From ddcf3ad4fe53f03f53114bc378118e3d4020bd9b Mon Sep 17 00:00:00 2001
From: Bent Bisballe Nyeng <deva@aasimon.org>
Date: Sat, 20 Sep 2014 14:04:58 +0200
Subject: Ringbuffer based audio player.

---
 src/soundplayer.cc | 65 +++++++++++-------------------------------------------
 src/soundplayer.h  | 14 +++++-------
 2 files changed, 19 insertions(+), 60 deletions(-)

diff --git a/src/soundplayer.cc b/src/soundplayer.cc
index 9802d1b..29c50ac 100644
--- a/src/soundplayer.cc
+++ b/src/soundplayer.cc
@@ -33,9 +33,11 @@
 #define BUFSZ 512
 
 SoundPlayer::SoundPlayer()
-  : sem_write(1)
 {
   start();
+  pread = 0;
+  pwrite = BUFSZ * 4;
+  memset(ringbuffer, 0, sizeof(ringbuffer));
 }
 
 SoundPlayer::~SoundPlayer()
@@ -63,51 +65,15 @@ void SoundPlayer::run()
   running = true;
 
   short s[BUFSZ];
+  memset(s, 0, sizeof(s));
   while(running) {
-    sem_read.acquire();
-
-    char *pcm;
-    size_t size;
-
-    {
-      QMutexLocker lock(&mutex);
-      pcm = qi.pcm;
-      size = qi.size;
+    for(int i = 0; i < BUFSZ; i++) {
+      s[i] = ringbuffer[pread % RINGBUFFER];
+      ringbuffer[pread % RINGBUFFER] = 0;
+      pread++;
     }
 
-    sem_write.release();
-
-    printf("."); fflush(stdout);
-
-    ao_play(dev, pcm, size);
-
-    free(pcm);
-
-    /*
-    memset(s, 0, BUFSZ * sizeof(short));
-    
-    QList<QueueItem>::iterator it = active.begin();
-    while(it != active.end()) {
-      QueueItem &item = *it;
-
-      for(size_t i = 0; i < BUFSZ; i++) {
-        if(item.pos >= item.size) {
-          free(item.samples);
-          it = active.erase(it);
-          goto nextitem;
-        }
-        s[i] += item.samples[item.pos];
-        item.pos++;
-      }
-
-      it++;
-
-    nextitem:
-      int a = 1;(void)a;
-    }
-
-    ao_play(dev, (char*)s, BUFSZ * sizeof(short));
-    */
+    ao_play(dev, (char *)s, sizeof(s));
   }
 
   ao_close(dev);
@@ -116,14 +82,9 @@ void SoundPlayer::run()
 
 void SoundPlayer::playSamples(const char *pcm, size_t size)
 {
-  sem_write.acquire();
-
-  {
-    QMutexLocker lock(&mutex);
-    qi.pcm = (char*)malloc(size);
-    memcpy(qi.pcm, pcm, size);
-    qi.size = size;
+  short *p = (short*)pcm;
+  for(int i = 0; i < size / sizeof(short); i++) {
+    ringbuffer[pwrite % RINGBUFFER] += p[i];
+    pwrite++;
   }
-
-  sem_read.release();
 }
diff --git a/src/soundplayer.h b/src/soundplayer.h
index 9a1e811..33ba248 100644
--- a/src/soundplayer.h
+++ b/src/soundplayer.h
@@ -36,6 +36,9 @@
 
 #include "frame.h"
 
+// Sixe of reingbuffer in samples (16KHz), delay will be half that value
+#define RINGBUFFER 16000
+
 class QueueItem {
 public:
   char *pcm;
@@ -53,14 +56,9 @@ public:
 
 private:
   volatile bool running;
-  QMutex mutex;
-  QSemaphore sem_read;
-  QSemaphore sem_write;
-
-  QueueItem qi;
-
-  QList<QueueItem> queue;
-  QList<QueueItem> active;
+  short ringbuffer[RINGBUFFER];
+  int pwrite;
+  int pread;
 };
 
 #endif/*__KAIMAN_SOUNDPLAYER_H__*/
-- 
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