modules/codec/twolame.c

   1 /*****************************************************************************
   2  * twolame.c: libtwolame encoder (MPEG-1/2 layer II) module
   3  *            (using libtwolame from http://www.twolame.org/)
   4  *****************************************************************************
   5  * Copyright (C) 2004-2005 VLC authors and VideoLAN
   6  * $Id$
   7  *
   8  * Authors: Christophe Massiot <massiot@via.ecp.fr>
   9  *          Gildas Bazin
  10  *
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU Lesser General Public License as published by
  13  * the Free Software Foundation; either version 2.1 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  19  * GNU Lesser General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public License
  22  * along with this program; if not, write to the Free Software Foundation,
  23  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  24  *****************************************************************************/
  25
  26 /*****************************************************************************
  27  * Preamble
  28  *****************************************************************************/
  29 #ifdef HAVE_CONFIG_H
  30 # include "config.h"
  31 #endif
  32
  33 #include <vlc_common.h>
  34 #include <vlc_plugin.h>
  35 #include <vlc_codec.h>
  36
  37 #include <twolame.h>
  38
  39 #define MPEG_FRAME_SIZE 1152
  40 #define MAX_CODED_FRAME_SIZE 1792
  41
  42 /****************************************************************************
  43  * Local prototypes
  44  ****************************************************************************/
  45 static int OpenEncoder   ( vlc_object_t * );
  46 static void CloseEncoder ( vlc_object_t * );
  47 static block_t *Encode   ( encoder_t *, block_t * );
  48
  49 /*****************************************************************************
  50  * Module descriptor
  51  *****************************************************************************/
  52 #define ENC_CFG_PREFIX "sout-twolame-"
  53
  54 #define ENC_QUALITY_TEXT N_("Encoding quality")
  55 #define ENC_QUALITY_LONGTEXT N_( \
  56   "Force a specific encoding quality between 0.0 (high) and 50.0 (low), " \
  57   "instead of specifying a particular bitrate. " \
  58   "This will produce a VBR stream." )
  59 #define ENC_MODE_TEXT N_("Stereo mode")
  60 #define ENC_MODE_LONGTEXT N_( "Handling mode for stereo streams" )
  61 #define ENC_VBR_TEXT N_("VBR mode")
  62 #define ENC_VBR_LONGTEXT N_( \
  63   "Use Variable BitRate. Default is to use Constant BitRate (CBR)." )
  64 #define ENC_PSY_TEXT N_("Psycho-acoustic model")
  65 #define ENC_PSY_LONGTEXT N_( \
  66   "Integer from -1 (no model) to 4." )
  67
  68 static const int pi_stereo_values[] = { 0, 1, 2 };
  69 static const char *const ppsz_stereo_descriptions[] =
  70 { N_("Stereo"), N_("Dual mono"), N_("Joint stereo") };
  71
  72
  73 vlc_module_begin ()
  74     set_shortname( "Twolame")
  75     set_description( N_("Libtwolame audio encoder") )
  76     set_capability( "encoder", 120 )
  77     set_callbacks( OpenEncoder, CloseEncoder )
