Don't generate unnecessary "note off" commands

For the Playtune format, don't generate a "note off" if it is immediately
followed by a "note on" for the same tone generator without a delay between.
This change is ported from MIDITONES V1.14.

Also:
 - Rename variable "restart" to "gen_restart" to match MIDITONES.
 - Update miditones_scroll.c to V1.6 from MIDITONES.
 - Create Windows 64 bit and 32 bit executables for midi2tones
   and miditones_scroll using Mingw-w64, and include documentation on
   how they were compiled.

Author: MLXXXp

README.txt

@@ -157,9 +157,9 @@
 *  If the high-order bit of the byte is 1, then it is one of the following commands:
 *
 *    9t nn [vv]
-*           Start playing note nn on tone generator t.  Generators are numbered
-*           starting with 0. The note numbers are the MIDI numbers for the chromatic
-*           scale, with decimal 60 being Middle C, and decimal 69 being Middle A (440 Hz).
+*           Start playing note nn on tone generator t, replacing any previous note.  
+*           Generators are numbered starting with 0. The note numbers are the MIDI 
+*           numbers for the chromatic scale, with decimal 69 being Middle A (440 Hz).
 *           If the -v option was given, a second byte is added to indicate note volume.
 *
 *    8t     Stop playing the note on tone generator t.

WINDOWS_EXE.txt

@@ -0,0 +1,13 @@
+Windows executable files were created using Mingw-w64
+https://mingw-w64.org/
+
+The following commands were used to create 64 bit and 32 bit executables:
+
+x86_64-w64-mingw32-gcc -O2 -Wall -o midi2tones_64bit.exe midi2tones.c
+
+i686-w64-mingw32-gcc -O2 -Wall -o midi2tones_32bit.exe midi2tones.c
+
+x86_64-w64-mingw32-gcc -O2 -Wall -o miditones_scroll_64bit.exe miditones_scroll.c
+
+i686-w64-mingw32-gcc -O2 -Wall -o miditones_scroll_32bit.exe miditones_scroll.c
+

midi2tones.c

@@ -157,9 +157,9 @@
 *  If the high-order bit of the byte is 1, then it is one of the following commands:
 *
 *    9t nn [vv]
-*           Start playing note nn on tone generator t.  Generators are numbered
-*           starting with 0. The note numbers are the MIDI numbers for the chromatic
-*           scale, with decimal 60 being Middle C, and decimal 69 being Middle A (440 Hz).
+*           Start playing note nn on tone generator t, replacing any previous note.  
+*           Generators are numbered starting with 0. The note numbers are the MIDI 
+*           numbers for the chromatic scale, with decimal 69 being Middle A (440 Hz).
 *           If the -v option was given, a second byte is added to indicate note volume.
 *
 *    8t     Stop playing the note on tone generator t.
@@ -322,6 +322,9 @@
 *     -Add alternate frequency/duration pair output format and options to support it
 *     -Add -r option to terminate output with "restart" instead of "stop"
 *     -Allow hex and octal entry, in addition to decimal, for -cn option
+*     -Prevent unnecessary "note off" commands from being generated by delaying
+*      them until we see if a "note on" is generated before the next wait.
+*      Ported from MIDITONES V1.14
 */
 #define VERSION "1.0.0"
 
@@ -434,7 +437,7 @@ struct track_header {
 
 bool loggen, logparse, parseonly, strategy1, strategy2, binaryoutput, define_progmem,
    velocityoutput, instrumentoutput, percussion_ignore, percussion_translate, do_header,
-   alt_out, restart, freq_style_a, freq_style_b, option_n;
+   alt_out, gen_restart, freq_style_a, freq_style_b, option_n;
 FILE *infile, *outfile, *logfile;
 uint8_t *buffer, *hdrptr;
 unsigned long buflen;
@@ -459,6 +462,7 @@ int alt_out_channel;            /* alt out format: MIDI channel used */
 
