Make audio ring buffer size a multiple of 3,5,7,8.

ChangeLog

@@ -1,6 +1,8 @@
 User johns
 Date:
 
+    Make audio ring buffer size a multiple of 3,5,7,8.
+    Add reset ring buffer support.
     Fix bug: alloca wrong size for audio buffer.
     Handle jump in stream like stream start.
     Always compile audio drift correction.

audio.c

@@ -178,8 +178,8 @@ static int AudioVolume;			///< current volume (0 .. 1000)
 
 extern int VideoAudioDelay;		///< import audio/video delay
 
-    /// default ring buffer size ~2s 8ch 16bit
-static const unsigned AudioRingBufferSize = 2 * 48000 * 8 * 2;
+    /// default ring buffer size ~2s 8ch 16bit (3 * 5 * 7 * 8)
+static const unsigned AudioRingBufferSize = 3 * 5 * 7 * 8 * 2 * 1000;
 
 static int AudioChannelsInHw[9];	///< table which channels are supported
 enum _audio_rates
@@ -684,9 +684,7 @@ static int AudioRingAdd(unsigned sample_rate, int channels, int use_ac3)
     AudioRing[AudioRingWrite].HwSampleRate = sample_rate;
     AudioRing[AudioRingWrite].HwChannels = AudioChannelMatrix[u][channels];
     AudioRing[AudioRingWrite].PTS = INT64_C(0x8000000000000000);
-    // reset ring-buffer
-    RingBufferReadAdvance(AudioRing[AudioRingWrite].RingBuffer,
-	RingBufferUsedBytes(AudioRing[AudioRingWrite].RingBuffer));
+    RingBufferReset(AudioRing[AudioRingWrite].RingBuffer);
 
     atomic_inc(&AudioRingFilled);
 
@@ -856,6 +854,11 @@ static int AlsaPlayRingbuffer(void)
 	    // FIXME: if not all are written, we double amplify them
 	}
 	frames = snd_pcm_bytes_to_frames(AlsaPCMHandle, avail);
+	if (avail != snd_pcm_frames_to_bytes(AlsaPCMHandle, frames)) {
+	    Error(_("audio/alsa: bytes lost -> out of sync\n"));
+	}
+#ifdef DEBUG
+#endif
 
 	for (;;) {
 	    if (AlsaUseMmap) {

ringbuffer.c

@@ -48,6 +48,18 @@ struct _ring_buffer_
     atomic_t Filled;			///< how many of the buffer is used
 };
 
+/**
+**	Reset ring buffer pointers.
+**
+**	@param rb	Ring buffer to reset read/write pointers.
+*/
+void RingBufferReset(RingBuffer * rb)
+{
+    rb->ReadPointer = rb->Buffer;
+    rb->WritePointer = rb->Buffer;
+    atomic_set(&rb->Filled, 0);
+}
+
 /**
 **	Allocate a new ring buffer.
 **
@@ -69,10 +81,8 @@ RingBuffer *RingBufferNew(size_t size)
     }
 
     rb->Size = size;
-    rb->ReadPointer = rb->Buffer;
-    rb->WritePointer = rb->Buffer;
     rb->BufferEnd = rb->Buffer + size;
-    atomic_set(&rb->Filled, 0);
+    RingBufferReset(rb);
 
     return rb;
 }
@@ -89,7 +99,7 @@ void RingBufferDel(RingBuffer * rb)
 /**
 **	Advance write pointer in ring buffer.
 **
-**	@param rb	Ring buffer to adance write pointer.
+**	@param rb	Ring buffer to advance write pointer.
 **	@param cnt	Number of bytes to be adavanced.
 **
 **	@returns	Number of bytes that could be advanced in ring buffer.
@@ -198,7 +208,7 @@ size_t RingBufferGetWritePointer(RingBuffer * rb, void **wp)
 /**
 **	Advance read pointer in ring buffer.
 **
-**	@param rb	Ring buffer to adance read pointer.
+**	@param rb	Ring buffer to advance read pointer.
 **	@param cnt	Number of bytes to be advanced.
 **
 **	@returns	Number of bytes that could be advanced in ring buffer.

ringbuffer.h

@@ -23,13 +23,16 @@
 /// @addtogroup Ringbuffer
 /// @{
 
-    ///< ring buffer typedef
+    /// ring buffer typedef
 typedef struct _ring_buffer_ RingBuffer;
 
-    ///< create new ring buffer
+    /// reset ring buffer pointers
+extern void RingBufferReset(RingBuffer *);
+
+    /// create new ring buffer
 extern RingBuffer *RingBufferNew(size_t);
 
-    ///< free ring buffer
+    /// free ring buffer
 extern void RingBufferDel(RingBuffer *);
 
     /// write into ring buffer