A S / wave_player

Add the function of adjusting volume

Dependents:   aos_mbed

Fork of wave_player by Steve Ravet

wave_player.cpp@2:1a9dbc4d2b46, 2014-02-02 (annotated)

Committer:
aos
Date:
Sun Feb 02 10:48:11 2014 +0000
Revision:
2:1a9dbc4d2b46
Parent:
0:62c18ade9a60 
Modified for adjusting volume

Who changed what in which revision?

UserRevisionLine numberNew contents of line
sravet 0:62c18ade9a60 1
aos 2:1a9dbc4d2b46 2
sravet 0:62c18ade9a60 3 #include <mbed.h>
sravet 0:62c18ade9a60 4 #include <stdio.h>
sravet 0:62c18ade9a60 5 #include <wave_player.h>
aos 2:1a9dbc4d2b46 6
aos 2:1a9dbc4d2b46 7 Serial pc(USBTX, USBRX);
sravet 0:62c18ade9a60 8 //-----------------------------------------------------------------------------
sravet 0:62c18ade9a60 9 // constructor -- accepts an mbed pin to use for AnalogOut. Only p18 will work
sravet 0:62c18ade9a60 10 wave_player::wave_player(AnalogOut *_dac)
sravet 0:62c18ade9a60 11 {
sravet 0:62c18ade9a60 12 wave_DAC=_dac;
sravet 0:62c18ade9a60 13 wave_DAC->write_u16(32768); //DAC is 0-3.3V, so idles at ~1.6V
sravet 0:62c18ade9a60 14 verbosity=0;
sravet 0:62c18ade9a60 15 }
aos 2:1a9dbc4d2b46 16
sravet 0:62c18ade9a60 17 //-----------------------------------------------------------------------------
sravet 0:62c18ade9a60 18 // if verbosity is set then wave player enters a mode where the wave file
sravet 0:62c18ade9a60 19 // is decoded and displayed to the screen, including sample values put into
sravet 0:62c18ade9a60 20 // the DAC FIFO, and values read out of the DAC FIFO by the ISR. The DAC output
sravet 0:62c18ade9a60 21 // itself is so slow as to be unusable, but this might be handy for debugging
sravet 0:62c18ade9a60 22 // wave files that don't play
sravet 0:62c18ade9a60 23 //-----------------------------------------------------------------------------
sravet 0:62c18ade9a60 24 void wave_player::set_verbosity(int v)
sravet 0:62c18ade9a60 25 {
sravet 0:62c18ade9a60 26 verbosity=v;
sravet 0:62c18ade9a60 27 }
aos 2:1a9dbc4d2b46 28
sravet 0:62c18ade9a60 29 //-----------------------------------------------------------------------------
sravet 0:62c18ade9a60 30 // player function. Takes a pointer to an opened wave file. The file needs
sravet 0:62c18ade9a60 31 // to be stored in a filesystem with enough bandwidth to feed the wave data.
sravet 0:62c18ade9a60 32 // LocalFileSystem isn't, but the SDcard is, at least for 22kHz files. The
sravet 0:62c18ade9a60 33 // SDcard filesystem can be hotrodded by increasing the SPI frequency it uses
sravet 0:62c18ade9a60 34 // internally.
sravet 0:62c18ade9a60 35 //-----------------------------------------------------------------------------
sravet 0:62c18ade9a60 36 void wave_player::play(FILE *wavefile)
sravet 0:62c18ade9a60 37 {
sravet 0:62c18ade9a60 38 unsigned chunk_id,chunk_size,channel;
sravet 0:62c18ade9a60 39 unsigned data,samp_int,i;
sravet 0:62c18ade9a60 40 short unsigned dac_data;
sravet 0:62c18ade9a60 41 long long slice_value;
