libhb/deca52.c

   1 /* $Id: deca52.c,v 1.14 2005/03/03 17:21:57 titer Exp $
   2
   3    This file is part of the HandBrake source code.
   4    Homepage: <http://handbrake.m0k.org/>.
   5    It may be used under the terms of the GNU General Public License. */
   6
   7 #include "hb.h"
   8
   9 #include "a52dec/a52.h"
  10
  11 struct hb_work_private_s
  12 {
  13     hb_job_t    * job;
  14
  15     /* liba52 handle */
  16     a52_state_t * state;
  17
  18     int           flags_in;
  19     int           flags_out;
  20     int           rate;
  21     int           bitrate;
  22     float         level;
  23
  24     int           error;
  25     int           sync;
  26     int           size;
  27
  28     int64_t       next_expected_pts;
  29
  30     uint8_t       frame[3840];
  31
  32     hb_list_t   * list;
  33
  34         int           out_discrete_channels;
  35
  36 };
  37
  38 int  deca52Init( hb_work_object_t *, hb_job_t * );
  39 int  deca52Work( hb_work_object_t *, hb_buffer_t **, hb_buffer_t ** );
  40 void deca52Close( hb_work_object_t * );
  41
  42 hb_work_object_t hb_deca52 =
  43 {
  44     WORK_DECA52,
  45     "AC3 decoder",
  46     deca52Init,
  47     deca52Work,
  48     deca52Close
  49 };
  50
  51 /***********************************************************************
  52  * Local prototypes
  53  **********************************************************************/
  54 static hb_buffer_t * Decode( hb_work_object_t * w );
  55
  56 /***********************************************************************
  57  * hb_work_deca52_init
  58  ***********************************************************************
  59  * Allocate the work object, initialize liba52
  60  **********************************************************************/
  61 int deca52Init( hb_work_object_t * w, hb_job_t * job )
  62 {
  63     hb_work_private_t * pv = calloc( 1, sizeof( hb_work_private_t ) );
  64     w->private_data = pv;
  65
  66     pv->job   = job;
  67
  68     pv->list      = hb_list_init();
  69     pv->state     = a52_init( 0 );
  70
  71         /* Decide what format we want out of a52dec
  72         work.c has already done some of this deduction for us in do_job() */
  73
  74         pv->flags_out = HB_AMIXDOWN_GET_A52_FORMAT(w->amixdown);
  75
  76         /* pass the number of channels used into the private work data */
  77         /* will only be actually used if we're not doing AC3 passthru */
  78         pv->out_discrete_channels = HB_AMIXDOWN_GET_DISCRETE_CHANNEL_COUNT(w->amixdown);
  79
  80     pv->level     = 32768.0;
  81     pv->next_expected_pts = 0;
  82
  83     return 0;
  84 }
  85
  86 /***********************************************************************
  87  * Close
  88  ***********************************************************************
  89  * Free memory
  90  **********************************************************************/
  91 void deca52Close( hb_work_object_t * w )
  92 {
  93     hb_work_private_t * pv = w->private_data;
  94     a52_free( pv->state );
  95     hb_list_empty( &pv->list );
  96     free( pv );
  97     w->private_data = NULL;
  98 }
  99
 100 /***********************************************************************
 101  * Work
 102  ***********************************************************************
 103  * Add the given buffer to the data we already have, and decode as much
 104  * as we can
 105  **********************************************************************/
 106 int deca52Work( hb_work_object_t * w, hb_buffer_t ** buf_in,
 107                 hb_buffer_t ** buf_out )
 108 {
 109     hb_work_private_t * pv = w->private_data;
 110     hb_buffer_t * buf;
 111
 112     hb_list_add( pv->list, *buf_in );
 113     *buf_in = NULL;
 114
