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Diffstat (limited to 'Project/RTDSP/enhance.c')
| -rw-r--r-- | Project/RTDSP/enhance.c | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/Project/RTDSP/enhance.c b/Project/RTDSP/enhance.c new file mode 100644 index 0000000..9829c00 --- /dev/null +++ b/Project/RTDSP/enhance.c @@ -0,0 +1,301 @@ +/************************************************************************************* + DEPARTMENT OF ELECTRICAL AND ELECTRONIC ENGINEERING + IMPERIAL COLLEGE LONDON + + EE 3.19: Real Time Digital Signal Processing + Dr Paul Mitcheson and Daniel Harvey + + PROJECT: Frame Processing + + ********* ENHANCE. C ********** + Shell for speech enhancement + + Demonstrates overlap-add frame processing (interrupt driven) on the DSK. + + ************************************************************************************* + By Danny Harvey: 21 July 2006 + Updated for use on CCS v4 Sept 2010 + ************************************************************************************/ +/* + * You should modify the code so that a speech enhancement project is built + * on top of this template. + */ +/**************************** Pre-processor statements ******************************/ +// library required when using calloc +#include <stdlib.h> +// Included so program can make use of DSP/BIOS configuration tool. +#include "dsp_bios_cfg.h" + +/* The file dsk6713.h must be included in every program that uses the BSL. This + example also includes dsk6713_aic23.h because it uses the + AIC23 codec module (audio interface). */ +#include "dsk6713.h" +#include "dsk6713_aic23.h" + +// math library (trig functions) +#include <math.h> + +/* Some functions to help with Complex algebra and FFT. */ +#include "cmplx.h" +#include "fft_functions.h" + +// Some functions to help with writing/reading the audio ports when using interrupts. +#include <helper_functions_ISR.h> + +#define WINCONST 0.85185 /* 0.46/0.54 for Hamming window */ +#define FSAMP 8000.0 /* sample frequency, ensure this matches Config for AIC */ +#define FFTLEN 256 /* fft length = frame length 256/8000 = 32 ms*/ +#define NFREQ (1+FFTLEN/2) /* number of frequency bins from a real FFT */ +#define OVERSAMP 4 /* oversampling ratio (2 or 4) */ +#define FRAMEINC (FFTLEN/OVERSAMP) /* Frame increment */ +#define CIRCBUF (FFTLEN+FRAMEINC) /* length of I/O buffers */ +#define FRAME_TIME 2.5 +#define MAX_COUNT 1000 +#define MAX_FLOAT 3.4E+38 +#define OUTGAIN 16000.0 /* Output gain for DAC */ +#define INGAIN (1.0/16000.0) /* Input gain for ADC */ +#define NUM_M 4 +// PI defined here for use in your code +#define PI 3.141592653589793 +#define TFRAME FRAMEINC/FSAMP /* time between calculation of each frame */ + +/******************************* Global declarations ********************************/ + +/* Audio port configuration settings: these values set registers in the AIC23 audio + interface to configure it. See TI doc SLWS106D 3-3 to 3-10 for more info. */ +DSK6713_AIC23_Config Config = { \ + /**********************************************************************/ + /* REGISTER FUNCTION SETTINGS */ + /**********************************************************************/\ + 0x0017, /* 0 LEFTINVOL Left line input channel volume 0dB */\ + 0x0017, /* 1 RIGHTINVOL Right line input channel volume 0dB */\ + 0x01f9, /* 2 LEFTHPVOL Left channel headphone volume 0dB */\ + 0x01f9, /* 3 RIGHTHPVOL Right channel headphone volume 0dB */\ + 0x0011, /* 4 ANAPATH Analog audio path control DAC on, Mic boost 