Use a one-dimensional vector for Block data
Puts the whole block in contiguous memory and reduce pointer look-up.
The change has been verified to be bit-exact.
Bug: webrtc:14089
Change-Id: I264aaf764bf53a29f23249105f704b2fdbd7e51c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/263203
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Commit-Queue: Gustaf Ullberg <gustaf@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#36983}
diff --git a/modules/audio_processing/aec3/block.h b/modules/audio_processing/aec3/block.h
index a250e4a..c1fc707 100644
--- a/modules/audio_processing/aec3/block.h
+++ b/modules/audio_processing/aec3/block.h
@@ -19,54 +19,72 @@
namespace webrtc {
+// Contains one or more channels of 4 milliseconds of audio data.
+// The audio is split in one or more frequency bands, each with a sampling
+// rate of 16 kHz.
class Block {
public:
Block(int num_bands, int num_channels, float default_value = 0.0f)
- : data_(num_bands,
- std::vector<std::array<float, kBlockSize>>(
- num_channels,
- std::array<float, kBlockSize>({default_value}))) {}
+ : num_bands_(num_bands),
+ num_channels_(num_channels),
+ data_(num_bands * num_channels * kBlockSize, default_value) {}
// Returns the number of bands.
- int NumBands() const { return data_.size(); }
+ int NumBands() const { return num_bands_; }
// Returns the number of channels.
- int NumChannels() const { return data_[0].size(); }
+ int NumChannels() const { return num_channels_; }
- // Modifies the number of channels.
+ // Modifies the number of channels and sets all samples to zero.
void SetNumChannels(int num_channels) {
- for (std::vector<std::array<float, kBlockSize>>& block_band : data_) {
- block_band.resize(num_channels, std::array<float, kBlockSize>({0.0f}));
- }
+ num_channels_ = num_channels;
+ data_.resize(num_bands_ * num_channels_ * kBlockSize);
+ std::fill(data_.begin(), data_.end(), 0.0f);
}
// Iterators for accessing the data.
- auto begin(int band, int channel) { return data_[band][channel].begin(); }
-
- auto begin(int band, int channel) const {
- return data_[band][channel].begin();
+ auto begin(int band, int channel) {
+ return data_.begin() + GetIndex(band, channel);
}
- auto end(int band, int channel) { return data_[band][channel].end(); }
+ auto begin(int band, int channel) const {
+ return data_.begin() + GetIndex(band, channel);
+ }
- auto end(int band, int channel) const { return data_[band][channel].end(); }
+ auto end(int band, int channel) { return begin(band, channel) + kBlockSize; }
+
+ auto end(int band, int channel) const {
+ return begin(band, channel) + kBlockSize;
+ }
// Access data via ArrayView.
rtc::ArrayView<float, kBlockSize> View(int band, int channel) {
- return rtc::ArrayView<float, kBlockSize>(data_[band][channel].data(),
+ return rtc::ArrayView<float, kBlockSize>(&data_[GetIndex(band, channel)],
kBlockSize);
}
rtc::ArrayView<const float, kBlockSize> View(int band, int channel) const {
- return rtc::ArrayView<const float, kBlockSize>(data_[band][channel].data(),
- kBlockSize);
+ return rtc::ArrayView<const float, kBlockSize>(
+ &data_[GetIndex(band, channel)], kBlockSize);
}
// Lets two Blocks swap audio data.
- void Swap(Block& b) { data_.swap(b.data_); }
+ void Swap(Block& b) {
+ std::swap(num_bands_, b.num_bands_);
+ std::swap(num_channels_, b.num_channels_);
+ data_.swap(b.data_);
+ }
private:
- std::vector<std::vector<std::array<float, kBlockSize>>> data_;
+ // Returns the index of the first sample of the requested |band| and
+ // |channel|.
+ int GetIndex(int band, int channel) const {
+ return (band * num_channels_ + channel) * kBlockSize;
+ }
+
+ int num_bands_;
+ int num_channels_;
+ std::vector<float> data_;
};
} // namespace webrtc
