diff options
Diffstat (limited to 'services/audioflinger/AudioResamplerSinc.cpp')
| -rw-r--r-- | services/audioflinger/AudioResamplerSinc.cpp | 31 |
1 files changed, 18 insertions, 13 deletions
diff --git a/services/audioflinger/AudioResamplerSinc.cpp b/services/audioflinger/AudioResamplerSinc.cpp index 952abb4..d68b839 100644 --- a/services/audioflinger/AudioResamplerSinc.cpp +++ b/services/audioflinger/AudioResamplerSinc.cpp @@ -637,17 +637,20 @@ template<int CHANNELS> void AudioResamplerSinc::filterCoefficient( int32_t* out, uint32_t phase, const int16_t *samples, uint32_t vRL) { + // NOTE: be very careful when modifying the code here. register + // pressure is very high and a small change might cause the compiler + // to generate far less efficient code. + // Always sanity check the result with objdump or test-resample. + // compute the index of the coefficient on the positive side and // negative side const Constants& c(*mConstants); + const int32_t ONE = c.cMask | c.pMask; uint32_t indexP = ( phase & c.cMask) >> c.cShift; - uint32_t indexN = (-phase & c.cMask) >> c.cShift; uint32_t lerpP = ( phase & c.pMask) >> c.pShift; - uint32_t lerpN = (-phase & c.pMask) >> c.pShift; - if ((indexP == 0) && (lerpP == 0)) { - indexN = c.cMask >> c.cShift; - lerpN = c.pMask >> c.pShift; - } + uint32_t indexN = ((ONE-phase) & c.cMask) >> c.cShift; + uint32_t lerpN = ((ONE-phase) & c.pMask) >> c.pShift; + const size_t offset = c.halfNumCoefs; indexP *= offset; indexN *= offset; @@ -677,7 +680,8 @@ void AudioResamplerSinc::filterCoefficient( asm ( "vmov.32 d2[0], %[lerpP] \n" // load the positive phase "vmov.32 d2[1], %[lerpN] \n" // load the negative phase - "veor q0, q0 \n" // result, initialize to 0 + "veor q0, q0, q0 \n" // result, initialize to 0 + "vshl.s32 d2, d2, #16 \n" // convert to 32 bits "1: \n" "vld1.16 { d4}, [%[sP]] \n" // load 4 16-bits stereo samples @@ -727,8 +731,8 @@ void AudioResamplerSinc::filterCoefficient( [coefsN1] "+r" (coefsN1), [sP] "+r" (sP), [sN] "+r" (sN) - : [lerpP] "r" (lerpP<<16), - [lerpN] "r" (lerpN<<16), + : [lerpP] "r" (lerpP), + [lerpN] "r" (lerpN), [vLR] "r" (mVolumeSIMD) : "cc", "memory", "q0", "q1", "q2", "q3", @@ -742,8 +746,9 @@ void AudioResamplerSinc::filterCoefficient( asm ( "vmov.32 d2[0], %[lerpP] \n" // load the positive phase "vmov.32 d2[1], %[lerpN] \n" // load the negative phase - "veor q0, q0 \n" // result, initialize to 0 - "veor q4, q4 \n" // result, initialize to 0 + "veor q0, q0, q0 \n" // result, initialize to 0 + "veor q4, q4, q4 \n" // result, initialize to 0 + "vshl.s32 d2, d2, #16 \n" // convert to 32 bits "1: \n" "vld2.16 {d4,d5}, [%[sP]] \n" // load 4 16-bits stereo samples @@ -802,8 +807,8 @@ void AudioResamplerSinc::filterCoefficient( [coefsN1] "+r" (coefsN1), [sP] "+r" (sP), [sN] "+r" (sN) - : [lerpP] "r" (lerpP<<16), - [lerpN] "r" (lerpN<<16), + : [lerpP] "r" (lerpP), + [lerpN] "r" (lerpN), [vLR] "r" (mVolumeSIMD) : "cc", "memory", "q0", "q1", "q2", "q3", "q4", |