Motown in-proc streaming framework used to implement media services.

services/media/framework/lpcm_util.cc

Index: services/media/framework/lpcm_util.cc
diff --git a/services/media/framework/lpcm_util.cc b/services/media/framework/lpcm_util.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c2121a4fe017dd69e8f1c22e82f78e0535bbe1ac
--- /dev/null
+++ b/services/media/framework/lpcm_util.cc
@@ -0,0 +1,127 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/logging.h"
+#include "services/media/framework/lpcm_util.h"
+#include "services/media/framework/ostream.h"
+
+namespace mojo {
+namespace media {
+
+LpcmUtil* LpcmUtil::Create(const LpcmStreamType& stream_type) {
+  switch (stream_type.sample_format()) {
+    case LpcmStreamType::SampleFormat::kUnsigned8:
+    case LpcmStreamType::SampleFormat::kAny:
+      return new LpcmUtilImpl<uint8_t>(stream_type);
+    case LpcmStreamType::SampleFormat::kSigned16:
+      return new LpcmUtilImpl<int16_t>(stream_type);
+    case LpcmStreamType::SampleFormat::kSigned24In32:
+      return new LpcmUtilImpl<int32_t>(stream_type);
+    case LpcmStreamType::SampleFormat::kFloat:
+      return new LpcmUtilImpl<float>(stream_type);
+    default:
+      NOTREACHED()
+          << "unsupported sample format " << stream_type.sample_format();
+      return nullptr;
+  }
+}
+
+template<typename T>
+LpcmUtilImpl<T>::LpcmUtilImpl(const LpcmStreamType& stream_type) :
+    stream_type_(stream_type) {}
+
+template<typename T>
+LpcmUtilImpl<T>::~LpcmUtilImpl() {}
+
+template<typename T>
+void LpcmUtilImpl<T>::Silence(void* buffer, uint64_t frame_count) const {
+  T* sample = reinterpret_cast<T*>(buffer);
+  for (
+      uint64_t sample_countdown = frame_count * stream_type_.channels();
+      sample_countdown != 0;
+      --sample_countdown) {
+    *sample = 0;
+    sample++;
+  }
+}
+
+template<>
+void LpcmUtilImpl<uint8_t>::Silence(void* buffer, uint64_t frame_count) const {
+  uint8_t* sample = reinterpret_cast<uint8_t*>(buffer);
+  for (
+      uint64_t sample_countdown = frame_count * stream_type_.channels();
+      sample_countdown != 0;
+      --sample_countdown) {
+    *sample = 0x80;
+    sample++;
+  }
+}
+
+template<typename T>
+void LpcmUtilImpl<T>::Copy(void* in, void* out, uint64_t frame_count) const {
+  std::memcpy(out, in, stream_type_.min_buffer_size(frame_count));
+}
+
+template<typename T>
+void LpcmUtilImpl<T>::Mix(void* in, void* out, uint64_t frame_count) const {
+  T* in_sample = reinterpret_cast<T*>(in);
+  T* out_sample = reinterpret_cast<T*>(out);
+  for (
+      uint64_t sample_countdown = frame_count * stream_type_.channels();
+      sample_countdown != 0;
+      --sample_countdown) {
+    *out_sample += *in_sample; // TODO(dalesat): Limit.
+    out_sample++;
+    in_sample++;
+  }
+}
+
+template<>
+void LpcmUtilImpl<uint8_t>::Mix(void* in, void* out, uint64_t frame_count)
+    const {
+  uint8_t* in_sample = reinterpret_cast<uint8_t*>(in);
+  uint8_t* out_sample = reinterpret_cast<uint8_t*>(out);
+  for (
+      uint64_t sample_countdown = frame_count * stream_type_.channels();
+      sample_countdown != 0;
+      --sample_countdown) {
+    *out_sample = uint8_t(uint16_t(*out_sample) + uint16_t(*in_sample) - 0x80);
+    // TODO(dalesat): Limit.
+    out_sample++;
+    in_sample++;
+  }
+}
+
+template<typename T>
+void LpcmUtilImpl<T>::Interleave(
+    void* in,
+    uint64_t in_byte_count,
+    void* out,
+    uint64_t frame_count) const {
+  DCHECK(in);
+  DCHECK(in_byte_count);
+  DCHECK(out);
+  DCHECK(frame_count);
+
+  uint32_t channels = stream_type_.channels();
+  uint64_t in_channel_stride = in_byte_count / channels;
+
+  uint8_t* in_channel = reinterpret_cast<uint8_t*>(in);
+  uint8_t* out_channel = reinterpret_cast<uint8_t*>(out);
+
+  for (uint32_t channel = channels; channel != 0; --channel) {
+    T* in_sample = reinterpret_cast<T*>(in_channel);
+    T* out_sample = reinterpret_cast<T*>(out_channel);
+    for (uint64_t frame = frame_count; frame != 0; --frame) {
+      *out_sample = *in_sample;
+      ++in_sample;
+      out_sample += channels;
+    }
+    in_channel += in_channel_stride;
+    out_channel += stream_type_.sample_size();
+  }
+}
+
+}  // namespace media
+}  // namespace mojo