diff options
Diffstat (limited to 'media/audio/audio_power_monitor.cc')
| -rw-r--r-- | media/audio/audio_power_monitor.cc | 30 |
1 files changed, 10 insertions, 20 deletions
diff --git a/media/audio/audio_power_monitor.cc b/media/audio/audio_power_monitor.cc index d8b9436..6536f46 100644 --- a/media/audio/audio_power_monitor.cc +++ b/media/audio/audio_power_monitor.cc @@ -11,6 +11,7 @@ #include "base/logging.h" #include "base/time/time.h" #include "media/base/audio_bus.h" +#include "media/base/vector_math.h" namespace media { @@ -36,30 +37,19 @@ void AudioPowerMonitor::Scan(const AudioBus& buffer, int num_frames) { return; // Calculate a new average power by applying a first-order low-pass filter - // over the audio samples in |buffer|. - // - // TODO(miu): Implement optimized SSE/NEON to more efficiently compute the - // results (in media/base/vector_math) in soon-upcoming change. + // (a.k.a. an exponentially-weighted moving average) over the audio samples in + // each channel in |buffer|. float sum_power = 0.0f; for (int i = 0; i < num_channels; ++i) { - float average_power_this_channel = average_power_; - bool clipped = false; - const float* p = buffer.channel(i); - const float* const end_of_samples = p + num_frames; - for (; p < end_of_samples; ++p) { - const float sample = *p; - const float sample_squared = sample * sample; - clipped |= (sample_squared > 1.0f); - average_power_this_channel += - (sample_squared - average_power_this_channel) * sample_weight_; - } + const std::pair<float, float> ewma_and_max = vector_math::EWMAAndMaxPower( + average_power_, buffer.channel(i), num_frames, sample_weight_); // If data in audio buffer is garbage, ignore its effect on the result. - if (base::IsNaN(average_power_this_channel)) { - average_power_this_channel = average_power_; - clipped = false; + if (!base::IsFinite(ewma_and_max.first)) { + sum_power += average_power_; + } else { + sum_power += ewma_and_max.first; + has_clipped_ |= (ewma_and_max.second > 1.0f); } - sum_power += average_power_this_channel; - has_clipped_ |= clipped; } // Update accumulated results, with clamping for sanity. |