  78     set_category( CAT_INPUT )
  79     set_subcategory( SUBCAT_INPUT_ACODEC )
  80
  81     add_float( ENC_CFG_PREFIX "quality", 0.0, ENC_QUALITY_TEXT,
  82                ENC_QUALITY_LONGTEXT, false )
  83     add_integer( ENC_CFG_PREFIX "mode", 0, ENC_MODE_TEXT,
  84                  ENC_MODE_LONGTEXT, false )
  85         change_integer_list( pi_stereo_values, ppsz_stereo_descriptions );
  86     add_bool( ENC_CFG_PREFIX "vbr", false, ENC_VBR_TEXT,
  87               ENC_VBR_LONGTEXT, false )
  88     add_integer( ENC_CFG_PREFIX "psy", 3, ENC_PSY_TEXT,
  89                  ENC_PSY_LONGTEXT, false )
  90 vlc_module_end ()
  91
  92 static const char *const ppsz_enc_options[] = {
  93     "quality", "mode", "vbr", "psy", NULL
  94 };
  95
  96 /*****************************************************************************
  97  * encoder_sys_t : twolame encoder descriptor
  98  *****************************************************************************/
  99 struct encoder_sys_t
 100 {
 101     /*
 102      * Input properties
 103      */
 104     int16_t p_buffer[MPEG_FRAME_SIZE * 2];
 105     int i_nb_samples;
 106     mtime_t i_pts;
 107
 108     /*
 109      * libtwolame properties
 110      */
 111     twolame_options *p_twolame;
 112     unsigned char p_out_buffer[MAX_CODED_FRAME_SIZE];
 113 };
 114
 115 /*****************************************************************************
 116  * OpenEncoder: probe the encoder and return score
 117  *****************************************************************************/
 118 static const uint16_t mpa_bitrate_tab[2][15] =
 119 {
 120     {0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384},
 121     {0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160}
 122 };
 123
 124 static const uint16_t mpa_freq_tab[6] =
 125 { 44100, 48000, 32000, 22050, 24000, 16000 };
 126
 127 static int OpenEncoder( vlc_object_t *p_this )
 128 {
 129     encoder_t *p_enc = (encoder_t *)p_this;
 130     encoder_sys_t *p_sys;
 131     int i_frequency;
 132
 133     if( p_enc->fmt_out.i_codec != VLC_CODEC_MP2 &&
 134         p_enc->fmt_out.i_codec != VLC_CODEC_MPGA &&
 135         p_enc->fmt_out.i_codec != VLC_FOURCC( 'm', 'p', '2', 'a' ) &&
 136         !p_enc->obj.force )
 137     {
 138         return VLC_EGENERIC;
 139     }
 140
 141     if( p_enc->fmt_in.audio.i_channels > 2 )
 142     {
 143         msg_Err( p_enc, "doesn't support > 2 channels" );
 144         return VLC_EGENERIC;
 145     }
 146
 147     for ( i_frequency = 0; i_frequency < 6; i_frequency++ )
 148     {
 149         if ( p_enc->fmt_out.audio.i_rate == mpa_freq_tab[i_frequency] )
 150             break;
 151     }
 152     if ( i_frequency == 6 )
 153     {
 154         msg_Err( p_enc, "MPEG audio doesn't support frequency=%d",
 155                  p_enc->fmt_out.audio.i_rate );
 156         return VLC_EGENERIC;
 157     }
 158
 159     /* Allocate the memory needed to store the decoder's structure */
 160     if( ( p_sys = (encoder_sys_t *)malloc(sizeof(encoder_sys_t)) ) == NULL )
 161         return VLC_ENOMEM;
 162     p_enc->p_sys = p_sys;
 163
 164     p_enc->fmt_in.i_codec = VLC_CODEC_S16N;
 165
