modules/codec/a52.c

   1 /*****************************************************************************
   2  * a52.c: ATSC A/52 aka AC-3 decoder plugin for VLC.
   3  *   This plugin makes use of liba52 to decode A/52 audio
   4  *   (http://liba52.sf.net/).
   5  *****************************************************************************
   6  * Copyright (C) 2001-2009 VLC authors and VideoLAN
   7  * $Id$
   8  *
   9  * Authors: Gildas Bazin <gbazin@videolan.org>
  10  *          Christophe Massiot <massiot@via.ecp.fr>
  11  *          Thomas Guillem <thomas@gllm.fr>
  12  *
  13  * This program is free software; you can redistribute it and/or modify it
  14  * under the terms of the GNU Lesser General Public License as published by
  15  * the Free Software Foundation; either version 2.1 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  21  * GNU Lesser General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU Lesser General Public License
  24  * along with this program; if not, write to the Free Software Foundation,
  25  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  26  *****************************************************************************/
  27
  28 /*****************************************************************************
  29  * NOTA BENE: this module requires the linking against a library which is
  30  * known to require licensing under the GNU General Public License version 2
  31  * (or later). Therefore, the result of compiling this module will normally
  32  * be subject to the terms of that later license.
  33  *****************************************************************************/
  34
  35 #ifdef HAVE_CONFIG_H
  36 # include "config.h"
  37 #endif
  38
  39 #include <vlc_common.h>
  40 #include <vlc_plugin.h>
  41 #include <vlc_cpu.h>
  42
  43 #include <stdint.h>                                         /* int16_t .. */
  44
  45 #ifdef USE_A52DEC_TREE                                 /* liba52 header file */
  46 #   include "include/a52.h"
  47 #else
  48 #   include "a52dec/a52.h"
  49 #endif
  50
  51 #include <vlc_aout.h>
  52 #include <vlc_block.h>
  53 #include <vlc_codec.h>
  54
  55 static int  Open ( vlc_object_t * );
  56 static void Close( vlc_object_t * );
  57
  58 struct decoder_sys_t
  59 {
  60     a52_state_t     *p_liba52; /* liba52 internal structure */
  61     bool            b_dynrng; /* see below */
  62     int             i_flags; /* liba52 flags, see a52dec/doc/liba52.txt */
  63     bool            b_dontwarn;
  64     int             i_nb_channels; /* number of float32 per sample */
  65
  66     uint8_t         pi_chan_table[AOUT_CHAN_MAX]; /* channel reordering */
  67     bool            b_synced;
  68 };
  69
  70 #define DYNRNG_TEXT N_("A/52 dynamic range compression")
  71 #define DYNRNG_LONGTEXT N_( \
  72     "Dynamic range compression makes the loud sounds softer, and the soft " \
  73     "sounds louder, so you can more easily listen to the stream in a noisy " \
  74     "environment without disturbing anyone. If you disable the dynamic range "\
  75     "compression the playback will be more adapted to a movie theater or a " \
  76     "listening room.")
  77
  78 vlc_module_begin ()
  79     set_shortname( "A/52" )
  80     set_description( N_("ATSC A/52 (AC-3) audio decoder") )
  81     set_category( CAT_INPUT )
  82     set_subcategory( SUBCAT_INPUT_ACODEC )
  83     add_bool( "a52-dynrng", true, DYNRNG_TEXT, DYNRNG_LONGTEXT, false )
  84     set_capability( "audio decoder", 60 )
  85     set_callbacks( Open, Close )
  86 vlc_module_end ()
  87
  88 /*
  89  * helper function to interleave channels
  90  */
  91 static void Interleave( sample_t *restrict p_out, const sample_t *restrict p_in,
  92                         unsigned i_nb_channels, uint8_t *restrict pi_chan_table )
  93 {
  94     /* We do not only have to interleave, but also reorder the channels */
  95     for( unsigned j = 0; j < i_nb_channels; j++ )
  96     {
  97         for( unsigned i = 0; i < 256; i++ )
  98         {
  99 #ifdef LIBA52_FIXED
 100             union { uint32_t u; int32_t i; } spl;
 101
 102             spl.u = ((uint32_t)p_in[j * 256 + i]) << 4;
 103             p_out[i * i_nb_channels + pi_chan_table[j]] = spl.i;
