added outputBufferChunkData()

Hiding OutputBuffer internals, again.  We get an extra assertion in
return.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7267 09075e82-0dd4-0310-85a5-a0d7c8717e4f

src/decode.c

@@ -506,10 +506,8 @@ static void decodeParent(PlayerControl * pc, DecoderControl * dc, OutputBuffer *
 				}
 				nextChunk = outputBufferAbsolute(cb, crossFadeChunks);
 				if (nextChunk >= 0) {
-					pcm_mix(cb->chunks +
+					pcm_mix(outputBufferChunkData(cb, cb->begin),
-						cb->begin * CHUNK_SIZE,
+						outputBufferChunkData(cb, nextChunk),
-						cb->chunks +
-						nextChunk * CHUNK_SIZE,
 						cb->chunkSize[cb->begin],
 						cb->chunkSize[nextChunk],
 						&(cb->audioFormat),

src/outputBuffer.c

@@ -92,6 +92,13 @@ int outputBufferAbsolute(const OutputBuffer * cb, unsigned relative)
 	return (int)i;
 }
 
+char * outputBufferChunkData(const OutputBuffer * cb, unsigned i)
+{
+	assert(i < buffered_chunks);
+
+	return cb->chunks + i * CHUNK_SIZE;
+}
+
 /**
  * Return the tail chunk has room for additional data.  If there is no
  * room in the queue, this function blocks until the player thread has

src/outputBuffer.h

@@ -73,6 +73,8 @@ unsigned availableOutputBuffer(const OutputBuffer * cb);
  */
 int outputBufferAbsolute(const OutputBuffer * cb, unsigned relative);
 
+char * outputBufferChunkData(const OutputBuffer * cb, unsigned i);
+
 /* we send inStream for buffering the inputStream while waiting to
    send the next chunk */
 int sendDataToOutputBuffer(OutputBuffer * cb,