YongChing Tee / wave_player

forked

Dependents:   Lab3 4180_FDP_Test2

Fork of wave_player by Steve Ravet

wave_player.cpp@2:73343f43feb1, 2013-03-06 (annotated)

Committer:
YongChingTee
Date:
Wed Mar 06 00:19:08 2013 +0000
Revision:
2:73343f43feb1
Parent:
0:62c18ade9a60 
first commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
YongChingTee 2:73343f43feb1 1 //-----------------------------------------------------------------------------
YongChingTee 2:73343f43feb1 2 // a sample mbed library to play back wave files.
YongChingTee 2:73343f43feb1 3 //
YongChingTee 2:73343f43feb1 4 // explanation of wave file format.
YongChingTee 2:73343f43feb1 5 // https://ccrma.stanford.edu/courses/422/projects/WaveFormat/
YongChingTee 2:73343f43feb1 6
YongChingTee 2:73343f43feb1 7 // if VERBOSE is uncommented then the wave player will enter a verbose
YongChingTee 2:73343f43feb1 8 // mode that displays all data values as it reads them from the file
YongChingTee 2:73343f43feb1 9 // and writes them to the DAC. Very slow and unusable output on the DAC,
YongChingTee 2:73343f43feb1 10 // but useful for debugging wave files that don't work.
YongChingTee 2:73343f43feb1 11 //#define VERBOSE
YongChingTee 2:73343f43feb1 12
YongChingTee 2:73343f43feb1 13
YongChingTee 2:73343f43feb1 14 #include <mbed.h>
YongChingTee 2:73343f43feb1 15 #include <stdio.h>
YongChingTee 2:73343f43feb1 16 #include <wave_player.h>
YongChingTee 2:73343f43feb1 17 #include "TextLCD.h"
YongChingTee 2:73343f43feb1 18
YongChingTee 2:73343f43feb1 19 Serial pc(USBTX, USBRX);
YongChingTee 2:73343f43feb1 20 DigitalIn pb_pause(p30);
YongChingTee 2:73343f43feb1 21 DigitalIn pb_stop(p29);
YongChingTee 2:73343f43feb1 22 DigitalIn pb_play(p28);
YongChingTee 2:73343f43feb1 23 TextLCD lcd_player(p5, p6, p7, p8, p19, p20, TextLCD::LCD20x4);
YongChingTee 2:73343f43feb1 24 AnalogIn position_player(p17); //slider
YongChingTee 2:73343f43feb1 25 //-----------------------------------------------------------------------------
YongChingTee 2:73343f43feb1 26 // constructor -- accepts an mbed pin to use for AnalogOut. Only p18 will work
YongChingTee 2:73343f43feb1 27 wave_player::wave_player(AnalogOut *_dac)
YongChingTee 2:73343f43feb1 28 {
YongChingTee 2:73343f43feb1 29 wave_DAC=_dac;
YongChingTee 2:73343f43feb1 30 wave_DAC->write_u16(32768); //DAC is 0-3.3V, so idles at ~1.6V
YongChingTee 2:73343f43feb1 31 verbosity=0;
YongChingTee 2:73343f43feb1 32 }
YongChingTee 2:73343f43feb1 33
YongChingTee 2:73343f43feb1 34 //-----------------------------------------------------------------------------
YongChingTee 2:73343f43feb1 35 // if verbosity is set then wave player enters a mode where the wave file
YongChingTee 2:73343f43feb1 36 // is decoded and displayed to the screen, including sample values put into
YongChingTee 2:73343f43feb1 37 // the DAC FIFO, and values read out of the DAC FIFO by the ISR. The DAC output
YongChingTee 2:73343f43feb1 38 // itself is so slow as to be unusable, but this might be handy for debugging
YongChingTee 2:73343f43feb1 39 // wave files that don't play
YongChingTee 2:73343f43feb1 40 //-----------------------------------------------------------------------------
YongChingTee 2:73343f43feb1 41 void wave_player::set_verbosity(int v)
YongChingTee 2:73343f43feb1 42 {
YongChingTee 2:73343f43feb1 43 verbosity=v;
YongChingTee 2:73343f43feb1 44 }
YongChingTee 2:73343f43feb1 45
YongChingTee 2:73343f43feb1 46 //-----------------------------------------------------------------------------
YongChingTee 2:73343f43feb1 47 // player function. Takes a pointer to an opened wave file. The file needs
YongChingTee 2:73343f43feb1 48 // to be stored in a filesystem with enough bandwidth to feed the wave data.