 104 #else
 105             p_out[i * i_nb_channels + pi_chan_table[j]] = p_in[j * 256 + i];
 106 #endif
 107         }
 108     }
 109 }
 110
 111 /*
 112  * helper function to duplicate a unique channel
 113  */
 114 static void Duplicate( sample_t *restrict p_out, const sample_t *restrict p_in )
 115 {
 116     for( unsigned i = 256; i--; )
 117     {
 118 #ifdef LIBA52_FIXED
 119         union { uint32_t u; int32_t i; } spl;
 120
 121         spl.u = ((uint32_t)*(p_in++)) << 4;
 122         *p_out++ = spl.i;
 123         *p_out++ = spl.i;
 124 #else
 125         sample_t s = *(p_in++);
 126
 127         *p_out++ = s;
 128         *p_out++ = s;
 129 #endif
 130     }
 131 }
 132
 133 static int Decode( decoder_t *p_dec, block_t *p_in_buf )
 134 {
 135     decoder_sys_t *p_sys = p_dec->p_sys;
 136
 137     if (p_in_buf == NULL) /* No drain */
 138         return VLCDEC_SUCCESS;
 139
 140 #ifdef LIBA52_FIXED
 141     sample_t i_sample_level = (1 << 24);
 142 #else
 143     sample_t i_sample_level = 1;
 144 #endif
 145     int i_flags = p_sys->i_flags;
 146     size_t i_bytes_per_block = 256 * p_sys->i_nb_channels * sizeof(sample_t);
 147
 148
 149     /* Every A/52 frame is composed of 6 blocks, each with an output of 256
 150      * samples for each channel. */
 151     block_t *p_out_buf = block_Alloc( 6 * i_bytes_per_block );
 152     if( unlikely(p_out_buf == NULL) )
 153     {
 154         block_Release( p_in_buf );
 155         return VLCDEC_SUCCESS;
 156     }
 157
 158     /* Do the actual decoding now. */
 159     a52_frame( p_sys->p_liba52, p_in_buf->p_buffer,
 160                &i_flags, &i_sample_level, 0 );
 161
 162     if ( (i_flags & A52_CHANNEL_MASK) != (p_sys->i_flags & A52_CHANNEL_MASK)
 163           && !p_sys->b_dontwarn )
 164     {
 165         msg_Warn( p_dec,
 166                   "liba52 couldn't do the requested downmix 0x%x->0x%x",
 167                   p_sys->i_flags  & A52_CHANNEL_MASK,
 168                   i_flags & A52_CHANNEL_MASK );
 169
 170         p_sys->b_dontwarn = 1;
 171     }
 172
 173     if( !p_sys->b_dynrng )
 174     {
 175         a52_dynrng( p_sys->p_liba52, NULL, NULL );
 176     }
 177
 178     for( unsigned i = 0; i < 6; i++ )
 179     {
 180         if( a52_block( p_sys->p_liba52 ) )
 181             msg_Warn( p_dec, "a52_block failed for block %d", i );
 182
 183         sample_t *p_samples = a52_samples( p_sys->p_liba52 );
 184
 185         if ( ((p_sys->i_flags & A52_CHANNEL_MASK) == A52_CHANNEL1
 186                || (p_sys->i_flags & A52_CHANNEL_MASK) == A52_CHANNEL2
 187                || (p_sys->i_flags & A52_CHANNEL_MASK) == A52_MONO)
 188               && (p_dec->fmt_out.audio.i_physical_channels
 189                    & (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)) )
 190         {
 191             Duplicate( (sample_t *)(p_out_buf->p_buffer + i * i_bytes_per_block),
 192                        p_samples );
 193         }
 194         else
 195         {
 196             /* Interleave the *$£%ù samples. */
 197             Interleave( (sample_t *)(p_out_buf->p_buffer + i * i_bytes_per_block),
 198                         p_samples, p_sys->i_nb_channels, p_sys->pi_chan_table);
 199         }
 200     }
 201
 202     p_out_buf->i_nb_samples = A52_FRAME_NB; /* 6 * 256 */
 203     p_out_buf->i_dts = p_in_buf->i_dts;
 204     p_out_buf->i_pts = p_in_buf->i_pts;
 205     p_out_buf->i_length = p_in_buf->i_length;
 206     block_Release( p_in_buf );
 207     decoder_QueueAudio( p_dec, p_out_buf );
 208     return VLCDEC_SUCCESS;
 209 }
 210
 211 static int channels_vlc2a52( const audio_format_t *p_audio, int *p_flags )
 212 {
 213     int i_flags = 0;
 214
 215     switch ( p_audio->i_physical_channels & ~AOUT_CHAN_LFE )
 216     {
 217     case AOUT_CHAN_CENTER:
 218         if ( (p_audio->i_physical_channels & AOUT_CHAN_CENTER)
 219               || (p_audio->i_physical_channels
 220                    & (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)) )
 221             i_flags = A52_MONO;
 222         else if ( p_audio->i_physical_channels & AOUT_CHAN_LEFT )
 223             i_flags = A52_CHANNEL1;
 224         else
 225             i_flags = A52_CHANNEL2;
 226         break;
 227
