modules/codec/twolame.c

   1 /*****************************************************************************
   2  * twolame.c: libtwolame encoder (MPEG-1/2 layer II) module
   3  *            (using libtwolame from http://users.tpg.com.au/adslblvi/)
   4  *****************************************************************************
   5  * Copyright (C) 2004-2005 the VideoLAN team
   6  * $Id$
   7  *
   8  * Authors: Christophe Massiot <massiot@via.ecp.fr>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28 #include <vlc/vlc.h>
  29 #include <vlc_codec.h>
  30 #include <vlc_sout.h>
  31 #include <vlc_aout.h>
  32
  33 #include <twolame.h>
  34
  35 #define MPEG_FRAME_SIZE 1152
  36 #define MAX_CODED_FRAME_SIZE 1792
  37
  38 /****************************************************************************
  39  * Local prototypes
  40  ****************************************************************************/
  41 static int OpenEncoder   ( vlc_object_t * );
  42 static void CloseEncoder ( vlc_object_t * );
  43 static block_t *Encode   ( encoder_t *, aout_buffer_t * );
  44
  45 /*****************************************************************************
  46  * Module descriptor
  47  *****************************************************************************/
  48 #define ENC_CFG_PREFIX "sout-twolame-"
  49
  50 #define ENC_QUALITY_TEXT N_("Encoding quality")
  51 #define ENC_QUALITY_LONGTEXT N_( \
  52   "Force a specific encoding quality between 0.0 (high) and 50.0 (low), " \
  53   "instead of specifying a particular bitrate. " \
  54   "This will produce a VBR stream." )
  55 #define ENC_MODE_TEXT N_("Stereo mode")
  56 #define ENC_MODE_LONGTEXT N_( "Handling mode for stereo streams" )
  57 #define ENC_VBR_TEXT N_("VBR mode")
  58 #define ENC_VBR_LONGTEXT N_( \
  59   "Use Variable BitRate. Default is to use Constant BitRate (CBR)." )
  60 #define ENC_PSY_TEXT N_("Psycho-acoustic model")
  61 #define ENC_PSY_LONGTEXT N_( \
  62   "Integer from -1 (no model) to 4." )
  63
  64 static int pi_stereo_values[] = { 0, 1, 2 };
  65 static char *ppsz_stereo_descriptions[] =
  66 { N_("Stereo"), N_("Dual mono"), N_("Joint stereo") };
  67
  68
  69 vlc_module_begin();
  70     set_shortname( "Twolame");
  71     set_description( _("Libtwolame audio encoder") );
  72     set_capability( "encoder", 50 );
  73     set_callbacks( OpenEncoder, CloseEncoder );
  74     set_category( CAT_INPUT );
  75     set_subcategory( SUBCAT_INPUT_ACODEC );
  76
  77     add_float( ENC_CFG_PREFIX "quality", 0.0, NULL, ENC_QUALITY_TEXT,
  78                ENC_QUALITY_LONGTEXT, VLC_FALSE );
  79     add_integer( ENC_CFG_PREFIX "mode", 0, NULL, ENC_MODE_TEXT,
  80                  ENC_MODE_LONGTEXT, VLC_FALSE );
  81         change_integer_list( pi_stereo_values, ppsz_stereo_descriptions, 0 );
  82     add_bool( ENC_CFG_PREFIX "vbr", 0, NULL, ENC_VBR_TEXT,
  83               ENC_VBR_LONGTEXT, VLC_FALSE );
  84     add_integer( ENC_CFG_PREFIX "psy", 3, NULL, ENC_PSY_TEXT,
  85                  ENC_PSY_LONGTEXT, VLC_FALSE );
  86 vlc_module_end();
  87
  88 static const char *ppsz_enc_options[] = {
  89     "quality", "mode", "vbr", "psy", NULL
  90 };
  91
  92 /*****************************************************************************
  93  * encoder_sys_t : twolame encoder descriptor
  94  *****************************************************************************/
  95 struct encoder_sys_t
  96 {
  97     /*
  98      * Input properties
  99      */
 100     int16_t p_buffer[MPEG_FRAME_SIZE * 2];
 101     int i_nb_samples;
 102     mtime_t i_pts;
 103
 104     /*
 105      * libtwolame properties
 106      */
 107     twolame_options *p_twolame;
 108     unsigned char p_out_buffer[MAX_CODED_FRAME_SIZE];
 109 };
 110
 111 /*****************************************************************************
 112  * OpenEncoder: probe the encoder and return score
 113  *****************************************************************************/
 114 static const uint16_t mpa_bitrate_tab[2][15] =
 115 {
 116     {0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384},
 117     {0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160}
 118 };
 119
 120 static const uint16_t mpa_freq_tab[6] =
 121 { 44100, 48000, 32000, 22050, 24000, 16000 };
 122
 123 static int OpenEncoder( vlc_object_t *p_this )
 124 {
 125     encoder_t *p_enc = (encoder_t *)p_this;
 126     encoder_sys_t *p_sys;
 127     vlc_value_t val;
