Support arbitrary input/output rates and downmixing in AudioProcessing.

Select "processing" rates based on the input and output sampling rates.
Resample the input streams to those rates, and if necessary to the
output rate.

- Remove deprecated stream format APIs.
- Remove deprecated device sample rate APIs.
- Add a ChannelBuffer class to help manage deinterleaved channels.
- Clean up the splitting filter state.
- Add a unit test which verifies the output against known-working
native format output.

BUG=2894
R=aluebs@webrtc.org, bjornv@webrtc.org, xians@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/9919004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5959 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_processing/audio_buffer.cc b/webrtc/modules/audio_processing/audio_buffer.cc
index 8d26f52..6936155 100644
--- a/webrtc/modules/audio_processing/audio_buffer.cc
+++ b/webrtc/modules/audio_processing/audio_buffer.cc
@@ -11,6 +11,7 @@
 #include "webrtc/modules/audio_processing/audio_buffer.h"
 
 #include "webrtc/common_audio/include/audio_util.h"
+#include "webrtc/common_audio/resampler/push_sinc_resampler.h"
 #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
 
 namespace webrtc {
@@ -22,76 +23,166 @@
   kSamplesPer32kHzChannel = 320
 };
 
-void StereoToMono(const int16_t* left, const int16_t* right,
-                  int16_t* out, int samples_per_channel) {
-  assert(left != NULL && right != NULL && out != NULL);
-  for (int i = 0; i < samples_per_channel; i++)
-    out[i] = (static_cast<int32_t>(left[i]) +
-              static_cast<int32_t>(right[i])) >> 1;
+void StereoToMono(const float* left, const float* right, float* out,
+                  int samples_per_channel) {
+  for (int i = 0; i < samples_per_channel; ++i) {
+    out[i] = (left[i] + right[i]) / 2;
+  }
 }
+
+void StereoToMono(const int16_t* left, const int16_t* right, int16_t* out,
+                  int samples_per_channel) {
+  for (int i = 0; i < samples_per_channel; i++)
+    out[i] = (left[i] + right[i]) >> 1;
+}
+
 }  // namespace
 
-struct AudioChannel {
-  AudioChannel() {
-    memset(data, 0, sizeof(data));
+class SplitChannelBuffer {
+ public:
+  SplitChannelBuffer(int samples_per_split_channel, int num_channels)
+      : low_(samples_per_split_channel, num_channels),
+        high_(samples_per_split_channel, num_channels) {
   }
+  ~SplitChannelBuffer() {}
 
-  int16_t data[kSamplesPer32kHzChannel];
+  int16_t* low_channel(int i) { return low_.channel(i); }
+  int16_t* high_channel(int i) { return high_.channel(i); }
+
+ private:
+  ChannelBuffer<int16_t> low_;
+  ChannelBuffer<int16_t> high_;
 };
 