YongChingTee 2:73343f43feb1 49 // LocalFileSystem isn't, but the SDcard is, at least for 22kHz files. The
YongChingTee 2:73343f43feb1 50 // SDcard filesystem can be hotrodded by increasing the SPI frequency it uses
YongChingTee 2:73343f43feb1 51 // internally.
YongChingTee 2:73343f43feb1 52 //-----------------------------------------------------------------------------
YongChingTee 2:73343f43feb1 53 void wave_player::play(FILE *wavefile)
YongChingTee 2:73343f43feb1 54 {
YongChingTee 2:73343f43feb1 55 unsigned chunk_id,chunk_size,channel;
YongChingTee 2:73343f43feb1 56 unsigned data,samp_int,i;
YongChingTee 2:73343f43feb1 57 short unsigned dac_data;
YongChingTee 2:73343f43feb1 58 long long slice_value;
YongChingTee 2:73343f43feb1 59 char *slice_buf;
YongChingTee 2:73343f43feb1 60 short *data_sptr;
YongChingTee 2:73343f43feb1 61 unsigned char *data_bptr;
YongChingTee 2:73343f43feb1 62 int *data_wptr;
YongChingTee 2:73343f43feb1 63 FMT_STRUCT wav_format;
YongChingTee 2:73343f43feb1 64 long slice,num_slices;
YongChingTee 2:73343f43feb1 65 pb_pause.mode(PullUp);
YongChingTee 2:73343f43feb1 66 pb_stop.mode(PullUp);
YongChingTee 2:73343f43feb1 67 pb_play.mode(PullUp);
YongChingTee 2:73343f43feb1 68 int volume_player = 0;
YongChingTee 2:73343f43feb1 69 int count = 0;
YongChingTee 2:73343f43feb1 70 DAC_wptr=0;
YongChingTee 2:73343f43feb1 71 DAC_rptr=0;
YongChingTee 2:73343f43feb1 72 for (i=0;i<256;i+=2) {
YongChingTee 2:73343f43feb1 73 DAC_fifo[i]=0;
YongChingTee 2:73343f43feb1 74 DAC_fifo[i+1]=3000;
YongChingTee 2:73343f43feb1 75 }
YongChingTee 2:73343f43feb1 76 DAC_wptr=4;
YongChingTee 2:73343f43feb1 77 DAC_on=0;
YongChingTee 2:73343f43feb1 78
YongChingTee 2:73343f43feb1 79 fread(&chunk_id,4,1,wavefile);
YongChingTee 2:73343f43feb1 80 fread(&chunk_size,4,1,wavefile);
YongChingTee 2:73343f43feb1 81 while (!feof(wavefile)) {
YongChingTee 2:73343f43feb1 82 if (verbosity)
YongChingTee 2:73343f43feb1 83 pc.printf("Read chunk ID 0x%x, size 0x%x\n",chunk_id,chunk_size);
YongChingTee 2:73343f43feb1 84 switch (chunk_id) {
YongChingTee 2:73343f43feb1 85 case 0x46464952:
YongChingTee 2:73343f43feb1 86 fread(&data,4,1,wavefile);
YongChingTee 2:73343f43feb1 87 if (verbosity) {
YongChingTee 2:73343f43feb1 88 pc.printf("RIFF chunk\n");
YongChingTee 2:73343f43feb1 89 pc.printf(" chunk size %d (0x%x)\n",chunk_size,chunk_size);
YongChingTee 2:73343f43feb1 90 pc.printf(" RIFF type 0x%x\n",data);
YongChingTee 2:73343f43feb1 91 }
YongChingTee 2:73343f43feb1 92 pc.printf("case1\n");
YongChingTee 2:73343f43feb1 93 break;
YongChingTee 2:73343f43feb1 94 case 0x20746d66:
YongChingTee 2:73343f43feb1 95 fread(&wav_format,sizeof(wav_format),1,wavefile);
YongChingTee 2:73343f43feb1 96 if (verbosity) {
YongChingTee 2:73343f43feb1 97 pc.printf("FORMAT chunk\n");
YongChingTee 2:73343f43feb1 98 pc.printf(" chunk size %d (0x%x)\n",chunk_size,chunk_size);
YongChingTee 2:73343f43feb1 99 pc.printf(" compression code %d\n",wav_format.comp_code);
