Diff: WaveFileReader.h

Revision:

11:e48cb1e38995

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WaveFileReader.h	Tue Apr 14 03:46:33 2015 +0000
@@ -0,0 +1,132 @@
+/* Read the wavefile */
+
+typedef struct uFMT_STRUCT {
+  short comp_code;
+  short num_channels;
+  unsigned sample_rate;
+  unsigned avg_Bps;
+  short block_align;
+  short sig_bps;
+} FMT_STRUCT;
+
+class WaveFileReader {
+
+private:
+    FILE * wavefile;
+    bool isRepeat;
+    unsigned dataChunkSize;
+    long int startofdata;
+    void readHeader();
+    FMT_STRUCT wav_format;
+
+public:
+    WaveFileReader( FILE *, bool);
+    float readSamplePeriod();
+    size_t read(unsigned short *buf, size_t size);
+};
+
+WaveFileReader::WaveFileReader(FILE *wavefile, bool isRepeat){
+    this->wavefile = wavefile;
+    this->isRepeat = isRepeat;
+    readHeader();
+}
+
+float WaveFileReader::readSamplePeriod(){
+    return 1000000/(wav_format.sample_rate);
+}
+
+void WaveFileReader::readHeader(){
+    unsigned chunk_id, data, chunk_size;
+    fread(&chunk_id,4,1,wavefile);
+    fread(&chunk_size,4,1,wavefile);
+    
+    while (!feof(wavefile)){
+        switch (chunk_id) {
+            case 0x46464952:
+                fread(&data,4,1,wavefile);
+                break;
+            case 0x20746d66:
+                fread(&wav_format,sizeof(wav_format),1,wavefile); 
+                if (chunk_size > sizeof(wav_format))
+                    fseek(wavefile,chunk_size-sizeof(wav_format),SEEK_CUR);
+                break;
+            case 0x5453494c:
+                fseek(wavefile,chunk_size,SEEK_CUR);
+                break;
+            case 0x61746164:
+              startofdata = ftell(wavefile);
+              dataChunkSize = chunk_size;
+              fseek(wavefile,chunk_size,SEEK_CUR);
+              break;
+          default:
+            data=fseek(wavefile,chunk_size,SEEK_CUR);
+            break;
+        }
+        fread(&chunk_id,4,1,wavefile);
+        fread(&chunk_size,4,1,wavefile);
+    }
+    fseek(wavefile,startofdata,SEEK_SET);
+}
+
+size_t WaveFileReader::read(unsigned short *DAC_fifo, size_t size){
+    unsigned channel;
+    short unsigned dac_data;
+    long long slice_value;
+    char *slice_buf;
+    short *data_sptr;
+    unsigned char *data_bptr;
+    int *data_wptr;
+    
+    slice_buf=(char *)malloc(wav_format.block_align);
+    if (!slice_buf) {
+      printf("Unable to malloc slice buffer");
+      exit(1);
+    }
+
+    for (size_t i=0; i<size; i++){
+        fread(slice_buf,wav_format.block_align,1,wavefile);
+        if (feof(wavefile)) {
+            if(isRepeat){
+                fseek(wavefile,startofdata,SEEK_SET);
+                printf("Reached end of file, reapeat is on");
+            }else{  
+                printf("Reached end of file, reapeat is off");
+                return i;
+            }
+        }
+        data_sptr=(short *)slice_buf;     // 16 bit samples
+        data_bptr=(unsigned char *)slice_buf;     // 8 bit samples
+        data_wptr=(int *)slice_buf;     // 32 bit samples
+        slice_value=0;
+        for (channel=0;channel<wav_format.num_channels;channel++) {
+            switch (wav_format.sig_bps) {
+                case 16:
+                    slice_value+=data_sptr[channel];
+                    break;
+                case 32:
+                    slice_value+=data_wptr[channel];
+                    break;
+                case 8:
+                  slice_value+=data_bptr[channel];
+                  break;
+            }
+        }
+        slice_value/=wav_format.num_channels;
+        switch (wav_format.sig_bps) {
+            case 8:     
+                slice_value<<=8;
+                break;
+            case 16:
+                slice_value+=32768;
+                break;
+            case 32: 
+                slice_value>>=16;
+                slice_value+=32768;
+                break;
+        }
+        dac_data=(short unsigned)slice_value;
+        DAC_fifo[i]=dac_data;
+    }
+    free(slice_buf);
+    return size;
+}
\ No newline at end of file