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 <string.h>
  29
  30
  31 #ifdef HAVE_UNISTD_H
  32 #   include <unistd.h>
  33 #endif
  34
  35 #include <vlc_aout.h>
  36
  37 /*****************************************************************************
  38  * Local structures
  39  *****************************************************************************/
  40 struct aout_filter_sys_t
  41 {
  42     /* 3 DTS frames have to be packed into an S/PDIF frame.
  43      * We accumulate DTS frames from the decoder until we have enough to
  44      * send. */
  45
  46     uint8_t *p_buf;
  47
  48     mtime_t start_date;
  49
  50     int i_frames;
  51     unsigned int i_frame_size;
  52 };
  53
  54 /*****************************************************************************
  55  * Local prototypes
  56  *****************************************************************************/
  57 static int  Create    ( vlc_object_t * );
  58 static void Close     ( vlc_object_t * );
  59 static void DoWork    ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
  60                         aout_buffer_t * );
  61
  62 /*****************************************************************************
  63  * Module descriptor
  64  *****************************************************************************/
  65 vlc_module_begin();
  66     set_category( CAT_AUDIO );
  67     set_subcategory( SUBCAT_AUDIO_MISC );
  68     set_description( _("Audio filter for DTS->S/PDIF encapsulation") );
  69     set_capability( "audio filter", 10 );
  70     set_callbacks( Create, Close );
  71 vlc_module_end();
  72
  73 /*****************************************************************************
  74  * Create:
  75  *****************************************************************************/
  76 static int Create( vlc_object_t *p_this )
  77 {
  78     aout_filter_t * p_filter = (aout_filter_t *)p_this;
  79
  80     if( p_filter->input.i_format != VLC_FOURCC('d','t','s',' ') ||
  81         ( p_filter->output.i_format != VLC_FOURCC('s','p','d','i') &&
  82           p_filter->output.i_format != VLC_FOURCC('s','p','d','b') ) )
  83     {
  84         return -1;
  85     }
  86
  87     /* Allocate the memory needed to store the module's structure */
  88     p_filter->p_sys = malloc( sizeof(struct aout_filter_sys_t) );
  89     if( p_filter->p_sys == NULL )
  90     {
  91         msg_Err( p_filter, "out of memory" );
  92         return VLC_ENOMEM;
  93     }
  94     memset( p_filter->p_sys, 0, sizeof(struct aout_filter_sys_t) );
  95     p_filter->p_sys->p_buf = 0;
  96
  97     p_filter->pf_do_work = DoWork;
  98     p_filter->b_in_place = 1;
  99
 100     return 0;
 101 }
 102
 103 /*****************************************************************************
 104  * Close: free our resources
 105  *****************************************************************************/
 106 static void Close( vlc_object_t * p_this )
 107 {
 108     aout_filter_t * p_filter = (aout_filter_t *)p_this;
 109     if( p_filter->p_sys->i_frame_size ) free( p_filter->p_sys->p_buf );
 110     free( p_filter->p_sys );
 111 }
 112
 113 /*****************************************************************************
 114  * DoWork: convert a buffer
 115  *****************************************************************************/
 116 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
 117                     aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
 118 {
 119     uint32_t i_ac5_spdif_type = 0;
 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_le[6] = { 0x72, 0xF8, 0x1F, 0x4E, 0x00, 0x00 };
 123     static const uint8_t p_sync_be[6] = { 0xF8, 0x72, 0x4E, 0x1F, 0x00, 0x00 };
 124
