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Refactoring vad_filterbank: Style changes.

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Consists of:
- variable names.
- variable initialization.
- ordered input/output parameters.

TEST=vad_unittest, audioproc_unittest
Review URL: http://webrtc-codereview.appspot.com/339004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@1345 4adac7df-926f-26a2-2b94-8c16560cd09d
This commit is contained in:
bjornv@webrtc.org 2012-01-05 08:42:39 +00:00
parent 3aa25de346
commit 8f4a4ce13b
2 changed files with 136 additions and 134 deletions
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246
src/common_audio/vad/vad_filterbank.c
View File

@ -34,14 +34,14 @@ static const int16_t kAllPassCoefsQ15[2] = { 20972, 5571 };
static const int16_t kOffsetVector[6] = { 368, 368, 272, 176, 176, 176 };
void WebRtcVad_HpOutput(int16_t* in_vector,
int16_t in_vector_length,
int16_t* out_vector,
int16_t* filter_state) {
int16_t i, *pi, *outPtr;
int32_t tmpW32;
int in_vector_length,
int16_t* filter_state,
int16_t* out_vector) {
int i;
int16_t* in_ptr = in_vector;
int16_t* out_ptr = out_vector;
int32_t tmp32 = 0;
pi = &in_vector[0];
outPtr = &out_vector[0];
// The sum of the absolute values of the impulse response:
// The zero/pole-filter has a max amplification of a single sample of: 1.4546
@ -53,41 +53,40 @@ void WebRtcVad_HpOutput(int16_t* in_vector,
for (i = 0; i < in_vector_length; i++) {
// all-zero section (filter coefficients in Q14)
tmpW32 = (int32_t) WEBRTC_SPL_MUL_16_16(kHpZeroCoefs[0], (*pi));
tmpW32 += (int32_t) WEBRTC_SPL_MUL_16_16(kHpZeroCoefs[1], filter_state[0]);
tmpW32 += (int32_t) WEBRTC_SPL_MUL_16_16(kHpZeroCoefs[2],
filter_state[1]); // Q14
tmp32 = (int32_t) WEBRTC_SPL_MUL_16_16(kHpZeroCoefs[0], (*in_ptr));
tmp32 += (int32_t) WEBRTC_SPL_MUL_16_16(kHpZeroCoefs[1], filter_state[0]);
tmp32 += (int32_t) WEBRTC_SPL_MUL_16_16(kHpZeroCoefs[2],
filter_state[1]); // Q14
filter_state[1] = filter_state[0];
filter_state[0] = *pi++;
filter_state[0] = *in_ptr++;
// all-pole section
tmpW32 -= (int32_t) WEBRTC_SPL_MUL_16_16(kHpPoleCoefs[1],
filter_state[2]); // Q14
tmpW32 -= (int32_t) WEBRTC_SPL_MUL_16_16(kHpPoleCoefs[2], filter_state[3]);
tmp32 -= (int32_t) WEBRTC_SPL_MUL_16_16(kHpPoleCoefs[1],
filter_state[2]); // Q14
tmp32 -= (int32_t) WEBRTC_SPL_MUL_16_16(kHpPoleCoefs[2], filter_state[3]);
filter_state[3] = filter_state[2];
filter_state[2] = (int16_t) WEBRTC_SPL_RSHIFT_W32 (tmpW32, 14);
*outPtr++ = filter_state[2];
filter_state[2] = (int16_t) WEBRTC_SPL_RSHIFT_W32 (tmp32, 14);
*out_ptr++ = filter_state[2];
}
}
void WebRtcVad_Allpass(int16_t* in_vector,
int16_t* out_vector,
int16_t filter_coefficients,
int vector_length,
int16_t* filter_state) {
int16_t* filter_state,
int16_t* out_vector) {
// The filter can only cause overflow (in the w16 output variable)
// if more than 4 consecutive input numbers are of maximum value and
// has the the same sign as the impulse responses first taps.
