modules/codec/aes3.c

   1 /*****************************************************************************
   2  * aes3.c: aes3 decoder/packetizer module
   3  *****************************************************************************
   4  * Copyright (C) 2008 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir@videolan.org>
   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 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <vlc_common.h>
  32 #include <vlc_plugin.h>
  33 #include <vlc_codec.h>
  34 #include <vlc_aout.h>
  35 #include <assert.h>
  36
  37 /*****************************************************************************
  38  * Module descriptor
  39  *****************************************************************************/
  40 static int  OpenDecoder   ( vlc_object_t * );
  41 static int  OpenPacketizer( vlc_object_t * );
  42 static void Close         ( vlc_object_t * );
  43
  44 vlc_module_begin ()
  45
  46     set_category( CAT_INPUT )
  47     set_subcategory( SUBCAT_INPUT_ACODEC )
  48     set_description( N_("AES3/SMPTE 302M audio decoder") )
  49     set_capability( "decoder", 100 )
  50     set_callbacks( OpenDecoder, Close )
  51
  52     add_submodule ()
  53     set_description( N_("AES3/SMPTE 302M audio packetizer") )
  54     set_capability( "packetizer", 100 )
  55     set_callbacks( OpenPacketizer, Close )
  56
  57 vlc_module_end ()
  58
  59 /*****************************************************************************
  60  * decoder_sys_t : aes3 decoder descriptor
  61  *****************************************************************************/
  62 struct decoder_sys_t
  63 {
  64     /*
  65      * Output properties
  66      */
  67     date_t end_date;
  68 };
  69
  70 #define AES3_HEADER_LEN 4
  71
  72 /*****************************************************************************
  73  * Local prototypes
  74  *****************************************************************************/
  75 static int Open( decoder_t *p_dec, bool b_packetizer );
  76
  77 static block_t *Parse( decoder_t *p_dec, int *pi_frame_length, int *pi_bits,
  78                        block_t **pp_block, bool b_packetizer );
  79
  80 static inline uint8_t Reverse8( int n )
  81 {
  82     n = ((n >> 1) & 0x55) | ((n << 1) & 0xaa);
  83     n = ((n >> 2) & 0x33) | ((n << 2) & 0xcc);
  84     n = ((n >> 4) & 0x0f) | ((n << 4) & 0xf0);
  85     return n;
  86 }
  87
  88 /*****************************************************************************
  89  * OpenDecoder:
  90  *****************************************************************************/
  91 static int OpenDecoder( vlc_object_t *p_this )
  92 {
  93     decoder_t *p_dec = (decoder_t*)p_this;
  94
  95     return Open( p_dec, false );
  96 }
  97
  98 /*****************************************************************************
  99  * OpenPacketizer:
 100  *****************************************************************************/
 101 static int OpenPacketizer( vlc_object_t *p_this )
 102 {
 103     decoder_t *p_dec = (decoder_t*)p_this;
 104
 105     return Open( p_dec, true );
 106 }
 107
 108 /*****************************************************************************
 109  * Close : aes3 decoder destruction
 110  *****************************************************************************/
 111 static void Close( vlc_object_t *p_this )
 112 {
 113     decoder_t *p_dec = (decoder_t*)p_this;
 114     free( p_dec->p_sys );
 115 }
 116
 117 /*****************************************************************************
 118  * Decode: decodes an aes3 frame.
 119  ****************************************************************************
 120  * Beware, this function must be fed with complete frames (PES packet).
