1 files changed, 240 insertions, 0 deletions
diff --git a/dom/media/AudioConverter.h b/dom/media/AudioConverter.h
new file mode 100644
index 000000000..2806813df
--- /dev/null
+++ b/dom/media/AudioConverter.h
@@ -0,0 +1,240 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#if !defined(AudioConverter_h)
+#define AudioConverter_h
+
+#include "MediaInfo.h"
+
+// Forward declaration
+typedef struct SpeexResamplerState_ SpeexResamplerState;
+
+namespace mozilla {
+
+template <AudioConfig::SampleFormat T> struct AudioDataBufferTypeChooser;
+template <> struct AudioDataBufferTypeChooser<AudioConfig::FORMAT_U8>
+{ typedef uint8_t Type; };
+template <> struct AudioDataBufferTypeChooser<AudioConfig::FORMAT_S16>
+{ typedef int16_t Type; };
+template <> struct AudioDataBufferTypeChooser<AudioConfig::FORMAT_S24LSB>
+{ typedef int32_t Type; };
+template <> struct AudioDataBufferTypeChooser<AudioConfig::FORMAT_S24>
+{ typedef int32_t Type; };
+template <> struct AudioDataBufferTypeChooser<AudioConfig::FORMAT_S32>
+{ typedef int32_t Type; };
+template <> struct AudioDataBufferTypeChooser<AudioConfig::FORMAT_FLT>
+{ typedef float Type; };
+
+// 'Value' is the type used externally to deal with stored value.
+// AudioDataBuffer can perform conversion between different SampleFormat content.
+template <AudioConfig::SampleFormat Format, typename Value = typename AudioDataBufferTypeChooser<Format>::Type>
+class AudioDataBuffer
+{
+public:
+  AudioDataBuffer() {}
+  AudioDataBuffer(Value* aBuffer, size_t aLength)
+    : mBuffer(aBuffer, aLength)
+  {}
+  explicit AudioDataBuffer(const AudioDataBuffer& aOther)
+    : mBuffer(aOther.mBuffer)
+  {}
+  AudioDataBuffer(AudioDataBuffer&& aOther)
+    : mBuffer(Move(aOther.mBuffer))
+  {}
+  template <AudioConfig::SampleFormat OtherFormat, typename OtherValue>
+  explicit AudioDataBuffer(const AudioDataBuffer<OtherFormat, OtherValue>& other)
+  {
+    // TODO: Convert from different type, may use asm routines.
+    MOZ_CRASH("Conversion not implemented yet");
+  }
+
+  // A u8, s16 and float aligned buffer can only be treated as
+  // FORMAT_U8, FORMAT_S16 and FORMAT_FLT respectively.
+  // So allow them as copy and move constructors.
+  explicit AudioDataBuffer(const AlignedByteBuffer& aBuffer)
+    : mBuffer(aBuffer)
+  {
+    static_assert(Format == AudioConfig::FORMAT_U8,
+                  "Conversion not implemented yet");
+  }
+  explicit AudioDataBuffer(const AlignedShortBuffer& aBuffer)
+    : mBuffer(aBuffer)
+  {
+    static_assert(Format == AudioConfig::FORMAT_S16,
+                  "Conversion not implemented yet");
+  }
+  explicit AudioDataBuffer(const AlignedFloatBuffer& aBuffer)
+    : mBuffer(aBuffer)
+  {
+    static_assert(Format == AudioConfig::FORMAT_FLT,
+                  "Conversion not implemented yet");
+  }
+  explicit AudioDataBuffer(AlignedByteBuffer&& aBuffer)
+    : mBuffer(Move(aBuffer))
+  {
+    static_assert(Format == AudioConfig::FORMAT_U8,
+                  "Conversion not implemented yet");
+  }
+  explicit AudioDataBuffer(AlignedShortBuffer&& aBuffer)
+    : mBuffer(Move(aBuffer))
+  {
+    static_assert(Format == AudioConfig::FORMAT_S16,
+                  "Conversion not implemented yet");
+  }
+  explicit AudioDataBuffer(AlignedFloatBuffer&& aBuffer)
+    : mBuffer(Move(aBuffer))
+  {
+    static_assert(Format == AudioConfig::FORMAT_FLT,
+                  "Conversion not implemented yet");
+  }
+  AudioDataBuffer& operator=(AudioDataBuffer&& aOther)
+  {
+    mBuffer = Move(aOther.mBuffer);
+    return *this;
+  }
+  AudioDataBuffer& operator=(const AudioDataBuffer& aOther)
+  {
+    mBuffer = aOther.mBuffer;
+    return *this;
+  }
+
+  Value* Data() const { return mBuffer.Data(); }
+  size_t Length() const { return mBuffer.Length(); }
+  size_t Size() const { return mBuffer.Size(); }
+  AlignedBuffer<Value> Forget()
+  {
+    // Correct type -> Just give values as-is.
+    return Move(mBuffer);
+  }
+private:
+  AlignedBuffer<Value> mBuffer;
+};
+
+typedef AudioDataBuffer<AudioConfig::FORMAT_DEFAULT> AudioSampleBuffer;
+
+class AudioConverter {
+public:
+  AudioConverter(const AudioConfig& aIn, const AudioConfig& aOut);
+  ~AudioConverter();
+
+  // Convert the AudioDataBuffer.
+  // Conversion will be done in place if possible. Otherwise a new buffer will
+  // be returned.
+  // Providing an empty buffer and resampling is expected, the resampler
+  // will be drained.
