git.sesse.net Git - vlc/blob - modules/audio_filter/converter/dtstospdif.c

   1 /*****************************************************************************
   2  * dtstospdif.c : encapsulates DTS frames into S/PDIF packets
   3  *****************************************************************************
   4  * Copyright (C) 2003 VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Jon Lech Johansen <jon-vl@nanocrew.net>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #include <stdlib.h>                                      /* malloc(), free() */
  28 #include <string.h>
  29
  30 #include <vlc/vlc.h>
  31
  32 #ifdef HAVE_UNISTD_H
  33 #   include <unistd.h>
  34 #endif
  35
  36 #include "audio_output.h"
  37 #include "aout_internal.h"
  38
  39 /*****************************************************************************
  40  * Local structures
  41  *****************************************************************************/
  42 struct aout_filter_sys_t
  43 {
  44     /* 3 DTS frames have to be packed into an S/PDIF frame.
  45      * We accumulate DTS frames from the decoder until we have enough to
  46      * send. */
  47
  48     uint8_t *p_buf;
  49
  50     mtime_t start_date;
  51
  52     int i_frames;
  53     unsigned int i_frame_size;
  54 };
  55
  56 /*****************************************************************************
  57  * Local prototypes
  58  *****************************************************************************/
  59 static int  Create    ( vlc_object_t * );
  60 static void Close     ( vlc_object_t * );
  61 static void DoWork    ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
  62                         aout_buffer_t * );
  63
  64 /*****************************************************************************
  65  * Module descriptor
  66  *****************************************************************************/
  67 vlc_module_begin();
  68     set_category( CAT_AUDIO );
  69     set_subcategory( SUBCAT_AUDIO_MISC );
  70     set_description( _("audio filter for DTS->S/PDIF encapsulation") );
  71     set_capability( "audio filter", 10 );
  72     set_callbacks( Create, Close );
  73 vlc_module_end();
  74
  75 /*****************************************************************************
  76  * Create:
  77  *****************************************************************************/
  78 static int Create( vlc_object_t *p_this )
  79 {
  80     aout_filter_t * p_filter = (aout_filter_t *)p_this;
  81
  82     if ( p_filter->input.i_format != VLC_FOURCC('d','t','s',' ')
  83           || p_filter->output.i_format != VLC_FOURCC('s','p','d','i') )
  84     {
  85         return -1;
  86     }
  87
  88     /* Allocate the memory needed to store the module's structure */
  89     p_filter->p_sys = malloc( sizeof(struct aout_filter_sys_t) );
  90     if( p_filter->p_sys == NULL )
  91     {
  92         msg_Err( p_filter, "out of memory" );
  93         return VLC_ENOMEM;
  94     }
  95     memset( p_filter->p_sys, 0, sizeof(struct aout_filter_sys_t) );
  96     p_filter->p_sys->p_buf = 0;
  97
  98     p_filter->pf_do_work = DoWork;
  99     p_filter->b_in_place = 1;
 100
 101     return 0;
 102 }
 103
 104 /*****************************************************************************
 105  * Close: free our resources
 106  *****************************************************************************/
 107 static void Close( vlc_object_t * p_this )
 108 {
 109     aout_filter_t * p_filter = (aout_filter_t *)p_this;
 110     if( p_filter->p_sys->i_frame_size ) free( p_filter->p_sys->p_buf );
 111     free( p_filter->p_sys );
 112 }
 113
 114 /*****************************************************************************
 115  * DoWork: convert a buffer
 116  *****************************************************************************/
 117 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
 118                     aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
 119 {
 120     uint16_t i_fz = p_in_buf->i_nb_samples * 4;
 121     uint16_t i_frame, i_length = p_in_buf->i_nb_bytes;
 122     static const uint8_t p_sync[6] = { 0x72, 0xF8, 0x1F, 0x4E, 0x00, 0x00 };
 123
 124     if( p_in_buf->i_nb_bytes != p_filter->p_sys->i_frame_size )
 125     {
 126         /* Frame size changed, reset everything */
 127         p_filter->p_sys->i_frame_size = p_in_buf->i_nb_bytes;
 128         p_filter->p_sys->p_buf = realloc( p_filter->p_sys->p_buf,
 129                                           p_in_buf->i_nb_bytes * 3 );
 130         p_filter->p_sys->i_frames = 0;
 131     }
 132
 133     /* Backup frame */
 134     p_filter->p_vlc->pf_memcpy( p_filter->p_sys->p_buf + p_in_buf->i_nb_bytes *
 135                                 p_filter->p_sys->i_frames, p_in_buf->p_buffer,
 136                                 p_in_buf->i_nb_bytes );
 137
 138     p_filter->p_sys->i_frames++;
 139
 140     if( p_filter->p_sys->i_frames < 3 )
 141     {
 142         if( !p_filter->p_sys->i_frames )
 143             /* We'll need the starting date */
 144             p_filter->p_sys->start_date = p_in_buf->start_date;
 145
 146         /* Not enough data */
 147         p_out_buf->i_nb_samples = 0;
 148         p_out_buf->i_nb_bytes = 0;
 149         return;
 150     }
 151
 152     p_filter->p_sys->i_frames = 0;
 153
 154     for( i_frame = 0; i_frame < 3; i_frame++ )
 155     {
 156         byte_t * p_out = p_out_buf->p_buffer + (i_frame * i_fz);
 157         byte_t * p_in = p_filter->p_sys->p_buf + (i_frame * i_length);
 158
 159         /* Copy the S/PDIF headers. */
 160         memcpy( p_out, p_sync, 6 );
 161
 162         switch( p_in_buf->i_nb_samples )
 163         {
 164             case  512: *(p_out + 4) = 0x0B; break;
 165             case 1024: *(p_out + 4) = 0x0C; break;
 166             case 2048: *(p_out + 4) = 0x0D; break;
 167         }
 168
 169         *(p_out + 6) = (i_length * 8) & 0xff;
 170         *(p_out + 7) = (i_length * 8) >> 8;
 171
 172         if( p_in[0] == 0x1f || p_in[0] == 0x7f )
 173         {
 174             /* We are dealing with a big endian bitstream.
 175              * Convert to little endian */
 176 #ifdef HAVE_SWAB
 177             swab( p_in, p_out + 8, i_length );
 178 #else
 179             uint16_t i;
 180             byte_t * p_tmp, tmp;
 181             p_tmp = p_out + 8;
 182             for( i = i_length / 2 ; i-- ; )
 183             {
 184                 tmp = p_in[0]; /* in-place filter */
 185                 p_tmp[0] = p_in[1];
 186                 p_tmp[1] = tmp;
 187                 p_tmp += 2; p_in += 2;
 188             }
 189 #endif
 190         }
 191         else
 192         {
 193             /* Little endian */
 194             memcpy( p_out + 8, p_in, i_length );
 195         }
 196
 197         if( i_fz > i_length + 8 )
 198         {
 199             p_filter->p_vlc->pf_memset( p_out + 8 + i_length, 0,
 200                                         i_fz - i_length - 8 );
 201         }
 202     }
 203
 204     p_out_buf->start_date = p_filter->p_sys->start_date;
 205     p_out_buf->i_nb_samples = p_in_buf->i_nb_samples * 3;
 206     p_out_buf->i_nb_bytes = p_out_buf->i_nb_samples * 4;
 207 }