Added audio_bytes_per_sample() helper function

Change-Id: Ibfcd75c4c241a53d5f052c25ada091904991048a
diff --git a/media/libmedia/AudioRecord.cpp b/media/libmedia/AudioRecord.cpp
index a41d7ab..03518bf 100644
--- a/media/libmedia/AudioRecord.cpp
+++ b/media/libmedia/AudioRecord.cpp
@@ -70,7 +70,7 @@
     size <<= 1;
 
     if (audio_is_linear_pcm(format)) {
-        size /= channelCount * (format == AUDIO_FORMAT_PCM_16_BIT ? 2 : 1);
+        size /= channelCount * audio_bytes_per_sample(format);
     }
 
     *frameCount = size;
@@ -258,7 +258,7 @@
 int AudioRecord::frameSize() const
 {
     if (audio_is_linear_pcm(mFormat)) {
-        return channelCount()*((format() == AUDIO_FORMAT_PCM_8_BIT) ? sizeof(uint8_t) : sizeof(int16_t));
+        return channelCount()*audio_bytes_per_sample(mFormat);
     } else {
         return sizeof(uint8_t);
     }
diff --git a/media/libmedia/AudioTrack.cpp b/media/libmedia/AudioTrack.cpp
index 37fe182..5172809 100644
--- a/media/libmedia/AudioTrack.cpp
+++ b/media/libmedia/AudioTrack.cpp
@@ -298,7 +298,7 @@
 int AudioTrack::frameSize() const
 {
     if (audio_is_linear_pcm(mFormat)) {
-        return channelCount()*((format() == AUDIO_FORMAT_PCM_8_BIT) ? sizeof(uint8_t) : sizeof(int16_t));
+        return channelCount()*audio_bytes_per_sample(mFormat);
     } else {
         return sizeof(uint8_t);
     }