2023.03.15

VERSION

@@ -1,3 +1,2 @@
-February 08 2023
-
+March 15 2023
 

doc/drums.txt

@@ -0,0 +1,82 @@
+Advamced Percussion Analysis
+in the Midistats Program
+
+This is an addendum to the midistats.1 file.
+
+The MIDI file devotes channel 9 to the percussion instruments
+and over 60 percussion instruments are defined in the MIDI
+standard. Though there is a lot of diversity in the percussion
+track, for most MIDI files only the first 10 or so percussion
+instruments are important in defining the character of the track. The
+program Midiexplorer has various tools for exposing the percussion
+channel which are described in the documentation. The goal
+here is to find the essential characteristics of the percussion
+track which distinguishes the MIDI files. This is attempted
+in the program midistats.  Here is a short description.
+
+-corestats
+Produces a line with 3 numbers separated by tabs. eg
+384	8349	448
+It returns the number of divisions per quarter note beat (ppqn),
+the number of note onsets in the midi file, and the maximum
+number of quarter note beats in midi file.
+
+-pulseanalysis
+Counts the number of note onsets as a function of its onset time
+relative to a beat, grouping them into 12 intervals and returns
+the result as a discrete probability density function. Generally,
+the distribution consists of a couple of peaks corresponding
+to quarter notes or eigth notes. If the distribution is flat,
+it indicates that the times of the note occurrences have not been
+quantized into beats and fractions. Here is a sample output.
+0.3496,0.0000,0.0000,0.1602,0.0000,0.0002,0.2983,0.0000,0.0000,0.1914,0.0002,0.0001
+
+-panal
+Counts the number of note onsets for each percussion instrument. The first
+number is the code (pitch) of the instrument, the second number is the
+number of occurrences. eg.
+35 337	37 16	38 432	39 208	40 231	42 1088	46 384	49 42	54 1104	57 5	70 1040	85 16	
+
+-ppatfor n
+where n is the code number of the percussion instrument. Each beat
+is represented by a 4 bit number where the position of the on-bit
+indicates the time in the beat when the drum onset occurs. Thus
+0 indicates that there was no note onset in that beat, 1 indicates
+a note onset in the beginning of the beat, 4 indicates a note onset
+in the middle of the beat, and etc. The function returns a string
+of numbers ranging from 0 to 7 indicating the presence of note onsets
+for the selected percussion instrument for the sequence of beats
+in the midi file. Here is a truncated sample of the output.
+
+0 0 0 0 0 0 0 0 1 0 0 4 1 0 0 4 1 0 0 4 1 0 0 4 1 0 0 4 1 0 0 4 1 4 4 0
+1 0 0 0 1 0 5 0 1 0 5 0 1 0 5 0 1 0 5 0 1 0 5 0 1 0 5 0 1 0 5 0 1 0 0 0
+1 0 5 0 1 0 5 0 1 etc.
+
+One can see a repeating 4 beat pattern.
+
+-ppat
+midistats attempts to find two percussion instruments in the midi file
+which come closest to acting as the bass drum and snare drum.
+If it is unsuccessful, it returns a message of its failue. Otherwise,
+encodes the position of these drum onsets in a 8 bit byte for each
+quarter note beat in the midi file. The lower (right) 4 bits encode the
+bass drum and the higher (left) 4 bits encode the snare drum in the
+same manner as described above for -ppatfor.
+0 0 0 0 0 0 0 0 0 0 33 145 33 145 33 145 33 145 33 145 33 145 33 145 33 145
+33 145 33 145 33 145 33 145 33 145 33 145 33 145 33 145 33 145 33 145 33 145
+33 145 33 145 33 145 33 145 33 145 33 and etc.
+
+-ppathist
+computes and displays the histogram of the values that would appear
+when running the -ppat. eg.
+bass 35 337
+snare 38 432
+1 (0.1) 64  32 (2.0) 8  33 (2.1) 136  144 (9.0) 8  145 (9.1) 136 
+
+The bass percussion code, the number of onsets, and the snare
+percussion code and the number of onsets are given in the
+first two lines. In the next line the number of occurrences of
+each value in the -ppat listing is given. The number in parentheses
+splits the two 4-bit values with a period. Thus 33 = (2*16 + 1).
+
+