 struct tonegen_status {         /* current status of a tone generator */
    bool playing;                /* is it playing? */
+   bool stopnote_pending;       /* do we need to stop this generator before the next wait? */
    int track;                   /* if so, which track is the note from? */
    int note;                    /* what note is playing? */
    int instrument;              /* what instrument? */
@@ -472,11 +476,11 @@ struct track_status {           /* current processing point of a MIDI track */
    uint8_t *trkend;             /* ptr past the end of the track */
    unsigned long time;          /* what time we're at in the score */
    unsigned long tempo;         /* the tempo last set, in usec per qnote */
-   unsigned int preferred_tonegen;      /* for strategy2, try to use this generator */
-   unsigned char cmd;           /* CMD_xxxx  next to do */
+   unsigned int preferred_tonegen; /* for strategy2, try to use this generator */
+   unsigned char cmd;           /* CMD_xxxx next to do */
    unsigned char note;          /* for which note */
    unsigned char chan;          /* from which channel it was */
-   unsigned char velocity;
+   unsigned char velocity;      /* the current volume */
    unsigned char last_event;    /* the last event, for MIDI's "running status" */
    bool tonegens[MAX_TONEGENS]; /* which tone generators our notes are playing on */
 } track[MAX_TRACKS] = {
@@ -719,7 +723,7 @@ does not start with a dash or a slash*/
                goto opterror;
             break;
          case 'R':
-            restart = true;
+            gen_restart = true;
             if (argv[i][2] != '\0')
                goto opterror;
             break;
@@ -1145,6 +1149,26 @@ void find_note (int tracknum) {
 }
 
 
+/*  generate "stop note" commands for any channels that have them pending */
+
+void gen_stopnotes(void) {
+   struct tonegen_status *tg;
+   for (int tgnum = 0; tgnum < num_tonegens; ++tgnum) {
+      tg = &tonegen[tgnum];
+      if (tg->stopnote_pending) {
+         if (binaryoutput) {
+            putc (CMD_STOPNOTE | tgnum, outfile);
+            outfile_bytecount += 1;
+         } else {
+            fprintf (outfile, " 0x%02X,", CMD_STOPNOTE | tgnum);
+            outfile_items (1);
+         }
+         tg->stopnote_pending = false;
+      }
+   }
+}
+
+
 /*********************  main  ****************************/
 
 int main (int argc, char *argv[]) {
@@ -1291,7 +1315,7 @@ int main (int argc, char *argv[]) {
          }
       } else if (do_header) {   // write the binary file header
          for (int i = 0; i < sizeof (file_header); ++i)
-            fputc (((unsigned char *) &file_header)[i], outfile);
+            putc (((unsigned char *) &file_header)[i], outfile);
          file_header_num_tgens_position = (char *) &file_header.num_tgens - (char *) &file_header;
          outfile_bytecount += sizeof (file_header);
       }
@@ -1371,6 +1395,8 @@ This is not unlike multiway merging used for tape sorting algoritms in the 50's!
 
          delta_time = earliest_time - timenow;
          if (delta_time) {
+            if (!alt_out)
+               gen_stopnotes(); /* first check if any tone generators have "stop note" commands pending */
             /* Convert ticks to milliseconds based on the current tempo */
             unsigned long long temp;
             temp = ((unsigned long long) delta_time * tempo) / ticks_per_beat;
@@ -1449,19 +1475,11 @@ This is not unlike multiway merging used for tape sorting algoritms in the 50's!
                            fprintf (logfile,
                                     "->Stop note %d, generator %d, track %d\n",
                                     tg->note, tgnum, tracknum);
-                        if (!alt_out) {
-                           if (binaryoutput) {
-                              putc (CMD_STOPNOTE | tgnum, outfile);
-                              outfile_bytecount += 1;
-                           } else {
-                              fprintf (outfile, " 0x%02X,", CMD_STOPNOTE | tgnum);
-                              outfile_items (1);
-                           }
-                        } else {
-                           pending_note = pending_velocity = 0;
-                        }
+                        tg->stopnote_pending = true;  /* must stop the current note if another doesn't start first */
                         tg->playing = false;
                         trk->tonegens[tgnum] = false;
+                        if (alt_out)
+                           pending_note = pending_velocity = 0;
                      }
                   }
                find_note (tracknum);    // use up the note
@@ -1507,6 +1525,7 @@ This is not unlike multiway merging used for tape sorting algoritms in the 50's!
                   tg->playing = true;
                   tg->track = tracknum;
                   tg->note = trk->note;
+                  tg->stopnote_pending = false;
                   trk->tonegens[tgnum] = true;
                   trk->preferred_tonegen = tgnum;
                   ++note_on_commands;
@@ -1580,25 +1599,28 @@ This is not unlike multiway merging used for tape sorting algoritms in the 50's!
       }                         /* !parseonly do */
       while (tracks_done < num_tracks);
 
