diff --git a/services/audioflinger/AudioMixer.h b/services/audioflinger/AudioMixer.h
index 381036b..e283b83 100644
--- a/services/audioflinger/AudioMixer.h
+++ b/services/audioflinger/AudioMixer.h
@@ -29,6 +29,7 @@
 #include <utils/threads.h>
 
 #include "AudioResampler.h"
+#include "BufferProviders.h"
 
 // FIXME This is actually unity gain, which might not be max in future, expressed in U.12
 #define MAX_GAIN_INT AudioMixer::UNITY_GAIN_INT
@@ -159,7 +160,6 @@
 
     struct state_t;
     struct track_t;
-    class CopyBufferProvider;
 
     typedef void (*hook_t)(track_t* t, int32_t* output, size_t numOutFrames, int32_t* temp,
                            int32_t* aux);
@@ -225,11 +225,10 @@
          *    the downmixer requirements to the mixer engine input requirements.
          */
         AudioBufferProvider*     mInputBufferProvider;    // externally provided buffer provider.
-        CopyBufferProvider*      mReformatBufferProvider; // provider wrapper for reformatting.
-        CopyBufferProvider*      downmixerBufferProvider; // wrapper for channel conversion.
-        CopyBufferProvider*      mPostDownmixReformatBufferProvider;
+        PassthruBufferProvider*  mReformatBufferProvider; // provider wrapper for reformatting.
+        PassthruBufferProvider*  downmixerBufferProvider; // wrapper for channel conversion.
+        PassthruBufferProvider*  mPostDownmixReformatBufferProvider;
 
-        // 16-byte boundary
         int32_t     sessionId;
 
         audio_format_t mMixerFormat;     // output mix format: AUDIO_FORMAT_PCM_(FLOAT|16_BIT)
@@ -282,112 +281,6 @@
         track_t         tracks[MAX_NUM_TRACKS] __attribute__((aligned(32)));
     };
 
-    // Base AudioBufferProvider class used for DownMixerBufferProvider, RemixBufferProvider,
-    // and ReformatBufferProvider.
-    // It handles a private buffer for use in converting format or channel masks from the
-    // input data to a form acceptable by the mixer.
-    // TODO: Make a ResamplerBufferProvider when integers are entirely removed from the
-    // processing pipeline.
-    class CopyBufferProvider : public AudioBufferProvider {
-    public:
-        // Use a private buffer of bufferFrameCount frames (each frame is outputFrameSize bytes).
-        // If bufferFrameCount is 0, no private buffer is created and in-place modification of
-        // the upstream buffer provider's buffers is performed by copyFrames().
-        CopyBufferProvider(size_t inputFrameSize, size_t outputFrameSize,
-                size_t bufferFrameCount);
-        virtual ~CopyBufferProvider();
-
-        // Overrides AudioBufferProvider methods
-        virtual status_t getNextBuffer(Buffer* buffer, int64_t pts);
-        virtual void releaseBuffer(Buffer* buffer);
-
-        // Other public methods
-
-        // call this to release the buffer to the upstream provider.
-        // treat it as an audio discontinuity for future samples.
-        virtual void reset();
-
-        // this function should be supplied by the derived class.  It converts
-        // #frames in the *src pointer to the *dst pointer.  It is public because
-        // some providers will allow this to work on arbitrary buffers outside
-        // of the internal buffers.
-        virtual void copyFrames(void *dst, const void *src, size_t frames) = 0;
-
-        // set the upstream buffer provider. Consider calling "reset" before this function.
-        void setBufferProvider(AudioBufferProvider *p) {
-            mTrackBufferProvider = p;
-        }
-
-    protected:
-        AudioBufferProvider* mTrackBufferProvider;
-        const size_t         mInputFrameSize;
-        const size_t         mOutputFrameSize;
-    private:
-        AudioBufferProvider::Buffer mBuffer;
-        const size_t         mLocalBufferFrameCount;
-        void*                mLocalBufferData;
-        size_t               mConsumed;
-    };
-
-    // DownmixerBufferProvider wraps a track AudioBufferProvider to provide
-    // position dependent downmixing by an Audio Effect.
-    class DownmixerBufferProvider : public CopyBufferProvider {
-    public:
-        DownmixerBufferProvider(audio_channel_mask_t inputChannelMask,
-                audio_channel_mask_t outputChannelMask, audio_format_t format,
-                uint32_t sampleRate, int32_t sessionId, size_t bufferFrameCount);
-        virtual ~DownmixerBufferProvider();
-        virtual void copyFrames(void *dst, const void *src, size_t frames);
-        bool isValid() const { return mDownmixHandle != NULL; }
-
-        static status_t init();
-        static bool isMultichannelCapable() { return sIsMultichannelCapable; }
-
-    protected:
-        effect_handle_t    mDownmixHandle;
-        effect_config_t    mDownmixConfig;
-
-        // effect descriptor for the downmixer used by the mixer
-        static effect_descriptor_t sDwnmFxDesc;
-        // indicates whether a downmix effect has been found and is usable by this mixer
-        static bool                sIsMultichannelCapable;
-        // FIXME: should we allow effects outside of the framework?
-        // We need to here. A special ioId that must be <= -2 so it does not map to a session.
-        static const int32_t SESSION_ID_INVALID_AND_IGNORED = -2;
-    };
-
-    // RemixBufferProvider wraps a track AudioBufferProvider to perform an
-    // upmix or downmix to the proper channel count and mask.
-    class RemixBufferProvider : public CopyBufferProvider {
-    public:
-        RemixBufferProvider(audio_channel_mask_t inputChannelMask,
-                audio_channel_mask_t outputChannelMask, audio_format_t format,
-                size_t bufferFrameCount);
-        virtual void copyFrames(void *dst, const void *src, size_t frames);
-
-    protected:
-        const audio_format_t mFormat;
-        const size_t         mSampleSize;
-        const size_t         mInputChannels;
-        const size_t         mOutputChannels;
-        int8_t               mIdxAry[sizeof(uint32_t)*8]; // 32 bits => channel indices
-    };
-
-    // ReformatBufferProvider wraps a track AudioBufferProvider to convert the input data
-    // to an acceptable mixer input format type.
-    class ReformatBufferProvider : public CopyBufferProvider {
-    public:
-        ReformatBufferProvider(int32_t channels,
-                audio_format_t inputFormat, audio_format_t outputFormat,
-                size_t bufferFrameCount);
-        virtual void copyFrames(void *dst, const void *src, size_t frames);
-
-    protected:
-        const int32_t        mChannels;
-        const audio_format_t mInputFormat;
-        const audio_format_t mOutputFormat;
-    };
-
     // bitmask of allocated track names, where bit 0 corresponds to TRACK0 etc.
     uint32_t        mTrackNames;