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, 2006 the VideoLAN team
   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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #include <vlc/vlc.h>
  28 #include <stdlib.h>                                      /* malloc(), free() */
  29 #include <string.h>
  30
  31
  32 #ifdef HAVE_UNISTD_H
  33 #   include <unistd.h>
  34 #endif
  35
  36 #include <vlc_aout.h>
  37
  38 /*****************************************************************************
  39  * Local structures
  40  *****************************************************************************/
  41 struct aout_filter_sys_t
  42 {
  43     /* 3 DTS frames have to be packed into an S/PDIF frame.
  44      * We accumulate DTS frames from the decoder until we have enough to
  45      * send. */
  46
  47     uint8_t *p_buf;
  48
  49     mtime_t start_date;
  50
  51     int i_frames;
  52     unsigned int i_frame_size;
  53 };
  54
  55 /*****************************************************************************
  56  * Local prototypes
  57  *****************************************************************************/
  58 static int  Create    ( vlc_object_t * );
  59 static void Close     ( vlc_object_t * );
  60 static void DoWork    ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
  61                         aout_buffer_t * );
  62
  63 /*****************************************************************************
  64  * Module descriptor
  65  *****************************************************************************/
  66 vlc_module_begin();
  67     set_category( CAT_AUDIO );
  68     set_subcategory( SUBCAT_AUDIO_MISC );
  69     set_description( _("Audio filter for DTS->S/PDIF encapsulation") );
  70     set_capability( "audio filter", 10 );
  71     set_callbacks( Create, Close );
  72 vlc_module_end();
  73
  74 /*****************************************************************************
  75  * Create:
  76  *****************************************************************************/
  77 static int Create( vlc_object_t *p_this )
  78 {
  79     aout_filter_t * p_filter = (aout_filter_t *)p_this;
  80
  81     if( p_filter->input.i_format != VLC_FOURCC('d','t','s',' ') ||
  82         ( p_filter->output.i_format != VLC_FOURCC('s','p','d','i') &&
  83           p_filter->output.i_format != VLC_FOURCC('s','p','d','b') ) )
  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     uint32_t i_ac5_spdif_type = 0;
 121     uint16_t i_fz = p_in_buf->i_nb_samples * 4;
 122     uint16_t i_frame, i_length = p_in_buf->i_nb_bytes;
 123     static const uint8_t p_sync_le[6] = { 0x72, 0xF8, 0x1F, 0x4E, 0x00, 0x00 };
 124     static const uint8_t p_sync_be[6] = { 0xF8, 0x72, 0x4E, 0x1F, 0x00, 0x00 };
 125
 126     if( p_in_buf->i_nb_bytes != p_filter->p_sys->i_frame_size )
 127     {
 128         /* Frame size changed, reset everything */
 129         p_filter->p_sys->i_frame_size = p_in_buf->i_nb_bytes;
 130         p_filter->p_sys->p_buf = realloc( p_filter->p_sys->p_buf,
 131                                           p_in_buf->i_nb_bytes * 3 );
 132         p_filter->p_sys->i_frames = 0;
 133     }
 134
 135     /* Backup frame */
 136     p_filter->p_libvlc->pf_memcpy( p_filter->p_sys->p_buf + p_in_buf->i_nb_bytes *
 137                                 p_filter->p_sys->i_frames, p_in_buf->p_buffer,
 138                                 p_in_buf->i_nb_bytes );
 139
 140     p_filter->p_sys->i_frames++;
 141
 142     if( p_filter->p_sys->i_frames < 3 )
 143     {
 144         if( !p_filter->p_sys->i_frames )
 145             /* We'll need the starting date */
 146             p_filter->p_sys->start_date = p_in_buf->start_date;
 147
 148         /* Not enough data */
 149         p_out_buf->i_nb_samples = 0;
 150         p_out_buf->i_nb_bytes = 0;
 151         return;
 152     }
 153
 154     p_filter->p_sys->i_frames = 0;
 155
 156     for( i_frame = 0; i_frame < 3; i_frame++ )
 157     {
 158         byte_t * p_out = p_out_buf->p_buffer + (i_frame * i_fz);
 159         byte_t * p_in = p_filter->p_sys->p_buf + (i_frame * i_length);
 160
 161         switch( p_in_buf->i_nb_samples )
 162         {
 163             case  512: i_ac5_spdif_type = 0x0B; break;
 164             case 1024: i_ac5_spdif_type = 0x0C; break;
 165             case 2048: i_ac5_spdif_type = 0x0D; break;
 166         }
 167
 168         /* Copy the S/PDIF headers. */
 169         if( p_filter->output.i_format == VLC_FOURCC('s','p','d','b') )
 170         {
 171             p_filter->p_libvlc->pf_memcpy( p_out, p_sync_be, 6 );
 172             p_out[5] = i_ac5_spdif_type;
 173             p_out[6] = (( i_length ) >> 5 ) & 0xFF;
 174             p_out[7] = ( i_length << 3 ) & 0xFF;
 175         }
 176         else
 177         {
 178             p_filter->p_libvlc->pf_memcpy( p_out, p_sync_le, 6 );
 179             p_out[4] = i_ac5_spdif_type;
 180             p_out[6] = ( i_length << 3 ) & 0xFF;
 181             p_out[7] = (( i_length ) >> 5 ) & 0xFF;
 182         }
 183
 184         if( ( (p_in[0] == 0x1F || p_in[0] == 0x7F) && p_filter->output.i_format == VLC_FOURCC('s','p','d','i') ) ||
 185             ( (p_in[0] == 0xFF || p_in[0] == 0xFE) && p_filter->output.i_format == VLC_FOURCC('s','p','d','b') ) )
 186         {
 187             /* We are dealing with a big endian bitstream and a little endian output
 188              * or a little endian bitstream and a big endian output.
 189              * Byteswap the stream */
 190 #ifdef HAVE_SWAB
 191             swab( p_in, p_out + 8, i_length );
 192 #else
 193             uint16_t i;
 194             byte_t * p_tmp, tmp;
 195             p_tmp = p_out + 8;
 196             for( i = i_length / 2 ; i-- ; )
 197             {
 198                 tmp = p_in[0]; /* in-place filter */
 199                 p_tmp[0] = p_in[1];
 200                 p_tmp[1] = tmp;
 201                 p_tmp += 2; p_in += 2;
 202             }
 203 #endif
 204         }
 205         else
 206         {
 207             p_filter->p_libvlc->pf_memcpy( p_out + 8, p_in, i_length );
 208         }
 209
 210         if( i_fz > i_length + 8 )
 211         {
 212             p_filter->p_libvlc->pf_memset( p_out + 8 + i_length, 0,
 213                                         i_fz - i_length - 8 );
 214         }
 215     }
 216
 217     p_out_buf->start_date = p_filter->p_sys->start_date;
 218     p_out_buf->i_nb_samples = p_in_buf->i_nb_samples * 3;
 219     p_out_buf->i_nb_bytes = p_out_buf->i_nb_samples * 4;
 220 }