// First 6 taps of the impulse response: 0.6399 0.5905 -0.3779
// 0.2418 -0.1547 0.0990
int n;
int16_t tmp16;
int32_t tmp32, in32, state32;
int i;
int16_t tmp16 = 0;
int32_t tmp32 = 0, in32 = 0;
int32_t state32 = WEBRTC_SPL_LSHIFT_W32((int32_t) (*filter_state), 16); // Q31
state32 = WEBRTC_SPL_LSHIFT_W32(((int32_t) (*filter_state)), 16); // Q31
for (n = 0; n < vector_length; n++) {
for (i = 0; i < vector_length; i++) {
tmp32 = state32 + WEBRTC_SPL_MUL_16_16(filter_coefficients, (*in_vector));
tmp16 = (int16_t) WEBRTC_SPL_RSHIFT_W32(tmp32, 16);
*out_vector++ = tmp16;
@ -101,30 +100,28 @@ void WebRtcVad_Allpass(int16_t* in_vector,
}
void WebRtcVad_SplitFilter(int16_t* in_vector,
int16_t* out_vector_hp,
int16_t* out_vector_lp,
int in_vector_length,
int16_t* upper_state,
int16_t* lower_state,
int in_vector_length) {
int16_t tmpOut;
int k, halflen;
// Downsampling by 2 and get two branches
halflen = WEBRTC_SPL_RSHIFT_W16(in_vector_length, 1);
int16_t* out_vector_hp,
int16_t* out_vector_lp) {
int16_t tmp_out;
int i;
int half_length = WEBRTC_SPL_RSHIFT_W16(in_vector_length, 1);
// All-pass filtering upper branch
WebRtcVad_Allpass(&in_vector[0], out_vector_hp, kAllPassCoefsQ15[0], halflen,
upper_state);
WebRtcVad_Allpass(&in_vector[0], kAllPassCoefsQ15[0], half_length,
upper_state, out_vector_hp);
// All-pass filtering lower branch
WebRtcVad_Allpass(&in_vector[1], out_vector_lp, kAllPassCoefsQ15[1], halflen,
lower_state);
WebRtcVad_Allpass(&in_vector[1], kAllPassCoefsQ15[1], half_length,
lower_state, out_vector_lp);
// Make LP and HP signals
for (k = 0; k < halflen; k++) {
tmpOut = *out_vector_hp;
for (i = 0; i < half_length; i++) {
tmp_out = *out_vector_hp;
*out_vector_hp++ -= *out_vector_lp;
*out_vector_lp++ += tmpOut;
*out_vector_lp++ += tmp_out;
}
}
@ -132,145 +129,150 @@ int16_t WebRtcVad_get_features(VadInstT* inst,
int16_t* in_vector,
int frame_size,
int16_t* out_vector) {
int curlen, filtno;
int16_t vecHP1[120], vecLP1[120];
int16_t vecHP2[60], vecLP2[60];
int16_t *ptin;
int16_t *hptout, *lptout;
int16_t power = 0;
// We expect |frame_size| to be 80, 160 or 240 samples, which corresponds to
// 10, 20 or 30 ms in 8 kHz. Therefore, the intermediate downsampled data will
// have at most 120 samples after the first split and at most 60 samples after
// the second split.
int16_t hp_120[120], lp_120[120];
int16_t hp_60[60], lp_60[60];
// Initialize variables for the first SplitFilter().
int length = frame_size;
int frequency_band = 0;
int16_t* in_ptr = in_vector;
int16_t* hp_out_ptr = hp_120;
int16_t* lp_out_ptr = lp_120;
// Split at 2000 Hz and downsample
filtno = 0;
ptin = in_vector;
hptout = vecHP1;
lptout = vecLP1;
curlen = frame_size;
WebRtcVad_SplitFilter(ptin, hptout, lptout, &inst->upper_state[filtno],
&inst->lower_state[filtno], curlen);
WebRtcVad_SplitFilter(in_ptr, length, &inst->upper_state[frequency_band],
&inst->lower_state[frequency_band], hp_out_ptr,
lp_out_ptr);
// Split at 3000 Hz and downsample
filtno = 1;
ptin = vecHP1;
hptout = vecHP2;
lptout = vecLP2;
curlen = WEBRTC_SPL_RSHIFT_W16(frame_size, 1);
frequency_band = 1;
in_ptr = hp_120;
hp_out_ptr = hp_60;
lp_out_ptr = lp_60;
length = WEBRTC_SPL_RSHIFT_W16(frame_size, 1);
WebRtcVad_SplitFilter(ptin, hptout, lptout, &inst->upper_state[filtno],
&inst->lower_state[filtno], curlen);
WebRtcVad_SplitFilter(in_ptr, length, &inst->upper_state[frequency_band],
&inst->lower_state[frequency_band], hp_out_ptr,
lp_out_ptr);
// Energy in 3000 Hz - 4000 Hz
curlen = WEBRTC_SPL_RSHIFT_W16(curlen, 1);
