Revert "Reland Process 8 kHz audio as 16 kHz internally of the audio processing module"

This reverts commit b7b8e30cb44c41f51dbbefb9a9160e6dfe869c5b.

Reason for revert: Broke ApmTest.Process test in internal iOS waterfall

Original change's description:
> Reland Process 8 kHz audio as 16 kHz internally of the audio processing module
> 
> This CL relands the code from the CL "Process 8 kHz audio as 16 kHz internally
> of the audio processing module" which by mistake was reverted via a rebase in
> another CL.
> 
> The CL changes the behavior of APM for 8 kHz so that it is internally
> processed as 16 kHz.
> 
> Bug: webrtc:10863
> Change-Id: I32a57b2d279c2134125667c19b09cfda381a33c3
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/150221
> Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org>
> Commit-Queue: Per Åhgren <peah@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#28944}

TBR=gustaf@webrtc.org,peah@webrtc.org

Change-Id: Ia49e07b0c25c49da646917516e317f1d57cc4e84
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:10863
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/150326
Reviewed-by: Artem Titarenko <artit@webrtc.org>
Commit-Queue: Artem Titarenko <artit@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28948}

5 files changed, 20 insertions, 19 deletions

diff --git a/modules/audio_processing/audio_processing_impl.cc b/modules/audio_processing/audio_processing_impl.cc
index 97babf99c8..464c61b848 100644
--- a/modules/audio_processing/audio_processing_impl.cc
+++ b/modules/audio_processing/audio_processing_impl.cc
@@ -84,17 +84,22 @@ bool SampleRateSupportsMultiBand(int sample_rate_hz) {
          sample_rate_hz == AudioProcessing::kSampleRate48kHz;
 }
 
-// Identify the native processing rate that best handles a sample rate.
-int SuitableProcessRate(int minimum_rate, bool band_splitting_required) {
+int FindNativeProcessRateToUse(int minimum_rate, bool band_splitting_required) {
 #ifdef WEBRTC_ARCH_ARM_FAMILY
-  constexpr int kMaxSplittingRate = 32000;
+  constexpr int kMaxSplittingNativeProcessRate =
+      AudioProcessing::kSampleRate32kHz;
 #else
-  constexpr int kMaxSplittingRate = 48000;
+  constexpr int kMaxSplittingNativeProcessRate =
+      AudioProcessing::kSampleRate48kHz;
 #endif
-  static_assert(kMaxSplittingRate <= 48000, "");
-  const int uppermost_native_rate =
-      band_splitting_required ? kMaxSplittingRate : 48000;
-  for (auto rate : {16000, 32000, 48000}) {
+  static_assert(
+      kMaxSplittingNativeProcessRate <= AudioProcessing::kMaxNativeSampleRateHz,
+      "");
+  const int uppermost_native_rate = band_splitting_required
+                                        ? kMaxSplittingNativeProcessRate
+                                        : AudioProcessing::kSampleRate48kHz;
+
+  for (auto rate : AudioProcessing::kNativeSampleRatesHz) {
     if (rate >= uppermost_native_rate) {
       return uppermost_native_rate;
     }
@@ -590,19 +595,18 @@ int AudioProcessingImpl::InitializeLocked(const ProcessingConfig& config) {
 
   formats_.api_format = config;
 
-  int capture_processing_rate = SuitableProcessRate(
+  int capture_processing_rate = FindNativeProcessRateToUse(
       std::min(formats_.api_format.input_stream().sample_rate_hz(),
                formats_.api_format.output_stream().sample_rate_hz()),
       submodule_states_.CaptureMultiBandSubModulesActive() ||
           submodule_states_.RenderMultiBandSubModulesActive());
-  RTC_DCHECK_NE(8000, capture_processing_rate);
 
   capture_nonlocked_.capture_processing_format =
       StreamConfig(capture_processing_rate);
 
