Revision 0:286582877314, committed 2016-03-16

Comitter:

ebradley6

Date:

Wed Mar 16 03:28:44 2016 +0000

Child:

1:11a670498598

Commit message:

Wave player using MODDMA library

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MODDMA.lib	Wed Mar 16 03:28:44 2016 +0000
@@ -0,0 +1,1 @@
+http://developer.mbed.org/users/AjK/code/MODDMA/#97a16bf2ff43

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wave_player.cpp	Wed Mar 16 03:28:44 2016 +0000
@@ -0,0 +1,346 @@
+//-----------------------------------------------------------------------------
+// a sample mbed library to play back wave files using MODDMA 
+// Based on the wave_player library by Steve Ravet and the 
+// MODDMA library by Andy Kirkham. 
+// 
+// The wave_player library is located here:
+// https://developer.mbed.org/users/sravet/code/wave_player/
+// 
+// The MODDMA library is located here:
+// https://developer.mbed.org/users/AjK/code/MODDMA/
+// A wiki page and example are located here:
+// https://developer.mbed.org/cookbook/MODDMA
+//
+// explanation of wave file format.
+// https://ccrma.stanford.edu/courses/422/projects/WaveFormat/
+
+// if VERBOSE is uncommented then the wave player will enter a verbose
+// mode that displays all data values as it reads them from the file
+// and writes them to the DAC.  Very slow and unusable output on the DAC,
+// but useful for debugging wave files that don't work.
+//#define VERBOSE
+
+
+#include <mbed.h>
+#include <stdio.h>
+#include <wave_player.h>
+
+//-----------------------------------------------------------------------------
+// constructor -- accepts an mbed pin to use for AnalogOut.  Only p18 will work
+wave_player::wave_player(AnalogOut *_dac)
+{
+  wave_DAC=_dac;
+  wave_DAC->write_u16(32768);        //DAC is 0-3.3V, so idles at ~1.6V
+  verbosity=0;
+}
+
+//-----------------------------------------------------------------------------
+// if verbosity is set then wave player enters a mode where the wave file
+// is decoded and displayed to the screen, including sample values put into
+// the DAC FIFO, and values read out of the DAC FIFO by the ISR.  The DAC output
+// itself is so slow as to be unusable, but this might be handy for debugging
+// wave files that don't play
+//-----------------------------------------------------------------------------
+void wave_player::set_verbosity(int v)
+{
+  verbosity=v;
+}
+
+//-----------------------------------------------------------------------------
+// player function.  Takes a pointer to an opened wave file.  The file needs
+// to be stored in a filesystem with enough bandwidth to feed the wave data.
+// LocalFileSystem isn't, but the SDcard is, at least for 22kHz files.  The
+// SDcard filesystem can be hotrodded by increasing the SPI frequency it uses
+// internally.
+//-----------------------------------------------------------------------------
+void wave_player::play(FILE *wavefile)
+{
+    unsigned chunk_id,chunk_size,channel;
+    unsigned data,i;
+    unsigned j,k;
+    int dac_cntval;
+    bool buf0_flag;
+    long long slice_value;
+    char *slice_buf;
+    short *data_sptr;
+    unsigned char *data_bptr;
+    int *data_wptr;
+    FMT_STRUCT wav_format;
+    long num_slices;
+  
+    for(i=0; i<BUF_SIZE; i++){
+        DAC_buf0[i]=0;
+        DAC_buf1[i]=0;
+    }   
+  
+    DAC_on=0;
+  
+    int time=0;
+
+    fread(&chunk_id,4,1,wavefile);
+    fread(&chunk_size,4,1,wavefile);
+  
+    while (!feof(wavefile)) {
+        if (verbosity)
+            printf("Read chunk ID 0x%x, size 0x%x\n",chunk_id,chunk_size);
+        switch (chunk_id) {
+            case 0x46464952:
+                fread(&data,4,1,wavefile);
+                if (verbosity) {
+                    printf("RIFF chunk\n");
+                    printf("  chunk size %d (0x%x)\n",chunk_size,chunk_size);
+                    printf("  RIFF type 0x%x\n",data);
+                }
+                break;
+            case 0x20746d66:
+                fread(&wav_format,sizeof(wav_format),1,wavefile);
+                if (verbosity) {
+                    printf("FORMAT chunk\n");
+                    printf("  chunk size %d (0x%x)\n",chunk_size,chunk_size);