sravet 0:62c18ade9a60 42 char *slice_buf;
sravet 0:62c18ade9a60 43 short *data_sptr;
sravet 0:62c18ade9a60 44 unsigned char *data_bptr;
sravet 0:62c18ade9a60 45 int *data_wptr;
sravet 0:62c18ade9a60 46 FMT_STRUCT wav_format;
sravet 0:62c18ade9a60 47 long slice,num_slices;
sravet 0:62c18ade9a60 48 DAC_wptr=0;
sravet 0:62c18ade9a60 49 DAC_rptr=0;
sravet 0:62c18ade9a60 50 for (i=0;i<256;i+=2) {
sravet 0:62c18ade9a60 51 DAC_fifo[i]=0;
sravet 0:62c18ade9a60 52 DAC_fifo[i+1]=3000;
sravet 0:62c18ade9a60 53 }
sravet 0:62c18ade9a60 54 DAC_wptr=4;
sravet 0:62c18ade9a60 55 DAC_on=0;
aos 2:1a9dbc4d2b46 56
sravet 0:62c18ade9a60 57 fread(&chunk_id,4,1,wavefile);
sravet 0:62c18ade9a60 58 fread(&chunk_size,4,1,wavefile);
sravet 0:62c18ade9a60 59 while (!feof(wavefile)) {
sravet 0:62c18ade9a60 60 if (verbosity)
aos 2:1a9dbc4d2b46 61 pc.printf("Read chunk ID 0x%x, size 0x%x\n",chunk_id,chunk_size);
sravet 0:62c18ade9a60 62 switch (chunk_id) {
sravet 0:62c18ade9a60 63 case 0x46464952:
sravet 0:62c18ade9a60 64 fread(&data,4,1,wavefile);
sravet 0:62c18ade9a60 65 if (verbosity) {
aos 2:1a9dbc4d2b46 66 pc.printf("RIFF chunk\n");
aos 2:1a9dbc4d2b46 67 pc.printf(" chunk size %d (0x%x)\n",chunk_size,chunk_size);
aos 2:1a9dbc4d2b46 68 pc.printf(" RIFF type 0x%x\n",data);
sravet 0:62c18ade9a60 69 }
aos 2:1a9dbc4d2b46 70 pc.printf("case1\n");
sravet 0:62c18ade9a60 71 break;
sravet 0:62c18ade9a60 72 case 0x20746d66:
sravet 0:62c18ade9a60 73 fread(&wav_format,sizeof(wav_format),1,wavefile);
sravet 0:62c18ade9a60 74 if (verbosity) {
aos 2:1a9dbc4d2b46 75 pc.printf("FORMAT chunk\n");
aos 2:1a9dbc4d2b46 76 pc.printf(" chunk size %d (0x%x)\n",chunk_size,chunk_size);
aos 2:1a9dbc4d2b46 77 pc.printf(" compression code %d\n",wav_format.comp_code);
aos 2:1a9dbc4d2b46 78 pc.printf(" %d channels\n",wav_format.num_channels);
aos 2:1a9dbc4d2b46 79 pc.printf(" %d samples/sec\n",wav_format.sample_rate);
aos 2:1a9dbc4d2b46 80 pc.printf(" %d bytes/sec\n",wav_format.avg_Bps);
aos 2:1a9dbc4d2b46 81 pc.printf(" block align %d\n",wav_format.block_align);
aos 2:1a9dbc4d2b46 82 pc.printf(" %d bits per sample\n",wav_format.sig_bps);
sravet 0:62c18ade9a60 83 }
sravet 0:62c18ade9a60 84 if (chunk_size > sizeof(wav_format))
sravet 0:62c18ade9a60 85 fseek(wavefile,chunk_size-sizeof(wav_format),SEEK_CUR);
aos 2:1a9dbc4d2b46 86 pc.printf("case2\n");
sravet 0:62c18ade9a60 87 break;
sravet 0:62c18ade9a60 88 case 0x61746164:
sravet 0:62c18ade9a60 89 // allocate a buffer big enough to hold a slice
sravet 0:62c18ade9a60 90 slice_buf=(char *)malloc(wav_format.block_align);
sravet 0:62c18ade9a60 91 if (!slice_buf) {
aos 2:1a9dbc4d2b46 92 pc.printf("Unable to malloc slice buffer");
sravet 0:62c18ade9a60 93 exit(1);
sravet 0:62c18ade9a60 94 }
sravet 0:62c18ade9a60 95 num_slices=chunk_size/wav_format.block_align;
sravet 0:62c18ade9a60 96 samp_int=1000000/(wav_format.sample_rate);
sravet 0:62c18ade9a60 97 if (verbosity) {
aos 2:1a9dbc4d2b46 98 pc.printf("DATA chunk\n");