WebRtcVad_LogOfEnergy(vecHP2, &out_vector[5], &power, kOffsetVector[5],
curlen);
length = WEBRTC_SPL_RSHIFT_W16(length, 1);
WebRtcVad_LogOfEnergy(hp_60, length, kOffsetVector[5], &power,
&out_vector[5]);
// Energy in 2000 Hz - 3000 Hz
WebRtcVad_LogOfEnergy(vecLP2, &out_vector[4], &power, kOffsetVector[4],
curlen);
WebRtcVad_LogOfEnergy(lp_60, length, kOffsetVector[4], &power,
&out_vector[4]);
// Split at 1000 Hz and downsample
filtno = 2;
ptin = vecLP1;
hptout = vecHP2;
lptout = vecLP2;
curlen = WEBRTC_SPL_RSHIFT_W16(frame_size, 1);
WebRtcVad_SplitFilter(ptin, hptout, lptout, &inst->upper_state[filtno],
&inst->lower_state[filtno], curlen);
frequency_band = 2;
in_ptr = lp_120;
hp_out_ptr = hp_60;
lp_out_ptr = lp_60;
length = WEBRTC_SPL_RSHIFT_W16(frame_size, 1);
WebRtcVad_SplitFilter(in_ptr, length, &inst->upper_state[frequency_band],
&inst->lower_state[frequency_band], hp_out_ptr,
lp_out_ptr);
// Energy in 1000 Hz - 2000 Hz
curlen = WEBRTC_SPL_RSHIFT_W16(curlen, 1);
WebRtcVad_LogOfEnergy(vecHP2, &out_vector[3], &power, kOffsetVector[3],
curlen);
length = WEBRTC_SPL_RSHIFT_W16(length, 1);
WebRtcVad_LogOfEnergy(hp_60, length, kOffsetVector[3], &power,
&out_vector[3]);
// Split at 500 Hz
filtno = 3;
ptin = vecLP2;
hptout = vecHP1;
lptout = vecLP1;
frequency_band = 3;
in_ptr = lp_60;
hp_out_ptr = hp_120;
lp_out_ptr = lp_120;
WebRtcVad_SplitFilter(ptin, hptout, lptout, &inst->upper_state[filtno],
&inst->lower_state[filtno], curlen);
WebRtcVad_SplitFilter(in_ptr, length, &inst->upper_state[frequency_band],
&inst->lower_state[frequency_band], hp_out_ptr,
lp_out_ptr);
// Energy in 500 Hz - 1000 Hz
curlen = WEBRTC_SPL_RSHIFT_W16(curlen, 1);
WebRtcVad_LogOfEnergy(vecHP1, &out_vector[2], &power, kOffsetVector[2],
curlen);
// Split at 250 Hz
filtno = 4;
ptin = vecLP1;
hptout = vecHP2;
lptout = vecLP2;
length = WEBRTC_SPL_RSHIFT_W16(length, 1);
WebRtcVad_LogOfEnergy(hp_120, length, kOffsetVector[2], &power,
&out_vector[2]);
WebRtcVad_SplitFilter(ptin, hptout, lptout, &inst->upper_state[filtno],
&inst->lower_state[filtno], curlen);
// Split at 250 Hz
frequency_band = 4;
in_ptr = lp_120;
hp_out_ptr = hp_60;
lp_out_ptr = lp_60;
WebRtcVad_SplitFilter(in_ptr, length, &inst->upper_state[frequency_band],
&inst->lower_state[frequency_band], hp_out_ptr,
lp_out_ptr);
// Energy in 250 Hz - 500 Hz
curlen = WEBRTC_SPL_RSHIFT_W16(curlen, 1);
WebRtcVad_LogOfEnergy(vecHP2, &out_vector[1], &power, kOffsetVector[1],
curlen);
length = WEBRTC_SPL_RSHIFT_W16(length, 1);
WebRtcVad_LogOfEnergy(hp_60, length, kOffsetVector[1], &power,
&out_vector[1]);
// Remove DC and LFs
WebRtcVad_HpOutput(vecLP2, curlen, vecHP1, inst->hp_filter_state);
WebRtcVad_HpOutput(lp_60, length, inst->hp_filter_state, hp_120);
// Power in 80 Hz - 250 Hz
WebRtcVad_LogOfEnergy(vecHP1, &out_vector[0], &power, kOffsetVector[0],
curlen);
WebRtcVad_LogOfEnergy(hp_120, length, kOffsetVector[0], &power,
&out_vector[0]);
return power;
}
void WebRtcVad_LogOfEnergy(int16_t* vector,
int16_t* enerlogval,
int16_t* power,
int vector_length,
int16_t offset,
int vector_length) {
int16_t enerSum = 0;
int16_t zeros, frac, log2;
int32_t energy;
int shfts = 0, shfts2;
energy = WebRtcSpl_Energy(vector, vector_length, &shfts);
int16_t* power,
int16_t* log_energy) {
int shfts = 0, shfts2 = 0;
int16_t energy_s16 = 0;
int16_t zeros = 0, frac = 0, log2 = 0;
int32_t energy = WebRtcSpl_Energy(vector, vector_length, &shfts);
if (energy > 0) {
shfts2 = 16 - WebRtcSpl_NormW32(energy);
shfts += shfts2;
// "shfts" is the total number of right shifts that has been done to
// enerSum.