-struct SplitAudioChannel {
-  SplitAudioChannel() {
-    memset(low_pass_data, 0, sizeof(low_pass_data));
-    memset(high_pass_data, 0, sizeof(high_pass_data));
-    memset(analysis_filter_state1, 0, sizeof(analysis_filter_state1));
-    memset(analysis_filter_state2, 0, sizeof(analysis_filter_state2));
-    memset(synthesis_filter_state1, 0, sizeof(synthesis_filter_state1));
-    memset(synthesis_filter_state2, 0, sizeof(synthesis_filter_state2));
-  }
-
-  int16_t low_pass_data[kSamplesPer16kHzChannel];
-  int16_t high_pass_data[kSamplesPer16kHzChannel];
-
-  int32_t analysis_filter_state1[6];
-  int32_t analysis_filter_state2[6];
-  int32_t synthesis_filter_state1[6];
-  int32_t synthesis_filter_state2[6];
-};
-
-// TODO(andrew): check range of input parameters?
-AudioBuffer::AudioBuffer(int max_num_channels,
-                         int samples_per_channel)
-  : max_num_channels_(max_num_channels),
-    num_channels_(0),
+AudioBuffer::AudioBuffer(int input_samples_per_channel,
+                         int num_input_channels,
+                         int process_samples_per_channel,
+                         int num_process_channels,
+                         int output_samples_per_channel)
+  : input_samples_per_channel_(input_samples_per_channel),
+    num_input_channels_(num_input_channels),
+    proc_samples_per_channel_(process_samples_per_channel),
+    num_proc_channels_(num_process_channels),
+    output_samples_per_channel_(output_samples_per_channel),
+    samples_per_split_channel_(proc_samples_per_channel_),
     num_mixed_channels_(0),
     num_mixed_low_pass_channels_(0),
     data_was_mixed_(false),
-    samples_per_channel_(samples_per_channel),
-    samples_per_split_channel_(samples_per_channel),
     reference_copied_(false),
     activity_(AudioFrame::kVadUnknown),
     is_muted_(false),
     data_(NULL),
-    channels_(NULL),
-    split_channels_(NULL),
-    mixed_channels_(NULL),
-    mixed_low_pass_channels_(NULL),
-    low_pass_reference_channels_(NULL) {
-  channels_.reset(new AudioChannel[max_num_channels_]);
-  mixed_channels_.reset(new AudioChannel[max_num_channels_]);
-  mixed_low_pass_channels_.reset(new AudioChannel[max_num_channels_]);
-  low_pass_reference_channels_.reset(new AudioChannel[max_num_channels_]);
+    channels_(new ChannelBuffer<int16_t>(proc_samples_per_channel_,
+                                         num_proc_channels_)) {
+  assert(input_samples_per_channel_ > 0);
+  assert(proc_samples_per_channel_ > 0);
+  assert(output_samples_per_channel_ > 0);
+  assert(num_input_channels_ > 0 && num_input_channels_ <= 2);
+  assert(num_proc_channels_ <= num_input_channels);
 
-  if (samples_per_channel_ == kSamplesPer32kHzChannel) {
-    split_channels_.reset(new SplitAudioChannel[max_num_channels_]);
+  if (num_input_channels_ == 2 && num_proc_channels_ == 1) {
+    input_buffer_.reset(new ChannelBuffer<float>(input_samples_per_channel_,
+                                                 num_proc_channels_));
+  }
+
+  if (input_samples_per_channel_ != proc_samples_per_channel_ ||
+      output_samples_per_channel_ != proc_samples_per_channel_) {
+    // Create an intermediate buffer for resampling.
+    process_buffer_.reset(new ChannelBuffer<float>(proc_samples_per_channel_,
+                                                   num_proc_channels_));
+  }
+
+  if (input_samples_per_channel_ != proc_samples_per_channel_) {
+    input_resamplers_.reserve(num_proc_channels_);
+    for (int i = 0; i < num_proc_channels_; ++i) {
+      input_resamplers_.push_back(
+          new PushSincResampler(input_samples_per_channel_,
+                                proc_samples_per_channel_));
+    }
+  }
+
+  if (output_samples_per_channel_ != proc_samples_per_channel_) {
+    output_resamplers_.reserve(num_proc_channels_);
+    for (int i = 0; i < num_proc_channels_; ++i) {
+      output_resamplers_.push_back(
+          new PushSincResampler(proc_samples_per_channel_,
+                                output_samples_per_channel_));
+    }
+  }
+
+  if (proc_samples_per_channel_ == kSamplesPer32kHzChannel) {
     samples_per_split_channel_ = kSamplesPer16kHzChannel;
+    split_channels_.reset(new SplitChannelBuffer(samples_per_split_channel_,
+                                                 num_proc_channels_));
+    filter_states_.reset(new SplitFilterStates[num_proc_channels_]);
+  }
+}
+
+void AudioBuffer::CopyFrom(const float* const* data,
+                           int samples_per_channel,
+                           AudioProcessing::ChannelLayout layout) {
+  assert(samples_per_channel == input_samples_per_channel_);
+  assert(ChannelsFromLayout(layout) == num_input_channels_);
+  InitForNewData();
+
+  // Downmix.
+  const float* const* data_ptr = data;
+  if (num_input_channels_ == 2 && num_proc_channels_ == 1) {
+    StereoToMono(data[0],
+                 data[1],
+                 input_buffer_->channel(0),
+                 input_samples_per_channel_);
+    data_ptr = input_buffer_->channels();
+  }
+
+  // Resample.
+  if (input_samples_per_channel_ != proc_samples_per_channel_) {
+    for (int i = 0; i < num_proc_channels_; ++i) {
+      input_resamplers_[i]->Resample(data_ptr[i],
+                                     input_samples_per_channel_,
+                                     process_buffer_->channel(i),
+                                     proc_samples_per_channel_);
+    }
+    data_ptr = process_buffer_->channels();
+  }
+
+  // Convert to int16.
+  for (int i = 0; i < num_proc_channels_; ++i) {
+    ScaleAndRoundToInt16(data_ptr[i], proc_samples_per_channel_,
+                         channels_->channel(i));
+  }
+}
+
+void AudioBuffer::CopyTo(int samples_per_channel,
+                         AudioProcessing::ChannelLayout layout,
+                         float* const* data) {
+  assert(samples_per_channel == output_samples_per_channel_);
+  assert(ChannelsFromLayout(layout) == num_proc_channels_);
+
+  // Convert to float.
+  float* const* data_ptr = data;
+  if (output_samples_per_channel_ != proc_samples_per_channel_) {
+    // Convert to an intermediate buffer for subsequent resampling.
+    data_ptr = process_buffer_->channels();
+  }
+  for (int i = 0; i < num_proc_channels_; ++i) {
+    ScaleToFloat(channels_->channel(i), proc_samples_per_channel_, data_ptr[i]);
+  }
+
+  // Resample.
+  if (output_samples_per_channel_ != proc_samples_per_channel_) {
+    for (int i = 0; i < num_proc_channels_; ++i) {
+      output_resamplers_[i]->Resample(data_ptr[i],
+                                      proc_samples_per_channel_,
+                                      data[i],
+                                      output_samples_per_channel_);
+    }
   }
 }
 
