git.sesse.net Git - vlc/blob - modules/codec/lpcm.c

   1 /*****************************************************************************
   2  * lpcm.c: lpcm decoder/packetizer module
   3  *****************************************************************************
   4  * Copyright (C) 1999-2008 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Samuel Hocevar <sam@zoy.org>
   8  *          Henri Fallon <henri@videolan.org>
   9  *          Christophe Massiot <massiot@via.ecp.fr>
  10  *          Gildas Bazin <gbazin@videolan.org>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  25  *****************************************************************************/
  26
  27 /*****************************************************************************
  28  * Preamble
  29  *****************************************************************************/
  30 #ifdef HAVE_CONFIG_H
  31 # include "config.h"
  32 #endif
  33
  34 #include <vlc_common.h>
  35 #include <vlc_plugin.h>
  36 #include <vlc_codec.h>
  37 #include <vlc_aout.h>
  38
  39 /*****************************************************************************
  40  * Module descriptor
  41  *****************************************************************************/
  42 static int  OpenDecoder   ( vlc_object_t * );
  43 static int  OpenPacketizer( vlc_object_t * );
  44 static void CloseCommon   ( vlc_object_t * );
  45
  46 vlc_module_begin ()
  47
  48     set_category( CAT_INPUT )
  49     set_subcategory( SUBCAT_INPUT_ACODEC )
  50     set_description( N_("Linear PCM audio decoder") )
  51     set_capability( "decoder", 100 )
  52     set_callbacks( OpenDecoder, CloseCommon )
  53
  54     add_submodule ()
  55     set_description( N_("Linear PCM audio packetizer") )
  56     set_capability( "packetizer", 100 )
  57     set_callbacks( OpenPacketizer, CloseCommon )
  58
  59 vlc_module_end ()
  60
  61
  62 /*****************************************************************************
  63  * decoder_sys_t : lpcm decoder descriptor
  64  *****************************************************************************/
  65 struct decoder_sys_t
  66 {
  67     /* Module mode */
  68     bool b_packetizer;
  69
  70     /*
  71      * Output properties
  72      */
  73     audio_date_t end_date;
  74
  75     /* */
  76     unsigned int i_header_size;
  77 };
  78
  79 /*
  80  * LPCM DVD header :
  81  * - frame number (8 bits)
  82  * - unknown (16 bits) == 0x0003 ?
  83  * - unknown (4 bits)
  84  * - current frame (4 bits)
  85  * - unknown (2 bits)
  86  * - frequency (2 bits) 0 == 48 kHz, 1 == 32 kHz, 2 == ?, 3 == ?
  87  * - unknown (1 bit)
  88  * - number of channels - 1 (3 bits) 1 == 2 channels
  89  * - start code (8 bits) == 0x80
  90  */
  91
  92 #define LPCM_DVD_HEADER_LEN (6)
  93
  94 /*****************************************************************************
  95  * Local prototypes
  96  *****************************************************************************/
  97 static void *DecodeFrame  ( decoder_t *, block_t ** );
  98
  99 /*****************************************************************************
 100  * OpenCommon:
 101  *****************************************************************************/
 102 static int OpenCommon( vlc_object_t *p_this, bool b_packetizer )
 103 {
 104     decoder_t *p_dec = (decoder_t*)p_this;
 105     decoder_sys_t *p_sys;
 106
 107     switch( p_dec->fmt_in.i_codec )
 108     {
 109     case VLC_FOURCC('l','p','c','m'):
 110     case VLC_FOURCC('l','p','c','b'):
 111         break;
 112     default:
 113         return VLC_EGENERIC;
 114     }
 115
 116     /* Allocate the memory needed to store the decoder's structure */
 117     if( ( p_dec->p_sys = p_sys = malloc(sizeof(decoder_sys_t)) ) == NULL )
 118         return VLC_ENOMEM;
 119
 120     /* Misc init */
 121     p_sys->b_packetizer = b_packetizer;
 122     p_sys->i_header_size = LPCM_DVD_HEADER_LEN;
 123     aout_DateSet( &p_sys->end_date, 0 );
 124
 125     /* Set output properties */
 126     p_dec->fmt_out.i_cat = AUDIO_ES;
 127
 128     if( b_packetizer )
 129     {
 130         p_dec->fmt_out.i_codec = VLC_FOURCC('l','p','c','m');
 131     }
 132     else
 133     {
 134         switch( p_dec->fmt_out.audio.i_bitspersample )
 135         {
 136         case 24:
 137         case 20:
 138             p_dec->fmt_out.i_codec = VLC_FOURCC('s','2','4','b');
 139             break;
 140         default:
 141             p_dec->fmt_out.i_codec = VLC_FOURCC('s','1','6','b');
 142             p_dec->fmt_out.audio.i_bitspersample = 16;
 143             break;
 144         }
 145     }
 146
 147     /* Set callback */
 148     p_dec->pf_decode_audio = (aout_buffer_t *(*)(decoder_t *, block_t **))
 149         DecodeFrame;
 150     p_dec->pf_packetize    = (block_t *(*)(decoder_t *, block_t **))
 151         DecodeFrame;
 152
 153     return VLC_SUCCESS;
 154 }
 155 static int OpenDecoder( vlc_object_t *p_this )
 156 {
 157     return OpenCommon( p_this, false );
 158 }
 159 static int OpenPacketizer( vlc_object_t *p_this )
 160 {
 161     return OpenCommon( p_this, true );
 162 }
 163
 164 /*****************************************************************************
 165  * DecodeFrame: decodes an lpcm frame.
