libhb/decavcodec.c

   1 /* $Id: decavcodec.c,v 1.6 2005/03/06 04:08:54 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 "ffmpeg/avcodec.h"
  10
  11 int  decavcodecInit( hb_work_object_t *, hb_job_t * );
  12 int  decavcodecWork( hb_work_object_t *, hb_buffer_t **, hb_buffer_t ** );
  13 void decavcodecClose( hb_work_object_t * );
  14
  15 hb_work_object_t hb_decavcodec =
  16 {
  17     WORK_DECAVCODEC,
  18     "MPGA decoder (libavcodec)",
  19     decavcodecInit,
  20     decavcodecWork,
  21     decavcodecClose
  22 };
  23
  24 struct hb_work_private_s
  25 {
  26     hb_job_t       * job;
  27
  28     AVCodecContext * context;
  29     int64_t          pts_last;
  30 };
  31
  32
  33 /***********************************************************************
  34  * hb_work_decavcodec_init
  35  ***********************************************************************
  36  *
  37  **********************************************************************/
  38 int decavcodecInit( hb_work_object_t * w, hb_job_t * job )
  39 {
  40     AVCodec * codec;
  41     hb_work_private_t * pv = calloc( 1, sizeof( hb_work_private_t ) );
  42     w->private_data = pv;
  43
  44     pv->job   = job;
  45
  46     codec = avcodec_find_decoder( CODEC_ID_MP2 );
  47     pv->context = avcodec_alloc_context();
  48     avcodec_open( pv->context, codec );
  49     pv->pts_last = -1;
  50
  51     return 0;
  52 }
  53
  54 /***********************************************************************
  55  * Close
  56  ***********************************************************************
  57  *
  58  **********************************************************************/
  59 void decavcodecClose( hb_work_object_t * w )
  60 {
  61     hb_work_private_t * pv = w->private_data;
  62     avcodec_close( pv->context );
  63 }
  64
  65 /***********************************************************************
  66  * Work
  67  ***********************************************************************
  68  *
  69  **********************************************************************/
  70 int decavcodecWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
  71                     hb_buffer_t ** buf_out )
  72 {
  73     hb_work_private_t * pv = w->private_data;
  74     hb_buffer_t * in = *buf_in, * buf, * last = NULL;
  75     int   pos, len, out_size, i;
  76     short buffer[AVCODEC_MAX_AUDIO_FRAME_SIZE];
  77     uint64_t cur;
  78
  79     *buf_out = NULL;
  80
  81     if( in->start < 0 ||
  82         ( pv->pts_last > 0 &&
  83           in->start > pv->pts_last &&
  84           in->start - pv->pts_last < 5000 ) ) /* Hacky */
  85     {
  86         cur = pv->pts_last;
  87     }
  88     else
  89     {
  90         cur = in->start;
  91     }
  92
  93     pos = 0;
  94     while( pos < in->size )
  95     {
  96         len = avcodec_decode_audio( pv->context, buffer, &out_size,
  97                                     in->data + pos, in->size - pos );
  98         if( out_size )
  99         {
 100             short * s16;
 101             float * fl32;
 102
 103             buf = hb_buffer_init( 2 * out_size );
 104
 105             buf->start = cur;
 106             buf->stop  = cur + 90000 * ( out_size / 4 ) /
 107                          pv->context->sample_rate;
 108             cur = buf->stop;
 109
 110             s16  = buffer;
 111             fl32 = (float *) buf->data;
 112             for( i = 0; i < out_size / 2; i++ )
 113             {
 114                 fl32[i] = s16[i];
 115             }
 116
 117             if( last )
 118             {
 119                 last = last->next = buf;
 120             }
 121             else
 122             {
 123                 *buf_out = last = buf;
 124             }
 125         }
 126
 127         pos += len;
 128     }
 129
 130     pv->pts_last = cur;
 131
 132     return HB_WORK_OK;
 133 }
 134