doc/midistats.1

@@ -80,6 +80,17 @@ all channels except the percussion channel.
 collisions. Midistats counts the bar rhythm patterns using a hashing
 function. Presently collisions are ignored so occasionally two
 distinct rhythm patterns are counted as one.
+.SH Advance Percussion Analysis Tools
+.PP
+A number of experimental tools for analyzing the percussion channel
+(track) were introduced into midistats and are accessible through
+the runtime arguments. When these tools are used in a script which
+runs through a collection of midi files, you can build a database
+of percussion descriptors. Some more details are given in the
+file drums.txt which comes with this documentation.
+
+
+
 .SH AUTHOR
 Seymour Shlien <fy733@ncf.ca>
 

midistats.c

@@ -18,7 +18,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  */
  
-#define VERSION "0.59 February 08 2023 midistats"
+#define VERSION "0.67 March 14 2023 midistats"
 
 #include <limits.h>
 /* Microsoft Visual C++ Version 6.0 or higher */
@@ -72,17 +72,39 @@ int trackno;
 int maintrack;
 int format; /* MIDI file type                                   */
 int debug;
+int pulseanalysis;
+int percanalysis;
+int percpattern;
+int percpatternfor;
+int percpatternhist;
+int corestats;
 int chordthreshold; /* number of maximum number of pulses separating note */
 int beatsPerBar = 4; /* 4/4 time */
 int divisionsPerBar;
 int unitDivision;
+int maximumPulse;
+int lastBeat;
 
 
+struct eventstruc {int onsetTime;
+                   unsigned char channel;
+		   unsigned char pitch;
+		   unsigned char velocity;
+                   ;} midievents[40000];
+
+int lastEvent = 0;
+
 
 int tempocount=0;  /* number of tempo indications in MIDI file */
 
 int stats = 0; /* flag - gather and print statistics            */
 
+int pulseanalysis = 0;
+int percanalysis = 0;
+int percpattern = 0;
+int percpatternfor = 0;
+int percpatternhist = 0;
+int corestats = 0;
 
 
 /* can cope with up to 64 track MIDI files */
@@ -93,6 +115,9 @@ int notechan[2048],notechanvol[2048]; /*for linking on and off midi
 int last_tick[17]; /* for getting last pulse number in MIDI file */
 int last_on_tick[17]; /* for detecting chords [SS] 2019-08-02 */
 
+int histogram[256];
+unsigned char drumpat[8000];
+int percnum;
 
 
 
@@ -130,7 +155,7 @@ struct trkstat {
  */
 
 int progcolor[17]; /* used by stats_program */
-int drumhistogram[82]; /* counts drum noteons */
+int drumhistogram[100]; /* counts drum noteons */
 int pitchhistogram[12]; /* pitch distribution for non drum notes */
 int channel2prog[17]; /* maps channel to program */
 int channel2nnotes[17]; /*maps channel to note count */
@@ -159,6 +184,8 @@ static int progmapper[] = {
 16, 16, 16, 16, 16, 16, 16, 16
 };
 
+int pulseCounter[480];
+int pulseDistribution[24];
 
 struct barPattern {
 	int activeBarNumber;
@@ -395,7 +422,7 @@ void stats_header (int format, int ntrks, int ldivision)
     channel2nnotes[i] = 0;
     chnactivity[i] = 0; /* [SS] 2018-02-02 */
     }
-  for (i=0;i<82;i++) drumhistogram[i] = 0;
+  for (i=0;i<100;i++) drumhistogram[i] = 0;
   for (i=0;i<12;i++) pitchhistogram[i] = 0; /* [SS] 2017-11-01 */
   for (i=0;i<12;i++) pitchclass_activity[i] = 0; /* [SS] 2018-02-02 */
   for (i=0;i<128;i++) progactivity[i] = 0; /* [SS] 2018-02-02 */
@@ -467,11 +494,11 @@ else
 printf("\n");
   
 printf("drums ");
-for (i=35;i<82;i++) {
+for (i=35;i<100;i++) {
   if (drumhistogram[i] > 0) printf("%d ",i);
   }
 printf("\ndrumhits ");
-for (i=35;i<82;i++) {
+for (i=35;i<100;i++) {
   if (drumhistogram[i] > 0) printf("%d ",drumhistogram[i]);
   }
 
