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/* $Id: deca52.c,v 1.14 2005/03/03 17:21:57 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 "hb.h"
#include "a52dec/a52.h"
struct hb_work_private_s
{
hb_job_t * job;
/* liba52 handle */
a52_state_t * state;
int flags_in;
int flags_out;
int rate;
int bitrate;
float level;
int error;
int sync;
int size;
uint8_t frame[3840];
hb_list_t * list;
int channelsused;
};
int deca52Init( hb_work_object_t *, hb_job_t * );
int deca52Work( hb_work_object_t *, hb_buffer_t **, hb_buffer_t ** );
void deca52Close( hb_work_object_t * );
hb_work_object_t hb_deca52 =
{
WORK_DECA52,
"AC3 decoder",
deca52Init,
deca52Work,
deca52Close
};
/***********************************************************************
* Local prototypes
**********************************************************************/
static hb_buffer_t * Decode( hb_work_object_t * w );
/***********************************************************************
* hb_work_deca52_init
***********************************************************************
* Allocate the work object, initialize liba52
**********************************************************************/
int deca52Init( hb_work_object_t * w, hb_job_t * job )
{
hb_work_private_t * pv = calloc( 1, sizeof( hb_work_private_t ) );
w->private_data = pv;
pv->job = job;
pv->list = hb_list_init();
pv->state = a52_init( 0 );
/* Decide what format we want out of a52dec
work.c has already done some of this deduction for us in do_job() */
if (job->channelsused == 6) {
/* we're going to be encoding to AAC,
and have turned on the "preserve 5.1" flag */
pv->flags_out = A52_3F2R | A52_LFE;
} else if (job->channelsused == 1) {
/* we're going to be encoding to AAC, */
/* and want to keep the mono-ness of the source audio */
pv->flags_out = A52_MONO;
} else if (job->channelsused == 2 && job->channels == 5 && job->lfechannels == 1) {
/* we are mixing a 5.1 source down to stereo, so use dolby surround */
pv->flags_out = A52_DOLBY;
} else if (job->channelsused == 2 && ((job->ac3flags & A52_CHANNEL_MASK) == A52_DOLBY)) {
/* we have a dolby stereo surround source, so preserve it */
pv->flags_out = A52_DOLBY;
} else {
/* mix everything else down to plain stereo */
pv->flags_out = A52_STEREO;
}
/* pass the number of channels used into the private work data */
pv->channelsused = job->channelsused;
pv->level = 32768.0;
return 0;
}
/***********************************************************************
* Close
***********************************************************************
* Free memory
**********************************************************************/
void deca52Close( hb_work_object_t * w )
{
hb_work_private_t * pv = w->private_data;
a52_free( pv->state );
}
/***********************************************************************
* Work
***********************************************************************
* Add the given buffer to the data we already have, and decode as much
* as we can
**********************************************************************/
int deca52Work( hb_work_object_t * w, hb_buffer_t ** buf_in,
hb_buffer_t ** buf_out )
{
hb_work_private_t * pv = w->private_data;
hb_buffer_t * buf;
hb_list_add( pv->list, *buf_in );
*buf_in = NULL;
/* If we got more than a frame, chain raw buffers */
*buf_out = buf = Decode( w );
while( buf )
{
buf->next = Decode( w );
buf = buf->next;
}
return HB_WORK_OK;
}
/***********************************************************************
* Decode
***********************************************************************
*
**********************************************************************/
static hb_buffer_t * Decode( hb_work_object_t * w )
{
hb_work_private_t * pv = w->private_data;
hb_buffer_t * buf;
int i, j, k;
uint64_t pts;
int pos;
/* Get a frame header if don't have one yet */
if( !pv->sync )
{
while( hb_list_bytes( pv->list ) >= 7 )
{
/* We have 7 bytes, check if this is a correct header */
hb_list_seebytes( pv->list, pv->frame, 7 );
pv->size = a52_syncinfo( pv->frame, &pv->flags_in, &pv->rate,
&pv->bitrate );
if( pv->size )
{
/* It is. W00t. */
if( pv->error )
{
hb_log( "a52_syncinfo ok" );
}
pv->error = 0;
pv->sync = 1;
break;
}
/* It is not */
if( !pv->error )
{
hb_log( "a52_syncinfo failed" );
pv->error = 1;
}
/* Try one byte later */
hb_list_getbytes( pv->list, pv->frame, 1, NULL, NULL );
}
}
if( !pv->sync ||
hb_list_bytes( pv->list ) < pv->size )
{
/* Need more data */
return NULL;
}
/* Get the whole frame */
hb_list_getbytes( pv->list, pv->frame, pv->size, &pts, &pos );
/* AC3 passthrough: don't decode the AC3 frame */
if( pv->job->acodec & HB_ACODEC_AC3 )
{
buf = hb_buffer_init( pv->size );
memcpy( buf->data, pv->frame, pv->size );
buf->start = pts + ( pos / pv->size ) * 6 * 256 * 90000 / pv->rate;
buf->stop = buf->start + 6 * 256 * 90000 / pv->rate;
pv->sync = 0;
return buf;
}
/* Feed liba52 */
a52_frame( pv->state, pv->frame, &pv->flags_out, &pv->level, 0 );
/* 6 blocks per frame, 256 samples per block, channelsused channels */
buf = hb_buffer_init( 6 * 256 * pv->channelsused * sizeof( float ) );
buf->start = pts + ( pos / pv->size ) * 6 * 256 * 90000 / pv->rate;
buf->stop = buf->start + 6 * 256 * 90000 / pv->rate;
for( i = 0; i < 6; i++ )
{
sample_t * samples_in;
float * samples_out;
a52_block( pv->state );
samples_in = a52_samples( pv->state );
samples_out = ((float *) buf->data) + 256 * pv->channelsused * i;
/* Interleave */
for( j = 0; j < 256; j++ )
{
for ( k = 0; k < pv->channelsused; k++ )
{
samples_out[(pv->channelsused*j)+k] = samples_in[(256*k)+j]; // DJA
}
}
}
pv->sync = 0;
return buf;
}
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