 128     int i_frequency;
 129
 130     if( p_enc->fmt_out.i_codec != VLC_FOURCC('m','p','g','a') &&
 131         p_enc->fmt_out.i_codec != VLC_FOURCC('m','p','2','a') &&
 132         p_enc->fmt_out.i_codec != VLC_FOURCC('m','p','2',' ') &&
 133         !p_enc->b_force )
 134     {
 135         return VLC_EGENERIC;
 136     }
 137
 138     if( p_enc->fmt_in.audio.i_channels > 2 )
 139     {
 140         msg_Err( p_enc, "doesn't support > 2 channels" );
 141         return VLC_EGENERIC;
 142     }
 143
 144     for ( i_frequency = 0; i_frequency < 6; i_frequency++ )
 145     {
 146         if ( p_enc->fmt_out.audio.i_rate == mpa_freq_tab[i_frequency] )
 147             break;
 148     }
 149     if ( i_frequency == 6 )
 150     {
 151         msg_Err( p_enc, "MPEG audio doesn't support frequency=%d",
 152                  p_enc->fmt_out.audio.i_rate );
 153         return VLC_EGENERIC;
 154     }
 155
 156     /* Allocate the memory needed to store the decoder's structure */
 157     if( ( p_sys = (encoder_sys_t *)malloc(sizeof(encoder_sys_t)) ) == NULL )
 158     {
 159         msg_Err( p_enc, "out of memory" );
 160         return VLC_EGENERIC;
 161     }
 162     p_enc->p_sys = p_sys;
 163
 164     p_enc->pf_encode_audio = Encode;
 165     p_enc->fmt_in.i_codec = AOUT_FMT_S16_NE;
 166     p_enc->fmt_out.i_codec = VLC_FOURCC('m','p','g','a');
 167
 168     config_ChainParse( p_enc, ENC_CFG_PREFIX, ppsz_enc_options, p_enc->p_cfg );
 169
 170     p_sys->p_twolame = twolame_init();
 171
 172     /* Set options */
 173     twolame_set_in_samplerate( p_sys->p_twolame, p_enc->fmt_out.audio.i_rate );
 174     twolame_set_out_samplerate( p_sys->p_twolame, p_enc->fmt_out.audio.i_rate );
 175
 176     var_Get( p_enc, ENC_CFG_PREFIX "vbr", &val );
 177     if ( val.b_bool )
 178     {
 179         float i_quality;
 180         var_Get( p_enc, ENC_CFG_PREFIX "quality", &val );
 181         i_quality = val.i_int;
 182         if ( i_quality > 50.0 ) i_quality = 50.0;
 183         if ( i_quality < 0.0 ) i_quality = 0.0;
 184         twolame_set_VBR( p_sys->p_twolame, 1 );
 185         twolame_set_VBR_q( p_sys->p_twolame, i_quality );
 186     }
 187     else
 188     {
 189         int i;
 190         for ( i = 1; i < 14; i++ )
 191         {
 192             if ( p_enc->fmt_out.i_bitrate / 1000
 193                   <= mpa_bitrate_tab[i_frequency / 3][i] )
 194                 break;
 195         }
 196         if ( p_enc->fmt_out.i_bitrate / 1000
 197               != mpa_bitrate_tab[i_frequency / 3][i] )
 198         {
 199             msg_Warn( p_enc, "MPEG audio doesn't support bitrate=%d, using %d",
 200                       p_enc->fmt_out.i_bitrate,
 201                       mpa_bitrate_tab[i_frequency / 3][i] * 1000 );
 202             p_enc->fmt_out.i_bitrate = mpa_bitrate_tab[i_frequency / 3][i]
 203                                         * 1000;
 204         }
 205
 206         twolame_set_bitrate( p_sys->p_twolame,
 207                              p_enc->fmt_out.i_bitrate / 1000 );
 208     }
 209
 210     if ( p_enc->fmt_in.audio.i_channels == 1 )
 211     {
 212         twolame_set_num_channels( p_sys->p_twolame, 1 );
 213         twolame_set_mode( p_sys->p_twolame, TWOLAME_MONO );
 214     }
 215     else
 216     {
 217         twolame_set_num_channels( p_sys->p_twolame, 2 );
 218         var_Get( p_enc, ENC_CFG_PREFIX "mode", &val );
 219         switch ( val.i_int )
 220         {
 221         case 1:
 222             twolame_set_mode( p_sys->p_twolame, TWOLAME_DUAL_CHANNEL );
 223             break;
 224         case 2:
 225             twolame_set_mode( p_sys->p_twolame, TWOLAME_JOINT_STEREO );
 226             break;
 227         case 0:
 228         default:
 229             twolame_set_mode( p_sys->p_twolame, TWOLAME_STEREO );
 230             break;
 231         }
 232     }
 233
 234     var_Get( p_enc, ENC_CFG_PREFIX "psy", &val );
 235     twolame_set_psymodel( p_sys->p_twolame, val.i_int );
 236
 237     if ( twolame_init_params( p_sys->p_twolame ) )
 238     {
 239         msg_Err( p_enc, "twolame initialization failed" );
 240         return -VLC_EGENERIC;
 241     }
 242
 243     p_sys->i_nb_samples = 0;
 244
 245     return VLC_SUCCESS;
 246 }
 247
 248 /****************************************************************************
 249  * Encode: the whole thing
 250  ****************************************************************************
 251  * This function spits out MPEG packets.