20dB*/\ + 0x0000, /* 5 DIGPATH Digital audio path control All Filters off */\ + 0x0000, /* 6 DPOWERDOWN Power down control All Hardware on */\ + 0x0043, /* 7 DIGIF Digital audio interface format 16 bit */\ + 0x008d, /* 8 SAMPLERATE Sample rate control 8 KHZ-ensure matches FSAMP */\ + 0x0001 /* 9 DIGACT Digital interface activation On */\ + /**********************************************************************/ +}; + +typedef struct { + complex *spec; + float mag_avg; +} Spectrum; + +// Codec handle:- a variable used to identify audio interface +DSK6713_AIC23_CodecHandle H_Codec; + +float *inbuffer, *outbuffer; /* Input/output circular buffers */ +float *inframe, *outframe; /* Input and output frames */ +float *inwin, *outwin; /* Input and output windows */ +float ingain, outgain; /* ADC and DAC gains */ +float cpufrac; /* Fraction of CPU time used */ +complex *fft_out; /* FFT output */ +volatile int io_ptr=0; /* Input/ouput pointer for circular buffers */ +volatile int frame_ptr=0; /* Frame pointer */ +volatile int frame_ctr =0; +double avg = 0; +Spectrum M[NUM_M]; + /******************************* Function prototypes *******************************/ +void init_hardware(void); /* Initialize codec */ +void init_HWI(void); /* Initialize hardware interrupts */ +void ISR_AIC(void); /* Interrupt service routine for codec */ +void process_frame(void); /* Frame processing routine */ + +/********************************** Main routine ************************************/ +void main() +{ + + int k; // used in various for loops + +/* Initialize and zero fill arrays */ + + inbuffer = (float *) calloc(CIRCBUF, sizeof(float)); /* Input array */ + outbuffer = (float *) calloc(CIRCBUF, sizeof(float)); /* Output array */ + inframe = (float *) calloc(FFTLEN, sizeof(float)); /* Array for processing*/ + outframe = (float *) calloc(FFTLEN, sizeof(float)); /* Array for processing*/ + inwin = (float *) calloc(FFTLEN, sizeof(float)); /* Input window */ + outwin = (float *) calloc(FFTLEN, sizeof(float)); /* Output window */ + fft_out = (complex *) calloc(FFTLEN, sizeof(complex)); /* FFT Output */ + + /* initialize board and the audio port */ + init_hardware(); + + /* initialize hardware interrupts */ + init_HWI(); + +/* initialize algorithm constants */ + + for (k=0;k<FFTLEN;++k) + { + inwin[k] = sqrt((1.0-WINCONST*cos(PI*(2*k+1)/FFTLEN))/OVERSAMP); + outwin[k] = inwin[k]; + } + ingain=INGAIN; + outgain=OUTGAIN; + + for (k = 0; k < NUM_M; ++k) + { + int i; + M[k].spec = (complex *) calloc(FFTLEN, sizeof(complex)); + M[k].mag_avg = MAX_FLOAT; + for(i = 0; i < FFTLEN; ++i) { + M[k].spec[i].r = MAX_FLOAT; + M[k].spec[i].i = MAX_FLOAT; + } + } + + + /* main loop, wait for interrupt */ + while(1) process_frame(); +} + +/********************************** init_hardware() *********************************/ +void init_hardware() +{ + // Initialize the board support library, must be called first + DSK6713_init(); + + // Start the AIC23 codec using the settings defined above in config + H_Codec = DSK6713_AIC23_openCodec(0, &Config); + + /* Function below sets the number of bits in word used by MSBSP (serial port) for + receives from AIC23 (audio port). We are using a 32 bit packet containing two + 16 bit numbers hence 32BIT is set for receive */ + MCBSP_FSETS(RCR1, RWDLEN1, 32BIT); + + /* Configures interrupt to activate on each consecutive available 32 bits + from Audio port hence an interrupt is generated for each L & R sample pair */ + MCBSP_FSETS(SPCR1, RINTM, FRM); + + /* These