+  template <AudioConfig::SampleFormat Format, typename Value>
+  AudioDataBuffer<Format, Value> Process(AudioDataBuffer<Format, Value>&& aBuffer)
+  {
+    MOZ_DIAGNOSTIC_ASSERT(mIn.Format() == mOut.Format() && mIn.Format() == Format);
+    AudioDataBuffer<Format, Value> buffer = Move(aBuffer);
+    if (CanWorkInPlace()) {
+      size_t frames = SamplesInToFrames(buffer.Length());
+      frames = ProcessInternal(buffer.Data(), buffer.Data(), frames);
+      if (frames && mIn.Rate() != mOut.Rate()) {
+        frames = ResampleAudio(buffer.Data(), buffer.Data(), frames);
+      }
+      AlignedBuffer<Value> temp = buffer.Forget();
+      temp.SetLength(FramesOutToSamples(frames));
+      return AudioDataBuffer<Format, Value>(Move(temp));;
+    }
+    return Process(buffer);
+  }
+
+  template <AudioConfig::SampleFormat Format, typename Value>
+  AudioDataBuffer<Format, Value> Process(const AudioDataBuffer<Format, Value>& aBuffer)
+  {
+    MOZ_DIAGNOSTIC_ASSERT(mIn.Format() == mOut.Format() && mIn.Format() == Format);
+    // Perform the downmixing / reordering in temporary buffer.
+    size_t frames = SamplesInToFrames(aBuffer.Length());
+    AlignedBuffer<Value> temp1;
+    if (!temp1.SetLength(FramesOutToSamples(frames))) {
+      return AudioDataBuffer<Format, Value>(Move(temp1));
+    }
+    frames = ProcessInternal(temp1.Data(), aBuffer.Data(), frames);
+    if (mIn.Rate() == mOut.Rate()) {
+      MOZ_ALWAYS_TRUE(temp1.SetLength(FramesOutToSamples(frames)));
+      return AudioDataBuffer<Format, Value>(Move(temp1));
+    }
+
+    // At this point, temp1 contains the buffer reordered and downmixed.
+    // If we are downsampling we can re-use it.
+    AlignedBuffer<Value>* outputBuffer = &temp1;
+    AlignedBuffer<Value> temp2;
+    if (!frames || mOut.Rate() > mIn.Rate()) {
+      // We are upsampling or about to drain, we can't work in place.
+      // Allocate another temporary buffer where the upsampling will occur.
+      if (!temp2.SetLength(FramesOutToSamples(ResampleRecipientFrames(frames)))) {
+        return AudioDataBuffer<Format, Value>(Move(temp2));
+      }
+      outputBuffer = &temp2;
+    }
+    if (!frames) {
+      frames = DrainResampler(outputBuffer->Data());
+    } else {
+      frames = ResampleAudio(outputBuffer->Data(), temp1.Data(), frames);
+    }
+    MOZ_ALWAYS_TRUE(outputBuffer->SetLength(FramesOutToSamples(frames)));
+    return AudioDataBuffer<Format, Value>(Move(*outputBuffer));
+  }
+
+  // Attempt to convert the AudioDataBuffer in place.
+  // Will return 0 if the conversion wasn't possible.
+  template <typename Value>
+  size_t Process(Value* aBuffer, size_t aFrames)
+  {
+    MOZ_DIAGNOSTIC_ASSERT(mIn.Format() == mOut.Format());
+    if (!CanWorkInPlace()) {
+      return 0;
+    }
+    size_t frames = ProcessInternal(aBuffer, aBuffer, aFrames);
+    if (frames && mIn.Rate() != mOut.Rate()) {
+      frames = ResampleAudio(aBuffer, aBuffer, aFrames);
+    }
+    return frames;
+  }
+
+  bool CanWorkInPlace() const;
+  bool CanReorderAudio() const
+  {
+    return mIn.Layout().MappingTable(mOut.Layout());
+  }
+
+  const AudioConfig& InputConfig() const { return mIn; }
+  const AudioConfig& OutputConfig() const { return mOut; }
+
+private:
+  const AudioConfig mIn;
+  const AudioConfig mOut;
+  uint8_t mChannelOrderMap[MAX_AUDIO_CHANNELS];
+  /**
+   * ProcessInternal
+   * Parameters:
+   * aOut  : destination buffer where converted samples will be copied
+   * aIn   : source buffer
+   * aSamples: number of frames in source buffer
+   *
+   * Return Value: number of frames converted or 0 if error
+   */
+  size_t ProcessInternal(void* aOut, const void* aIn, size_t aFrames);
+  void ReOrderInterleavedChannels(void* aOut, const void* aIn, size_t aFrames) const;
+  size_t DownmixAudio(void* aOut, const void* aIn, size_t aFrames) const;
+  size_t UpmixAudio(void* aOut, const void* aIn, size_t aFrames) const;
+
+  size_t FramesOutToSamples(size_t aFrames) const;
+  size_t SamplesInToFrames(size_t aSamples) const;
+  size_t FramesOutToBytes(size_t aFrames) const;
+
+  // Resampler context.
+  SpeexResamplerState* mResampler;
+  size_t ResampleAudio(void* aOut, const void* aIn, size_t aFrames);
+  size_t ResampleRecipientFrames(size_t aFrames) const;
+  void RecreateResampler();
+  size_t DrainResampler(void* aOut);
+};
+
+} // namespace mozilla
+
+#endif /* AudioConverter_h */