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/* $Id: Ac3Dec.c,v 1.4 2003/11/04 20:16:44 titer Exp $
This file is part of the HandBrake source code.
Homepage: <http://handbrake.m0k.org/>.
It may be used under the terms of the GNU General Public License. */
#include "Ac3Dec.h"
#include "Fifo.h"
#include "Work.h"
#include <a52dec/a52.h>
/* Local prototypes */
static int Ac3DecWork( HBWork * );
static int GetBytes( HBAc3Dec *, int );
struct HBAc3Dec
{
HB_WORK_COMMON_MEMBERS
HBHandle * handle;
HBAudio * audio;
/* liba52 stuff */
a52_state_t * state;
int inFlags;
int outFlags;
float sampleLevel;
/* Buffers */
uint8_t ac3Frame[3840]; /* Max size of a A52 frame */
int ac3FrameSize; /* In bytes */
HBBuffer * ac3Buffer;
int ac3BufferPos; /* In bytes */
int nextFrameSize; /* In bytes */
float position;
HBBuffer * rawBuffer;
};
HBAc3Dec * HBAc3DecInit( HBHandle * handle, HBAudio * audio )
{
HBAc3Dec * a;
if( !( a = malloc( sizeof( HBAc3Dec ) ) ) )
{
HBLog( "HBAc3DecInit: malloc() failed, gonna crash" );
return NULL;
}
a->name = strdup( "Ac3Dec" );
a->work = Ac3DecWork;
a->handle = handle;
a->audio = audio;
/* Init liba52 */
a->state = a52_init( 0 );
a->inFlags = 0;
/* Let it do the downmixing */
a->outFlags = A52_STEREO;
/* Lame wants samples from -32768 to 32768 */
a->sampleLevel = 32768.0;
a->ac3FrameSize = 0;
a->ac3Buffer = NULL;
a->ac3BufferPos = 0;
a->nextFrameSize = 0;
a->position = 0.0;
a->rawBuffer = NULL;
return a;
}
void HBAc3DecClose( HBAc3Dec ** _a )
{
HBAc3Dec * a = *_a;
if( a->ac3Buffer ) HBBufferClose( &a->ac3Buffer );
if( a->rawBuffer ) HBBufferClose( &a->rawBuffer );
a52_free( a->state );
free( a->name );
free( a );
*_a = NULL;
}
static int Ac3DecWork( HBWork * w )
{
HBAc3Dec * a = (HBAc3Dec*) w;
HBAudio * audio = a->audio;
int didSomething = 0;
/* Push decoded buffer */
if( a->rawBuffer )
{
if( HBFifoPush( audio->rawFifo, &a->rawBuffer ) )
{
didSomething = 1;
}
else
{
return didSomething;
}
}
/* Get a frame header (7 bytes) */
if( a->ac3FrameSize < 7 )
{
if( GetBytes( a, 7 ) )
{
didSomething = 1;
}
else
{
return didSomething;
}
a->nextFrameSize = a52_syncinfo( a->ac3Frame, &a->inFlags,
&audio->inSampleRate,
&audio->inBitrate );
if( !a->nextFrameSize )
{
HBLog( "HBAc3Dec: a52_syncinfo() failed" );
HBErrorOccured( a->handle, HB_ERROR_A52_SYNC );
return didSomething;
}
}
/* Get the whole frame */
if( a->ac3FrameSize >= 7 )
{
sample_t * samples;
HBBuffer * rawBuffer;
int i;
if( GetBytes( a, a->nextFrameSize ) )
{
didSomething = 1;
}
else
{
return didSomething;
}
/* Feed liba52 */
a52_frame( a->state, a->ac3Frame, &a->outFlags,
&a->sampleLevel, 0 );
a->ac3FrameSize = 0;
/* 6 blocks per frame, 256 samples per block, 2 channels */
rawBuffer = HBBufferInit( 12 * 256 * sizeof( float ) );
rawBuffer->position = a->position;
for( i = 0; i < 6; i++ )
{
/* Decode a block */
a52_block( a->state );
/* Get a pointer to the raw data */
samples = a52_samples( a->state );
/* Copy left channel data */
memcpy( rawBuffer->data + i * 256 * sizeof( float ),
samples,
256 * sizeof( float ) );
/* Copy right channel data */
memcpy( rawBuffer->data + ( 6 + i ) * 256 * sizeof( float ),
samples + 256,
256 * sizeof( float ) );
}
a->rawBuffer = rawBuffer;
}
return didSomething;
}
static int GetBytes( HBAc3Dec * a, int size )
{
int i;
while( a->ac3FrameSize < size )
{
if( !a->ac3Buffer )
{
if( !( a->ac3Buffer = HBFifoPop( a->audio->ac3Fifo ) ) )
{
return 0;
}
a->ac3BufferPos = 0;
a->position = a->ac3Buffer->position;
if( a->ac3Buffer->last )
{
HBDone( a->handle );
}
}
i = MIN( size - a->ac3FrameSize,
a->ac3Buffer->size - a->ac3BufferPos );
memcpy( a->ac3Frame + a->ac3FrameSize,
a->ac3Buffer->data + a->ac3BufferPos,
i );
a->ac3FrameSize += i;
a->ac3BufferPos += i;
if( a->ac3BufferPos == a->ac3Buffer->size )
{
HBBufferClose( &a->ac3Buffer );
}
}
return 1;
}
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