@@ -640,7 +667,7 @@ int chan, pitch, vol;
 
 
  if (chan == 9) {
-   if (pitch < 0 || pitch > 81) 
+   if (pitch < 0 || pitch > 100) 
          printf("****illegal drum value %d\n",pitch);
    else  drumhistogram[pitch]++;
    }
@@ -776,7 +803,41 @@ int nn, dd, cc, bb;
   printf("timesig %d/%d %6.2f\n",nn,denom,beatnumber);
 } 
 
+void record_noteon(int chan,int pitch,int vol)
+{
+if (maximumPulse < Mf_currtime) maximumPulse = Mf_currtime;
+if (vol < 1) return; /* noteoff ? */
+midievents[lastEvent].onsetTime = Mf_currtime;
+midievents[lastEvent].channel = chan;
+midievents[lastEvent].pitch = pitch;
+midievents[lastEvent].velocity = vol;
+lastEvent++;
+if (lastEvent > 39999) {printf("ran out of space in midievents structure\n");
+	exit(1);
+        }
+}
 
+void record_noteoff(int chan,int pitch,int vol)
+{
+}
+void record_trackend()
+{
+}
+
+int int_compare_events(const void *a, const void *b) {
+   struct eventstruc *ia  = (struct eventstruc *)a;
+   struct eventstruc *ib  = (struct eventstruc *)b;
+   if (ib->onsetTime > ia->onsetTime)
+       return -1;
+   else if (ia ->onsetTime > ib->onsetTime)
+       return  1;
+   else return 0;
+   }
+
+void load_header (int format, int ntrks, int ldivision)
+{
+  division = ldivision;
+}
 