enerSum = (int16_t) WEBRTC_SPL_SHIFT_W32(energy, -shfts2);
// energy_s16.
energy_s16 = (int16_t) WEBRTC_SPL_SHIFT_W32(energy, -shfts2);
// Find:
// 160*log10(enerSum*2^shfts) = 160*log10(2)*log2(enerSum*2^shfts) =
// 160*log10(2)*(log2(enerSum) + log2(2^shfts)) =
// 160*log10(2)*(log2(enerSum) + shfts)
// 160*log10(energy_s16*2^shfts) = 160*log10(2)*log2(energy_s16*2^shfts) =
// 160*log10(2)*(log2(energy_s16) + log2(2^shfts)) =
// 160*log10(2)*(log2(energy_s16) + shfts)
zeros = WebRtcSpl_NormU32(enerSum);
frac = (int16_t) (((uint32_t) ((int32_t) (enerSum) << zeros) & 0x7FFFFFFF)
>> 21);
zeros = WebRtcSpl_NormU32(energy_s16);
frac = (int16_t) (((uint32_t) ((int32_t) (energy_s16) << zeros)
& 0x7FFFFFFF) >> 21);
log2 = (int16_t) (((31 - zeros) << 10) + frac);
*enerlogval = (int16_t) WEBRTC_SPL_MUL_16_16_RSFT(kLogConst, log2, 19)
*log_energy = (int16_t) WEBRTC_SPL_MUL_16_16_RSFT(kLogConst, log2, 19)
+ (int16_t) WEBRTC_SPL_MUL_16_16_RSFT(shfts, kLogConst, 9);
if (*enerlogval < 0) {
*enerlogval = 0;
if (*log_energy < 0) {
*log_energy = 0;
}
} else {
*enerlogval = 0;
*log_energy = 0;
shfts = -15;
enerSum = 0;
energy_s16 = 0;
}
*enerlogval += offset;
*log_energy += offset;
// Total power in frame
if (*power <= MIN_ENERGY) {
if (shfts > 0) {
*power += MIN_ENERGY + 1;
} else if (WEBRTC_SPL_SHIFT_W16(enerSum, shfts) > MIN_ENERGY) {
} else if (WEBRTC_SPL_SHIFT_W16(energy_s16, shfts) > MIN_ENERGY) {
*power += MIN_ENERGY + 1;
} else {
*power += WEBRTC_SPL_SHIFT_W16(enerSum, shfts);
*power += WEBRTC_SPL_SHIFT_W16(energy_s16, shfts);
}
}
}

24
src/common_audio/vad/vad_filterbank.h
View File

@ -36,9 +36,9 @@
*
*/
void WebRtcVad_HpOutput(int16_t* in_vector,
int16_t in_vector_length,
int16_t* out_vector,
int16_t* filter_state);
int in_vector_length,
int16_t* filter_state,
int16_t* out_vector);
/****************************************************************************
* WebRtcVad_Allpass(...)
@ -60,10 +60,10 @@ void WebRtcVad_HpOutput(int16_t* in_vector,
*
*/
void WebRtcVad_Allpass(int16_t* in_vector,
int16_t* outw16,
int16_t filter_coefficients,
int vector_length,
int16_t* filter_state);
int16_t* filter_state,
int16_t* outw16);
/****************************************************************************
* WebRtcVad_SplitFilter(...)
@ -85,11 +85,11 @@ void WebRtcVad_Allpass(int16_t* in_vector,
*
*/
void WebRtcVad_SplitFilter(int16_t* in_vector,
int16_t* out_vector_hp,
int16_t* out_vector_lp,
int in_vector_length,
int16_t* upper_state,
int16_t* lower_state,
int in_vector_length);
int16_t* out_vector_hp,
int16_t* out_vector_lp);
/****************************************************************************
* WebRtcVad_get_features(...)
@ -130,15 +130,15 @@ int16_t WebRtcVad_get_features(VadInstT* inst,
* - vector_length : Length of input vector
*
* Output:
* - enerlogval : 10*log10(energy);
* - log_energy : 10*log10(energy);
* - power : Update total power in speech frame. NOTE! This value
* is not exact since it is only used in a comparison.
*
*/
void WebRtcVad_LogOfEnergy(int16_t* vector,
int16_t* enerlogval,
int16_t* power,
int vector_length,
int16_t offset,
int vector_length);
int16_t* power,
int16_t* log_energy);
#endif // WEBRTC_COMMON_AUDIO_VAD_VAD_FILTERBANK_H_