diff options
Diffstat (limited to 'services/audioflinger/test-resample.cpp')
| -rw-r--r-- | services/audioflinger/test-resample.cpp | 21 |
1 files changed, 5 insertions, 16 deletions
diff --git a/services/audioflinger/test-resample.cpp b/services/audioflinger/test-resample.cpp index 78c9927..84a655a 100644 --- a/services/audioflinger/test-resample.cpp +++ b/services/audioflinger/test-resample.cpp @@ -383,20 +383,8 @@ int main(int argc, char* argv[]) { AudioResampler* resampler = AudioResampler::create(format, channels, output_freq, quality); - - /* set volume precision to 12 bits, so the volume scale is 1<<12. - * The output int32_t is represented as Q4.27, with 4 bits of guard - * followed by the int16_t Q.15 portion, and then 12 trailing bits of - * additional precision. - * - * Generally 0 < volumePrecision <= 14 (due to the limits of - * int16_t values for Volume). volumePrecision cannot be 0 due - * to rounding and shifts. - */ - const int volumePrecision = 12; // in bits - resampler->setSampleRate(input_freq); - resampler->setVolume(1 << volumePrecision, 1 << volumePrecision); + resampler->setVolume(AudioResampler::UNITY_GAIN_FLOAT, AudioResampler::UNITY_GAIN_FLOAT); if (profileResample) { /* @@ -481,19 +469,20 @@ int main(int argc, char* argv[]) { int32_t* out = (int32_t*) output_vaddr; int16_t* convert = (int16_t*) malloc(output_frames * channels * sizeof(int16_t)); + const int volumeShift = 12; // shift requirement for Q4.27 to Q.15 // round to half towards zero and saturate at int16 (non-dithered) - const int roundVal = (1<<(volumePrecision-1)) - 1; // volumePrecision > 0 + const int roundVal = (1<<(volumeShift-1)) - 1; // volumePrecision > 0 for (size_t i = 0; i < output_frames; i++) { for (int j = 0; j < channels; j++) { int32_t s = out[i * output_channels + j] + roundVal; // add offset here if (s < 0) { - s = (s + 1) >> volumePrecision; // round to 0 + s = (s + 1) >> volumeShift; // round to 0 if (s < -32768) { s = -32768; } } else { - s = s >> volumePrecision; + s = s >> volumeShift; if (s > 32767) { s = 32767; } |