YongChingTee 2:73343f43feb1 100 pc.printf(" %d channels\n",wav_format.num_channels);
YongChingTee 2:73343f43feb1 101 pc.printf(" %d samples/sec\n",wav_format.sample_rate);
YongChingTee 2:73343f43feb1 102 pc.printf(" %d bytes/sec\n",wav_format.avg_Bps);
YongChingTee 2:73343f43feb1 103 pc.printf(" block align %d\n",wav_format.block_align);
YongChingTee 2:73343f43feb1 104 pc.printf(" %d bits per sample\n",wav_format.sig_bps);
YongChingTee 2:73343f43feb1 105 }
YongChingTee 2:73343f43feb1 106 if (chunk_size > sizeof(wav_format))
YongChingTee 2:73343f43feb1 107 fseek(wavefile,chunk_size-sizeof(wav_format),SEEK_CUR);
YongChingTee 2:73343f43feb1 108 pc.printf("case2\n");
YongChingTee 2:73343f43feb1 109 break;
YongChingTee 2:73343f43feb1 110 case 0x61746164:
YongChingTee 2:73343f43feb1 111 // allocate a buffer big enough to hold a slice
YongChingTee 2:73343f43feb1 112 slice_buf=(char *)malloc(wav_format.block_align);
YongChingTee 2:73343f43feb1 113 if (!slice_buf) {
YongChingTee 2:73343f43feb1 114 pc.printf("Unable to malloc slice buffer");
YongChingTee 2:73343f43feb1 115 exit(1);
YongChingTee 2:73343f43feb1 116 }
YongChingTee 2:73343f43feb1 117 num_slices=chunk_size/wav_format.block_align;
YongChingTee 2:73343f43feb1 118 samp_int=1000000/(wav_format.sample_rate);
YongChingTee 2:73343f43feb1 119 if (verbosity) {
YongChingTee 2:73343f43feb1 120 pc.printf("DATA chunk\n");
YongChingTee 2:73343f43feb1 121 pc.printf(" chunk size %d (0x%x)\n",chunk_size,chunk_size);
YongChingTee 2:73343f43feb1 122 pc.printf(" %d slices\n",num_slices);
YongChingTee 2:73343f43feb1 123 pc.printf(" Ideal sample interval=%d\n",(unsigned)(1000000.0/wav_format.sample_rate));
YongChingTee 2:73343f43feb1 124 pc.printf(" programmed interrupt tick interval=%d\n",samp_int);
YongChingTee 2:73343f43feb1 125 }
YongChingTee 2:73343f43feb1 126
YongChingTee 2:73343f43feb1 127 // starting up ticker to write samples out -- no printfs until tick.detach is called
YongChingTee 2:73343f43feb1 128 if (verbosity)
YongChingTee 2:73343f43feb1 129 tick.attach_us(this,&wave_player::dac_out, 500000);
YongChingTee 2:73343f43feb1 130 else
YongChingTee 2:73343f43feb1 131 tick.attach_us(this,&wave_player::dac_out, samp_int);
YongChingTee 2:73343f43feb1 132 DAC_on=1;
YongChingTee 2:73343f43feb1 133
YongChingTee 2:73343f43feb1 134 // start reading slices, which contain one sample each for however many channels
YongChingTee 2:73343f43feb1 135 // are in the wave file. one channel=mono, two channels=stereo, etc. Since
YongChingTee 2:73343f43feb1 136 // mbed only has a single AnalogOut, all of the channels present are averaged
YongChingTee 2:73343f43feb1 137 // to produce a single sample value. This summing and averaging happens in
YongChingTee 2:73343f43feb1 138 // a variable of type signed long long, to make sure that the data doesn't
YongChingTee 2:73343f43feb1 139 // overflow regardless of sample size (8 bits, 16 bits, 32 bits).