aos 2:1a9dbc4d2b46 99 pc.printf(" chunk size %d (0x%x)\n",chunk_size,chunk_size);
aos 2:1a9dbc4d2b46 100 pc.printf(" %d slices\n",num_slices);
aos 2:1a9dbc4d2b46 101 pc.printf(" Ideal sample interval=%d\n",(unsigned)(1000000.0/wav_format.sample_rate));
aos 2:1a9dbc4d2b46 102 pc.printf(" programmed interrupt tick interval=%d\n",samp_int);
sravet 0:62c18ade9a60 103 }
aos 2:1a9dbc4d2b46 104
sravet 0:62c18ade9a60 105 // starting up ticker to write samples out -- no printfs until tick.detach is called
sravet 0:62c18ade9a60 106 if (verbosity)
sravet 0:62c18ade9a60 107 tick.attach_us(this,&wave_player::dac_out, 500000);
sravet 0:62c18ade9a60 108 else
sravet 0:62c18ade9a60 109 tick.attach_us(this,&wave_player::dac_out, samp_int);
sravet 0:62c18ade9a60 110 DAC_on=1;
aos 2:1a9dbc4d2b46 111
sravet 0:62c18ade9a60 112 // start reading slices, which contain one sample each for however many channels
sravet 0:62c18ade9a60 113 // are in the wave file. one channel=mono, two channels=stereo, etc. Since
sravet 0:62c18ade9a60 114 // mbed only has a single AnalogOut, all of the channels present are averaged
sravet 0:62c18ade9a60 115 // to produce a single sample value. This summing and averaging happens in
sravet 0:62c18ade9a60 116 // a variable of type signed long long, to make sure that the data doesn't
sravet 0:62c18ade9a60 117 // overflow regardless of sample size (8 bits, 16 bits, 32 bits).
sravet 0:62c18ade9a60 118 //
sravet 0:62c18ade9a60 119 // note that from what I can find that 8 bit wave files use unsigned data,
sravet 0:62c18ade9a60 120 // while 16 and 32 bit wave files use signed data
sravet 0:62c18ade9a60 121 //
sravet 0:62c18ade9a60 122 for (slice=0;slice<num_slices;slice+=1) {
sravet 0:62c18ade9a60 123 fread(slice_buf,wav_format.block_align,1,wavefile);
sravet 0:62c18ade9a60 124 if (feof(wavefile)) {
aos 2:1a9dbc4d2b46 125 pc.printf("Oops -- not enough slices in the wave file\n");
sravet 0:62c18ade9a60 126 exit(1);
sravet 0:62c18ade9a60 127 }
sravet 0:62c18ade9a60 128 data_sptr=(short *)slice_buf; // 16 bit samples
sravet 0:62c18ade9a60 129 data_bptr=(unsigned char *)slice_buf; // 8 bit samples
sravet 0:62c18ade9a60 130 data_wptr=(int *)slice_buf; // 32 bit samples
sravet 0:62c18ade9a60 131 slice_value=0;
sravet 0:62c18ade9a60 132 for (channel=0;channel<wav_format.num_channels;channel++) {
aos 2:1a9dbc4d2b46 133
sravet 0:62c18ade9a60 134 switch (wav_format.sig_bps) {
sravet 0:62c18ade9a60 135 case 16:
sravet 0:62c18ade9a60 136 if (verbosity)
aos 2:1a9dbc4d2b46 137 pc.printf("16 bit channel %d data=%d ",channel,data_sptr[channel]);
sravet 0:62c18ade9a60 138 slice_value+=data_sptr[channel];
sravet 0:62c18ade9a60 139 break;
sravet 0:62c18ade9a60 140 case 32:
sravet 0:62c18ade9a60 141 if (verbosity)
aos 2:1a9dbc4d2b46 142 pc.printf("32 bit channel %d data=%d ",channel,data_wptr[channel]);
sravet 0:62c18ade9a60 143 slice_value+=data_wptr[channel];
sravet 0:62c18ade9a60 144 break;