   int render_processing_rate;
   if (!capture_nonlocked_.echo_controller_enabled) {
-    render_processing_rate = SuitableProcessRate(
+    render_processing_rate = FindNativeProcessRateToUse(
         std::min(formats_.api_format.reverse_input_stream().sample_rate_hz(),
                  formats_.api_format.reverse_output_stream().sample_rate_hz()),
         submodule_states_.CaptureMultiBandSubModulesActive() ||
@@ -630,8 +634,6 @@ int AudioProcessingImpl::InitializeLocked(const ProcessingConfig& config) {
         std::max(render_processing_rate, static_cast<int>(kSampleRate16kHz));
   }
 
-  RTC_DCHECK_NE(8000, render_processing_rate);
-
   // Always downmix the render stream to mono for analysis. This has been
   // demonstrated to work well for AEC in most practical scenarios.
   if (submodule_states_.RenderMultiBandSubModulesActive()) {
diff --git a/modules/audio_processing/audio_processing_unittest.cc b/modules/audio_processing/audio_processing_unittest.cc
index 7fa684565e..831799f775 100644
--- a/modules/audio_processing/audio_processing_unittest.cc
+++ b/modules/audio_processing/audio_processing_unittest.cc
@@ -65,7 +65,7 @@ namespace {
 // When false, this will compare the output data with the results stored to
 // file. This is the typical case. When the file should be updated, it can
 // be set to true with the command-line switch --write_ref_data.
-bool write_ref_data = true;
+bool write_ref_data = false;
 const int32_t kChannels[] = {1, 2};
 const int kSampleRates[] = {8000, 16000, 32000, 48000};
 
@@ -1200,8 +1200,8 @@ TEST_F(ApmTest, NoProcessingWhenAllComponentsDisabled) {
 
 TEST_F(ApmTest, NoProcessingWhenAllComponentsDisabledFloat) {
   // Test that ProcessStream copies input to output even with no processing.
-  const size_t kSamples = 160;
-  const int sample_rate = 16000;
+  const size_t kSamples = 80;
+  const int sample_rate = 8000;
   const float src[kSamples] = {-1.0f, 0.0f, 1.0f};
   float dest[kSamples] = {};
 
diff --git a/modules/audio_processing/include/audio_processing.h b/modules/audio_processing/include/audio_processing.h
index fb62f7793a..eb12a66890 100644
--- a/modules/audio_processing/include/audio_processing.h
+++ b/modules/audio_processing/include/audio_processing.h
@@ -698,7 +698,6 @@ class AudioProcessing : public rtc::RefCountInterface {
     kBadStreamParameterWarning = -13
   };
 
-  // Native rates supported by the AudioFrame interfaces.
   enum NativeRate {
     kSampleRate8kHz = 8000,
     kSampleRate16kHz = 16000,
diff --git a/resources/audio_processing/output_data_fixed.pb.sha1 b/resources/audio_processing/output_data_fixed.pb.sha1
index e4444a92ff..072dc4fa90 100644
--- a/resources/audio_processing/output_data_fixed.pb.sha1
+++ b/resources/audio_processing/output_data_fixed.pb.sha1
@@ -1 +1 @@
-91f6018874f4cbce414918d053e1d6c36d3e51c4
\ No newline at end of file
+7481cf57b2ade2f600d91e8bc77fd9780a56b62e
\ No newline at end of file
diff --git a/resources/audio_processing/output_data_float.pb.sha1 b/resources/audio_processing/output_data_float.pb.sha1
index a8b35f8f53..c1b6f1a984 100644
--- a/resources/audio_processing/output_data_float.pb.sha1
+++ b/resources/audio_processing/output_data_float.pb.sha1
@@ -1 +1 @@
-4794107799631a85c4aa4671979c6fa7edbef08b
\ No newline at end of file
+d67b879f3b4a31b3c4f3587bd4418be5f9df5105
\ No newline at end of file