+      if (!alt_out)
+         gen_stopnotes(); /* flush out any pending "stop note" commands */
+
       // generate the end-of-score command and some commentary
       if (binaryoutput) {
          if (!alt_out) {
-            putc (restart ? CMD_RESTART : CMD_STOP, outfile);
+            putc (gen_restart ? CMD_RESTART : CMD_STOP, outfile);
             outfile_bytecount++;
          } else {
-            output_word (restart ? TONES_REPEAT : TONES_END);
+            output_word (gen_restart ? TONES_REPEAT : TONES_END);
          }
       } else {
          if (outfile_itemcount != 0)
             putc ('\n', outfile);
          if (!alt_out) {
-            fprintf (outfile, " 0x%02x", restart ? CMD_RESTART : CMD_STOP);
+            fprintf (outfile, " 0x%02x", gen_restart ? CMD_RESTART : CMD_STOP);
             outfile_bytecount++;
          } else {
             if (freq_style_b)
-               fprintf (outfile, " 0x%04x", restart ? TONES_REPEAT : TONES_END);
+               fprintf (outfile, " 0x%04x", gen_restart ? TONES_REPEAT : TONES_END);
             else
-               fprintf (outfile, " %s", restart ? "TONES_REPEAT" : "TONES_END");
+               fprintf (outfile, " %s", gen_restart ? "TONES_REPEAT" : "TONES_END");
             outfile_bytecount += 2;
          }
          fprintf (outfile, "\n};\n// This score contains %ld bytes", outfile_bytecount);

midi2tones_32bit.exe

@@ -104,9 +104,11 @@
 * 6 August 2016, L. Shustek, V1.5
 *     - Handle optional instrument change information.
 *     - Look for the optional self-describing file header.
+* 30 September 2016, L. Shustek, V1.6
+*     - Count the number of unnecessary "stop note" commands in the bytestream
 */
 
-#define VERSION "1.5"
+#define VERSION "1.6"
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -126,13 +128,15 @@ int gen_note[MAX_TONEGENS];     // the note we're playing, or SILENT
 int gen_volume[MAX_TONEGENS];   // the volume we're playing
 int gen_instrument[MAX_TONEGENS];       // the instrument we're playing
 bool gen_instrument_changed[MAX_TONEGENS];
+bool gen_did_stopnote[MAX_TONEGENS]; // did we just do a stopnote?
 
 FILE *infile, *outfile;
 unsigned char *buffer, *bufptr;
 unsigned long buflen;
 unsigned int num_tonegens = 6;  // default number of generators
 unsigned int max_tonegen_found = 0;
-unsigned int notes_skipped;
+unsigned int notes_skipped = 0;
+unsigned int stopnotes_before_startnote = 0;
 
 unsigned long timenow = 0;
 unsigned char cmd, gen;
@@ -512,6 +516,8 @@ int main (int argc, char *argv[]) {
          delay = ((unsigned int) cmd << 8) + *++bufptr;
          print_status ();       // tone generator status now
          timenow += delay;      // advance time
+         for (gen = 0; gen < MAX_TONEGENS; ++gen)
+             gen_did_stopnote[gen] = false;
       } else if (cmd != 0xf0) { /* a command */
          gen = cmd & 0x0f;
          if (gen > max_tonegen_found)
@@ -520,6 +526,10 @@ int main (int argc, char *argv[]) {
          if (cmd == 0x90) {     /*  note on  */
             gen_note[gen] = *++bufptr;  // note number
             tonegens_used |= 1 << gen;  // record that we used this generator at least once
+            if (gen_did_stopnote[gen]) {
+                ++stopnotes_before_startnote;
+                // printf("unnecessary stopnote on gen %d\n", gen);
+            }
             if (expect_volume)
                gen_volume[gen] = *++bufptr;     // volume
             if (gen >= num_tonegens)
@@ -528,6 +538,7 @@ int main (int argc, char *argv[]) {
             if (gen_note[gen] == SILENT)
                file_error ("tone generator not on", bufptr);
             gen_note[gen] = SILENT;
+            gen_did_stopnote[gen] = true;
          } else if (cmd == 0xc0) {      /* change instrument */
             gen_instrument[gen] = *++bufptr & 0x7f;
             gen_instrument_changed[gen] = true;
@@ -555,5 +566,6 @@ int main (int argc, char *argv[]) {
    if (notes_skipped)
       printf ("%u notes were not displayed because we were told to show only %u generators.\n",
               notes_skipped, num_tonegens);
+   printf("%u stopnote commands were unnecessary.\n", stopnotes_before_startnote);
    printf ("Done.\n");
 }