YongChingTee 2:73343f43feb1 140 //
YongChingTee 2:73343f43feb1 141 // note that from what I can find that 8 bit wave files use unsigned data,
YongChingTee 2:73343f43feb1 142 // while 16 and 32 bit wave files use signed data
YongChingTee 2:73343f43feb1 143 //
YongChingTee 2:73343f43feb1 144 for (slice=0;slice<num_slices;slice+=1) {
YongChingTee 2:73343f43feb1 145 fread(slice_buf,wav_format.block_align,1,wavefile);
YongChingTee 2:73343f43feb1 146 if (feof(wavefile)) {
YongChingTee 2:73343f43feb1 147 pc.printf("Oops -- not enough slices in the wave file\n");
YongChingTee 2:73343f43feb1 148 exit(1);
YongChingTee 2:73343f43feb1 149 }
YongChingTee 2:73343f43feb1 150 data_sptr=(short *)slice_buf; // 16 bit samples
YongChingTee 2:73343f43feb1 151 data_bptr=(unsigned char *)slice_buf; // 8 bit samples
YongChingTee 2:73343f43feb1 152 data_wptr=(int *)slice_buf; // 32 bit samples
YongChingTee 2:73343f43feb1 153 slice_value=0;
YongChingTee 2:73343f43feb1 154 for (channel=0;channel<wav_format.num_channels;channel++) {
YongChingTee 2:73343f43feb1 155
YongChingTee 2:73343f43feb1 156 switch (wav_format.sig_bps) {
YongChingTee 2:73343f43feb1 157 case 16:
YongChingTee 2:73343f43feb1 158 if (verbosity)
YongChingTee 2:73343f43feb1 159 pc.printf("16 bit channel %d data=%d ",channel,data_sptr[channel]);
YongChingTee 2:73343f43feb1 160 slice_value+=data_sptr[channel];
YongChingTee 2:73343f43feb1 161 break;
YongChingTee 2:73343f43feb1 162 case 32:
YongChingTee 2:73343f43feb1 163 if (verbosity)
YongChingTee 2:73343f43feb1 164 pc.printf("32 bit channel %d data=%d ",channel,data_wptr[channel]);
YongChingTee 2:73343f43feb1 165 slice_value+=data_wptr[channel];
YongChingTee 2:73343f43feb1 166 break;
YongChingTee 2:73343f43feb1 167 case 8:
YongChingTee 2:73343f43feb1 168 if (verbosity)
YongChingTee 2:73343f43feb1 169 pc.printf("8 bit channel %d data=%d ",channel,(int)data_bptr[channel]);
YongChingTee 2:73343f43feb1 170 slice_value+=data_bptr[channel];
YongChingTee 2:73343f43feb1 171 break;
YongChingTee 2:73343f43feb1 172 }
YongChingTee 2:73343f43feb1 173 }
YongChingTee 2:73343f43feb1 174 slice_value/=wav_format.num_channels;
YongChingTee 2:73343f43feb1 175
YongChingTee 2:73343f43feb1 176 // slice_value is now averaged. Next it needs to be scaled to an unsigned 16 bit value
YongChingTee 2:73343f43feb1 177 // with DC offset so it can be written to the DAC.
YongChingTee 2:73343f43feb1 178 switch (wav_format.sig_bps) {
YongChingTee 2:73343f43feb1 179 case 8: slice_value<<=8;
YongChingTee 2:73343f43feb1 180 break;
YongChingTee 2:73343f43feb1 181 case 16: slice_value+=32768;
YongChingTee 2:73343f43feb1 182 break;
YongChingTee 2:73343f43feb1 183 case 32: slice_value>>=16;
YongChingTee 2:73343f43feb1 184 slice_value+=32768;
YongChingTee 2:73343f43feb1 185 break;
YongChingTee 2:73343f43feb1 186 }
YongChingTee 2:73343f43feb1 187 dac_data=(short unsigned)slice_value;
YongChingTee 2:73343f43feb1 188 if (verbosity)
YongChingTee 2:73343f43feb1 189 pc.printf("sample %d wptr %d slice_value %d dac_data %u\n",slice,DAC_wptr,(int)slice_value,dac_data);
YongChingTee 2:73343f43feb1 190 DAC_fifo[DAC_wptr]=dac_data;
YongChingTee 2:73343f43feb1 191 //controls
YongChingTee 2:73343f43feb1 192 count++;
YongChingTee 2:73343f43feb1 193
YongChingTee 2:73343f43feb1 194 if(count%10000 == 0)
YongChingTee 2:73343f43feb1 195 {
YongChingTee 2:73343f43feb1 196 volume_player = position_player*300;
YongChingTee 2:73343f43feb1 197 lcd_player.cls();
YongChingTee 2:73343f43feb1 198 lcd_player.printf("Volume: %d \n", volume_player); //Print out Count
YongChingTee 2:73343f43feb1 199 lcd_player.printf("Mode: PLAY");
YongChingTee 2:73343f43feb1 200 }
YongChingTee 2:73343f43feb1 201 if(!pb_pause)