 166     p_enc->fmt_out.i_cat = AUDIO_ES;
 167     p_enc->fmt_out.i_codec = VLC_CODEC_MPGA;
 168
 169     config_ChainParse( p_enc, ENC_CFG_PREFIX, ppsz_enc_options, p_enc->p_cfg );
 170
 171     p_sys->p_twolame = twolame_init();
 172
 173     /* Set options */
 174     twolame_set_in_samplerate( p_sys->p_twolame, p_enc->fmt_out.audio.i_rate );
 175     twolame_set_out_samplerate( p_sys->p_twolame, p_enc->fmt_out.audio.i_rate );
 176
 177     if( var_GetBool( p_enc, ENC_CFG_PREFIX "vbr" ) )
 178     {
 179         float f_quality = var_GetFloat( p_enc, ENC_CFG_PREFIX "quality" );
 180         if ( f_quality > 50.f ) f_quality = 50.f;
 181         if ( f_quality < 0.f ) f_quality = 0.f;
 182         twolame_set_VBR( p_sys->p_twolame, 1 );
 183         twolame_set_VBR_q( p_sys->p_twolame, f_quality );
 184     }
 185     else
 186     {
 187         int i;
 188         for ( i = 1; i < 14; i++ )
 189         {
 190             if ( p_enc->fmt_out.i_bitrate / 1000
 191                   <= mpa_bitrate_tab[i_frequency / 3][i] )
 192                 break;
 193         }
 194         if ( p_enc->fmt_out.i_bitrate / 1000
 195               != mpa_bitrate_tab[i_frequency / 3][i] )
 196         {
 197             msg_Warn( p_enc, "MPEG audio doesn't support bitrate=%d, using %d",
 198                       p_enc->fmt_out.i_bitrate,
 199                       mpa_bitrate_tab[i_frequency / 3][i] * 1000 );
 200             p_enc->fmt_out.i_bitrate = mpa_bitrate_tab[i_frequency / 3][i]
 201                                         * 1000;
 202         }
 203
 204         twolame_set_bitrate( p_sys->p_twolame,
 205                              p_enc->fmt_out.i_bitrate / 1000 );
 206     }
 207
 208     if ( p_enc->fmt_in.audio.i_channels == 1 )
 209     {
 210         twolame_set_num_channels( p_sys->p_twolame, 1 );
 211         twolame_set_mode( p_sys->p_twolame, TWOLAME_MONO );
 212     }
 213     else
 214     {
 215         twolame_set_num_channels( p_sys->p_twolame, 2 );
 216         switch( var_GetInteger( p_enc, ENC_CFG_PREFIX "mode" ) )
 217         {
 218         case 1:
 219             twolame_set_mode( p_sys->p_twolame, TWOLAME_DUAL_CHANNEL );
 220             break;
 221         case 2:
 222             twolame_set_mode( p_sys->p_twolame, TWOLAME_JOINT_STEREO );
 223             break;
 224         case 0:
 225         default:
 226             twolame_set_mode( p_sys->p_twolame, TWOLAME_STEREO );
 227             break;
 228         }
 229     }
 230
 231     twolame_set_psymodel( p_sys->p_twolame,
 232                           var_GetInteger( p_enc, ENC_CFG_PREFIX "psy" ) );
 233
 234     if ( twolame_init_params( p_sys->p_twolame ) )
 235     {
 236         msg_Err( p_enc, "twolame initialization failed" );
 237         return -VLC_EGENERIC;
 238     }
 239
 240     p_enc->pf_encode_audio = Encode;
 241
 242     p_sys->i_nb_samples = 0;
 243
 244     return VLC_SUCCESS;
 245 }
 246
 247 /****************************************************************************
 248  * Encode: the whole thing
 249  ****************************************************************************
 250  * This function spits out MPEG packets.
