phonerec.c

基于AVR制作的电话语音录制系统

        //dtmf_string[9]='$';
    } else {
        //dtmf_string[9]=' ';
#endif // HAVE_MMC        
        if (monitor_mode) {
            OCR2=(monitor_mode==2 || last_reported_hook==OffHook)?sample8:0;
        } else {
            OCR2=0;
        } 
#ifdef HAVE_MMC        
    }
    if (audio_status & AS_RECORDING_IN_PROGRESS) {
        *p=sample8;
    }
    if (audio_status) {
        audio_cnt++;
        audio_cnt&=(MMC_BLOCK_SIZE-1);
    }
#endif // HAVE_MMC

    unsigned char out=sample8;
    
    // ADPCM compression and on-hook/off-hook/disconnect logic
    // We are actually working with the previous sample; we run while the ADC
    // is busy converting, since it takes 832 cycles perform a conversion
    // (adc clock=64 main clock cycles * 13 adc clocks = 832 cycles).
    // Remember that we get here every 1000 cycles (8MHz/8KHz sampling rate)


#ifdef USE_ADPCM_COMPRESSION
#ifdef ADPCM_USES_LONGS

    unsigned char sign;      /* Current adpcm sign bit */
    unsigned char delta;     /* Current adpcm output value */
    long step;               /* Stepsize */
    long diff;               /* Difference between val and valprev */
    long vpdiff;             /* Current change to valpred */

#else // ADPCM_USES_LONGS

    unsigned char sign;      /* Current adpcm sign bit */
    unsigned char delta;     /* Current adpcm output value */
    short step;               /* Stepsize */
    short diff;               /* Difference between val and valprev */
    short vpdiff;             /* Current change to valpred */

#endif // ADPCM_USES_LONGS
#endif // USE_ADPCM_COMPRESSION

    enum hook_status_t hook=HookUnknown;

    // if (in>=126 && in<=130) val=128;
    // Transmit only if off-hook
    // if (!(ACSR & _BV(ACO))) xmit(val);

#ifdef USE_ADPCM_COMPRESSION

#ifdef USE_PROGMEM_CONSTANTS
    step = pgm_read_word(stepsizeTable+idx);
#else
    step = stepsizeTable[idx];
#endif

	diff = sample16 - inpred;
	sign = (diff < 0) ? 8 : 0;
	if ( sign ) diff = (-diff);

	/* Step 2 - Divide and clamp */
	/* Note:
	** This code *approximately* computes:
	**    delta = diff*4/step;
	**    vpdiff = (delta+0.5)*step/4;
	** but in shift step bits are dropped. The net result of this is
	** that even if you have fast mul/div hardware you cannot put it to
	** good use since the fixup would be too expensive.
	*/
	delta = 0;
	vpdiff = (step >> 3);
	
	if ( diff >= step ) {
	    delta = 4;
	    diff -= step;
	    vpdiff += step;
	}
	step >>= 1;
	if ( diff >= step  ) {
	    delta |= 2;
	    diff -= step;
	    vpdiff += step;
	}
	step >>= 1;
	if ( diff >= step ) {
	    delta |= 1;
	    vpdiff += step;
	}

#ifdef ADPCM_USES_LONGS
	/* Step 3 - Update previous value */
	if ( sign )
	  inpred -= vpdiff;
	else
	  inpred += vpdiff;

	/* Step 4 - Clamp previous value to 16 bits */
	if ( inpred > 32767 )
	  inpred = 32767;
	else if ( inpred < -32768 )
	  inpred = -32768;
#else
	/* Step 3 - Update previous value */
    if (sign) {
        if (vpdiff>0 && inpred<vpdiff-32767)
            inpred=-32768;
        else
            inpred-=vpdiff;
    } else {
        if (vpdiff>0 && inpred>32767-vpdiff)
            inpred=32767;
        else
            inpred+=vpdiff;
    }
#endif // ADPCM_USES_LONGS

	/* Step 5 - Assemble value, update index and step values */
	delta |= sign;

