audio_format: added audio_format_frame_size()

A frame contains one sample per channel, thus it is sample_size *
channels.  This patch includes some cleanup for various locations
where the sample size for 24 bit audio was still 3 bytes (instead of
4).

5 files changed, 12 insertions, 7 deletions

diff --git a/src/audio.c b/src/audio.c
index a4d4e3ea4..353f8b8d2 100644
--- a/src/audio.c
+++ b/src/audio.c
@@ -315,7 +315,7 @@ static int flushAudioBuffer(void)
 
 static size_t audio_buffer_size(const struct audio_format *af)
 {
-	return (af->bits >> 3) * af->channels * (af->sample_rate >> 5);
+	return audio_format_frame_size(af) * (af->sample_rate >> 5);
 }
 
 static void audio_buffer_resize(size_t size)
diff --git a/src/audioOutputs/audioOutput_alsa.c b/src/audioOutputs/audioOutput_alsa.c
index 30ad449f3..9d47ff244 100644
--- a/src/audioOutputs/audioOutput_alsa.c
+++ b/src/audioOutputs/audioOutput_alsa.c
@@ -288,7 +288,7 @@ configure_hw:
 	if (err < 0)
 		goto error;
 
-	ad->sampleSize = audio_format_sample_size(audioFormat) * audioFormat->channels;
+	ad->sampleSize = audio_format_frame_size(audioFormat);
 
 	DEBUG("ALSA device \"%s\" will be playing %i bit, %u channel audio at "
 	      "%u Hz\n", ad->device, audioFormat->bits,
diff --git a/src/audioOutputs/audioOutput_osx.c b/src/audioOutputs/audioOutput_osx.c
index 1fc0a5d9e..65060cc8c 100644
--- a/src/audioOutputs/audioOutput_osx.c
+++ b/src/audioOutputs/audioOutput_osx.c
@@ -266,8 +266,7 @@ static int osx_openDevice(struct audio_output *audioOutput,
 	streamDesc.mFormatFlags |= kLinearPCMFormatFlagIsBigEndian;
 #endif
 
-	streamDesc.mBytesPerPacket =
-		audioFormat->channels * audio_format_sample_size(audioFormat);
+	streamDesc.mBytesPerPacket = audio_format_frame_size(audioFormat);
 	streamDesc.mFramesPerPacket = 1;
 	streamDesc.mBytesPerFrame = streamDesc.mBytesPerPacket;
 	streamDesc.mChannelsPerFrame = audioFormat->channels;
@@ -284,7 +283,7 @@ static int osx_openDevice(struct audio_output *audioOutput,
 
 	/* create a buffer of 1s */
 	od->bufferSize = (audioFormat->sample_rate) *
-	    (audioFormat->bits >> 3) * (audioFormat->channels);
+		audio_format_frame_size(audioFormat);
 	od->buffer = xrealloc(od->buffer, od->bufferSize);
 
 	od->pos = 0;
diff --git a/src/audio_format.h b/src/audio_format.h
index 2475aa77e..bbebc51b1 100644
--- a/src/audio_format.h
+++ b/src/audio_format.h
@@ -61,9 +61,15 @@ static inline unsigned audio_format_sample_size(const struct audio_format *af)
 		return 4;
 }
 
+static inline unsigned
+audio_format_frame_size(const struct audio_format *af)
+{
+	return audio_format_sample_size(af) * af->channels;
+}
+
 static inline double audio_format_time_to_size(const struct audio_format *af)
 {
-	return af->sample_rate * af->channels * audio_format_sample_size(af);
+	return af->sample_rate * audio_format_frame_size(af);
 }
 
 static inline double audioFormatSizeToTime(const struct audio_format *af)
diff --git a/src/timer.c b/src/timer.c
index 84c03fbe6..46e1cdd86 100644
--- a/src/timer.c
+++ b/src/timer.c
@@ -40,7 +40,7 @@ Timer *timer_new(const struct audio_format *af)
 	timer = xmalloc(sizeof(Timer));
 	timer->time = 0;
 	timer->started = 0;
-	timer->rate = af->sample_rate * (af->bits / CHAR_BIT) * af->channels;
+	timer->rate = af->sample_rate * audio_format_frame_size(af);
 
 	return timer;
 }