EA_WavPlayer - Demo of Embedded Artists LPCXpresso baseboard SD …

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Tom Coxon / Mbed 2 deprecated EA_WavPlayer

Demo of Embedded Artists LPCXpresso baseboard SD card reader and audio facilities. Updated to put wav file player in a separate library and use the high capacity SD card library provided by Klaus Bu.

Dependencies: mbed

wavplayer.cpp@2:affcc36a50b4, 2010-07-25 (annotated)

Committer:: tom_coxon
Date:: Sun Jul 25 17:51:19 2010 +0000
Revision:: 2:affcc36a50b4

Who changed what in which revision?

User	Revision	Line number	New contents of line
tom_coxon	2:affcc36a50b4	1	/*
tom_coxon	2:affcc36a50b4	2	Library wave file player by Tom Coxon
tom_coxon	2:affcc36a50b4	3
tom_coxon	2:affcc36a50b4	4	Based on WAVEplayer by Vlad Cazan/Stephan Rochon modified by Tom Coxon to:
tom_coxon	2:affcc36a50b4	5
tom_coxon	2:affcc36a50b4	6	1. Run correctly on the Embedded Artists LPCXpresso baseboard.
tom_coxon	2:affcc36a50b4	7	2. To play 8 bit sample size in addition to original 16 bit
tom_coxon	2:affcc36a50b4	8	3. To be more fault tolerant when playing wav files.
tom_coxon	2:affcc36a50b4	9	*/
tom_coxon	2:affcc36a50b4	10
tom_coxon	2:affcc36a50b4	11	#include "wavplayer.h"
tom_coxon	2:affcc36a50b4	12
tom_coxon	2:affcc36a50b4	13	Ticker tick;
tom_coxon	2:affcc36a50b4	14
tom_coxon	2:affcc36a50b4	15	AnalogOut DACout(p18);
tom_coxon	2:affcc36a50b4	16
tom_coxon	2:affcc36a50b4	17	void WavPlayer::dac_out() {
tom_coxon	2:affcc36a50b4	18	if (DAC_on) {
tom_coxon	2:affcc36a50b4	19	DACout.write_u16(DAC_fifo[DAC_rptr]);
tom_coxon	2:affcc36a50b4	20	DAC_rptr=(DAC_rptr+1) & 0xff;
tom_coxon	2:affcc36a50b4	21	}
tom_coxon	2:affcc36a50b4	22	}
tom_coxon	2:affcc36a50b4	23
tom_coxon	2:affcc36a50b4	24	//void play_wave(char *wavname) {
tom_coxon	2:affcc36a50b4	25	void WavPlayer::play_wave(char *wavname) {
tom_coxon	2:affcc36a50b4	26	unsigned chunk_id,chunk_size,channel;
tom_coxon	2:affcc36a50b4	27	unsigned data,samp_int,i;
tom_coxon	2:affcc36a50b4	28	short dac_data;
tom_coxon	2:affcc36a50b4	29	char *slice_buf;
tom_coxon	2:affcc36a50b4	30	short *data_sptr;
tom_coxon	2:affcc36a50b4	31	FMT_STRUCT wav_format;
tom_coxon	2:affcc36a50b4	32	FILE *wavfile;
tom_coxon	2:affcc36a50b4	33	long slice,num_slices;
tom_coxon	2:affcc36a50b4	34	DAC_wptr=0;
tom_coxon	2:affcc36a50b4	35	DAC_rptr=0;
tom_coxon	2:affcc36a50b4	36
tom_coxon	2:affcc36a50b4	37	size_t result;
tom_coxon	2:affcc36a50b4	38
tom_coxon	2:affcc36a50b4	39	for (i=0;i<256;i+=2) {
tom_coxon	2:affcc36a50b4	40	DAC_fifo[i]=0;
tom_coxon	2:affcc36a50b4	41	DAC_fifo[i+1]=3000;
tom_coxon	2:affcc36a50b4	42	}
tom_coxon	2:affcc36a50b4	43	DAC_wptr=4;
tom_coxon	2:affcc36a50b4	44	DAC_on=0;
tom_coxon	2:affcc36a50b4	45
tom_coxon	2:affcc36a50b4	46	printf("Playing wave file '%s'\r\n",wavname);
tom_coxon	2:affcc36a50b4	47
tom_coxon	2:affcc36a50b4	48	wavfile=fopen(wavname,"rb");
tom_coxon	2:affcc36a50b4	49	if (!wavfile) {
tom_coxon	2:affcc36a50b4	50	printf("Unable to open wav file '%s'\r\n",wavname);
tom_coxon	2:affcc36a50b4	51	exit(1);
