Merge branch 'master' of github.com:limelight-stream/limelight-ios

# By Cameron Gutman
# Via Cameron Gutman
* 'master' of github.com:limelight-stream/limelight-ios:
  Change video background to black
  Don't try to be clever and stall the audio thread while we await samples. Start audio output earlier to allow it some extra warmup time.
  Revert "Use a semaphore to prevent us from having to busy wait on the audio buffer queue"
  Fix the memory leak in the video decoder

Limelight/Connection.m

@@ -11,8 +11,6 @@
 #import <AudioUnit/AudioUnit.h>
 #import <AVFoundation/AVFoundation.h>
 
-#include <dispatch/dispatch.h>
-
 #include "Limelight.h"
 #include "opus.h"
 
@@ -42,7 +40,6 @@ struct AUDIO_BUFFER_QUEUE_ENTRY {
 static short decodedPcmBuffer[512];
 static NSLock *audioLock;
 static struct AUDIO_BUFFER_QUEUE_ENTRY *audioBufferQueue;
-static dispatch_semaphore_t audioQueueSemaphore;
 static int audioBufferQueueLength;
 static AudioComponentInstance audioUnit;
 static VideoDecoderRenderer* renderer;
@@ -65,9 +62,8 @@ void DrSubmitDecodeUnit(PDECODE_UNIT decodeUnit)
             entry = entry->next;
         }
         
+        // This function will take our buffer
         [renderer submitDecodeBuffer:data length:decodeUnit->fullLength];
-        
-        free(data);
     }
 }
 
@@ -95,8 +91,6 @@ void ArInit(void)
     opusDecoder = opus_decoder_create(48000, 2, &err);
     
     audioLock = [[NSLock alloc] init];
-    
-    audioQueueSemaphore = dispatch_semaphore_create(0);
 }
 
 void ArRelease(void)
@@ -112,7 +106,6 @@ void ArRelease(void)
 void ArStart(void)
 {
     printf("Start audio\n");
-    AudioOutputUnitStart(audioUnit);
 }
 
 void ArStop(void)
@@ -141,15 +134,9 @@ void ArDecodeAndPlaySample(char* sampleData, int sampleLength)
                 // Clear all values from the buffer queue
                 struct AUDIO_BUFFER_QUEUE_ENTRY *entry;
                 while (audioBufferQueue != NULL) {
-                    // Unlink the current entry
                     entry = audioBufferQueue;
                     audioBufferQueue = entry->next;
-                    
-                    // Decrease the semaphore count and queue length
                     audioBufferQueueLength--;
-                    dispatch_semaphore_wait(audioQueueSemaphore, DISPATCH_TIME_NOW);
-                    
-                    // Free the entry
                     free(entry);
                 }
             }
@@ -164,13 +151,9 @@ void ArDecodeAndPlaySample(char* sampleData, int sampleLength)
                 }
                 lastEntry->next = newEntry;
             }
-            
-            // Increment the queue size and unlock
             audioBufferQueueLength++;
-            [audioLock unlock];
             
-            // Signal the other thread
-            dispatch_semaphore_signal(audioQueueSemaphore);
+            [audioLock unlock];
         }
     }
 }
@@ -312,6 +295,13 @@ void ClDisplayTransientMessage(char* message)
         NSLog(@"Unable to initialize audioUnit: %d", (int32_t)status);
     }
     
+    // We start here because it seems to need some warmup time
+    // before it starts accepting samples
+    status = AudioOutputUnitStart(audioUnit);
+    if (status) {
+        NSLog(@"Unable to start audioUnit: %d", (int32_t)status);
+    }
+    
     return self;
 }
 
@@ -325,9 +315,15 @@ static OSStatus playbackCallback(void *inRefCon,
     // Fill them up as much as you can. Remember to set the size value in each buffer to match how
     // much data is in the buffer.
     
+    bool ranOutOfData = false;
     for (int i = 0; i < ioData->mNumberBuffers; i++) {
         ioData->mBuffers[i].mNumberChannels = 2;
         
+        if (ranOutOfData) {
+            ioData->mBuffers[i].mDataByteSize = 0;
+            continue;
+        }
+        
         if (ioData->mBuffers[i].mDataByteSize != 0) {
             int thisBufferOffset = 0;
             
@@ -337,22 +333,22 @@ static OSStatus playbackCallback(void *inRefCon,
                 continue;
             }
             
-            // Wait for a buffer to be available
             struct AUDIO_BUFFER_QUEUE_ENTRY *audioEntry = NULL;
-            while (audioEntry == NULL)
-            {
-                // Wait for an entry to be present in the queue
-                dispatch_semaphore_wait(audioQueueSemaphore, DISPATCH_TIME_FOREVER);
-                
-                // If there's an entry there, dequeue it
-                [audioLock lock];
-                if (audioBufferQueue != NULL) {
-                    // Dequeue this entry temporarily
-                    audioEntry = audioBufferQueue;
-                    audioBufferQueue = audioBufferQueue->next;
-                    audioBufferQueueLength--;
-                }
-                [audioLock unlock];
+            
+            [audioLock lock];
+            if (audioBufferQueue != NULL) {
+                // Dequeue this entry temporarily
+                audioEntry = audioBufferQueue;
+                audioBufferQueue = audioBufferQueue->next;
+                audioBufferQueueLength--;
+            }
+            [audioLock unlock];
+            
+            if (audioEntry == NULL) {
+                // No data left
+                ranOutOfData = true;
+                ioData->mBuffers[i].mDataByteSize = thisBufferOffset;
+                continue;
             }
             
             // Figure out how much data we can write
@@ -373,7 +369,6 @@ static OSStatus playbackCallback(void *inRefCon,
                 audioBufferQueue = audioEntry;
                 audioBufferQueueLength++;
                 [audioLock unlock];
-                dispatch_semaphore_signal(audioQueueSemaphore);
             }
             else {
                 // This entry is fully depleted so free it