+                    printf("  compression code %d\n",wav_format.comp_code);
+                    printf("  %d channels\n",wav_format.num_channels);
+                    printf("  %d samples/sec\n",wav_format.sample_rate);
+                    printf("  %d bytes/sec\n",wav_format.avg_Bps);
+                    printf("  block align %d\n",wav_format.block_align);
+                    printf("  %d bits per sample\n",wav_format.sig_bps);
+                }
+                if (chunk_size > sizeof(wav_format))
+                    fseek(wavefile,chunk_size-sizeof(wav_format),SEEK_CUR);
+                break;
+            case 0x61746164:
+                // allocate a buffer big enough to hold a slice
+                slice_buf=(char *)malloc(wav_format.block_align);
+                if (!slice_buf) {
+                    printf("Unable to malloc slice buffer");
+                    exit(1);
+                }
+                num_slices=chunk_size/wav_format.block_align;
+        
+                // Calculating the transfer frequency:
+                // By default, the Mbed library sets the PCLK_DAC clock value
+                // to 24MHz. 
+        
+                dac_cntval=(24000000/wav_format.sample_rate);
+       
+                if (verbosity) {
+                    printf("DATA chunk\n\r");
+                    printf("  chunk size %d (0x%x)\n\r",chunk_size,chunk_size);
+                    printf("  %d slices\n\r",num_slices);
+                    printf("  sample rate is %d\r\n", wav_format.sample_rate);
+                    printf("  Ideal sample interval=%d\n\r",(unsigned)(1000000.0/wav_format.sample_rate));
+                    printf("  programmed interrupt tick interval=%d\n\r",dac_cntval);
+                }
+  
+                // Prepare the GPDMA system for buffer0.
+                conf0 = new MODDMA_Config;
+                conf0
+                ->channelNum    ( MODDMA::Channel_0 )
+                ->srcMemAddr    ( (uint32_t) &DAC_buf0 )
+                ->dstMemAddr    ( MODDMA::DAC )
+                ->transferSize  ( BUF_SIZE )
+                ->transferType  ( MODDMA::m2p )
+                ->dstConn       ( MODDMA::DAC )
+                ->attach_tc     ( this,&wave_player::TC0_callback )
+                ->attach_err    ( this,&wave_player::ERR0_callback )     
+                ; // config end
+    
+                // Prepare the GPDMA system for buffer1.
+                conf1 = new MODDMA_Config;
+                conf1
+                ->channelNum    ( MODDMA::Channel_1 )
+                ->srcMemAddr    ( (uint32_t) &DAC_buf1 )
+                ->dstMemAddr    ( MODDMA::DAC )
+                ->transferSize  ( BUF_SIZE )
+                ->transferType  ( MODDMA::m2p )
+                ->dstConn       ( MODDMA::DAC )
+                ->attach_tc     ( this,&wave_player::TC1_callback )
+                ->attach_err    ( this,&wave_player::ERR1_callback )     
+                ; // config end
+    
+                LPC_DAC->DACCNTVAL = dac_cntval;
+    
+                // Begin (enable DMA and counter). Note, don't enable
+                // DBLBUF_ENA as we are using DMA double buffering.
+                LPC_DAC->DACCTRL |= (3UL << 2);
+  
+                DAC_on=1; 
+
+                // start reading slices, which contain one sample each for however many channels
+                // are in the wave file.  one channel=mono, two channels=stereo, etc.  Since
+                // mbed only has a single AnalogOut, all of the channels present are averaged
+                // to produce a single sample value.  This summing and averaging happens in
+                // a variable of type signed long long, to make sure that the data doesn't
+                // overflow regardless of sample size (8 bits, 16 bits, 32 bits).
+                //
+                // note that from what I can find that 8 bit wave files use unsigned data,
+                // while 16 and 32 bit wave files use signed data
+                //
+                
+                buf0_flag=1;
+        
+                // Separate slices into sections of BUF_SIZE samples        