commands do the same thing as above but applied to data transfers to the + audio port */ + MCBSP_FSETS(XCR1, XWDLEN1, 32BIT); + MCBSP_FSETS(SPCR1, XINTM, FRM); + + +} +/********************************** init_HWI() **************************************/ +void init_HWI(void) +{ + IRQ_globalDisable(); // Globally disables interrupts + IRQ_nmiEnable(); // Enables the NMI interrupt (used by the debugger) + IRQ_map(IRQ_EVT_RINT1,4); // Maps an event to a physical interrupt + IRQ_enable(IRQ_EVT_RINT1); // Enables the event + IRQ_globalEnable(); // Globally enables interrupts + +} + +/******************************** process_frame() ***********************************/ +void process_frame(void) +{ + int k, m; + int io_ptr0; + avg = 0; + /* work out fraction of available CPU time used by algorithm */ + cpufrac = ((float) (io_ptr & (FRAMEINC - 1)))/FRAMEINC; + + /* wait until io_ptr is at the start of the current frame */ + while((io_ptr/FRAMEINC) != frame_ptr); + + /* then increment the framecount (wrapping if required) */ + if (++frame_ptr >= (CIRCBUF/FRAMEINC)) frame_ptr=0; + + /* save a pointer to the position in the I/O buffers (inbuffer/outbuffer) where the + data should be read (inbuffer) and saved (outbuffer) for the purpose of processing */ + io_ptr0=frame_ptr * FRAMEINC; + + /* copy input data from inbuffer into inframe (starting from the pointer position) */ + + m=io_ptr0; + for (k=0;k<FFTLEN;k++) + { + inframe[k] = inbuffer[m] * inwin[k]; + if (++m >= CIRCBUF) m=0; /* wrap if required */ + } + + /************************* DO PROCESSING OF FRAME HERE **************************/ + + for (k = 0; k < FFTLEN; ++k) { + fft_out[k].i = 0.0; + fft_out[k].r = inframe[k]; + } + + fft(FFTLEN, fft_out); + + for(k = 0; k < FFTLEN; ++k) { + avg += cabs(fft_out[k]); + } + avg /= FFTLEN; + + if(avg < M[0].mag_avg) { + M[0].mag_avg = avg; + for(k = 0; k < FFTLEN; ++k) { + M[0].spec[k] = fft_out[k]; + } + } + + for(k = 0; k < FFTLEN; ++k) { + fft_out[k] = M[0].spec[k]; + } + + ifft(FFTLEN, fft_out); + + if(frame_ctr > MAX_COUNT-1) { + int i; + frame_ctr = 0; + free(M[NUM_M-1].spec); + for(k = NUM_M-1; k > 0; ++k) { + M[k] = M[k-1]; + } + M[0].spec = (complex *) malloc(FFTLEN * sizeof(complex)); + M[0].mag_avg = MAX_FLOAT; + for(i = 0; i < FFTLEN; ++i) { + M[0].spec[i].r = MAX_FLOAT; + M[0].spec[i].i = MAX_FLOAT; + } + } + + for (k = 0; k < FFTLEN; ++k) { + outframe[k] = fft_out[k].r; + } + /********************************************************************************/ + + /* multiply outframe by output window and overlap-add into output buffer */ + + m=io_ptr0; + + for (k=0;k<(FFTLEN-FRAMEINC);k++) + { /* this loop adds into outbuffer */ + outbuffer[m] = outbuffer[m]+outframe[k]*outwin[k]; + if (++m >= CIRCBUF) m=0; /* wrap if required */ + } + for (;k<FFTLEN;k++) + { + outbuffer[m] = outframe[k]*outwin[k]; /* this loop over-writes outbuffer */ + m++; + } +} +/*************************** INTERRUPT SERVICE ROUTINE *****************************/ + +// Map this to the appropriate interrupt in the CDB file + +void ISR_AIC(void) +{ + short sample; + /* Read and write the ADC and DAC using inbuffer and outbuffer */ + frame_ctr++; + sample = mono_read_16Bit(); + inbuffer[io_ptr] = ((float)sample)*ingain; + /* write new output data */ + mono_write_16Bit((int)(outbuffer[io_ptr]*outgain)); + + /* update io_ptr and check for buffer wraparound */ + + if (++io_ptr >= CIRCBUF) io_ptr=0; +} + +/************************************************************************************/ |