diff --git a/include/media/AudioRecord.h b/include/media/AudioRecord.h
index baab2e8..605680a 100644
--- a/include/media/AudioRecord.h
+++ b/include/media/AudioRecord.h
@@ -130,7 +130,7 @@
      * sampleRate:         Track sampling rate in Hz.
      * format:             Audio format (e.g AUDIO_FORMAT_PCM_16_BIT for signed
      *                     16 bits per sample).
-     * channels:           Channel mask: see audio_channels_t.
+     * channelMask:        Channel mask: see audio_channels_t.
      * frameCount:         Total size of track PCM buffer in frames. This defines the
      *                     latency of the track.
      * flags:              A bitmask of acoustic values from enum record_flags.  It enables
@@ -151,7 +151,7 @@
                         AudioRecord(int inputSource,
                                     uint32_t sampleRate = 0,
                                     int format          = 0,
-                                    uint32_t channels = AUDIO_CHANNEL_IN_MONO,
+                                    uint32_t channelMask = AUDIO_CHANNEL_IN_MONO,
                                     int frameCount      = 0,
                                     uint32_t flags      = 0,
                                     callback_t cbf = 0,
@@ -177,7 +177,7 @@
             status_t    set(int inputSource     = 0,
                             uint32_t sampleRate = 0,
                             int format          = 0,
-                            uint32_t channels = AUDIO_CHANNEL_IN_MONO,
+                            uint32_t channelMask = AUDIO_CHANNEL_IN_MONO,
                             int frameCount      = 0,
                             uint32_t flags      = 0,
                             callback_t cbf = 0,
@@ -348,8 +348,8 @@
 
             bool processAudioBuffer(const sp<ClientRecordThread>& thread);
             status_t openRecord_l(uint32_t sampleRate,
-                                int format,
-                                int channelCount,
+                                uint32_t format,
+                                uint32_t channelMask,
                                 int frameCount,
                                 uint32_t flags,
                                 audio_io_handle_t input);
@@ -364,10 +364,10 @@
     uint32_t                mFrameCount;
 
     audio_track_cblk_t*     mCblk;
-    uint8_t                 mFormat;
+    uint32_t                mFormat;
     uint8_t                 mChannelCount;
     uint8_t                 mInputSource;
-    uint8_t                 mReserved;
+    uint8_t                 mReserved[2];
     status_t                mStatus;
     uint32_t                mLatency;
 
@@ -382,7 +382,7 @@
     uint32_t                mNewPosition;
     uint32_t                mUpdatePeriod;
     uint32_t                mFlags;
-    uint32_t                mChannels;
+    uint32_t                mChannelMask;
     audio_io_handle_t       mInput;
     int                     mSessionId;
 };
diff --git a/include/media/AudioTrack.h b/include/media/AudioTrack.h
index de928da..df30e8c 100644
--- a/include/media/AudioTrack.h
+++ b/include/media/AudioTrack.h
@@ -69,8 +69,8 @@
             MUTE    = 0x00000001
         };
         uint32_t    flags;
-        int         channelCount;
         int         format;
+        int         channelCount; // will be removed in the future, do not use
         size_t      frameCount;
         size_t      size;
         union {
@@ -129,7 +129,7 @@
      * sampleRate:         Track sampling rate in Hz.
      * format:             Audio format (e.g AUDIO_FORMAT_PCM_16_BIT for signed
      *                     16 bits per sample).
-     * channels:           Channel mask: see audio_channels_t.
+     * channelMask:        Channel mask: see audio_channels_t.
      * frameCount:         Total size of track PCM buffer in frames. This defines the
      *                     latency of the track.
      * flags:              Reserved for future use.
@@ -143,7 +143,7 @@
                         AudioTrack( int streamType,
                                     uint32_t sampleRate  = 0,
                                     int format           = 0,
-                                    int channels         = 0,
+                                    int channelMask      = 0,
                                     int frameCount       = 0,
                                     uint32_t flags       = 0,
                                     callback_t cbf       = 0,
@@ -163,7 +163,7 @@
                         AudioTrack( int streamType,
                                     uint32_t sampleRate = 0,
                                     int format          = 0,
-                                    int channels        = 0,
+                                    int channelMask     = 0,
                                     const sp<IMemory>& sharedBuffer = 0,
                                     uint32_t flags      = 0,
                                     callback_t cbf      = 0,
@@ -187,7 +187,7 @@
             status_t    set(int streamType      =-1,
                             uint32_t sampleRate = 0,
                             int format          = 0,
-                            int channels        = 0,
+                            int channelMask     = 0,
                             int frameCount      = 0,
                             uint32_t flags      = 0,
                             callback_t cbf      = 0,
@@ -438,8 +438,8 @@
             bool processAudioBuffer(const sp<AudioTrackThread>& thread);
             status_t createTrack_l(int streamType,
                                  uint32_t sampleRate,
-                                 int format,
-                                 int channelCount,
+                                 uint32_t format,
+                                 uint32_t channelMask,
                                  int frameCount,
                                  uint32_t flags,
                                  const sp<IMemory>& sharedBuffer,
@@ -459,11 +459,12 @@
     uint32_t                mFrameCount;
 
