1 files changed, 167 insertions, 0 deletions
diff --git a/dom/media/MediaData.h b/dom/media/MediaData.h
index bec9c6076b..909841eb98 100644
--- a/dom/media/MediaData.h
+++ b/dom/media/MediaData.h
@@ -22,6 +22,173 @@
 
 namespace mozilla {
 
+  // Maximum channel number we can currently handle (7.1)
+#define MAX_AUDIO_CHANNELS 8
+
+class AudioConfig {
+public:
+  enum Channel {
+    CHANNEL_INVALID = -1,
+    CHANNEL_MONO = 0,
+    CHANNEL_LEFT,
+    CHANNEL_RIGHT,
+    CHANNEL_CENTER,
+    CHANNEL_LS,
+    CHANNEL_RS,
+    CHANNEL_RLS,
+    CHANNEL_RCENTER,
+    CHANNEL_RRS,
+    CHANNEL_LFE,
+  };
+
+  class ChannelLayout {
+  public:
+    ChannelLayout()
+      : mChannelMap(0)
+      , mValid(false)
+    {}
+    explicit ChannelLayout(uint32_t aChannels)
+      : ChannelLayout(aChannels, SMPTEDefault(aChannels))
+    {}
+    ChannelLayout(uint32_t aChannels, const Channel* aConfig)
+      : ChannelLayout()
+    {
+      if (!aConfig) {
+        mValid = false;
+        return;
+      }
+      mChannels.AppendElements(aConfig, aChannels);
+      UpdateChannelMap();
+    }
+    bool operator==(const ChannelLayout& aOther) const
+    {
+      return mChannels == aOther.mChannels;
+    }
+    bool operator!=(const ChannelLayout& aOther) const
+    {
+      return mChannels != aOther.mChannels;
+    }
+    const Channel& operator[](uint32_t aIndex) const
+    {
+      return mChannels[aIndex];
+    }
+    uint32_t Count() const
+    {
+      return mChannels.Length();
+    }
+    uint32_t Map() const
+    {
+      return mChannelMap;
+    }
+    // Calculate the mapping table from the current layout to aOther such that
+    // one can easily go from one layout to the other by doing:
+    // out[channel] = in[map[channel]].
+    // Returns true if the reordering is possible or false otherwise.
+    // If true, then aMap, if set, will be updated to contain the mapping table
+    // allowing conversion from the current layout to aOther.
+    // If aMap is nullptr, then MappingTable can be used to simply determine if
+    // the current layout can be easily reordered to aOther.
+    // aMap must be an array of size MAX_AUDIO_CHANNELS.
+    bool MappingTable(const ChannelLayout& aOther, uint8_t* aMap = nullptr) const;
+    bool IsValid() const {
+      return mValid;
+    }
+    bool HasChannel(Channel aChannel) const
+    {
+      return mChannelMap & (1 << aChannel);
+    }
+  private:
+    void UpdateChannelMap();
+    const Channel* SMPTEDefault(uint32_t aChannels) const;
+    AutoTArray<Channel, MAX_AUDIO_CHANNELS> mChannels;
+    uint32_t mChannelMap;
+    bool mValid;
+  };
+
+  enum SampleFormat {
+    FORMAT_NONE = 0,
+    FORMAT_U8,
+    FORMAT_S16,
+    FORMAT_S24LSB,
+    FORMAT_S24,
+    FORMAT_S32,
+    FORMAT_FLT,
+#if defined(MOZ_SAMPLE_TYPE_FLOAT32)
+    FORMAT_DEFAULT = FORMAT_FLT
+#elif defined(MOZ_SAMPLE_TYPE_S16)
+    FORMAT_DEFAULT = FORMAT_S16
+#else
+#error "Not supported audio type"
+#endif
+  };
+
+  AudioConfig(const ChannelLayout& aChannelLayout, uint32_t aRate,
+              AudioConfig::SampleFormat aFormat = FORMAT_DEFAULT,
+              bool aInterleaved = true);
+  // Will create a channel configuration from default SMPTE ordering.
+  AudioConfig(uint32_t aChannels, uint32_t aRate,
+              AudioConfig::SampleFormat aFormat = FORMAT_DEFAULT,
+              bool aInterleaved = true);
+
+  const ChannelLayout& Layout() const
+  {
+    return mChannelLayout;
+  }
+  uint32_t Channels() const
+  {
+    if (!mChannelLayout.IsValid()) {
+      return mChannels;
+    }
+    return mChannelLayout.Count();
+  }
+  uint32_t Rate() const
+  {
+    return mRate;
+  }
+  SampleFormat Format() const
+  {
+    return mFormat;
+  }
+  bool Interleaved() const
+  {
+    return mInterleaved;
+  }
+  bool operator==(const AudioConfig& aOther) const
+  {
+    return mChannelLayout == aOther.mChannelLayout &&
+      mRate == aOther.mRate && mFormat == aOther.mFormat &&
+      mInterleaved == aOther.mInterleaved;
+  }
+  bool operator!=(const AudioConfig& aOther) const
+  {
+    return !(*this == aOther);
+  }
+
+  bool IsValid() const
+  {
+    return mChannelLayout.IsValid() && Format() != FORMAT_NONE && Rate() > 0;
+  }
+
+  static const char* FormatToString(SampleFormat aFormat);
+  static uint32_t SampleSize(SampleFormat aFormat);
+  static uint32_t FormatToBits(SampleFormat aFormat);
+
+private:
+  // Channels configuration.
+  ChannelLayout mChannelLayout;
+
+  // Channel count.
+  uint32_t mChannels;
+
+  // Sample rate.
+  uint32_t mRate;
+
+  // Sample format.
+  SampleFormat mFormat;
+
+  bool mInterleaved;
+};
+
 namespace layers {
 class Image;
 class ImageContainer;