libhb/declpcm.c

   1 /* $Id: declpcm.c,v 1.8 2005/11/04 14:44:01 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 int  declpcmInit( hb_work_object_t *, hb_job_t * );
  10 int  declpcmWork( hb_work_object_t *, hb_buffer_t **, hb_buffer_t ** );
  11 void declpcmClose( hb_work_object_t * );
  12
  13 hb_work_object_t hb_declpcm =
  14 {
  15     WORK_DECLPCM,
  16     "LPCM decoder",
  17     declpcmInit,
  18     declpcmWork,
  19     declpcmClose
  20 };
  21
  22 int declpcmInit( hb_work_object_t * w, hb_job_t * job )
  23 {
  24     return 0;
  25 }
  26
  27 int declpcmWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
  28                  hb_buffer_t ** buf_out )
  29 {
  30     hb_buffer_t * in = *buf_in, * out;
  31     int samplerate = 0;
  32     int count;
  33     uint8_t * samples_u8;
  34     float   * samples_fl32;
  35     int i;
  36     uint64_t duration;
  37
  38     *buf_out = NULL;
  39
  40     if( in->data[5] != 0x80 )
  41     {
  42         hb_log( "no LPCM frame sync (%02x)", in->data[5] );
  43         return HB_WORK_OK;
  44     }
  45
  46     switch( ( in->data[4] >> 4 ) & 0x3 )
  47     {
  48         case 0:
  49             samplerate = 48000;
  50             break;
  51         case 1:
  52             samplerate = 96000;//32000; /* FIXME vlc says it is 96000 */
  53             break;
  54         case 2:
  55             samplerate = 44100;
  56             break;
  57         case 3:
  58             samplerate = 32000;
  59             break;
  60     }
  61
  62     count       = ( in->size - 6 ) / 2;
  63     out         = hb_buffer_init( count * sizeof( float ) );
  64     duration    = count * 90000 / samplerate / 2;
  65     out->start  = in->start;
  66     out->stop   = out->start + duration;
  67
  68     samples_u8   = in->data + 6;
  69     samples_fl32 = (float *) out->data;
  70
  71     /* Big endian int16 -> float conversion */
  72     for( i = 0; i < count; i++ )
  73     {
  74 #ifdef WORDS_BIGENDIAN
  75         samples_fl32[0] = *( (int16_t *) samples_u8 );
  76 #else
  77         samples_fl32[0] = (int16_t) ( ( samples_u8[0] << 8 ) | samples_u8[1] );
  78 #endif
  79         samples_u8   += 2;
  80         samples_fl32 += 1;
  81     }
  82
  83     *buf_out = out;
  84
  85     return HB_WORK_OK;
  86 }
  87
  88 void declpcmClose( hb_work_object_t * w )
  89 {
  90 }