 
 void initfunc_for_stats()
@@ -806,6 +867,224 @@ void initfunc_for_stats()
 }
 
 
+void initfunc_for_loadNoteEvents()
+{
+    Mf_error = error;
+    Mf_header = load_header;
+    Mf_trackstart = no_op0;
+    Mf_trackend = record_trackend;
+    Mf_noteon = record_noteon;
+    Mf_noteoff = record_noteoff;
+    Mf_pressure = no_op3;
+    Mf_parameter = no_op3;
+    Mf_pitchbend = no_op3;
+    Mf_program = no_op0;
+    Mf_chanpressure = no_op3;
+    Mf_sysex = no_op2;
+    Mf_metamisc = no_op3;
+    Mf_seqnum = no_op1;
+    Mf_eot = no_op0;
+    Mf_timesig = no_op4;
+    Mf_smpte = no_op5;
+    Mf_tempo = no_op1;
+    Mf_keysig = no_op2;
+    Mf_seqspecific = no_op3;
+    Mf_text = no_op3;
+    Mf_arbitrary = no_op2;
+}
+
+void dumpMidievents (int from , int to)
+{
+int i;
+for (i = from; i < to; i++) {
+  printf("%5d %d %d %d\n",midievents[i].onsetTime, midievents[i].channel,
+		  midievents[i].pitch, midievents[i].velocity);
+  }
+}
+
+void load_finish()
+{
+qsort(midievents,lastEvent,sizeof(struct eventstruc),int_compare_events);
+/*dumpMidievents(0,50);*/
+}
+
+
+void pulseHistogram() {
+int i,j;
+int pulsePosition;
+int decimate;
+float fraction;
+int resolution = 12;
+for (i = 0; i< 480; i++) pulseCounter[i] = 0;
+for (i = 0; i < lastEvent; i++) {
+  pulsePosition = midievents[i].onsetTime % division;
+  pulseCounter[pulsePosition]++;
+  if (pulsePosition >= 480) {printf("pulsePosition = %d too large\n",pulsePosition);
+	     exit(1);
+             }
+  }
+for (i = 0; i < resolution; i++) pulseDistribution[i] = 0;
+  /*for (i = 0; i < 480; i++) printf(" %d",pulseCounter[i]);
+  printf("\n");
+  */
+decimate = division/resolution;
+for (i = 0; i < division; i++) {
+   j = i/decimate;
+   pulseDistribution[j] += pulseCounter[i];
+   }
+for (i = 0; i < resolution; i++)
+   {fraction = (float) pulseDistribution[i] / (float) lastEvent;
+    if (i == 0)
+      printf("%6.4f",fraction);
+    else
+      printf(",%6.4f",fraction);
+   }
+printf("\n");
+}
+
+void drumanalysis () {
+int i;
+int channel;
+int pitch;
+for (i=0;i<100;i++) drumhistogram[i] = 0;
+for (i = 0; i < lastEvent; i++) {
+  channel = midievents[i].channel;
+  if (channel != 9) continue;
+  pitch = midievents[i].pitch;
+  if (pitch < 0 || pitch > 100) {
+    printf("illegal percussion instrument %d\n",pitch);
+    exit(1);
+    }
+  drumhistogram[pitch]++;
+  }
+}
+
+void drumpattern (int perc) {
+int i;
+int channel;
+int pitch;
+int onset;
+int index;
+int quarter;
+int remainder;
+int part;
+quarter = division/4;
+for (i = 0; i<8000; i++) drumpat[i] = 0;
+for (i = 0; i <lastEvent; i++) {
+  channel = midievents[i].channel;
+  if (channel != 9) continue;
+  pitch = midievents[i].pitch;
+  if (pitch != perc) continue;
+  onset = midievents[i].onsetTime;
+  index = onset/division;
+  remainder = onset % division;
+  part = remainder/quarter;
+  if (index >= 8000) {printf("index too large in drumpattern\n");
+	              break;
+                      }
+  drumpat[index] = drumpat[index] |= 1 << part;
+  }
+}
+
+void dualDrumPattern (int perc1, int perc2) {
+int i;
+int channel;
+int pitch;
+int onset;
+int index;
+int quarter;
+int remainder;
+int part;
+quarter = division/4;
+for (i = 0; i<8000; i++) drumpat[i] = 0;
+for (i = 0; i <lastEvent; i++) {
+  channel = midievents[i].channel;
+  if (channel != 9) continue;
+  pitch = midievents[i].pitch;
+  if (pitch != perc1  && pitch != perc2) continue;
+  onset = midievents[i].onsetTime;
+  index = onset/division;
+  if (index >= 8000) {printf("index too large in drumpattern\n");
+	              break;
+                      }
+  remainder = onset % division;
+  part = remainder/quarter;
+  if (pitch == perc1) drumpat[index] = drumpat[index] |= 1 << part;
+  else drumpat[index] = drumpat[index] |= 16 * (1 << part);
+  }
+}
+
+void output_perc_pattern (int i) {
+int left,right;
+left = i/16;
+right = i % 16;
+printf(" (%d.%d)",left,right);
+}
+
+
+void drumPatternHistogram () {
+int i;
+for (i=0;i<256;i++) {
+ histogram[i] = 0;
+}
+for (i=0;i<lastBeat;i++) {
+  histogram[drumpat[i]]++;
+  }
+for (i=1;i<256;i++) {
+  if (histogram[i] > 0) {
+	  printf(" %d",i);
+	  output_perc_pattern(i);
+	  printf(" %d ", histogram[i]);
+         }
+    }
+  printf("\n");
+}
+
+
+void output_drumpat () {
+int i;
+for (i=0;i<lastBeat;i++) printf("%d ",drumpat[i]);
+/*for (i=0;i<lastBeat;i++) output_perc_pattern(drumpat[i]);*/
+printf("\n");
+}
+
+
+
+void percsummary () {
+int i;
+int bassindex,snareindex;
+int bassmax,snaremax;
+int bassdrum[] = {35,36,41,45};
+int snaredrum[] = {37,38,39,40};
+bassmax = 0;
+snaremax = 0;
+for (i=0;i<4;i++) {
+  if(drumhistogram[bassdrum[i]] > bassmax) {
+      bassindex = bassdrum[i];
+      bassmax = drumhistogram[bassindex];
+      }
+  if(drumhistogram[snaredrum[i]] > snaremax) {
+      snareindex = snaredrum[i];
+      snaremax = drumhistogram[snareindex];
+      }
+  }
+if (bassmax && snaremax) {
+	printf("bass %d %d\n",bassindex,bassmax);
+	printf("snare %d %d\n",snareindex,snaremax);
+   } else {
+        printf("missing bass or snare\n");
+	return;
+   }
+dualDrumPattern(bassindex,snareindex);
+}
+
+  
+void corestatsOutput() {
+printf("%d\t%d\t%d\n", division,lastEvent,lastBeat);
+}
+
+
+
 int readnum(num) 
 /* read a number from a string */
 /* used for processing command line */
@@ -910,8 +1189,45 @@ int argc;
   if ((arg != -1) && (arg <argc)) {
    debug = readnum(argv[arg]);
    }
+  arg = getarg("-pulseanalysis",argc,argv);
+  if (arg != -1) {
+	  pulseanalysis = 1;
+	  stats = 0;
+          }
 