 252  ****************************************************************************/
 253 static void Bufferize( encoder_t *p_enc, int16_t *p_in, int i_nb_samples )
 254 {
 255     int16_t *p_buffer = p_enc->p_sys->p_buffer
 256                          + (p_enc->p_sys->i_nb_samples
 257                              * p_enc->fmt_in.audio.i_channels);
 258
 259     memcpy( p_buffer, p_in, i_nb_samples * p_enc->fmt_in.audio.i_channels
 260                              * sizeof(int16_t) );
 261 }
 262
 263 static block_t *Encode( encoder_t *p_enc, aout_buffer_t *p_aout_buf )
 264 {
 265     encoder_sys_t *p_sys = p_enc->p_sys;
 266     int16_t *p_buffer = (int16_t *)p_aout_buf->p_buffer;
 267     int i_nb_samples = p_aout_buf->i_nb_samples;
 268     block_t *p_chain = NULL;
 269
 270     p_sys->i_pts = p_aout_buf->start_date -
 271                 (mtime_t)1000000 * (mtime_t)p_sys->i_nb_samples /
 272                 (mtime_t)p_enc->fmt_out.audio.i_rate;
 273
 274     while ( p_sys->i_nb_samples + i_nb_samples >= MPEG_FRAME_SIZE )
 275     {
 276         int i_used;
 277         block_t *p_block;
 278
 279         Bufferize( p_enc, p_buffer, MPEG_FRAME_SIZE - p_sys->i_nb_samples );
 280         i_nb_samples -= MPEG_FRAME_SIZE - p_sys->i_nb_samples;
 281         p_buffer += (MPEG_FRAME_SIZE - p_sys->i_nb_samples) * 2;
 282
 283         i_used = twolame_encode_buffer_interleaved( p_sys->p_twolame,
 284                                p_sys->p_buffer, MPEG_FRAME_SIZE,
 285                                p_sys->p_out_buffer, MAX_CODED_FRAME_SIZE );
 286         p_sys->i_nb_samples = 0;
 287         p_block = block_New( p_enc, i_used );
 288         p_enc->p_libvlc->pf_memcpy( p_block->p_buffer, p_sys->p_out_buffer,
 289                                  i_used );
 290         p_block->i_length = (mtime_t)1000000 *
 291                 (mtime_t)MPEG_FRAME_SIZE / (mtime_t)p_enc->fmt_out.audio.i_rate;
 292         p_block->i_dts = p_block->i_pts = p_sys->i_pts;
 293         p_sys->i_pts += p_block->i_length;
 294         block_ChainAppend( &p_chain, p_block );
 295     }
 296
 297     if ( i_nb_samples )
 298     {
 299         Bufferize( p_enc, p_buffer, i_nb_samples );
 300         p_sys->i_nb_samples += i_nb_samples;
 301     }
 302
 303     return p_chain;
 304 }
 305
 306 /*****************************************************************************
 307  * CloseEncoder: twolame encoder destruction
 308  *****************************************************************************/
 309 static void CloseEncoder( vlc_object_t *p_this )
 310 {
 311     encoder_t *p_enc = (encoder_t *)p_this;
 312     encoder_sys_t *p_sys = p_enc->p_sys;
 313
 314     twolame_close( &p_sys->p_twolame );
 315
 316     free( p_sys );
 317 }