Use libsamplerate to convert samples not at the same rate as the plugin is running at

This adds a dependency on libsamplerate

Makefile

@@ -8,10 +8,10 @@ $(BUNDLE): manifest.ttl drmr.ttl drmr.so drmr_ui.so
 	cp manifest.ttl drmr.ttl drmr.so drmr_ui.so $(BUNDLE)
 
 drmr.so: drmr.c drmr_hydrogen.c
-	$(CC) -shared -fPIC -DPIC drmr.c drmr_hydrogen.c `pkg-config --cflags --libs lv2-plugin sndfile` -lexpat -lm -o drmr.so
+	$(CC) -shared -fPIC -DPIC drmr.c drmr_hydrogen.c `pkg-config --cflags --libs lv2-plugin sndfile samplerate` -lexpat -lm -o drmr.so
 
 drmr_ui.so: drmr_ui.c drmr_hydrogen.c
-	$(CC) -shared -fPIC -DPIC drmr_ui.c drmr_hydrogen.c `pkg-config --cflags --libs lv2-plugin gtk+-2.0 sndfile` -lexpat -lm -o drmr_ui.so
+	$(CC) -shared -fPIC -DPIC drmr_ui.c drmr_hydrogen.c `pkg-config --cflags --libs lv2-plugin gtk+-2.0 sndfile samplerate` -lexpat -lm -o drmr_ui.so
 
 install: $(BUNDLE)
 	mkdir -p $(INSTALL_DIR)

README.md

@@ -28,6 +28,7 @@ Compilation and Install
 You'll need the following libraries to build and install DrMr:
 
 - [libsndfile](http://www.mega-nerd.com/libsndfile/)
+- [libsamplerate](http://www.mega-nerd.com/SRC/index.html)
 - [lv2](http://lv2plug.in/)
 - [libexpat](http://expat.sourceforge.net)
 

drmr.c

@@ -52,6 +52,7 @@ instantiate(const LV2_Descriptor*     descriptor,
   DrMr* drmr = malloc(sizeof(DrMr));
   drmr->map = NULL;
   drmr->num_samples = 0;
+  drmr->rate = rate;
 
   if (pthread_mutex_init(&drmr->load_mutex, 0)) {
     fprintf(stderr, "Could not initialize load_mutex.\n");

drmr.h

@@ -147,6 +147,7 @@ typedef struct {
   float** gains;
   float** pans;
   float* kitReq;
+  double rate;
 
   // URIs
   LV2_URI_Map_Feature* map;

drmr_hydrogen.c

@@ -22,7 +22,9 @@
 #include <sys/types.h>
 #include <dirent.h>
 #include <errno.h>
+#include <math.h>
 
+#include "samplerate.h"
 #include "drmr.h"
 #include "drmr_hydrogen.h"
 #include "expat.h"
@@ -36,6 +38,8 @@ static char* default_drumkit_locations[] = {
   NULL
 };
 
+#define RATE_CONV_QUALITY SRC_SINC_MEDIUM_QUALITY
+
 #define MAX_CHAR_DATA 512
 
 struct instrument_layer {
@@ -339,9 +343,9 @@ void free_kits(kits* kits) {
   free(kits);
 }
 
-int load_sample(char* path, drmr_layer* layer) {
+int load_sample(char* path, drmr_layer* layer, double target_rate) {
   SNDFILE* sndf;
-  int size;
+  long size;
   
   //printf("Loading: %s\n",path);
 
@@ -360,6 +364,7 @@ int load_sample(char* path, drmr_layer* layer) {
     free(layer->info);
     return 1;
   }
+
   size = layer->info->frames * layer->info->channels;
   layer->limit = size;
   layer->data = malloc(size*sizeof(float));
@@ -371,6 +376,41 @@ int load_sample(char* path, drmr_layer* layer) {
 
   sf_read_float(sndf,layer->data,size);
   sf_close(sndf); 
+
+  // convert rate if needed
+  if (layer->info->samplerate != target_rate) {
+    SRC_DATA src_data;
+    int stat;
+    double ratio = (target_rate/layer->info->samplerate);
+    long out_frames = (long)ceil(layer->info->frames * ratio);
+    long out_size = out_frames*layer->info->channels;
+    float *data_out = malloc(sizeof(float)*out_size);
+
+    src_data.data_in = layer->data;
+    src_data.input_frames = layer->info->frames;
+    src_data.data_out = data_out;
+    src_data.output_frames = out_frames;
+    src_data.src_ratio = ratio;
+
+    stat = src_simple(&src_data,RATE_CONV_QUALITY,layer->info->channels);
+    if (stat) {
+      fprintf(stderr,"Failed to convert rate for %s: %s.  Using original rate\n",
+	      path,src_strerror(stat));
+      free(data_out);
+      return 0;
+    }
+
+    if (src_data.input_frames_used != layer->info->frames)
+      fprintf(stderr,"Didn't consume all input frames. used: %i  had: %i  gened: %i\n",
+	      src_data.input_frames_used, layer->info->frames,src_data.output_frames_gen);
+
+    free(layer->data);
+
+    layer->data = data_out;
+    layer->limit = src_data.output_frames_gen*layer->info->channels;
+    layer->info->samplerate = target_rate;
+    layer->info->frames = src_data.output_frames_gen;
+  }
   return 0;
 }
 
@@ -435,7 +475,7 @@ int load_hydrogen_kit(DrMr* drmr, char* path) {
 	layer->min = 0;
 	layer->max = 1;
 	snprintf(buf,BUFSIZ,"%s/%s",path,cur_i->filename);
-	if (load_sample(buf,layer)) {
+	if (load_sample(buf,layer,drmr->rate)) {
 	  fprintf(stderr,"Could not load sample: %s\n",buf);
 	  // set limit to zero, will never try and play
 	  layer->info = NULL;
@@ -463,7 +503,7 @@ int load_hydrogen_kit(DrMr* drmr, char* path) {
 	j = 0;
 	while(cur_l) {
 	  snprintf(buf,BUFSIZ,"%s/%s",path,cur_l->filename);
-	  if (load_sample(buf,samples[i].layers+j)) {
+	  if (load_sample(buf,samples[i].layers+j,drmr->rate)) {
 	    fprintf(stderr,"Could not load sample: %s\n",buf);
 	    // set limit to zero, will never try and play
 	    samples[i].layers[j].info = NULL;

drmr_hydrogen.h

@@ -20,7 +20,7 @@
 
 kits* scan_kits();
 void free_samples(drmr_sample* samples, int num_samples);
-int load_sample(char* path,drmr_layer* layer);
+int load_sample(char* path,drmr_layer* layer,double target_rate);
 int load_hydrogen_kit(DrMr* drmr, char* path);
 
 #endif // DRMR_HYDRO_H