+  arg = getarg("-corestats",argc,argv);
+  if (arg != -1) {
+	  corestats = 1;
+	  stats = 0;
+          }
 
+  arg = getarg("-panal",argc,argv);
+  if (arg != -1) {
+	  percanalysis = 1;
+	  stats = 0;
+          }
+
+  arg = getarg("-ppat",argc,argv);
+  if (arg != -1) {
+	  percpattern = 1;
+	  stats = 0;
+          }
+
+  arg = getarg("-ppatfor",argc,argv);
+  if (arg != -1) {
+	  percpatternfor = 1;
+	  stats = 0;
+	  if (arg != -1 && arg <argc) {
+		  percnum = readnum(argv[arg]);
+	          printf("percnum = %d\n",percnum);
+                  }
+          }
+
+  arg = getarg("-ppathist",argc,argv);
+  if (arg != -1) {
+	  percpatternhist = 1;
+	  stats = 0;
+          }
 
 
   arg = getarg("-o",argc,argv);
@@ -934,10 +1250,16 @@ int argc;
   else {
     printf("midistats version %s\n  usage :\n",VERSION);
     printf("midistats filename <options>\n");
+    printf("         -corestats\n");
+    printf("         -pulseanalysis\n");
+    printf("         -panal\n");
+    printf("         -ppat\n");
+    printf("         -ppatfor\n");
+    printf("         -ppathist\n");
     printf("         -ver version number\n");
     printf("         -d <number> debug parameter\n");
     printf(" The input filename is assumed to be any string not\n");
-    printf(" beginning with a - (hyphen). It may be placed anywhere.\n");
+    printf(" beginning with a - (hyphen).\n");
     exit(0);
   };
   return arg;
@@ -955,6 +1277,39 @@ mfread();
 stats_finish();
 }
 
+void loadEvents() {
+int i;
+initfunc_for_loadNoteEvents();
+Mf_getc = filegetc;
+maximumPulse = 0;
+mfread();
+lastBeat = maximumPulse/division;
+load_finish();
+if (pulseanalysis) pulseHistogram(); 
+if (percanalysis) {
+	drumanalysis();
+        for (i = 0; i< 100; i++) {
+          if (drumhistogram[i] > 0) printf("%d %d\t",i,drumhistogram[i]);
+        }
+        printf("\n");
+      }
+if (percpattern) {
+    drumanalysis();
+    percsummary();
+    output_drumpat();
+    }
+if (percpatternfor) {
+    drumpattern(percnum);
+    output_drumpat();
+    }
+if (percpatternhist) {
+    drumanalysis();
+    percsummary();
+    drumPatternHistogram();
+    }
+if (corestats) corestatsOutput();
+}
+
 
 
 int main(argc,argv)
@@ -966,5 +1321,7 @@ int argc;
 
   arg = process_command_line_arguments(argc,argv);
   if(stats == 1)  midistats(argc,argv);
+  if(pulseanalysis || corestats || percanalysis ||\
+    percpatternfor || percpattern || percpatternhist) loadEvents();
   return 0;
 }