 125     if( p_in_buf->i_nb_bytes != p_filter->p_sys->i_frame_size )
 126     {
 127         /* Frame size changed, reset everything */
 128         p_filter->p_sys->i_frame_size = p_in_buf->i_nb_bytes;
 129         p_filter->p_sys->p_buf = realloc( p_filter->p_sys->p_buf,
 130                                           p_in_buf->i_nb_bytes * 3 );
 131         p_filter->p_sys->i_frames = 0;
 132     }
 133
 134     /* Backup frame */
 135     p_filter->p_libvlc->pf_memcpy( p_filter->p_sys->p_buf + p_in_buf->i_nb_bytes *
 136                                 p_filter->p_sys->i_frames, p_in_buf->p_buffer,
 137                                 p_in_buf->i_nb_bytes );
 138
 139     p_filter->p_sys->i_frames++;
 140
 141     if( p_filter->p_sys->i_frames < 3 )
 142     {
 143         if( !p_filter->p_sys->i_frames )
 144             /* We'll need the starting date */
 145             p_filter->p_sys->start_date = p_in_buf->start_date;
 146
 147         /* Not enough data */
 148         p_out_buf->i_nb_samples = 0;
 149         p_out_buf->i_nb_bytes = 0;
 150         return;
 151     }
 152
 153     p_filter->p_sys->i_frames = 0;
 154
 155     for( i_frame = 0; i_frame < 3; i_frame++ )
 156     {
 157         byte_t * p_out = p_out_buf->p_buffer + (i_frame * i_fz);
 158         byte_t * p_in = p_filter->p_sys->p_buf + (i_frame * i_length);
 159
 160         switch( p_in_buf->i_nb_samples )
 161         {
 162             case  512: i_ac5_spdif_type = 0x0B; break;
 163             case 1024: i_ac5_spdif_type = 0x0C; break;
 164             case 2048: i_ac5_spdif_type = 0x0D; break;
 165         }
 166
 167         /* Copy the S/PDIF headers. */
 168         if( p_filter->output.i_format == VLC_FOURCC('s','p','d','b') )
 169         {
 170             p_filter->p_libvlc->pf_memcpy( p_out, p_sync_be, 6 );
 171             p_out[5] = i_ac5_spdif_type;
 172             p_out[6] = (( i_length ) >> 5 ) & 0xFF;
 173             p_out[7] = ( i_length << 3 ) & 0xFF;
 174         }
 175         else
 176         {
 177             p_filter->p_libvlc->pf_memcpy( p_out, p_sync_le, 6 );
 178             p_out[4] = i_ac5_spdif_type;
 179             p_out[6] = ( i_length << 3 ) & 0xFF;
 180             p_out[7] = (( i_length ) >> 5 ) & 0xFF;
 181         }
 182
 183         if( ( (p_in[0] == 0x1F || p_in[0] == 0x7F) && p_filter->output.i_format == VLC_FOURCC('s','p','d','i') ) ||
 184             ( (p_in[0] == 0xFF || p_in[0] == 0xFE) && p_filter->output.i_format == VLC_FOURCC('s','p','d','b') ) )
 185         {
 186             /* We are dealing with a big endian bitstream and a little endian output
 187              * or a little endian bitstream and a big endian output.
 188              * Byteswap the stream */
 189 #ifdef HAVE_SWAB
 190             swab( p_in, p_out + 8, i_length );
 191 #else
 192             uint16_t i;
 193             byte_t * p_tmp, tmp;
 194             p_tmp = p_out + 8;
 195             for( i = i_length / 2 ; i-- ; )
 196             {
 197                 tmp = p_in[0]; /* in-place filter */
 198                 p_tmp[0] = p_in[1];
 199                 p_tmp[1] = tmp;
 200                 p_tmp += 2; p_in += 2;
 201             }
 202 #endif
 203         }
 204         else
 205         {
 206             p_filter->p_libvlc->pf_memcpy( p_out + 8, p_in, i_length );
 207         }
 208
 209         if( i_fz > i_length + 8 )
 210         {
 211             p_filter->p_libvlc->pf_memset( p_out + 8 + i_length, 0,
 212                                         i_fz - i_length - 8 );
 213         }
 214     }
 215
 216     p_out_buf->start_date = p_filter->p_sys->start_date;
 217     p_out_buf->i_nb_samples = p_in_buf->i_nb_samples * 3;
 218     p_out_buf->i_nb_bytes = p_out_buf->i_nb_samples * 4;
 219 }