admin/webrtc_m130
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

RNN VAD: LP residual optimized (part 4)

Browse Source 
This CL removes the circular shift to compute the convolution in
`ComputeLpResidual()`, which is now 4x faster (benchmarked with the
`RnnVadTest.DISABLED_ComputeLpResidualBenchmark` unit test).

Note that the `RnnVadTest.LpResidualPipelineBitExactness` unit test
is still passing.

Bug: webrtc:10480
Change-Id: Ia7767d9b57378c12c8ff31f58fea03905be5c5de
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/189964
Commit-Queue: Alessio Bazzica <alessiob@webrtc.org>
Reviewed-by: Per Åhgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32491}
This commit is contained in:
Alessio Bazzica 2020-10-26 12:09:28 +01:00 committed by Commit Bot
parent 83514a7704
commit 0fb0eb3e80
3 changed files with 18 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
modules/audio_processing/agc2/rnn_vad/BUILD.gn
View File

@ -75,6 +75,7 @@ rtc_library("rnn_vad_lp_residual") {
deps = [
"../../../../api:array_view",
"../../../../rtc_base:checks",
"../../../../rtc_base:safe_compare",
]
}

28
modules/audio_processing/agc2/rnn_vad/lp_residual.cc
View File

@ -16,6 +16,7 @@
#include <numeric>
#include "rtc_base/checks.h"
#include "rtc_base/numerics/safe_compare.h"
namespace webrtc {
namespace rnn_vad {
@ -117,19 +118,22 @@ void ComputeLpResidual(
rtc::ArrayView<const float, kNumLpcCoefficients> lpc_coeffs,
rtc::ArrayView<const float> x,
rtc::ArrayView<float> y) {
RTC_DCHECK_LT(kNumLpcCoefficients, x.size());
RTC_DCHECK_GT(x.size(), kNumLpcCoefficients);
RTC_DCHECK_EQ(x.size(), y.size());
std::array<float, kNumLpcCoefficients> input_chunk;
input_chunk.fill(0.f);
for (size_t i = 0; i < y.size(); ++i) {
const float sum = std::inner_product(input_chunk.begin(), input_chunk.end(),
lpc_coeffs.begin(), x[i]);
// Circular shift and add a new sample.
for (size_t j = kNumLpcCoefficients - 1; j > 0; --j)
input_chunk[j] = input_chunk[j - 1];
input_chunk[0] = x[i];
// Copy result.
y[i] = sum;
// The code below implements the following operation:
// y[i] = x[i] + dot_product({x[i], ..., x[i - kNumLpcCoefficients + 1]},
// lpc_coeffs)
// Edge case: i < kNumLpcCoefficients.
y[0] = x[0];
for (int i = 1; i < kNumLpcCoefficients; ++i) {
y[i] =
std::inner_product(x.crend() - i, x.crend(), lpc_coeffs.cbegin(), x[i]);
}
// Regular case.
auto last = x.crend();
for (int i = kNumLpcCoefficients; rtc::SafeLt(i, y.size()); ++i, --last) {
y[i] = std::inner_product(last - kNumLpcCoefficients, last,
lpc_coeffs.cbegin(), x[i]);
}
}

2
modules/audio_processing/agc2/rnn_vad/lp_residual.h
View File

@ -19,7 +19,7 @@ namespace webrtc {
namespace rnn_vad {
// LPC inverse filter length.
constexpr size_t kNumLpcCoefficients = 5;
constexpr int kNumLpcCoefficients = 5;
// Given a frame |x|, computes a post-processed version of LPC coefficients
// tailored for pitch estimation.