#ifdef USE_PROGMEM_CONSTANTS
    idx += (char)pgm_read_byte(indexTable+delta);	
#else
	idx += indexTable[delta];
#endif

	if ( idx < 0 )  idx = 0;
	if ( idx > 88 ) idx = 88;

	/* Step 6 - Output value */
    if (pending & 128) {
        out = (pending<<4)|delta;
        pending=0; 
        if (!--count) {
            count=AUDIO_BLOCK_LENGTH;
            xmit(CMD_BLOCK_START);
            xmit(CMD_ADPCM_STATE);
            xmit_short(inpred);
            xmit(idx);

            /* On-hook/Off-hook/Disconnected detection logic & debounce */
            if (ACSR & _BV(ACO)) {
                hook=Disconnected;
            } else {
                if (PINB & _BV(PB3)) {
                    hook=OnHook;
                } else {
                    hook=OffHook;
                }
            }
            if (inverts<0) inverts++;
            if (ring_age>0) {
                if (ring_age<255) ring_age--;
            } else {
                ring_age=255;
                call_timer_stop();
                call_status=CallIdle;
                stop_recording();
                ring_count=0;
            }        
            if (hook != last_hook) {
                steady=0; last_hook=hook;
                if (inverts>=0) {
                    inverts++;
                    if (inverts==4) {
                        lcd_home();
                        ring_count++;
                        if (ring_count==1) {
                            if (call_status!=CallIncoming) {
                                call_timer_reset(); 
                                call_status=CallIncoming;
                                start_recording(0);
                            }
                        }
                        inverts=-70;
                        ring_age=250;
                    }
                }
            } else {
                if (steady==STEADY_COUNT) {
                    if (inverts>0) inverts=0;
                    if (last_reported_hook!=hook) {
                        xmit(CMD_BLOCK_START);
                        xmit(hook);
                        steady=0;
                        last_reported_hook=hook;
                        if (hook==OffHook) {
                            if (call_status==CallIdle) {
                                call_timer_reset();
                                call_status=CallOutgoing;
                                dtmf_string_clear(); dialing_digits=TRUE;
                                digit_age=0;
                                start_recording(0);
                            }
                        }
                        if (hook==OnHook) {
                            call_timer_stop();
                            call_status=CallIdle;
                            stop_recording();
                            ring_count=0;
                            dtmf_string_clear();
                        }
                    }
                } else {
                    steady++;
                }
            }
        }
        if (out==CMD_BLOCK_START) xmit(out);
        xmit(out);
    } else {
        pending = (delta&15)|128; 
    }

#else   // USE_ADPCM_COMPRESSION

#ifdef HAVE_MMC
    spi_next_xmit();
#endif // HAVE_MMC

    //unsigned char ringdet=PINB & _BV(PB3);
    if (!ringdet_quell) {
        unsigned char ringdet=2;
        if (sample8>250) ringdet=1;
        if (sample8<5)   ringdet=0;
        if (ringdet==1) {
            ringdet_mids=0;
            if (last_ringdet) {
                ringdet_his++;
            } else {
                ringdet_his=0;
                if (ringdet_los>=60 || ringdet_los<=140) {
                    ringlike++;
                } else {
                    ringlike--;
                }
            }
        } else if (ringdet==0) {
            ringdet_mids=0;
            if (last_ringdet) {
                ringdet_los=0;
                if (ringdet_his>=60 || ringdet_his<=140) {
                    ringlike++;
                } else {
                    ringlike--;
                }
            } else {
                ringdet_los++;
            }
        } else {
            ringdet_mids++;
            if (ringdet_mids>100) ringdet_his=ringdet_los=ringlike=0;
        }
        last_ringdet=ringdet;
    }