 166  ****************************************************************************
 167  * Beware, this function must be fed with complete frames (PES packet).
 168  *****************************************************************************/
 169 static void *DecodeFrame( decoder_t *p_dec, block_t **pp_block )
 170 {
 171     decoder_sys_t *p_sys = p_dec->p_sys;
 172     block_t       *p_block;
 173     unsigned int  i_rate = 0, i_original_channels = 0, i_channels = 0;
 174     int           i_frame_length, i_bitspersample;
 175     uint8_t       i_header;
 176
 177     if( !pp_block || !*pp_block ) return NULL;
 178
 179     p_block = *pp_block;
 180     *pp_block = NULL; /* So the packet doesn't get re-sent */
 181
 182     /* Date management */
 183     if( p_block->i_pts > 0 &&
 184         p_block->i_pts != aout_DateGet( &p_sys->end_date ) )
 185     {
 186         aout_DateSet( &p_sys->end_date, p_block->i_pts );
 187     }
 188
 189     if( !aout_DateGet( &p_sys->end_date ) )
 190     {
 191         /* We've just started the stream, wait for the first PTS. */
 192         block_Release( p_block );
 193         return NULL;
 194     }
 195
 196     if( p_block->i_buffer <= p_sys->i_header_size )
 197     {
 198         msg_Err(p_dec, "frame is too short");
 199         block_Release( p_block );
 200         return NULL;
 201     }
 202
 203     i_header = p_block->p_buffer[4];
 204     switch ( (i_header >> 4) & 0x3 )
 205     {
 206     case 0:
 207         i_rate = 48000;
 208         break;
 209     case 1:
 210         i_rate = 96000;
 211         break;
 212     case 2:
 213         i_rate = 44100;
 214         break;
 215     case 3:
 216         i_rate = 32000;
 217         break;
 218     }
 219
 220     i_channels = (i_header & 0x7);
 221     switch ( i_channels )
 222     {
 223     case 0:
 224         i_original_channels = AOUT_CHAN_CENTER;
 225         break;
 226     case 1:
 227         i_original_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
 228         break;
 229     case 2:
 230         /* This is unsure. */
 231         i_original_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_LFE;
 232         break;
 233     case 3:
 234         i_original_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
 235                                | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
 236         break;
 237     case 4:
 238         /* This is unsure. */
 239         i_original_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
 240                                | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
 241                                | AOUT_CHAN_LFE;
 242         break;
 243     case 5:
 244         i_original_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
 245                                | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
 246                                | AOUT_CHAN_CENTER | AOUT_CHAN_LFE;
 247         break;
 248     case 6:
 249         i_original_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
 250                                | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
 251                                | AOUT_CHAN_CENTER | AOUT_CHAN_MIDDLELEFT
 252                                | AOUT_CHAN_MIDDLERIGHT;
 253         break;
 254     case 7:
 255         i_original_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
 256                                | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
 257                                | AOUT_CHAN_CENTER | AOUT_CHAN_MIDDLELEFT
 258                                | AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_LFE;
 259         break;
 260     }
 261
 262     switch ( (i_header >> 6) & 0x3 )
 263     {
 264     case 2:
 265         p_dec->fmt_out.i_codec = VLC_FOURCC('s','2','4','b');
 266         p_dec->fmt_out.audio.i_bitspersample = 24;
 267         i_bitspersample = 24;
 268         break;
 269     case 1:
 270         p_dec->fmt_out.i_codec = VLC_FOURCC('s','2','4','b');
 271         p_dec->fmt_out.audio.i_bitspersample = 24;
 272         i_bitspersample = 20;
 273         break;
 274     case 0:
 275     default:
 276         p_dec->fmt_out.i_codec = VLC_FOURCC('s','1','6','b');
 277         p_dec->fmt_out.audio.i_bitspersample = 16;
 278         i_bitspersample = 16;
 279         break;
 280     }
 281
 282     /* Check frame sync and drop it. */
 283     if( p_block->p_buffer[5] != 0x80 )
 284     {
 285         msg_Warn( p_dec, "no frame sync" );
 286         block_Release( p_block );
 287         return NULL;
 288     }
 289