 115     /* If we got more than a frame, chain raw buffers */
 116     *buf_out = buf = Decode( w );
 117     while( buf )
 118     {
 119         buf->next = Decode( w );
 120         buf       = buf->next;
 121     }
 122
 123     return HB_WORK_OK;
 124 }
 125
 126 /***********************************************************************
 127  * Decode
 128  ***********************************************************************
 129  *
 130  **********************************************************************/
 131 static hb_buffer_t * Decode( hb_work_object_t * w )
 132 {
 133     hb_work_private_t * pv = w->private_data;
 134     hb_buffer_t * buf;
 135     int           i, j, k;
 136     uint64_t      pts, pos;
 137
 138     /* Get a frame header if don't have one yet */
 139     if( !pv->sync )
 140     {
 141         while( hb_list_bytes( pv->list ) >= 7 )
 142         {
 143             /* We have 7 bytes, check if this is a correct header */
 144             hb_list_seebytes( pv->list, pv->frame, 7 );
 145             pv->size = a52_syncinfo( pv->frame, &pv->flags_in, &pv->rate,
 146                                     &pv->bitrate );
 147             if( pv->size )
 148             {
 149                 /* It is. W00t. */
 150                 if( pv->error )
 151                 {
 152                     hb_log( "a52_syncinfo ok" );
 153                 }
 154                 pv->error = 0;
 155                 pv->sync  = 1;
 156                 break;
 157             }
 158
 159             /* It is not */
 160             if( !pv->error )
 161             {
 162                 hb_log( "a52_syncinfo failed" );
 163                 pv->error = 1;
 164             }
 165
 166             /* Try one byte later */
 167             hb_list_getbytes( pv->list, pv->frame, 1, NULL, NULL );
 168         }
 169     }
 170
 171     if( !pv->sync ||
 172         hb_list_bytes( pv->list ) < pv->size )
 173     {
 174         /* Need more data */
 175         return NULL;
 176     }
 177
 178     /* Get the whole frame */
 179     hb_list_getbytes( pv->list, pv->frame, pv->size, &pts, &pos );
 180
 181     /* AC3 passthrough: don't decode the AC3 frame */
 182     if( pv->job->acodec & HB_ACODEC_AC3 )
 183     {
 184         buf = hb_buffer_init( pv->size );
 185         memcpy( buf->data, pv->frame, pv->size );
 186         buf->start = pts + ( pos / pv->size ) * 6 * 256 * 90000 / pv->rate;
 187         buf->stop  = buf->start + 6 * 256 * 90000 / pv->rate;
 188         pv->sync = 0;
 189         return buf;
 190     }
 191
 192     /* Feed liba52 */
 193     a52_frame( pv->state, pv->frame, &pv->flags_out, &pv->level, 0 );
 194
 195     /* 6 blocks per frame, 256 samples per block, channelsused channels */
 196     buf        = hb_buffer_init( 6 * 256 * pv->out_discrete_channels * sizeof( float ) );
 197     if (pts == -1)
 198     {
 199       pts = pv->next_expected_pts;
 200     }
 201     buf->start = pts + ( pos / pv->size ) * 6 * 256 * 90000 / pv->rate;
 202     buf->stop  = buf->start + 6 * 256 * 90000 / pv->rate;
 203
 204     pv->next_expected_pts = buf->stop;
 205
 206     for( i = 0; i < 6; i++ )
 207     {
 208         sample_t * samples_in;
 209         float    * samples_out;
 210
 211         a52_block( pv->state );
 212         samples_in  = a52_samples( pv->state );
 213         samples_out = ((float *) buf->data) + 256 * pv->out_discrete_channels * i;
 214
 215         /* Interleave */
 216         for( j = 0; j < 256; j++ )
 217         {
 218                         for ( k = 0; k < pv->out_discrete_channels; k++ )
 219                         {
 220                                 samples_out[(pv->out_discrete_channels*j)+k]   = samples_in[(256*k)+j];
 221                         }
 222         }
 223
 224     }
 225
 226     pv->sync = 0;
 227     return buf;
 228 }
 229