From 0eb19602a3a7bab20f31efe93f9de205106f5b48 Mon Sep 17 00:00:00 2001 From: ossu Date: Tue, 22 Nov 2016 05:15:21 -0800 Subject: [PATCH] ComfortNoise: Calculate used scale factor in Q13 BUG=chromium:666518 Review-Url: https://codereview.webrtc.org/2519873003 Cr-Commit-Position: refs/heads/master@{#15189} --- .../audio_coding/codecs/cng/webrtc_cng.cc | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/webrtc/modules/audio_coding/codecs/cng/webrtc_cng.cc b/webrtc/modules/audio_coding/codecs/cng/webrtc_cng.cc index b4da260dba..4c28f89c9e 100644 --- a/webrtc/modules/audio_coding/codecs/cng/webrtc_cng.cc +++ b/webrtc/modules/audio_coding/codecs/cng/webrtc_cng.cc @@ -12,6 +12,7 @@ #include +#include "webrtc/base/safe_conversions.h" #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h" namespace webrtc { @@ -118,7 +119,7 @@ bool ComfortNoiseDecoder::Generate(rtc::ArrayView out_data, int16_t ReflBetaCompStd = 6553; /* 0.2 in q15. */ int16_t ReflBetaNewP = 19661; /* 0.6 in q15. */ int16_t ReflBetaCompNewP = 13107; /* 0.4 in q15. */ - int16_t Beta, BetaC, tmp1, tmp2, tmp3; + int16_t Beta, BetaC; /* These are in Q15. */ int32_t targetEnergy; int16_t En; int16_t temp16; @@ -137,17 +138,16 @@ bool ComfortNoiseDecoder::Generate(rtc::ArrayView out_data, BetaC = ReflBetaCompStd; } - /* Here we use a 0.5 weighting, should possibly be modified to 0.6. */ - tmp1 = dec_used_scale_factor_ << 2; /* Q13->Q15 */ - tmp2 = dec_target_scale_factor_ << 2; /* Q13->Q15 */ - tmp3 = (int16_t) WEBRTC_SPL_MUL_16_16_RSFT(tmp1, Beta, 15); - tmp3 += (int16_t) WEBRTC_SPL_MUL_16_16_RSFT(tmp2, BetaC, 15); - dec_used_scale_factor_ = tmp3 >> 2; /* Q15->Q13 */ + /* Calculate new scale factor in Q13 */ + dec_used_scale_factor_ = + rtc::checked_cast( + WEBRTC_SPL_MUL_16_16_RSFT(dec_used_scale_factor_, Beta >> 2, 13) + + WEBRTC_SPL_MUL_16_16_RSFT(dec_target_scale_factor_, BetaC >> 2, 13)); dec_used_energy_ = dec_used_energy_ >> 1; dec_used_energy_ += dec_target_energy_ >> 1; - /* Do the same for the reflection coeffs. */ + /* Do the same for the reflection coeffs, albeit in Q15. */ for (size_t i = 0; i < WEBRTC_CNG_MAX_LPC_ORDER; i++) { dec_used_reflCoefs_[i] = (int16_t) WEBRTC_SPL_MUL_16_16_RSFT( dec_used_reflCoefs_[i], Beta, 15);