Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 114 insertions, 0 deletions

diff --git a/third_party/libwebrtc/modules/audio_coding/acm2/acm_remixing.cc b/third_party/libwebrtc/modules/audio_coding/acm2/acm_remixing.cc
new file mode 100644
index 0000000000..13709dbbee
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/acm2/acm_remixing.cc
@@ -0,0 +1,114 @@
+/*
+ *  Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "modules/audio_coding/acm2/acm_remixing.h"
+
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+
+void DownMixFrame(const AudioFrame& input, rtc::ArrayView<int16_t> output) {
+  RTC_DCHECK_EQ(input.num_channels_, 2);
+  RTC_DCHECK_EQ(output.size(), input.samples_per_channel_);
+
+  if (input.muted()) {
+    std::fill(output.begin(), output.begin() + input.samples_per_channel_, 0);
+  } else {
+    const int16_t* const input_data = input.data();
+    for (size_t n = 0; n < input.samples_per_channel_; ++n) {
+      output[n] = rtc::dchecked_cast<int16_t>(
+          (int32_t{input_data[2 * n]} + int32_t{input_data[2 * n + 1]}) >> 1);
+    }
+  }
+}
+
+void ReMixFrame(const AudioFrame& input,
+                size_t num_output_channels,
+                std::vector<int16_t>* output) {
+  const size_t output_size = num_output_channels * input.samples_per_channel_;
+  RTC_DCHECK(!(input.num_channels_ == 0 && num_output_channels > 0 &&
+               input.samples_per_channel_ > 0));
+
+  if (output->size() != output_size) {
+    output->resize(output_size);
+  }
+
+  // For muted frames, fill the frame with zeros.
+  if (input.muted()) {
+    std::fill(output->begin(), output->end(), 0);
+    return;
+  }
+
+  // Ensure that the special case of zero input channels is handled correctly
+  // (zero samples per channel is already handled correctly in the code below).
+  if (input.num_channels_ == 0) {
+    return;
+  }
+
+  const int16_t* const input_data = input.data();
+  size_t out_index = 0;
+
+  // When upmixing is needed and the input is mono copy the left channel
+  // into the left and right channels, and set any remaining channels to zero.
+  if (input.num_channels_ == 1 && input.num_channels_ < num_output_channels) {
+    for (size_t k = 0; k < input.samples_per_channel_; ++k) {
+      (*output)[out_index++] = input_data[k];
+      (*output)[out_index++] = input_data[k];
+      for (size_t j = 2; j < num_output_channels; ++j) {
+        (*output)[out_index++] = 0;
+      }
+      RTC_DCHECK_EQ(out_index, (k + 1) * num_output_channels);
+    }
+    RTC_DCHECK_EQ(out_index, input.samples_per_channel_ * num_output_channels);
+    return;
+  }
+
+  size_t in_index = 0;
+
+  // When upmixing is needed and the output is surround, copy the available
+  // channels directly, and set the remaining channels to zero.
+  if (input.num_channels_ < num_output_channels) {
+    for (size_t k = 0; k < input.samples_per_channel_; ++k) {
+      for (size_t j = 0; j < input.num_channels_; ++j) {
+        (*output)[out_index++] = input_data[in_index++];
+      }
+      for (size_t j = input.num_channels_; j < num_output_channels; ++j) {
+        (*output)[out_index++] = 0;
+      }
+      RTC_DCHECK_EQ(in_index, (k + 1) * input.num_channels_);
+      RTC_DCHECK_EQ(out_index, (k + 1) * num_output_channels);
+    }
+    RTC_DCHECK_EQ(in_index, input.samples_per_channel_ * input.num_channels_);
+    RTC_DCHECK_EQ(out_index, input.samples_per_channel_ * num_output_channels);
+
+    return;
+  }
+
+  // When downmixing is needed, and the input is stereo, average the channels.
+  if (input.num_channels_ == 2) {
+    for (size_t n = 0; n < input.samples_per_channel_; ++n) {
+      (*output)[n] = rtc::dchecked_cast<int16_t>(
+          (int32_t{input_data[2 * n]} + int32_t{input_data[2 * n + 1]}) >> 1);
+    }
+    return;
+  }
+
+  // When downmixing is needed, and the input is multichannel, drop the surplus
+  // channels.
+  const size_t num_channels_to_drop = input.num_channels_ - num_output_channels;
+  for (size_t k = 0; k < input.samples_per_channel_; ++k) {
+    for (size_t j = 0; j < num_output_channels; ++j) {
+      (*output)[out_index++] = input_data[in_index++];
+    }
+    in_index += num_channels_to_drop;
+  }
+}
+
+}  // namespace webrtc