Use audio_format_t consistently

Was int, uint32_t, uint16_t, and uint8_t with 2-bit bitfield.
Also replace 0 by AUDIO_FORMAT_DEFAULT and replace 1 by
AUDIO_FORMAT_PCM_16_BIT.

Change-Id: Ia8804f53f1725669e368857d5bb2044917e17975
diff --git a/include/media/mediaplayer.h b/include/media/mediaplayer.h
index e6a0cc5..2dc055e 100644
--- a/include/media/mediaplayer.h
+++ b/include/media/mediaplayer.h
@@ -190,8 +190,8 @@
             bool            isLooping();
             status_t        setVolume(float leftVolume, float rightVolume);
             void            notify(int msg, int ext1, int ext2, const Parcel *obj = NULL);
-    static  sp<IMemory>     decode(const char* url, uint32_t *pSampleRate, int* pNumChannels, int* pFormat);
-    static  sp<IMemory>     decode(int fd, int64_t offset, int64_t length, uint32_t *pSampleRate, int* pNumChannels, int* pFormat);
+    static  sp<IMemory>     decode(const char* url, uint32_t *pSampleRate, int* pNumChannels, audio_format_t* pFormat);
+    static  sp<IMemory>     decode(int fd, int64_t offset, int64_t length, uint32_t *pSampleRate, int* pNumChannels, audio_format_t* pFormat);
             status_t        invoke(const Parcel& request, Parcel *reply);
             status_t        setMetadataFilter(const Parcel& filter);
             status_t        getMetadata(bool update_only, bool apply_filter, Parcel *metadata);