+                for (j=0; j<((num_slices/BUF_SIZE)+1); j++)
+                {
+                    for(k=0; k<BUF_SIZE; k++)
+                    {
+                        // The last buffer will likely not be exactly BUF_SIZE,
+                        // so fill the remaining spots with 0
+                        if((j*BUF_SIZE+k)>num_slices){
+                            if(buf0_flag)
+                                DAC_buf0[k]=0;
+                            else
+                                DAC_buf1[k]=0;
+                        }
+                        else{
+                            fread(slice_buf,wav_format.block_align,1,wavefile);
+                            if (feof(wavefile)) {
+                                printf("Oops -- not enough slices in the wave file\n");
+                                exit(1);
+                            }
+                            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:
+                                        if (verbosity)
+                                            printf("16 bit channel %d data=%d ",channel,data_sptr[channel]);
+                                        slice_value+=data_sptr[channel];
+                                        break;
+                                    case 32:
+                                        if (verbosity)
+                                            printf("32 bit channel %d data=%d ",channel,data_wptr[channel]);
+                                        slice_value+=data_wptr[channel];
+                                        break;
+                                    case 8:
+                                        if (verbosity)
+                                            printf("8 bit channel %d data=%d ",channel,(int)data_bptr[channel]);
+                                        slice_value+=data_bptr[channel];
+                                        break;
+                                }
+                            }
+                            slice_value/=wav_format.num_channels;
+              
+                            // slice_value is now averaged.  Next it needs to be scaled to an unsigned 16 bit value
+                            // with DC offset so it can be written to the DAC.
+                            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;
+                            }
+
+                            if (verbosity)
+                                printf("sample %d slice_value %d\n",(j*BUF_SIZE+k),(int)slice_value);
+                            if(buf0_flag)
+                                DAC_buf0[k]=(uint32_t)slice_value;
+                            else
+                                DAC_buf1[k]=(uint32_t)slice_value;
+                        }
+                    }
+          
+                    // Except for the first buffer, wait until the previous DMA transfer is
+                    // complete before switching buffers
+                    if(j>0)
+                    {
+                        while((dma0_fin_flag==0)&(dma1_fin_flag==0)&(time<500000000)){
+                            wait_us(1);
+                            time++;
+                        }
+                    }
+                    
+                    if (time>499999999)
+                    {
+                        printf("timeout, %d of %d\r\n", (j*BUF_SIZE), num_slices);
+                        exit(1);
+                    }
+            
+                    time=0;
+                    dma0_fin_flag=0;
+                    dma1_fin_flag=0; 
+          
+                    // If finished filling buffer 0, set flag to fill buffer 1
+                    // and start the DMA transfer for buffer 0
+                    if(buf0_flag==1)
+                    {
+                        buf0_flag=0;
+                        dma.Setup(conf0);
+                        dma.Enable( conf0 );
+                    }
+                    else // Similarly for buffer 1
+                    {
+                        buf0_flag=1;
+                        dma.Setup(conf1);
+                        dma.Enable( conf1 );
+                    }
