diff options
Diffstat (limited to 'chromium/third_party/webrtc/common_audio/signal_processing/splitting_filter.c')
| -rw-r--r-- | chromium/third_party/webrtc/common_audio/signal_processing/splitting_filter.c | 60 |
1 files changed, 33 insertions, 27 deletions
diff --git a/chromium/third_party/webrtc/common_audio/signal_processing/splitting_filter.c b/chromium/third_party/webrtc/common_audio/signal_processing/splitting_filter.c index cf6ec9d7b16..dbda042277c 100644 --- a/chromium/third_party/webrtc/common_audio/signal_processing/splitting_filter.c +++ b/chromium/third_party/webrtc/common_audio/signal_processing/splitting_filter.c @@ -15,10 +15,12 @@ #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h" -// Number of samples in a low/high-band frame. +#include <assert.h> + +// Maximum number of samples in a low/high-band frame. enum { - kBandFrameLength = 160 + kMaxBandFrameLength = 240 // 10 ms at 48 kHz. }; // QMF filter coefficients in Q16. @@ -116,34 +118,37 @@ void WebRtcSpl_AllPassQMF(int32_t* in_data, int16_t data_length, filter_state[5] = out_data[data_length - 1]; // y[N-1], becomes y[-1] next time } -void WebRtcSpl_AnalysisQMF(const int16_t* in_data, int16_t* low_band, - int16_t* high_band, int32_t* filter_state1, - int32_t* filter_state2) +void WebRtcSpl_AnalysisQMF(const int16_t* in_data, int in_data_length, + int16_t* low_band, int16_t* high_band, + int32_t* filter_state1, int32_t* filter_state2) { int16_t i; int16_t k; int32_t tmp; - int32_t half_in1[kBandFrameLength]; - int32_t half_in2[kBandFrameLength]; - int32_t filter1[kBandFrameLength]; - int32_t filter2[kBandFrameLength]; + int32_t half_in1[kMaxBandFrameLength]; + int32_t half_in2[kMaxBandFrameLength]; + int32_t filter1[kMaxBandFrameLength]; + int32_t filter2[kMaxBandFrameLength]; + const int band_length = in_data_length / 2; + assert(in_data_length % 2 == 0); + assert(band_length <= kMaxBandFrameLength); // Split even and odd samples. Also shift them to Q10. - for (i = 0, k = 0; i < kBandFrameLength; i++, k += 2) + for (i = 0, k = 0; i < band_length; i++, k += 2) { half_in2[i] = WEBRTC_SPL_LSHIFT_W32((int32_t)in_data[k], 10); half_in1[i] = WEBRTC_SPL_LSHIFT_W32((int32_t)in_data[k + 1], 10); } // All pass filter even and odd samples, independently. - WebRtcSpl_AllPassQMF(half_in1, kBandFrameLength, filter1, WebRtcSpl_kAllPassFilter1, - filter_state1); - WebRtcSpl_AllPassQMF(half_in2, kBandFrameLength, filter2, WebRtcSpl_kAllPassFilter2, - filter_state2); + WebRtcSpl_AllPassQMF(half_in1, band_length, filter1, + WebRtcSpl_kAllPassFilter1, filter_state1); + WebRtcSpl_AllPassQMF(half_in2, band_length, filter2, + WebRtcSpl_kAllPassFilter2, filter_state2); // Take the sum and difference of filtered version of odd and even // branches to get upper & lower band. - for (i = 0; i < kBandFrameLength; i++) + for (i = 0; i < band_length; i++) { tmp = filter1[i] + filter2[i] + 1024; tmp = WEBRTC_SPL_RSHIFT_W32(tmp, 11); @@ -156,20 +161,21 @@ void WebRtcSpl_AnalysisQMF(const int16_t* in_data, int16_t* low_band, } void WebRtcSpl_SynthesisQMF(const int16_t* low_band, const int16_t* high_band, - int16_t* out_data, int32_t* filter_state1, - int32_t* filter_state2) + int band_length, int16_t* out_data, + int32_t* filter_state1, int32_t* filter_state2) { int32_t tmp; - int32_t half_in1[kBandFrameLength]; - int32_t half_in2[kBandFrameLength]; - int32_t filter1[kBandFrameLength]; - int32_t filter2[kBandFrameLength]; + int32_t half_in1[kMaxBandFrameLength]; + int32_t half_in2[kMaxBandFrameLength]; + int32_t filter1[kMaxBandFrameLength]; + int32_t filter2[kMaxBandFrameLength]; int16_t i; int16_t k; + assert(band_length <= kMaxBandFrameLength); // Obtain the sum and difference channels out of upper and lower-band channels. // Also shift to Q10 domain. - for (i = 0; i < kBandFrameLength; i++) + for (i = 0; i < band_length; i++) { tmp = (int32_t)low_band[i] + (int32_t)high_band[i]; half_in1[i] = WEBRTC_SPL_LSHIFT_W32(tmp, 10); @@ -178,15 +184,15 @@ void WebRtcSpl_SynthesisQMF(const int16_t* low_band, const int16_t* high_band, } // all-pass filter the sum and difference channels - WebRtcSpl_AllPassQMF(half_in1, kBandFrameLength, filter1, WebRtcSpl_kAllPassFilter2, - filter_state1); - WebRtcSpl_AllPassQMF(half_in2, kBandFrameLength, filter2, WebRtcSpl_kAllPassFilter1, - filter_state2); + WebRtcSpl_AllPassQMF(half_in1, band_length, filter1, + WebRtcSpl_kAllPassFilter2, filter_state1); + WebRtcSpl_AllPassQMF(half_in2, band_length, filter2, + WebRtcSpl_kAllPassFilter1, filter_state2); // The filtered signals are even and odd samples of the output. Combine // them. The signals are Q10 should shift them back to Q0 and take care of // saturation. - for (i = 0, k = 0; i < kBandFrameLength; i++) + for (i = 0, k = 0; i < band_length; i++) { tmp = WEBRTC_SPL_RSHIFT_W32(filter2[i] + 512, 10); out_data[k++] = WebRtcSpl_SatW32ToW16(tmp); |