     audio_track_cblk_t*     mCblk;
+    uint32_t                mFormat;
     uint8_t                 mStreamType;
-    uint8_t                 mFormat;
     uint8_t                 mChannelCount;
     uint8_t                 mMuted;
-    uint32_t                mChannels;
+    uint8_t                 mReserved;
+    uint32_t                mChannelMask;
     status_t                mStatus;
     uint32_t                mLatency;
 
diff --git a/include/media/IAudioFlinger.h b/include/media/IAudioFlinger.h
index d8fdc27..4037c46 100644
--- a/include/media/IAudioFlinger.h
+++ b/include/media/IAudioFlinger.h
@@ -48,8 +48,8 @@
                                 pid_t pid,
                                 int streamType,
                                 uint32_t sampleRate,
-                                int format,
-                                int channelCount,
+                                uint32_t format,
+                                uint32_t channelMask,
                                 int frameCount,
                                 uint32_t flags,
                                 const sp<IMemory>& sharedBuffer,
@@ -61,8 +61,8 @@
                                 pid_t pid,
                                 int input,
                                 uint32_t sampleRate,
-                                int format,
-                                int channelCount,
+                                uint32_t format,
+                                uint32_t channelMask,
                                 int frameCount,
                                 uint32_t flags,
                                 int *sessionId,
@@ -73,7 +73,7 @@
      */
     virtual     uint32_t    sampleRate(int output) const = 0;
     virtual     int         channelCount(int output) const = 0;
-    virtual     int         format(int output) const = 0;
+    virtual     uint32_t    format(int output) const = 0;
     virtual     size_t      frameCount(int output) const = 0;
     virtual     uint32_t    latency(int output) const = 0;
 
diff --git a/include/private/media/AudioTrackShared.h b/include/private/media/AudioTrackShared.h
index 1827c3e..072329d 100644
--- a/include/private/media/AudioTrackShared.h
+++ b/include/private/media/AudioTrackShared.h
@@ -82,7 +82,7 @@
                 // 16 bit because data is converted to 16 bit before being stored in buffer
 
                 uint8_t     frameSize;
-                uint8_t     channelCount;
+                uint8_t     pad1;
                 uint16_t    bufferTimeoutMs; // Maximum cumulated timeout before restarting audioflinger
 
                 uint16_t    waitTimeMs;      // Cumulated wait time
@@ -90,6 +90,7 @@
     volatile    int32_t     flags;
 
                 // Cache line boundary (32 bytes)
+
                             audio_track_cblk_t();
                 uint32_t    stepUser(uint32_t frameCount);
                 bool        stepServer(uint32_t frameCount);