+
+                }
+                DAC_on=0;
+                delete conf0;
+                delete conf1;
+                free(slice_buf);
+                break;
+            case 0x5453494c:
+                if (verbosity)
+                    printf("INFO chunk, size %d\n",chunk_size);
+                fseek(wavefile,chunk_size,SEEK_CUR);
+                break;
+            default:
+                printf("unknown chunk type 0x%x, size %d\n",chunk_id,chunk_size);
+                data=fseek(wavefile,chunk_size,SEEK_CUR);
+                break;
+        }
+        fread(&chunk_id,4,1,wavefile);
+        fread(&chunk_size,4,1,wavefile);
+    }
+}
+
+// Configuration callback on TC
+void wave_player::TC0_callback(void) {
+        
+    // Get configuration pointer.
+    MODDMA_Config *config = dma.getConfig();
+    
+    dma.haltAndWaitChannelComplete( (MODDMA::CHANNELS)config->channelNum());
+    
+    // Finish the DMA cycle by shutting down the channel.
+    dma.Disable( (MODDMA::CHANNELS)config->channelNum() );
+
+    // Clear DMA IRQ flags.
+    if (dma.irqType() == MODDMA::TcIrq) dma.clearTcIrq();
+    
+    // Indicate that buffer 0 has finished transferring
+    dma0_fin_flag=1; 
+}
+
+// Configuration callback on Error
+void wave_player::ERR0_callback(void) {
+    error("Oh no! My Mbed EXPLODED! :( Only kidding, go find the problem");
+}
+
+// Configuration callback on TC
+void wave_player::TC1_callback(void) {
+        
+    // Get configuration pointer.
+    MODDMA_Config *config = dma.getConfig();
+    
+    dma.haltAndWaitChannelComplete( (MODDMA::CHANNELS)config->channelNum());
+    
+    // Finish the DMA cycle by shutting down the channel.
+    dma.Disable( (MODDMA::CHANNELS)config->channelNum() );
+    
+    // Clear DMA IRQ flags.
+    if (dma.irqType() == MODDMA::TcIrq) dma.clearTcIrq(); 
+    
+    // Indicate that buffer 1 has finished transferring
+    dma1_fin_flag=1;
+}
+
+// Configuration callback on Error
+void wave_player::ERR1_callback(void) {
+    error("Oh no! My Mbed EXPLODED! :( Only kidding, go find the problem");
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wave_player.h	Wed Mar 16 03:28:44 2016 +0000
@@ -0,0 +1,81 @@
+#include <mbed.h>
+#include "MODDMA.h"
+
+#define BUF_SIZE 1000
+
+typedef struct uFMT_STRUCT {
+  short comp_code;
+  short num_channels;
+  unsigned sample_rate;
+  unsigned avg_Bps;
+  short block_align;
+  short sig_bps;
+} FMT_STRUCT;
+
+
+/** wave file player class.
+ *
+ * Example:
+ * @code
+ * #include <mbed.h>
+ * #include <wave_player.h>
+ *
+ * AnalogOut DACout(p18);
+ * wave_player waver(&DACout);
+ *
+ * int main() {
+ *  FILE *wave_file;
+ *  
+ *  printf("\n\n\nHello, wave world!\n");
+ *  wave_file=fopen("/sd/44_8_st.wav","r");
+ *  waver.play(wave_file);
+ *  fclose(wave_file); 
+ * }
+ * @endcode
+ */
+class wave_player {
+
+public:
+/** Create a wave player using a pointer to the given AnalogOut object.
+ *
+ * @param _dac pointer to an AnalogOut object to which the samples are sent.
+ */
+wave_player(AnalogOut *_dac);
+
+/** the player function.
+ *
+ * @param wavefile  A pointer to an opened wave file
+ */
+void play(FILE *wavefile);
+
+/** Set the printf verbosity of the wave player.  A nonzero verbosity level
+ * will put wave_player in a mode where the complete contents of the wave
+ * file are echoed to the screen, including header values, and including
+ * all of the sample values placed into the DAC FIFO, and the sample values
+ * removed from the DAC FIFO by the ISR.  The sample output frequency is
+ * fixed at 2 Hz in this mode, so it's all very slow and the DAC output isn't
+ * very useful, but it lets you see what's going on and may help for debugging
+ * wave files that don't play correctly.
+ *
+ * @param v the verbosity level
+ */
+void set_verbosity(int v);
+
+private:
+int verbosity;
+AnalogOut *wave_DAC;
+MODDMA dma;
+MODDMA_Config *conf0;
+MODDMA_Config *conf1;
+short DAC_on;
+uint32_t DAC_buf0[BUF_SIZE];
+uint32_t DAC_buf1[BUF_SIZE];
+void TC0_callback(void);
+void ERR0_callback(void);
+void TC1_callback(void);
+void ERR1_callback(void);
+bool dma0_fin_flag;
+bool dma1_fin_flag;
+};
+
+