue; + else + curch->pointer += curv->rep_start; + + /* mix samples. + * the sample is read and multiplied by the volume + */ + if (curch->pointer < curv->length) + /* in stereo, channels 1 & 3 and 2 & 4 are mixed + * seperately + */ + byte[channel & dsp_stereo] += (int) + ((curv->info[curch->pointer >> 16]) * + ((int) curch->volume << 2)); + /* advance the sample pointer */ + curch->pointer += curch->step; + } + + /* output sample */ + if (dsp_samplesize == 8) + { + if (dsp_stereo) + { + byte[0] >>= 9; + audioput (byte[0] + 128); + byte[1] >>= 9; + audioput (byte[1] + 128); + } + else + audioput ((byte[0] >> 10) + 128); + } + else + { + if (dsp_stereo) + { + audioput16 (byte[0] >> 1); + audioput16 (byte[1] >> 1); + } + else + audioput16 (byte[0] >> 2); + } + } + + /* Do end of vsync */ + if (vsync == 0) + continue; + curch = ch; + for (channel = 0; channel < 4; channel++, curch++) + { + if (mute[channel]) + continue; + if (curch->doarp) + curch->pitch = curch->arp[vsync % 3]; + else if (curch->doslide) + { + curch->arp[0] += curch->slide; + curch->arp[0] = MIN (curch->arp[0], 1023); + curch->arp[0] = MAX (curch->arp[0], 113); + curch->pitch = curch->arp[0]; + } + else if (curch->doporta) + { + if (curch->arp[0] < curch->pitchgoal) + { + curch->arp[0] += curch->portarate; + if (curch->arp[0] > curch->pitchgoal) + curch->arp[0] = curch->pitchgoal; + } + else if (curch->arp[0] > curch->pitchgoal) + { + curch->arp[0] -= curch->portarate; + if (curch->arp[0] < curch->pitchgoal) + curch->arp[0] = curch->pitchgoal; + } + curch->pitch = curch->arp[0]; + } + else if (curch->dovib) + { + if (curch->viboffs & 0x80) + curch->pitch = curch->arp[0] - ((sin_table + [(curch-> + viboffs >> 2) & + 0x1F] * + curch-> + vibamp) >> 6); + else + curch->pitch = curch->arp[0] + ((sin_table + [(curch-> + viboffs >> 2) & + 0x1F] * + curch-> + vibamp) >> 6); + curch->viboffs += curch->vibspeed; + } + else if (curch->doslidevol) + { + curch->volume += curch->volslide; + if (curch->volume < 0) + curch->volume = 0; + else if (curch->volume >= 64) + curch->volume = 64; + } + } + } + } + if (end_pattern == 1) + break; + } + } + + if (!quiet_mode) + printf ("\n"); +} |