 AudioBuffer::~AudioBuffer() {}
 
-void AudioBuffer::InitForNewData(int num_channels) {
-  num_channels_ = num_channels;
+void AudioBuffer::InitForNewData() {
   data_ = NULL;
   data_was_mixed_ = false;
   num_mixed_channels_ = 0;
@@ -102,71 +193,56 @@
 }
 
 int16_t* AudioBuffer::data(int channel) const {
-  assert(channel >= 0 && channel < num_channels_);
+  assert(channel >= 0 && channel < num_proc_channels_);
   if (data_ != NULL) {
     return data_;
   }
 
-  return channels_[channel].data;
+  return channels_->channel(channel);
 }
 
 int16_t* AudioBuffer::low_pass_split_data(int channel) const {
-  assert(channel >= 0 && channel < num_channels_);
+  assert(channel >= 0 && channel < num_proc_channels_);
   if (split_channels_.get() == NULL) {
     return data(channel);
   }
 
-  return split_channels_[channel].low_pass_data;
+  return split_channels_->low_channel(channel);
 }
 
 int16_t* AudioBuffer::high_pass_split_data(int channel) const {
-  assert(channel >= 0 && channel < num_channels_);
+  assert(channel >= 0 && channel < num_proc_channels_);
   if (split_channels_.get() == NULL) {
     return NULL;
   }
 
-  return split_channels_[channel].high_pass_data;
+  return split_channels_->high_channel(channel);
 }
 
 int16_t* AudioBuffer::mixed_data(int channel) const {
   assert(channel >= 0 && channel < num_mixed_channels_);
 
-  return mixed_channels_[channel].data;
+  return mixed_channels_->channel(channel);
 }
 
 int16_t* AudioBuffer::mixed_low_pass_data(int channel) const {
   assert(channel >= 0 && channel < num_mixed_low_pass_channels_);
 
-  return mixed_low_pass_channels_[channel].data;
+  return mixed_low_pass_channels_->channel(channel);
 }
 
 int16_t* AudioBuffer::low_pass_reference(int channel) const {
-  assert(channel >= 0 && channel < num_channels_);
+  assert(channel >= 0 && channel < num_proc_channels_);
   if (!reference_copied_) {
     return NULL;
   }
 
-  return low_pass_reference_channels_[channel].data;
+  return low_pass_reference_channels_->channel(channel);
 }
 