 121  *****************************************************************************/
 122 static aout_buffer_t *Decode( decoder_t *p_dec, block_t **pp_block )
 123 {
 124     decoder_sys_t *p_sys = p_dec->p_sys;
 125     block_t       *p_block;
 126     aout_buffer_t *p_aout_buffer;
 127     int            i_frame_length, i_bits;
 128
 129     p_block = Parse( p_dec, &i_frame_length, &i_bits, pp_block, false );
 130     if( !p_block )
 131         return NULL;
 132
 133     p_aout_buffer = decoder_NewAudioBuffer( p_dec, i_frame_length );
 134     if( p_aout_buffer == NULL )
 135         goto exit;
 136
 137     p_aout_buffer->i_pts = date_Get( &p_sys->end_date );
 138     p_aout_buffer->i_length = date_Increment( &p_sys->end_date,
 139                                       i_frame_length ) - p_aout_buffer->i_pts;
 140
 141     p_block->i_buffer -= AES3_HEADER_LEN;
 142     p_block->p_buffer += AES3_HEADER_LEN;
 143
 144     if( i_bits == 24 )
 145     {
 146         uint8_t *p_out = p_aout_buffer->p_buffer;
 147
 148         while( p_block->i_buffer / 7 )
 149         {
 150             p_out[0] = Reverse8( p_block->p_buffer[0] );
 151             p_out[1] = Reverse8( p_block->p_buffer[1] );
 152             p_out[2] = Reverse8( p_block->p_buffer[2] );
 153
 154             p_out[3] = (Reverse8( p_block->p_buffer[3] ) >> 4) | ( (Reverse8( p_block->p_buffer[4] ) << 4) & 0xf0 );
 155             p_out[4] = (Reverse8( p_block->p_buffer[4] ) >> 4) | ( (Reverse8( p_block->p_buffer[5] ) << 4) & 0xf0 );
 156             p_out[5] = (Reverse8( p_block->p_buffer[5] ) >> 4) | ( (Reverse8( p_block->p_buffer[6] ) << 4) & 0xf0 );
 157
 158             p_block->i_buffer -= 7;
 159             p_block->p_buffer += 7;
 160             p_out += 6;
 161         }
 162
 163     }
 164     else if( i_bits == 20 )
 165     {
 166         uint8_t *p_out = p_aout_buffer->p_buffer;
 167
 168         while( p_block->i_buffer / 6 )
 169         {
 170             p_out[0] =                                            ( (Reverse8( p_block->p_buffer[0] ) << 4) & 0xf0 );
 171             p_out[1] = ( Reverse8( p_block->p_buffer[0]) >> 4 ) | ( (Reverse8( p_block->p_buffer[1]) << 4 ) & 0xf0 );
 172             p_out[2] = ( Reverse8( p_block->p_buffer[1]) >> 4 ) | ( (Reverse8( p_block->p_buffer[2]) << 4 ) & 0xf0 );
 173
 174             p_out[3] =                                            ( (Reverse8( p_block->p_buffer[3] ) << 4) & 0xf0 );
 175             p_out[4] = ( Reverse8( p_block->p_buffer[3]) >> 4 ) | ( (Reverse8( p_block->p_buffer[4]) << 4 ) & 0xf0 );
 176             p_out[5] = ( Reverse8( p_block->p_buffer[4]) >> 4 ) | ( (Reverse8( p_block->p_buffer[5]) << 4 ) & 0xf0 );
 177
 178             p_block->i_buffer -= 6;
 179             p_block->p_buffer += 6;
 180             p_out += 6;
 181         }
 182     }
 183     else
 184     {
 185         uint8_t *p_out = p_aout_buffer->p_buffer;
 186
 187         assert( i_bits == 16 );
 188
 189         while( p_block->i_buffer / 5 )
 190         {
 191             p_out[0] = Reverse8( p_block->p_buffer[0] );
 192             p_out[1] = Reverse8( p_block->p_buffer[1] );
 193
 194             p_out[2] = (Reverse8( p_block->p_buffer[2] ) >> 4) | ( (Reverse8( p_block->p_buffer[3] ) << 4) & 0xf0 );
 195             p_out[3] = (Reverse8( p_block->p_buffer[3] ) >> 4) | ( (Reverse8( p_block->p_buffer[4] ) << 4) & 0xf0 );
 196
 197             p_block->i_buffer -= 5;
 198             p_block->p_buffer += 5;
 199             p_out += 4;
 200         }
 201     }
 202
 203 exit:
 204     block_Release( p_block );
 205     return p_aout_buffer;
 206 }
 207
 208 /*****************************************************************************
 209  * Packetize: packetizes an aes3 frame.
 210  ****************************************************************************
 211  * Beware, this function must be fed with complete frames (PES packet).