 290     /* Set output properties */
 291     if( p_dec->fmt_out.audio.i_rate != i_rate )
 292     {
 293         aout_DateInit( &p_sys->end_date, i_rate );
 294         aout_DateSet( &p_sys->end_date, p_block->i_pts );
 295     }
 296     p_dec->fmt_out.audio.i_rate = i_rate;
 297     p_dec->fmt_out.audio.i_channels = i_channels + 1;
 298     p_dec->fmt_out.audio.i_original_channels = i_original_channels;
 299     p_dec->fmt_out.audio.i_physical_channels
 300         = i_original_channels & AOUT_CHAN_PHYSMASK;
 301
 302     i_frame_length = (p_block->i_buffer - p_sys->i_header_size) /
 303         p_dec->fmt_out.audio.i_channels * 8 / i_bitspersample;
 304
 305     if( p_sys->b_packetizer )
 306     {
 307         p_dec->fmt_out.i_codec = VLC_FOURCC('l','p','c','m');
 308         p_block->i_pts = p_block->i_dts = aout_DateGet( &p_sys->end_date );
 309         p_block->i_length =
 310             aout_DateIncrement( &p_sys->end_date, i_frame_length ) -
 311             p_block->i_pts;
 312
 313         /* Just pass on the incoming frame */
 314         return p_block;
 315     }
 316     else
 317     {
 318         aout_buffer_t *p_aout_buffer;
 319         p_aout_buffer = decoder_NewAudioBuffer( p_dec, i_frame_length );
 320         if( p_aout_buffer == NULL ) return NULL;
 321
 322         p_aout_buffer->start_date = aout_DateGet( &p_sys->end_date );
 323         p_aout_buffer->end_date =
 324             aout_DateIncrement( &p_sys->end_date, i_frame_length );
 325
 326         p_block->p_buffer += p_sys->i_header_size;
 327         p_block->i_buffer -= p_sys->i_header_size;
 328
 329         /* 20/24 bits LPCM use special packing */
 330         if( i_bitspersample == 24 )
 331         {
 332             uint8_t *p_out = p_aout_buffer->p_buffer;
 333
 334             while( p_block->i_buffer / 12 )
 335             {
 336                 /* Sample 1 */
 337                 p_out[0] = p_block->p_buffer[0];
 338                 p_out[1] = p_block->p_buffer[1];
 339                 p_out[2] = p_block->p_buffer[8];
 340                 /* Sample 2 */
 341                 p_out[3] = p_block->p_buffer[2];
 342                 p_out[4] = p_block->p_buffer[3];
 343                 p_out[5] = p_block->p_buffer[9];
 344                 /* Sample 3 */
 345                 p_out[6] = p_block->p_buffer[4];
 346                 p_out[7] = p_block->p_buffer[5];
 347                 p_out[8] = p_block->p_buffer[10];
 348                 /* Sample 4 */
 349                 p_out[9] = p_block->p_buffer[6];
 350                 p_out[10] = p_block->p_buffer[7];
 351                 p_out[11] = p_block->p_buffer[11];
 352
 353                 p_block->i_buffer -= 12;
 354                 p_block->p_buffer += 12;
 355                 p_out += 12;
 356             }
 357         }
 358         else if( i_bitspersample == 20 )
 359         {
 360             uint8_t *p_out = p_aout_buffer->p_buffer;
 361
 362             while( p_block->i_buffer / 10 )
 363             {
 364                 /* Sample 1 */
 365                 p_out[0] = p_block->p_buffer[0];
 366                 p_out[1] = p_block->p_buffer[1];
 367                 p_out[2] = p_block->p_buffer[8] & 0xF0;
 368                 /* Sample 2 */
 369                 p_out[3] = p_block->p_buffer[2];
 370                 p_out[4] = p_block->p_buffer[3];
 371                 p_out[5] = p_block->p_buffer[8] << 4;
 372                 /* Sample 3 */
 373                 p_out[6] = p_block->p_buffer[4];
 374                 p_out[7] = p_block->p_buffer[5];
 375                 p_out[8] = p_block->p_buffer[9] & 0xF0;
 376                 /* Sample 4 */
 377                 p_out[9] = p_block->p_buffer[6];
 378                 p_out[10] = p_block->p_buffer[7];
 379                 p_out[11] = p_block->p_buffer[9] << 4;
 380
 381                 p_block->i_buffer -= 10;
 382                 p_block->p_buffer += 10;
 383                 p_out += 12;
 384             }
 385         }
 386         else
 387         {
 388             memcpy( p_aout_buffer->p_buffer,
 389                     p_block->p_buffer, p_block->i_buffer );
 390         }
 391
 392         block_Release( p_block );
 393         return p_aout_buffer;
 394     }
 395 }
 396
 397 /*****************************************************************************
 398  * CloseCommon : lpcm decoder destruction
 399  *****************************************************************************/
 400 static void CloseCommon( vlc_object_t *p_this )
 401 {
 402     decoder_t *p_dec = (decoder_t*)p_this;
 403     free( p_dec->p_sys );
 404 }
 405