4 files changed, 13 insertions, 14 deletions
diff --git a/include/media/nbaio/AudioBufferProviderSource.h b/include/media/nbaio/AudioBufferProviderSource.h
index 2c4aaff..b16e20a 100644
--- a/include/media/nbaio/AudioBufferProviderSource.h
+++ b/include/media/nbaio/AudioBufferProviderSource.h
@@ -27,7 +27,7 @@ namespace android {
 class AudioBufferProviderSource : public NBAIO_Source {
 
 public:
-    AudioBufferProviderSource(AudioBufferProvider *provider, NBAIO_Format format);
+    AudioBufferProviderSource(AudioBufferProvider *provider, const NBAIO_Format& format);
     virtual ~AudioBufferProviderSource();
 
     // NBAIO_Port interface
diff --git a/include/media/nbaio/MonoPipe.h b/include/media/nbaio/MonoPipe.h
index d3802fe..b09b35f 100644
--- a/include/media/nbaio/MonoPipe.h
+++ b/include/media/nbaio/MonoPipe.h
@@ -41,7 +41,7 @@ public:
     // Note: whatever shares this object with another thread needs to do so in an SMP-safe way (like
     // creating it the object before creating the other thread, or storing the object with a
     // release_store). Otherwise the other thread could see a partially-constructed object.
-    MonoPipe(size_t reqFrames, NBAIO_Format format, bool writeCanBlock = false);
+    MonoPipe(size_t reqFrames, const NBAIO_Format& format, bool writeCanBlock = false);
     virtual ~MonoPipe();
 
     // NBAIO_Port interface
diff --git a/include/media/nbaio/NBAIO.h b/include/media/nbaio/NBAIO.h
index 1da0c73..9c9721a 100644
--- a/include/media/nbaio/NBAIO.h
+++ b/include/media/nbaio/NBAIO.h
@@ -53,24 +53,23 @@ enum {
 // too large, then this decision should be re-visited.
 // Sample rate and channel count are explicit, PCM interleaved 16-bit is assumed.
 typedef unsigned NBAIO_Format;
-enum {
-    Format_Invalid
-};
+
+extern const NBAIO_Format Format_Invalid;
 
 // Return the frame size of an NBAIO_Format in bytes
-size_t Format_frameSize(NBAIO_Format format);
+size_t Format_frameSize(const NBAIO_Format& format);
 
 // Return the frame size of an NBAIO_Format as a bit shift
-size_t Format_frameBitShift(NBAIO_Format format);
+size_t Format_frameBitShift(const NBAIO_Format& format);
 
 // Convert a sample rate in Hz and channel count to an NBAIO_Format
 NBAIO_Format Format_from_SR_C(unsigned sampleRate, unsigned channelCount);
 
 // Return the sample rate in Hz of an NBAIO_Format
-unsigned Format_sampleRate(NBAIO_Format format);
+unsigned Format_sampleRate(const NBAIO_Format& format);
 
 // Return the channel count of an NBAIO_Format
-unsigned Format_channelCount(NBAIO_Format format);
+unsigned Format_channelCount(const NBAIO_Format& format);
 
 // Callbacks used by NBAIO_Sink::writeVia() and NBAIO_Source::readVia() below.
 typedef ssize_t (*writeVia_t)(void *user, void *buffer, size_t count);
@@ -115,8 +114,8 @@ public:
     virtual NBAIO_Format format() const { return mNegotiated ? mFormat : Format_Invalid; }
 
 protected:
-    NBAIO_Port(NBAIO_Format format) : mNegotiated(false), mFormat(format),
-                                      mBitShift(Format_frameBitShift(format)) { }
+    NBAIO_Port(const NBAIO_Format& format) : mNegotiated(false), mFormat(format),
+                                             mBitShift(Format_frameBitShift(format)) { }
     virtual ~NBAIO_Port() { }
 
     // Implementations are free to ignore these if they don't need them
@@ -220,7 +219,7 @@ public:
     virtual status_t getTimestamp(AudioTimestamp& timestamp) { return INVALID_OPERATION; }
 
 protected:
-    NBAIO_Sink(NBAIO_Format format = Format_Invalid) : NBAIO_Port(format), mFramesWritten(0) { }
+    NBAIO_Sink(const NBAIO_Format& format = Format_Invalid) : NBAIO_Port(format), mFramesWritten(0) { }
     virtual ~NBAIO_Sink() { }
 
     // Implementations are free to ignore these if they don't need them
@@ -311,7 +310,7 @@ public:
     virtual void    onTimestamp(const AudioTimestamp& timestamp) { }
 
 protected:
-    NBAIO_Source(NBAIO_Format format = Format_Invalid) : NBAIO_Port(format), mFramesRead(0) { }
+    NBAIO_Source(const NBAIO_Format& format = Format_Invalid) : NBAIO_Port(format), mFramesRead(0) { }
     virtual ~NBAIO_Source() { }
 
     // Implementations are free to ignore these if they don't need them
diff --git a/include/media/nbaio/Pipe.h b/include/media/nbaio/Pipe.h
index 79a4eee..c784129 100644
--- a/include/media/nbaio/Pipe.h
+++ b/include/media/nbaio/Pipe.h
@@ -30,7 +30,7 @@ class Pipe : public NBAIO_Sink {
 
 public:
     // maxFrames will be rounded up to a power of 2, and all slots are available. Must be >= 2.
-    Pipe(size_t maxFrames, NBAIO_Format format);
+    Pipe(size_t maxFrames, const NBAIO_Format& format);
     virtual ~Pipe();
 
     // NBAIO_Port interface