-int32_t* AudioBuffer::analysis_filter_state1(int channel) const {
-  assert(channel >= 0 && channel < num_channels_);
-  return split_channels_[channel].analysis_filter_state1;
-}
-
-int32_t* AudioBuffer::analysis_filter_state2(int channel) const {
-  assert(channel >= 0 && channel < num_channels_);
-  return split_channels_[channel].analysis_filter_state2;
-}
-
-int32_t* AudioBuffer::synthesis_filter_state1(int channel) const {
-  assert(channel >= 0 && channel < num_channels_);
-  return split_channels_[channel].synthesis_filter_state1;
-}
-
-int32_t* AudioBuffer::synthesis_filter_state2(int channel) const {
-  assert(channel >= 0 && channel < num_channels_);
-  return split_channels_[channel].synthesis_filter_state2;
+SplitFilterStates* AudioBuffer::filter_states(int channel) const {
+  assert(channel >= 0 && channel < num_proc_channels_);
+  return &filter_states_[channel];
 }
 
 void AudioBuffer::set_activity(AudioFrame::VADActivity activity) {
@@ -182,11 +258,11 @@
 }
 
 int AudioBuffer::num_channels() const {
-  return num_channels_;
+  return num_proc_channels_;
 }
 
 int AudioBuffer::samples_per_channel() const {
-  return samples_per_channel_;
+  return proc_samples_per_channel_;
 }
 
 int AudioBuffer::samples_per_split_channel() const {
@@ -195,46 +271,49 @@
 
 // TODO(andrew): Do deinterleaving and mixing in one step?
 void AudioBuffer::DeinterleaveFrom(AudioFrame* frame) {
-  assert(frame->num_channels_ <= max_num_channels_);
-  assert(frame->samples_per_channel_ ==  samples_per_channel_);
-
-  InitForNewData(frame->num_channels_);
+  assert(proc_samples_per_channel_ == input_samples_per_channel_);
+  assert(num_proc_channels_ == num_input_channels_);
+  assert(frame->num_channels_ == num_proc_channels_);
+  assert(frame->samples_per_channel_ ==  proc_samples_per_channel_);
+  InitForNewData();
   activity_ = frame->vad_activity_;
   if (frame->energy_ == 0) {
     is_muted_ = true;
   }
 
-  if (num_channels_ == 1) {
+  if (num_proc_channels_ == 1) {
     // We can get away with a pointer assignment in this case.
     data_ = frame->data_;
     return;
   }
 
   int16_t* interleaved = frame->data_;
-  for (int i = 0; i < num_channels_; i++) {
-    int16_t* deinterleaved = channels_[i].data;
+  for (int i = 0; i < num_proc_channels_; i++) {
+    int16_t* deinterleaved = channels_->channel(i);
     int interleaved_idx = i;
-    for (int j = 0; j < samples_per_channel_; j++) {
+    for (int j = 0; j < proc_samples_per_channel_; j++) {
       deinterleaved[j] = interleaved[interleaved_idx];
-      interleaved_idx += num_channels_;
+      interleaved_idx += num_proc_channels_;
     }
   }
 }
 
 void AudioBuffer::InterleaveTo(AudioFrame* frame, bool data_changed) const {
-  assert(frame->num_channels_ == num_channels_);
-  assert(frame->samples_per_channel_ == samples_per_channel_);
+  assert(proc_samples_per_channel_ == output_samples_per_channel_);
+  assert(num_proc_channels_ == num_input_channels_);
+  assert(frame->num_channels_ == num_proc_channels_);
+  assert(frame->samples_per_channel_ == proc_samples_per_channel_);
   frame->vad_activity_ = activity_;
 
   if (!data_changed) {
     return;
   }
 
-  if (num_channels_ == 1) {
+  if (num_proc_channels_ == 1) {
     if (data_was_mixed_) {
       memcpy(frame->data_,
-             channels_[0].data,
-             sizeof(int16_t) * samples_per_channel_);
+             channels_->channel(0),
+             sizeof(int16_t) * proc_samples_per_channel_);
     } else {
       // These should point to the same buffer in this case.
       assert(data_ == frame->data_);
@@ -244,74 +323,47 @@
   }
 
   int16_t* interleaved = frame->data_;
-  for (int i = 0; i < num_channels_; i++) {
-    int16_t* deinterleaved = channels_[i].data;
+  for (int i = 0; i < num_proc_channels_; i++) {
+    int16_t* deinterleaved = channels_->channel(i);
     int interleaved_idx = i;
-    for (int j = 0; j < samples_per_channel_; j++) {
+    for (int j = 0; j < proc_samples_per_channel_; j++) {
       interleaved[interleaved_idx] = deinterleaved[j];
-      interleaved_idx += num_channels_;
+      interleaved_idx += num_proc_channels_;
     }
   }
 }
 