    if (!--count) {
        count=AUDIO_BLOCK_LENGTH;
#define DO_HOOK_LOGIC
#ifdef DO_HOOK_LOGIC
        /* On-hook/Off-hook/Disconnected detection logic & debounce */
        if (ACSR & _BV(ACO)) {
            hook=Disconnected;
        } else {
            if (PINB & _BV(PB3)) {
                hook=OnHook;
            } else {
                hook=OffHook;
            }
        }
        if (hook != last_hook) {
            steady=0; last_hook=hook;
        } else {
            if (steady==STEADY_COUNT) {
                if (last_reported_hook!=hook) {
                    xmit(CMD_BLOCK_START);
                    xmit(hook);
                    steady=0;
                    last_reported_hook=hook;
                    if (hook==OffHook) {
                        if (call_status==CallIdle) {
                            call_timer_reset(); call_status=CallOutgoing;
                            dtmf_string_clear(); dialing_digits=TRUE;
#ifdef HAVE_LCD
                            digit_age=0;
#endif // HAVE_LCD
#ifdef HAVE_MMC
                            start_recording(0);
#endif // HAVE_MMC
                        } else if (call_status==CallIncoming) {
                            ring_age=255;
                        }
                    } else if (hook==OnHook) {
                        call_timer_stop();
                        call_status=CallIdle;
#ifdef HAVE_MMC
                        stop_recording();
#endif // HAVE_MMC
                        dtmf_string_clear();
                        ring_age=255;
                    }
                }
            } else {
                steady++;
            }
        }
#endif // DO_HOOK_LOGIC
        xmit(CMD_BLOCK_START);
        xmit(CMD_RAW_BLOCK);
    }
    //out=TCNT0;
    //if (out==CMD_BLOCK_START) xmit(out);
    //xmit(out);

#endif  // USE_ADPCM_COMPRESSION

    do_xmit();

#ifdef HAVE_MMC
#ifdef MMC_MANY_IO_BLOCKS
    spi_next_xmit(); ////////////// --- THIS
    /* MMC/SD read/write block 2 */
    do_block_mmc_io();
#endif // MMC_MANY_IO_BLOCKS
#endif // HAVE_MMC

// -- Goertzel algorithm for DTMF, ring and dial/ring/busy tone detection

#ifdef HAVE_GOERTZEL
        
    //unsigned char n;
    //for (n=0;n<3;n++) {
    //    unsigned char one=n<<1;
    //    unsigned char two=one+1;
    //    coef=pgm_read_word(gcos+n);
    //    short y=((d[one]*coef)>>8)-d[two]+sample8;
    //    d[two]=d[one]; d[one]=y;
    //}
    
    asm("lds    r30,(%0)+1  \n\t"
         "eor   r31,r31     \n\t"
         "sbrc  r30,7       \n\t"
         "com   r31         \n\t": : "m"(sample16) : "r30","r31");


    // Saves r1, which is clobbered by goertzel_inner
    asm("push r1\n\t"); 
    // Gets Y pointing to 'd'
    asm("lds  r28,%0     \n\t"
         "lds  r29,(%0)+1 \n\t" 
          : : "m" (d) : "r28", "r29");

    goertzel_inner_16(GCOS0440);
    goertzel_inner_16(GCOS0697);
    goertzel_inner_16(GCOS0770);
    goertzel_inner_16(GCOS0852);
    goertzel_inner_16(GCOS0941);
    goertzel_inner_16(GCOS1209);
    goertzel_inner_00(GCOS1336);
    goertzel_inner_08(GCOS1477);
    goertzel_inner_08(GCOS1633);
        
    do_xmit();
    
    // Restores r1
    asm("pop r1\n\t");

#ifdef HAVE_MMC
    spi_next_xmit();

#ifdef MMC_MANY_IO_BLOCKS
    /* MMC/SD read/write block 2 */
    do_block_mmc_io();
#endif // MMC_MANY_IO_BLOCKS
#endif // HAVE_MMC
            
    //y=((d[ 2]*0x1E3)>>8)-d[ 3]+c; d[ 3]=d[ 2]; d[ 2]=y;
    //y=((d[ 2]*0x1E3L)>>8)-d[ 3]+c; d[ 3]=d[ 2]; d[ 2]=y;
    //y=((d[ 4]*0x1B4L)>>8)-d[ 5]+c; d[ 5]=d[ 4]; d[ 4]=y;
    //y=((d[ 6]*0x1A3L)>>8)-d[ 7]+c; d[ 7]=d[ 6]; d[ 6]=y;