sravet 0:62c18ade9a60 145 case 8:
sravet 0:62c18ade9a60 146 if (verbosity)
aos 2:1a9dbc4d2b46 147 pc.printf("8 bit channel %d data=%d ",channel,(int)data_bptr[channel]);
sravet 0:62c18ade9a60 148 slice_value+=data_bptr[channel];
sravet 0:62c18ade9a60 149 break;
sravet 0:62c18ade9a60 150 }
sravet 0:62c18ade9a60 151 }
sravet 0:62c18ade9a60 152 slice_value/=wav_format.num_channels;
sravet 0:62c18ade9a60 153
sravet 0:62c18ade9a60 154 // slice_value is now averaged. Next it needs to be scaled to an unsigned 16 bit value
sravet 0:62c18ade9a60 155 // with DC offset so it can be written to the DAC.
sravet 0:62c18ade9a60 156 switch (wav_format.sig_bps) {
sravet 0:62c18ade9a60 157 case 8: slice_value<<=8;
sravet 0:62c18ade9a60 158 break;
sravet 0:62c18ade9a60 159 case 16: slice_value+=32768;
sravet 0:62c18ade9a60 160 break;
sravet 0:62c18ade9a60 161 case 32: slice_value>>=16;
sravet 0:62c18ade9a60 162 slice_value+=32768;
sravet 0:62c18ade9a60 163 break;
sravet 0:62c18ade9a60 164 }
sravet 0:62c18ade9a60 165 dac_data=(short unsigned)slice_value;
sravet 0:62c18ade9a60 166 if (verbosity)
aos 2:1a9dbc4d2b46 167 pc.printf("sample %d wptr %d slice_value %d dac_data %u\n",slice,DAC_wptr,(int)slice_value,dac_data);
aos 2:1a9dbc4d2b46 168 DAC_fifo[DAC_wptr]=dac_data*volume; //--> modified: adjusting the volume
aos 2:1a9dbc4d2b46 169
aos 2:1a9dbc4d2b46 170 //controls end
sravet 0:62c18ade9a60 171 DAC_wptr=(DAC_wptr+1) & 0xff;
sravet 0:62c18ade9a60 172 while (DAC_wptr==DAC_rptr) {
sravet 0:62c18ade9a60 173 }
sravet 0:62c18ade9a60 174 }
sravet 0:62c18ade9a60 175 DAC_on=0;
sravet 0:62c18ade9a60 176 tick.detach();
sravet 0:62c18ade9a60 177 free(slice_buf);
aos 2:1a9dbc4d2b46 178 pc.printf("case3\n");
sravet 0:62c18ade9a60 179 break;
sravet 0:62c18ade9a60 180 case 0x5453494c:
sravet 0:62c18ade9a60 181 if (verbosity)
aos 2:1a9dbc4d2b46 182 pc.printf("INFO chunk, size %d\n",chunk_size);
sravet 0:62c18ade9a60 183 fseek(wavefile,chunk_size,SEEK_CUR);
aos 2:1a9dbc4d2b46 184 pc.printf("case4\n");
sravet 0:62c18ade9a60 185 break;
sravet 0:62c18ade9a60 186 default:
aos 2:1a9dbc4d2b46 187 pc.printf("unknown chunk type 0x%x, size %d\n",chunk_id,chunk_size);
sravet 0:62c18ade9a60 188 data=fseek(wavefile,chunk_size,SEEK_CUR);
sravet 0:62c18ade9a60 189 break;
sravet 0:62c18ade9a60 190 }
sravet 0:62c18ade9a60 191 fread(&chunk_id,4,1,wavefile);
sravet 0:62c18ade9a60 192 fread(&chunk_size,4,1,wavefile);
sravet 0:62c18ade9a60 193 }
sravet 0:62c18ade9a60 194 }
aos 2:1a9dbc4d2b46 195
aos 2:1a9dbc4d2b46 196
sravet 0:62c18ade9a60 197 void wave_player::dac_out()
sravet 0:62c18ade9a60 198 {
sravet 0:62c18ade9a60 199 if (DAC_on) {
sravet 0:62c18ade9a60 200 #ifdef VERBOSE
aos 2:1a9dbc4d2b46 201 pc.printf("ISR rdptr %d got %u\n",DAC_rptr,DAC_fifo[DAC_rptr]);
sravet 0:62c18ade9a60 202 #endif
sravet 0:62c18ade9a60 203 wave_DAC->write_u16(DAC_fifo[DAC_rptr]);
sravet 0:62c18ade9a60 204 DAC_rptr=(DAC_rptr+1) & 0xff;
sravet 0:62c18ade9a60 205 }
aos 2:1a9dbc4d2b46 206 }