tom_coxon	2:affcc36a50b4	52	}
tom_coxon	2:affcc36a50b4	53
tom_coxon	2:affcc36a50b4	54	fread(&chunk_id,4,1,wavfile);
tom_coxon	2:affcc36a50b4	55	fread(&chunk_size,4,1,wavfile);
tom_coxon	2:affcc36a50b4	56	while (!feof(wavfile)) {
tom_coxon	2:affcc36a50b4	57	printf("Read chunk ID 0x%x, size 0x%x\r\n",chunk_id,chunk_size);
tom_coxon	2:affcc36a50b4	58	switch (chunk_id) {
tom_coxon	2:affcc36a50b4	59	case 0x46464952:
tom_coxon	2:affcc36a50b4	60	fread(&data,4,1,wavfile);
tom_coxon	2:affcc36a50b4	61	printf("RIFF chunk\r\n");
tom_coxon	2:affcc36a50b4	62	printf(" chunk size %d (0x%x)\r\n",chunk_size,chunk_size);
tom_coxon	2:affcc36a50b4	63	printf(" RIFF type 0x%x\r\n",data);
tom_coxon	2:affcc36a50b4	64	break;
tom_coxon	2:affcc36a50b4	65	case 0x20746d66:
tom_coxon	2:affcc36a50b4	66	fread(&wav_format,sizeof(wav_format),1,wavfile);
tom_coxon	2:affcc36a50b4	67	printf("FORMAT chunk\r\n");
tom_coxon	2:affcc36a50b4	68	printf(" chunk size %d (0x%x)\r\n",chunk_size,chunk_size);
tom_coxon	2:affcc36a50b4	69	printf(" compression code %d\r\n",wav_format.comp_code);
tom_coxon	2:affcc36a50b4	70	printf(" %d channels\r\n",wav_format.num_channels);
tom_coxon	2:affcc36a50b4	71	printf(" %d samples/sec\r\n",wav_format.sample_rate);
tom_coxon	2:affcc36a50b4	72	printf(" %d bytes/sec\r\n",wav_format.avg_Bps);
tom_coxon	2:affcc36a50b4	73	printf(" block align %d\r\n",wav_format.block_align);
tom_coxon	2:affcc36a50b4	74	printf(" %d bits per sample\r\n",wav_format.sig_bps);
tom_coxon	2:affcc36a50b4	75	if (chunk_size > sizeof(wav_format))
tom_coxon	2:affcc36a50b4	76	fseek(wavfile,chunk_size-sizeof(wav_format),SEEK_CUR);
tom_coxon	2:affcc36a50b4	77	// create a slice buffer large enough to hold multiple slices
tom_coxon	2:affcc36a50b4	78	slice_buf=(char )malloc(wav_format.block_alignSLICE_BUF_SIZE);
tom_coxon	2:affcc36a50b4	79	if (!slice_buf) {
tom_coxon	2:affcc36a50b4	80	printf("Unable to malloc slice buffer");
tom_coxon	2:affcc36a50b4	81	exit(1);
tom_coxon	2:affcc36a50b4	82	}
tom_coxon	2:affcc36a50b4	83	break;
tom_coxon	2:affcc36a50b4	84	case 0x61746164:
tom_coxon	2:affcc36a50b4	85	slice_buf=(char )malloc(wav_format.block_alignSLICE_BUF_SIZE);
tom_coxon	2:affcc36a50b4	86	if (!slice_buf) {
tom_coxon	2:affcc36a50b4	87	printf("Unable to malloc slice buffer");
tom_coxon	2:affcc36a50b4	88	exit(1);
tom_coxon	2:affcc36a50b4	89	}
tom_coxon	2:affcc36a50b4	90	num_slices=chunk_size/wav_format.block_align;
tom_coxon	2:affcc36a50b4	91	printf("DATA chunk\r\n");
tom_coxon	2:affcc36a50b4	92	printf(" chunk size %d (0x%x)\r\n",chunk_size,chunk_size);
tom_coxon	2:affcc36a50b4	93	printf(" %d slices\r\n",num_slices);
tom_coxon	2:affcc36a50b4	94	printf(" Ideal sample interval=%d\r\n",(unsigned)(1000000.0/wav_format.sample_rate));
tom_coxon	2:affcc36a50b4	95	samp_int=1000000/(wav_format.sample_rate);
tom_coxon	2:affcc36a50b4	96	printf(" programmed interrupt tick interval=%d\r\n",samp_int);
tom_coxon	2:affcc36a50b4	97
tom_coxon	2:affcc36a50b4	98	// starting up ticker to write samples out -- no printfs until tick.detach is called