 251  ****************************************************************************/
 252 static void Bufferize( encoder_t *p_enc, int16_t *p_in, int i_nb_samples )
 253 {
 254     encoder_sys_t *p_sys = p_enc->p_sys;
 255     const unsigned i_offset = p_sys->i_nb_samples * p_enc->fmt_in.audio.i_channels;
 256     const unsigned i_len = ARRAY_SIZE(p_sys->p_buffer);
 257
 258     if( i_offset >= i_len )
 259     {
 260         msg_Err( p_enc, "buffer full" );
 261         return;
 262     }
 263
 264     unsigned i_copy = i_nb_samples * p_enc->fmt_in.audio.i_channels;
 265     if( i_copy + i_offset > i_len)
 266     {
 267         msg_Err( p_enc, "dropping samples" );
 268         i_copy = i_len - i_offset;
 269     }
 270
 271     memcpy( p_sys->p_buffer + i_offset, p_in, i_copy * sizeof(int16_t) );
 272 }
 273
 274 static block_t *Encode( encoder_t *p_enc, block_t *p_aout_buf )
 275 {
 276     encoder_sys_t *p_sys = p_enc->p_sys;
 277     block_t *p_chain = NULL;
 278
 279     if( unlikely( !p_aout_buf ) ) {
 280         int i_used = 0;
 281         block_t *p_block;
 282
 283         i_used = twolame_encode_flush( p_sys->p_twolame,
 284                                 p_sys->p_out_buffer, MAX_CODED_FRAME_SIZE );
 285         if( i_used <= 0 )
 286             return NULL;
 287
 288         p_block = block_Alloc( i_used );
 289         if( !p_block )
 290             return NULL;
 291         memcpy( p_block->p_buffer, p_sys->p_out_buffer, i_used );
 292         p_block->i_length = CLOCK_FREQ *
 293                 (mtime_t)MPEG_FRAME_SIZE / (mtime_t)p_enc->fmt_out.audio.i_rate;
 294         p_block->i_dts = p_block->i_pts = p_sys->i_pts;
 295         p_sys->i_pts += p_block->i_length;
 296
 297         return p_block;
 298     }
 299
 300     int16_t *p_buffer = (int16_t *)p_aout_buf->p_buffer;
 301     int i_nb_samples = p_aout_buf->i_nb_samples;
 302
 303     p_sys->i_pts = p_aout_buf->i_pts -
 304                 (mtime_t)1000000 * (mtime_t)p_sys->i_nb_samples /
 305                 (mtime_t)p_enc->fmt_out.audio.i_rate;
 306
 307     while ( p_sys->i_nb_samples + i_nb_samples >= MPEG_FRAME_SIZE )
 308     {
 309         int i_used;
 310         block_t *p_block;
 311
 312         Bufferize( p_enc, p_buffer, MPEG_FRAME_SIZE - p_sys->i_nb_samples );
 313         i_nb_samples -= MPEG_FRAME_SIZE - p_sys->i_nb_samples;
 314         p_buffer += (MPEG_FRAME_SIZE - p_sys->i_nb_samples) * 2;
 315
 316         i_used = twolame_encode_buffer_interleaved( p_sys->p_twolame,
 317                                p_sys->p_buffer, MPEG_FRAME_SIZE,
 318                                p_sys->p_out_buffer, MAX_CODED_FRAME_SIZE );
 319         /* On error, buffer samples and return what was already encoded */
 320         if( i_used < 0 )
 321         {
 322             msg_Err( p_enc, "encoder error: %d", i_used );
 323             break;
 324         }
 325
 326         p_sys->i_nb_samples = 0;
 327         p_block = block_Alloc( i_used );
 328         if( !p_block )
 329         {
 330             if( p_chain )
 331                 block_ChainRelease( p_chain );
 332             return NULL;
 333         }
 334         memcpy( p_block->p_buffer, p_sys->p_out_buffer, i_used );
 335         p_block->i_length = CLOCK_FREQ *
 336                 (mtime_t)MPEG_FRAME_SIZE / (mtime_t)p_enc->fmt_out.audio.i_rate;
 337         p_block->i_dts = p_block->i_pts = p_sys->i_pts;
 338         p_sys->i_pts += p_block->i_length;
 339         block_ChainAppend( &p_chain, p_block );
 340     }
 341
 342     if ( i_nb_samples )
 343     {
 344         Bufferize( p_enc, p_buffer, i_nb_samples );
 345         p_sys->i_nb_samples += i_nb_samples;
 346     }
 347
 348     return p_chain;
 349 }
 350
 351 /*****************************************************************************
 352  * CloseEncoder: twolame encoder destruction
 353  *****************************************************************************/
 354 static void CloseEncoder( vlc_object_t *p_this )
 355 {
 356     encoder_t *p_enc = (encoder_t *)p_this;
 357     encoder_sys_t *p_sys = p_enc->p_sys;
 358
 359     twolame_close( &p_sys->p_twolame );
 360
 361     free( p_sys );
 362 }