This program is for Star Board Orange. Wave file into SD card is read, and its DAC signal output.
Dependencies: EthernetNetIf mbed HTTPServer
Diff: wavplayer.cpp
- Revision:
- 0:383bff20e783
diff -r 000000000000 -r 383bff20e783 wavplayer.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/wavplayer.cpp Thu Nov 25 14:59:16 2010 +0000 @@ -0,0 +1,153 @@ +/* + Library wave file player by Tom Coxon + + Based on WAVEplayer by Vlad Cazan/Stephan Rochon modified by Tom Coxon to: + + 1. Run correctly on the Embedded Artists LPCXpresso baseboard. + 2. To play 8 bit sample size in addition to original 16 bit + 3. To be more fault tolerant when playing wav files. +*/ + +#include "wavplayer.h" + +Ticker tick; + +AnalogOut DACout(p18); + +void WavPlayer::dac_out() { + if (DAC_on) { + DACout.write_u16(DAC_fifo[DAC_rptr]); + DAC_rptr=(DAC_rptr+1) & 0xff; + } +} + +//void play_wave(char *wavname) { +void WavPlayer::play_wave(char *wavname) { + unsigned chunk_id,chunk_size,channel; + unsigned data,samp_int,i; + short dac_data; + char *slice_buf; + short *data_sptr; + FMT_STRUCT wav_format; + FILE *wavfile; + long slice,num_slices; + DAC_wptr=0; + DAC_rptr=0; + + size_t result; + + for (i=0;i<256;i+=2) { + DAC_fifo[i]=0; + DAC_fifo[i+1]=3000; + } + DAC_wptr=4; + DAC_on=0; + + printf("Playing wave file '%s'\r\n",wavname); + + wavfile=fopen(wavname,"rb"); + if (!wavfile) { + printf("Unable to open wav file '%s'\r\n",wavname); + exit(1); + } + + fread(&chunk_id,4,1,wavfile); + fread(&chunk_size,4,1,wavfile); + while (!feof(wavfile)) { + printf("Read chunk ID 0x%x, size 0x%x\r\n",chunk_id,chunk_size); + switch (chunk_id) { + case 0x46464952: + fread(&data,4,1,wavfile); + printf("RIFF chunk\r\n"); + printf(" chunk size %d (0x%x)\r\n",chunk_size,chunk_size); + printf(" RIFF type 0x%x\r\n",data); + break; + case 0x20746d66: + fread(&wav_format,sizeof(wav_format),1,wavfile); + printf("FORMAT chunk\r\n"); + printf(" chunk size %d (0x%x)\r\n",chunk_size,chunk_size); + printf(" compression code %d\r\n",wav_format.comp_code); + printf(" %d channels\r\n",wav_format.num_channels); + printf(" %d samples/sec\r\n",wav_format.sample_rate); + printf(" %d bytes/sec\r\n",wav_format.avg_Bps); + printf(" block align %d\r\n",wav_format.block_align); + printf(" %d bits per sample\r\n",wav_format.sig_bps); + if (chunk_size > sizeof(wav_format)) + fseek(wavfile,chunk_size-sizeof(wav_format),SEEK_CUR); +// create a slice buffer large enough to hold multiple slices + slice_buf=(char *)malloc(wav_format.block_align*SLICE_BUF_SIZE); + if (!slice_buf) { + printf("Unable to malloc slice buffer"); + exit(1); + } + break; + case 0x61746164: + slice_buf=(char *)malloc(wav_format.block_align*SLICE_BUF_SIZE); + if (!slice_buf) { + printf("Unable to malloc slice buffer"); + exit(1); + } + num_slices=chunk_size/wav_format.block_align; + printf("DATA chunk\r\n"); + printf(" chunk size %d (0x%x)\r\n",chunk_size,chunk_size); + printf(" %d slices\r\n",num_slices); + printf(" Ideal sample interval=%d\r\n",(unsigned)(1000000.0/wav_format.sample_rate)); + samp_int=1000000/(wav_format.sample_rate); + printf(" programmed interrupt tick interval=%d\r\n",samp_int); + +// starting up ticker to write samples out -- no printfs until tick.detach is called + tick.attach_us(this,&WavPlayer::dac_out, samp_int); + DAC_on=1; + for (slice=0;slice<num_slices;slice+=SLICE_BUF_SIZE) { + + result = fread(slice_buf,wav_format.block_align*SLICE_BUF_SIZE,1,wavfile); + if (feof(wavfile)) { + printf("Oops -- not enough slices in the wave file\r\n"); + + break; + } + + data_sptr=(short *)slice_buf; + for (i=0;i<SLICE_BUF_SIZE;i++) { + dac_data=0; + +// for a stereo wave file average the two channels. + for (channel=0;channel<wav_format.num_channels;channel++) { + switch (wav_format.sig_bps) { + case 16: + dac_data+=( ((int)(*data_sptr++)) +32768 ); + break; + case 8: + dac_data+=( ((int)(*data_sptr++)) +32768 <<8); + break; + } + } + DAC_fifo[DAC_wptr]=dac_data; + DAC_wptr=(DAC_wptr+1) & 0xff; + while (DAC_wptr==DAC_rptr) { + wait_us(10); + } + } + } + DAC_on=0; + tick.detach(); + printf("Ticker detached\r\n"); + free(slice_buf); + break; + case 0x5453494c: + printf("INFO chunk, size %d\r\n",chunk_size); + fseek(wavfile,chunk_size,SEEK_CUR); + break; + default: + printf("unknown chunk type 0x%x, size %d\r\n",chunk_id,chunk_size); + data=fseek(wavfile,chunk_size,SEEK_CUR); + break; + } + fread(&chunk_id,4,1,wavfile); + fread(&chunk_size,4,1,wavfile); + } + printf("++++++++++++ Done with wave file ++++++++++\r\n"); + fclose(wavfile); +} + +