// Processes a 10 ms |frame| of the primary audio stream. On the client-side,
  // this is the near-end (or captured) audio.
  //
  // If needed for enabled functionality, any function with the set_stream_ tag
  // must be called prior to processing the current frame. Any getter function
  // with the stream_ tag which is needed should be called after processing.
  //
  // The |sample_rate_hz_|, |num_channels_|, and |samples_per_channel_|
  // members of |frame| must be valid. If changed from the previous call to this
  // method, it will trigger an initialization.
  virtual int ProcessStream(AudioFrame* frame) = 0;

  // Accepts deinterleaved float audio with the range [-1, 1]. Each element
  // of |src| points to a channel buffer, arranged according to
  // |input_layout|. At output, the channels will be arranged according to
  // |output_layout| at |output_sample_rate_hz| in |dest|.
  //
  // The output layout must have one channel or as many channels as the input.
  // |src| and |dest| may use the same memory, if desired.
  //
  // TODO(mgraczyk): Remove once clients are updated to use the new interface.
  virtual int ProcessStream(const float* const* src,
                            size_t samples_per_channel,
                            int input_sample_rate_hz,
                            ChannelLayout input_layout,
                            int output_sample_rate_hz,
                            ChannelLayout output_layout,
                            float* const* dest) = 0;

  // Accepts deinterleaved float audio with the range [-1, 1]. Each element of
  // |src| points to a channel buffer, arranged according to |input_stream|. At
  // output, the channels will be arranged according to |output_stream| in
  // |dest|.
  //
  // The output must have one channel or as many channels as the input. |src|
  // and |dest| may use the same memory, if desired.
  virtual int ProcessStream(const float* const* src,
                            const StreamConfig& input_config,
                            const StreamConfig& output_config,
                            float* const* dest) = 0;