 212  *****************************************************************************/
 213 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
 214 {
 215     decoder_sys_t *p_sys = p_dec->p_sys;
 216     block_t       *p_block;
 217     int           i_frame_length, i_bits;
 218
 219     p_block = Parse( p_dec, &i_frame_length, &i_bits, pp_block, true );
 220     if( !p_block )
 221         return NULL;
 222
 223     p_block->i_pts = p_block->i_dts = date_Get( &p_sys->end_date );
 224     p_block->i_length = date_Increment( &p_sys->end_date, i_frame_length ) - p_block->i_pts;
 225
 226     /* Just pass on the incoming frame */
 227     return p_block;
 228 }
 229
 230 /*****************************************************************************
 231  *
 232  ****************************************************************************/
 233 static int Open( decoder_t *p_dec, bool b_packetizer )
 234 {
 235     decoder_sys_t *p_sys;
 236
 237     if( p_dec->fmt_in.i_codec != VLC_CODEC_302M )
 238         return VLC_EGENERIC;
 239
 240     /* Allocate the memory needed to store the decoder's structure */
 241     p_dec->p_sys = p_sys = malloc( sizeof(decoder_sys_t) );
 242
 243     if( !p_sys )
 244         return VLC_EGENERIC;
 245
 246     /* Misc init */
 247     date_Init( &p_sys->end_date, 48000, 1 );
 248     date_Set( &p_sys->end_date, 0 );
 249
 250     /* Set output properties */
 251     p_dec->fmt_out.i_cat = AUDIO_ES;
 252     p_dec->fmt_out.audio.i_rate = 48000;
 253
 254     /* Set callback */
 255     if( b_packetizer )
 256     {
 257         p_dec->fmt_out.i_codec = VLC_CODEC_302M;
 258
 259         p_dec->pf_decode_audio = NULL;
 260         p_dec->pf_packetize    = Packetize;
 261     }
 262     else
 263     {
 264         p_dec->fmt_out.i_codec = VLC_CODEC_S16N;
 265         p_dec->fmt_out.audio.i_bitspersample = 16;
 266
 267         p_dec->pf_decode_audio = Decode;
 268         p_dec->pf_packetize    = NULL;
 269     }
 270     return VLC_SUCCESS;
 271 }
 272
 273 static const unsigned int pi_original_channels[4] = {
 274     AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT,
 275     AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
 276         AOUT_CHAN_CENTER | AOUT_CHAN_LFE,
 277     AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
 278         AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT |
 279         AOUT_CHAN_CENTER | AOUT_CHAN_LFE,
 280     AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
 281         AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT |
 282         AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT |
 283         AOUT_CHAN_CENTER | AOUT_CHAN_LFE,
 284 };
 285
 286 static block_t *Parse( decoder_t *p_dec, int *pi_frame_length, int *pi_bits,
 287                        block_t **pp_block, bool b_packetizer )
 288 {
 289     decoder_sys_t *p_sys = p_dec->p_sys;
 290     block_t       *p_block;
 291     uint32_t h;
 292     unsigned int i_size;
 293     int i_channels;
 294     int i_id;
 295     int i_bits;
 296
 297     if( !pp_block || !*pp_block ) return NULL;
 298
 299     p_block = *pp_block;
 300     *pp_block = NULL; /* So the packet doesn't get re-sent */
 301
 302     /* Date management */
 303     if( p_block->i_pts > VLC_TS_INVALID &&
 304         p_block->i_pts != date_Get( &p_sys->end_date ) )
 305     {
 306         date_Set( &p_sys->end_date, p_block->i_pts );
 307     }
 308
 309     if( !date_Get( &p_sys->end_date ) )
 310     {
 311         /* We've just started the stream, wait for the first PTS. */
 312         block_Release( p_block );
 313         return NULL;
 314     }
 315
 316     if( p_block->i_buffer <= AES3_HEADER_LEN )
 317     {
 318         msg_Err(p_dec, "frame is too short");
 319         block_Release( p_block );
 320         return NULL;
 321     }
 322
 323     /*
 324      * AES3 header :
 325      * size:            16
 326      * number channels   2
 327      * channel_id        8
 328      * bits per samples  2
 329      * alignments        4
 330      */
 331
 332     h = GetDWBE( p_block->p_buffer );
 333     i_size = (h >> 16) & 0xffff;
 334     i_channels = 2 + 2*( (h >> 14) & 0x03 );
 335     i_id = (h >> 6) & 0xff;
 336     i_bits = 16 + 4*( (h >> 4)&0x03 );
 337
 338     if( AES3_HEADER_LEN + i_size != p_block->i_buffer || i_bits > 24 )
 339     {
 340         msg_Err(p_dec, "frame has invalid header");
 341         block_Release( p_block );
 342         return NULL;
 343     }
 344
 345     /* Set output properties */
 346     if( b_packetizer )
 347     {
 348         p_dec->fmt_out.audio.i_bitspersample = i_bits;
 349     }
 350     else
 351     {
 352         p_dec->fmt_out.i_codec = i_bits == 16 ? VLC_CODEC_S16L : VLC_CODEC_S24L;
 353         p_dec->fmt_out.audio.i_bitspersample = i_bits == 16 ? 16 : 24;
 354     }
 355
 356     p_dec->fmt_out.audio.i_channels = i_channels;
 357     p_dec->fmt_out.audio.i_original_channels = pi_original_channels[i_channels/2-1];
 358     p_dec->fmt_out.audio.i_physical_channels = pi_original_channels[i_channels/2-1] & AOUT_CHAN_PHYSMASK;
 359
 360     *pi_frame_length = (p_block->i_buffer - AES3_HEADER_LEN) / ( (4+i_bits) * i_channels / 8 );
 361     *pi_bits = i_bits;
 362     return p_block;
 363 }
 364