1 files changed, 145 insertions, 0 deletions
diff --git a/core/Ac3Decoder.cpp b/core/Ac3Decoder.cpp
new file mode 100644
index 000000000..12eed05df
--- /dev/null
+++ b/core/Ac3Decoder.cpp
@@ -0,0 +1,145 @@
+/* $Id: Ac3Decoder.cpp,v 1.12 2003/09/30 14:38:15 titer Exp $
+
+   This file is part of the HandBrake source code.
+   Homepage: <http://beos.titer.org/handbrake/>.
+   It may be used under the terms of the GNU General Public License. */
+
+#include "Ac3Decoder.h"
+#include "Fifo.h"
+#include "Manager.h"
+
+extern "C" {
+#include <a52dec/a52.h>
+}
+
+HBAc3Decoder::HBAc3Decoder( HBManager * manager, HBAudio * audio )
+    : HBThread( "ac3decoder" )
+{
+    fManager     = manager;
+    fAudio       = audio;
+
+    /* Max size for a A52 frame is 3840 bytes */
+    fAc3Frame    = new HBBuffer( 3840 );
+    fAc3Buffer   = NULL;
+    fPosInBuffer = 0;
+    fPosition    = 0;
+}
+
+HBAc3Decoder::~HBAc3Decoder()
+{
+    delete fAc3Frame;
+}
+
+void HBAc3Decoder::DoWork()
+{
+    /* Init liba52 */
+    a52_state_t * state       = a52_init( 0 );
+    int           inFlags     = 0;
+    int           outFlags    = A52_STEREO;
+
+    /* Lame wants samples from -32768 to 32768 */
+    float         sampleLevel = 32768;
+
+    int           frameSize;
+    HBBuffer    * rawBuffer;
+    sample_t    * samples;
+
+    /* Main loop */
+    for( ;; )
+    {
+        while( fSuspend )
+        {
+            Snooze( 10000 );
+        }
+
+        fAc3Frame->fSize = 0;
+
+        /* Get a frame header (7 bytes) */
+        if( !( GetBytes( 7 ) ) )
+        {
+            break;
+        }
+
+        /* Get the size of the current frame */
+        frameSize = a52_syncinfo( fAc3Frame->fData, &inFlags,
+                                  &fAudio->fInSampleRate,
+                                  &fAudio->fInBitrate );
+
+        if( !frameSize )
+        {
+            Log( "HBAc3Decoder : a52_syncinfo failed" );
+            fManager->Error();
+            break;
+        }
+
+        /* Get the whole frame */
+        if( !( GetBytes( (uint32_t) frameSize ) ) )
+        {
+            break;
+        }
+
+        /* Feed liba52 */
+        a52_frame( state, fAc3Frame->fData, &outFlags, &sampleLevel, 0 );
+
+        /* 6 blocks per frame, 256 samples per block */
+        rawBuffer = new HBBuffer( 12 * 256 * sizeof( float ) );
+        rawBuffer->fPosition = fPosition;
+        for( int i = 0; i < 6; i++ )
+        {
+            /* Decode a block */
+            a52_block( state );
+
+            /* Get a pointer to the raw data */
+            samples = a52_samples( state );
+
+            /* Copy left channel data */
+            memcpy( (float*) rawBuffer->fData + i * 256,
+                    samples,
+                    256 * sizeof( float ) );
+
+            /* Copy right channel data */
+            memcpy( (float*) rawBuffer->fData + ( 6 + i ) * 256,
+                    samples + 256,
+                    256 * sizeof( float ) );
+        }
+
+        if( !Push( fAudio->fRawFifo, rawBuffer ) )
+        {
+            break;
+        }
+    }
+}
+
+/* GetBytes() : pops buffers from the AC3 fifo until fAc3Frame
+   contains <size> bytes */
+bool HBAc3Decoder::GetBytes( uint32_t size )
+{
+    while( fAc3Frame->fSize < size )
+    {
+        if( !fAc3Buffer )
+        {
+            if( !( fAc3Buffer = Pop( fAudio->fAc3Fifo ) ) )
+            {
+                return false;
+            }
+            fPosInBuffer = 0;
+            fPosition    = fAc3Buffer->fPosition;
+        }
+
+        int willCopy = MIN( size - fAc3Frame->fSize,
+                            fAc3Buffer->fSize - fPosInBuffer );
+        memcpy( fAc3Frame->fData + fAc3Frame->fSize,
+                fAc3Buffer->fData + fPosInBuffer,
+                willCopy );
+        fAc3Frame->fSize += willCopy;
+        fPosInBuffer     += willCopy;
+
+        if( fAc3Buffer->fSize == fPosInBuffer )
+        {
+            delete fAc3Buffer;
+            fAc3Buffer = NULL;
+        }
+    }
+
+    return true;
+}