 228     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT:
 229         if ( p_audio->i_chan_mode & AOUT_CHANMODE_DOLBYSTEREO )
 230             i_flags = A52_DOLBY;
 231         else if ( p_audio->i_chan_mode & AOUT_CHANMODE_DUALMONO )
 232             i_flags = A52_CHANNEL;
 233         else if ( !(p_audio->i_physical_channels & AOUT_CHAN_RIGHT) )
 234             i_flags = A52_CHANNEL1;
 235         else if ( !(p_audio->i_physical_channels & AOUT_CHAN_LEFT) )
 236             i_flags = A52_CHANNEL2;
 237         else
 238             i_flags = A52_STEREO;
 239         break;
 240
 241     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER:
 242         i_flags = A52_3F;
 243         break;
 244
 245     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_REARCENTER:
 246         i_flags = A52_2F1R;
 247         break;
 248
 249     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
 250           | AOUT_CHAN_REARCENTER:
 251         i_flags = A52_3F1R;
 252         break;
 253
 254     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
 255           | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT:
 256         i_flags = A52_2F2R;
 257         break;
 258
 259     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
 260           | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT:
 261         i_flags = A52_3F2R;
 262         break;
 263
 264     default:
 265         return VLC_EGENERIC;
 266     }
 267
 268     if ( p_audio->i_physical_channels & AOUT_CHAN_LFE )
 269         i_flags |= A52_LFE;
 270     *p_flags = i_flags;
 271     return VLC_SUCCESS;
 272 }
 273
 274 static int Open( vlc_object_t *p_this )
 275 {
 276     decoder_t *p_dec = (decoder_t *)p_this;
 277     decoder_sys_t *p_sys;
 278
 279     if( p_dec->fmt_in.i_codec != VLC_CODEC_A52
 280      || p_dec->fmt_in.audio.i_rate == 0
 281      || p_dec->fmt_in.audio.i_physical_channels == 0
 282      || p_dec->fmt_in.audio.i_bytes_per_frame == 0
 283      || p_dec->fmt_in.audio.i_frame_length == 0 )
 284         return VLC_EGENERIC;
 285
 286     /* Allocate the memory needed to store the module's structure */
 287     p_dec->p_sys = p_sys = malloc( sizeof(decoder_sys_t) );
 288     if( p_sys == NULL )
 289         return VLC_ENOMEM;
 290
 291     p_sys->b_dynrng = var_InheritBool( p_this, "a52-dynrng" );
 292     p_sys->b_dontwarn = 0;
 293
 294     p_sys->i_nb_channels = aout_FormatNbChannels( &p_dec->fmt_in.audio );
 295     if( channels_vlc2a52( &p_dec->fmt_in.audio, &p_sys->i_flags )
 296         != VLC_SUCCESS )
 297     {
 298         msg_Warn( p_this, "unknown sample format!" );
 299         free( p_sys );
 300         return VLC_EGENERIC;
 301     }
 302     p_sys->i_flags |= A52_ADJUST_LEVEL;
 303
 304     /* Initialize liba52 */
 305     p_sys->p_liba52 = a52_init( 0 );
 306     if( p_sys->p_liba52 == NULL )
 307     {
 308         msg_Err( p_this, "unable to initialize liba52" );
 309         free( p_sys );
 310         return VLC_EGENERIC;
 311     }
 312
 313     static const uint32_t pi_channels_in[] = {
 314         AOUT_CHAN_LFE, AOUT_CHAN_LEFT, AOUT_CHAN_CENTER, AOUT_CHAN_RIGHT,
 315         AOUT_CHAN_REARLEFT, AOUT_CHAN_REARCENTER, AOUT_CHAN_REARRIGHT, 0
 316     };
 317
 318     aout_CheckChannelReorder( pi_channels_in, NULL,
 319                               p_dec->fmt_in.audio.i_physical_channels,
 320                               p_sys->pi_chan_table );
 321
 322     p_dec->fmt_out.audio = p_dec->fmt_in.audio;
 323 #ifdef LIBA52_FIXED
 324     p_dec->fmt_out.audio.i_format = VLC_CODEC_S32N;
 325 #else
 326     p_dec->fmt_out.audio.i_format = VLC_CODEC_FL32;
 327 #endif
 328     p_dec->fmt_out.i_codec = p_dec->fmt_out.audio.i_format;
 329
 330     aout_FormatPrepare( &p_dec->fmt_out.audio );
 331
 332     if( decoder_UpdateAudioFormat( p_dec ) )
 333     {
 334         Close( p_this );
 335         return VLC_EGENERIC;
 336     }
 337
 338     p_dec->pf_decode = Decode;
 339     p_dec->pf_flush  = NULL;
 340     return VLC_SUCCESS;
 341 }
 342
 343 static void Close( vlc_object_t *p_this )
 344 {
 345     decoder_t *p_dec = (decoder_t *)p_this;
 346     decoder_sys_t *p_sys = p_dec->p_sys;
 347
 348     a52_free( p_sys->p_liba52 );
 349     free( p_sys );
 350 }