YongChingTee 2:73343f43feb1 202 {
YongChingTee 2:73343f43feb1 203 tick.detach();
YongChingTee 2:73343f43feb1 204 lcd_player.cls();
YongChingTee 2:73343f43feb1 205 lcd_player.printf("Volume: %d \n", volume_player); //Print out Count
YongChingTee 2:73343f43feb1 206 lcd_player.printf("Mode: PAUSE");
YongChingTee 2:73343f43feb1 207
YongChingTee 2:73343f43feb1 208 while(1)
YongChingTee 2:73343f43feb1 209 {
YongChingTee 2:73343f43feb1 210 count++;
YongChingTee 2:73343f43feb1 211 if(count%1000000 == 0)
YongChingTee 2:73343f43feb1 212 {
YongChingTee 2:73343f43feb1 213 volume_player = position_player*300;
YongChingTee 2:73343f43feb1 214 lcd_player.cls();
YongChingTee 2:73343f43feb1 215 lcd_player.printf("Volume: %d \n", volume_player); //Print out Count
YongChingTee 2:73343f43feb1 216 lcd_player.printf("Mode: PAUSE");
YongChingTee 2:73343f43feb1 217 }
YongChingTee 2:73343f43feb1 218 //lcd_player.printf("Volume: %d \n", volume_player); //Print out Count
YongChingTee 2:73343f43feb1 219 if(!pb_play)
YongChingTee 2:73343f43feb1 220 {
YongChingTee 2:73343f43feb1 221 tick.attach_us(this,&wave_player::dac_out, samp_int);
YongChingTee 2:73343f43feb1 222 lcd_player.cls();
YongChingTee 2:73343f43feb1 223 lcd_player.printf("Volume: %d \n", volume_player); //Print out Count
YongChingTee 2:73343f43feb1 224 lcd_player.printf("Mode: PLAY");
YongChingTee 2:73343f43feb1 225 break;
YongChingTee 2:73343f43feb1 226 }
YongChingTee 2:73343f43feb1 227 }
YongChingTee 2:73343f43feb1 228 }
YongChingTee 2:73343f43feb1 229 if(!pb_stop)
YongChingTee 2:73343f43feb1 230 {
YongChingTee 2:73343f43feb1 231 tick.detach();
YongChingTee 2:73343f43feb1 232 //while(!pb_stop){};//prevent from adding to playlist
YongChingTee 2:73343f43feb1 233 return;
YongChingTee 2:73343f43feb1 234 }
YongChingTee 2:73343f43feb1 235 //controls end
YongChingTee 2:73343f43feb1 236 DAC_wptr=(DAC_wptr+1) & 0xff;
YongChingTee 2:73343f43feb1 237 while (DAC_wptr==DAC_rptr) {
YongChingTee 2:73343f43feb1 238 }
YongChingTee 2:73343f43feb1 239 }
YongChingTee 2:73343f43feb1 240 DAC_on=0;
YongChingTee 2:73343f43feb1 241 tick.detach();
YongChingTee 2:73343f43feb1 242 free(slice_buf);
YongChingTee 2:73343f43feb1 243 pc.printf("case3\n");
YongChingTee 2:73343f43feb1 244 break;
YongChingTee 2:73343f43feb1 245 case 0x5453494c:
YongChingTee 2:73343f43feb1 246 if (verbosity)
YongChingTee 2:73343f43feb1 247 pc.printf("INFO chunk, size %d\n",chunk_size);
YongChingTee 2:73343f43feb1 248 fseek(wavefile,chunk_size,SEEK_CUR);
YongChingTee 2:73343f43feb1 249 pc.printf("case4\n");
YongChingTee 2:73343f43feb1 250 break;
YongChingTee 2:73343f43feb1 251 default:
YongChingTee 2:73343f43feb1 252 pc.printf("unknown chunk type 0x%x, size %d\n",chunk_id,chunk_size);
YongChingTee 2:73343f43feb1 253 data=fseek(wavefile,chunk_size,SEEK_CUR);
YongChingTee 2:73343f43feb1 254 break;
YongChingTee 2:73343f43feb1 255 }
YongChingTee 2:73343f43feb1 256 fread(&chunk_id,4,1,wavefile);
YongChingTee 2:73343f43feb1 257 fread(&chunk_size,4,1,wavefile);
YongChingTee 2:73343f43feb1 258 }
YongChingTee 2:73343f43feb1 259 }
YongChingTee 2:73343f43feb1 260
YongChingTee 2:73343f43feb1 261
YongChingTee 2:73343f43feb1 262 void wave_player::dac_out()
YongChingTee 2:73343f43feb1 263 {
YongChingTee 2:73343f43feb1 264 if (DAC_on) {
YongChingTee 2:73343f43feb1 265 #ifdef VERBOSE
YongChingTee 2:73343f43feb1 266 pc.printf("ISR rdptr %d got %u\n",DAC_rptr,DAC_fifo[DAC_rptr]);
YongChingTee 2:73343f43feb1 267 #endif
YongChingTee 2:73343f43feb1 268 wave_DAC->write_u16(DAC_fifo[DAC_rptr]);
YongChingTee 2:73343f43feb1 269 DAC_rptr=(DAC_rptr+1) & 0xff;
YongChingTee 2:73343f43feb1 270 }
YongChingTee 2:73343f43feb1 271 }
YongChingTee 2:73343f43feb1 272