-void AudioBuffer::CopyFrom(const float* const* data, int samples_per_channel,
-                           int num_channels) {
-  assert(num_channels <= max_num_channels_);
-  assert(samples_per_channel ==  samples_per_channel_);
-
-  InitForNewData(num_channels);
-  for (int i = 0; i < num_channels_; ++i) {
-    ScaleAndRoundToInt16(data[i], samples_per_channel, channels_[i].data);
-  }
-}
-
-void AudioBuffer::CopyTo(int samples_per_channel, int num_channels,
-                         float* const* data) const {
-  assert(num_channels == num_channels_);
-  assert(samples_per_channel == samples_per_channel_);
-  for (int i = 0; i < num_channels_; ++i) {
-    ScaleToFloat(channels_[i].data, samples_per_channel, data[i]);
-  }
-}
-
-// TODO(andrew): would be good to support the no-mix case with pointer
-// assignment.
-// TODO(andrew): handle mixing to multiple channels?
-void AudioBuffer::Mix(int num_mixed_channels) {
-  // We currently only support the stereo to mono case.
-  assert(num_channels_ == 2);
-  assert(num_mixed_channels == 1);
-
-  StereoToMono(channels_[0].data,
-               channels_[1].data,
-               channels_[0].data,
-               samples_per_channel_);
-
-  num_channels_ = num_mixed_channels;
-  data_was_mixed_ = true;
-}
-
 void AudioBuffer::CopyAndMix(int num_mixed_channels) {
   // We currently only support the stereo to mono case.
-  assert(num_channels_ == 2);
+  assert(num_proc_channels_ == 2);
   assert(num_mixed_channels == 1);
+  if (!mixed_channels_.get()) {
+    mixed_channels_.reset(
+        new ChannelBuffer<int16_t>(proc_samples_per_channel_,
+                                   num_mixed_channels));
+  }
 
-  StereoToMono(channels_[0].data,
-               channels_[1].data,
-               mixed_channels_[0].data,
-               samples_per_channel_);
+  StereoToMono(channels_->channel(0),
+               channels_->channel(1),
+               mixed_channels_->channel(0),
+               proc_samples_per_channel_);
 
   num_mixed_channels_ = num_mixed_channels;
 }
 
 void AudioBuffer::CopyAndMixLowPass(int num_mixed_channels) {
   // We currently only support the stereo to mono case.
-  assert(num_channels_ == 2);
+  assert(num_proc_channels_ == 2);
   assert(num_mixed_channels == 1);
+  if (!mixed_low_pass_channels_.get()) {
+    mixed_low_pass_channels_.reset(
+        new ChannelBuffer<int16_t>(samples_per_split_channel_,
+                                   num_mixed_channels));
+  }
 
   StereoToMono(low_pass_split_data(0),
                low_pass_split_data(1),
-               mixed_low_pass_channels_[0].data,
+               mixed_low_pass_channels_->channel(0),
                samples_per_split_channel_);
 
   num_mixed_low_pass_channels_ = num_mixed_channels;
@@ -319,10 +371,14 @@
 
 void AudioBuffer::CopyLowPassToReference() {
   reference_copied_ = true;
-  for (int i = 0; i < num_channels_; i++) {
-    memcpy(low_pass_reference_channels_[i].data,
-           low_pass_split_data(i),
-           sizeof(int16_t) * samples_per_split_channel_);
+  if (!low_pass_reference_channels_.get()) {
+    low_pass_reference_channels_.reset(
+        new ChannelBuffer<int16_t>(samples_per_split_channel_,
+                                   num_proc_channels_));
+  }
+  for (int i = 0; i < num_proc_channels_; i++) {
+    low_pass_reference_channels_->CopyFrom(low_pass_split_data(i), i);
   }
 }
+
 }  // namespace webrtc