tom_coxon	2:affcc36a50b4	99	tick.attach_us(this,&WavPlayer::dac_out, samp_int);
tom_coxon	2:affcc36a50b4	100	DAC_on=1;
tom_coxon	2:affcc36a50b4	101	for (slice=0;slice<num_slices;slice+=SLICE_BUF_SIZE) {
tom_coxon	2:affcc36a50b4	102
tom_coxon	2:affcc36a50b4	103	result = fread(slice_buf,wav_format.block_align*SLICE_BUF_SIZE,1,wavfile);
tom_coxon	2:affcc36a50b4	104	if (feof(wavfile)) {
tom_coxon	2:affcc36a50b4	105	printf("Oops -- not enough slices in the wave file\r\n");
tom_coxon	2:affcc36a50b4	106
tom_coxon	2:affcc36a50b4	107	break;
tom_coxon	2:affcc36a50b4	108	}
tom_coxon	2:affcc36a50b4	109
tom_coxon	2:affcc36a50b4	110	data_sptr=(short *)slice_buf;
tom_coxon	2:affcc36a50b4	111	for (i=0;i<SLICE_BUF_SIZE;i++) {
tom_coxon	2:affcc36a50b4	112	dac_data=0;
tom_coxon	2:affcc36a50b4	113
tom_coxon	2:affcc36a50b4	114	// for a stereo wave file average the two channels.
tom_coxon	2:affcc36a50b4	115	for (channel=0;channel<wav_format.num_channels;channel++) {
tom_coxon	2:affcc36a50b4	116	switch (wav_format.sig_bps) {
tom_coxon	2:affcc36a50b4	117	case 16:
tom_coxon	2:affcc36a50b4	118	dac_data+=( ((int)(*data_sptr++)) +32768 );
tom_coxon	2:affcc36a50b4	119	break;
tom_coxon	2:affcc36a50b4	120	case 8:
tom_coxon	2:affcc36a50b4	121	dac_data+=( ((int)(*data_sptr++)) +32768 <<8);
tom_coxon	2:affcc36a50b4	122	break;
tom_coxon	2:affcc36a50b4	123	}
tom_coxon	2:affcc36a50b4	124	}
tom_coxon	2:affcc36a50b4	125	DAC_fifo[DAC_wptr]=dac_data;
tom_coxon	2:affcc36a50b4	126	DAC_wptr=(DAC_wptr+1) & 0xff;
tom_coxon	2:affcc36a50b4	127	while (DAC_wptr==DAC_rptr) {
tom_coxon	2:affcc36a50b4	128	wait_us(10);
tom_coxon	2:affcc36a50b4	129	}
tom_coxon	2:affcc36a50b4	130	}
tom_coxon	2:affcc36a50b4	131	}
tom_coxon	2:affcc36a50b4	132	DAC_on=0;
tom_coxon	2:affcc36a50b4	133	tick.detach();
tom_coxon	2:affcc36a50b4	134	printf("Ticker detached\r\n");
tom_coxon	2:affcc36a50b4	135	free(slice_buf);
tom_coxon	2:affcc36a50b4	136	break;
tom_coxon	2:affcc36a50b4	137	case 0x5453494c:
tom_coxon	2:affcc36a50b4	138	printf("INFO chunk, size %d\r\n",chunk_size);
tom_coxon	2:affcc36a50b4	139	fseek(wavfile,chunk_size,SEEK_CUR);
tom_coxon	2:affcc36a50b4	140	break;
tom_coxon	2:affcc36a50b4	141	default:
tom_coxon	2:affcc36a50b4	142	printf("unknown chunk type 0x%x, size %d\r\n",chunk_id,chunk_size);
tom_coxon	2:affcc36a50b4	143	data=fseek(wavfile,chunk_size,SEEK_CUR);
tom_coxon	2:affcc36a50b4	144	break;
tom_coxon	2:affcc36a50b4	145	}
tom_coxon	2:affcc36a50b4	146	fread(&chunk_id,4,1,wavfile);
tom_coxon	2:affcc36a50b4	147	fread(&chunk_size,4,1,wavfile);
tom_coxon	2:affcc36a50b4	148	}
tom_coxon	2:affcc36a50b4	149	printf("++++++++++++ Done with wave file ++++++++++\r\n");
tom_coxon	2:affcc36a50b4	150	fclose(wavfile);
tom_coxon	2:affcc36a50b4	151	}
tom_coxon	2:affcc36a50b4	152
tom_coxon	2:affcc36a50b4	153

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	03 Jul 2010
Imports:	48
Forks:	0
Commits:	3
Dependents:	0
Dependencies:	1
Followers:	1

wavplayer.cpp@2:affcc36a50b4, 2010-07-25 (annotated)

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