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 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_codec.h>
  35 #include <vlc_sout.h>
  36 #include <vlc_aout.h>
  37
  38 #include <twolame.h>
  39
  40 #define MPEG_FRAME_SIZE 1152
  41 #define MAX_CODED_FRAME_SIZE 1792
  42
  43 /****************************************************************************
  44  * Local prototypes
  45  ****************************************************************************/
  46 static int OpenEncoder   ( vlc_object_t * );
  47 static void CloseEncoder ( vlc_object_t * );
  48 static block_t *Encode   ( encoder_t *, aout_buffer_t * );
  49
  50 /*****************************************************************************
  51  * Module descriptor
  52  *****************************************************************************/
  53 #define ENC_CFG_PREFIX "sout-twolame-"
  54
  55 #define ENC_QUALITY_TEXT N_("Encoding quality")
  56 #define ENC_QUALITY_LONGTEXT N_( \
  57   "Force a specific encoding quality between 0.0 (high) and 50.0 (low), " \
  58   "instead of specifying a particular bitrate. " \
  59   "This will produce a VBR stream." )
  60 #define ENC_MODE_TEXT N_("Stereo mode")
  61 #define ENC_MODE_LONGTEXT N_( "Handling mode for stereo streams" )
  62 #define ENC_VBR_TEXT N_("VBR mode")
  63 #define ENC_VBR_LONGTEXT N_( \
  64   "Use Variable BitRate. Default is to use Constant BitRate (CBR)." )
  65 #define ENC_PSY_TEXT N_("Psycho-acoustic model")
  66 #define ENC_PSY_LONGTEXT N_( \
  67   "Integer from -1 (no model) to 4." )
  68
  69 static const int pi_stereo_values[] = { 0, 1, 2 };
  70 static const char *const ppsz_stereo_descriptions[] =
  71 { N_("Stereo"), N_("Dual mono"), N_("Joint stereo") };
  72
  73
  74 vlc_module_begin ()
  75     set_shortname( "Twolame")
  76     set_description( N_("Libtwolame audio encoder") )
  77     set_capability( "encoder", 50 )
  78     set_callbacks( OpenEncoder, CloseEncoder )
  79     set_category( CAT_INPUT )
  80     set_subcategory( SUBCAT_INPUT_ACODEC )
  81
  82     add_float( ENC_CFG_PREFIX "quality", 0.0, NULL, ENC_QUALITY_TEXT,
  83                ENC_QUALITY_LONGTEXT, false );
  84     add_integer( ENC_CFG_PREFIX "mode", 0, NULL, ENC_MODE_TEXT,
  85                  ENC_MODE_LONGTEXT, false );
  86         change_integer_list( pi_stereo_values, ppsz_stereo_descriptions, NULL );
  87     add_bool( ENC_CFG_PREFIX "vbr", 0, NULL, ENC_VBR_TEXT,
  88               ENC_VBR_LONGTEXT, false );
  89     add_integer( ENC_CFG_PREFIX "psy", 3, NULL, ENC_PSY_TEXT,
  90                  ENC_PSY_LONGTEXT, false );
  91 vlc_module_end ()
  92
  93 static const char *const ppsz_enc_options[] = {
  94     "quality", "mode", "vbr", "psy", NULL
  95 };
  96
  97 /*****************************************************************************
  98  * encoder_sys_t : twolame encoder descriptor
  99  *****************************************************************************/
 100 struct encoder_sys_t
 101 {
 102     /*
 103      * Input properties
 104      */
 105     int16_t p_buffer[MPEG_FRAME_SIZE * 2];
 106     int i_nb_samples;
 107     mtime_t i_pts;
 108
 109     /*
 110      * libtwolame properties
 111      */
 112     twolame_options *p_twolame;
 113     unsigned char p_out_buffer[MAX_CODED_FRAME_SIZE];
 114 };
 115
 116 /*****************************************************************************
 117  * OpenEncoder: probe the encoder and return score
 118  *****************************************************************************/
 119 static const uint16_t mpa_bitrate_tab[2][15] =
 120 {
 121     {0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384},
 122     {0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160}
 123 };
 124
 125 static const uint16_t mpa_freq_tab[6] =
 126 { 44100, 48000, 32000, 22050, 24000, 16000 };
 127
 128 static int OpenEncoder( vlc_object_t *p_this )
 129 {
 130     encoder_t *p_enc = (encoder_t *)p_this;
 131     encoder_sys_t *p_sys;
 132     vlc_value_t val;
 133     int i_frequency;
 134
 135     if( p_enc->fmt_out.i_codec != VLC_FOURCC('m','p','g','a') &&
 136         p_enc->fmt_out.i_codec != VLC_FOURCC('m','p','2','a') &&
 137         p_enc->fmt_out.i_codec != VLC_FOURCC('m','p','2',' ') &&
 138         !p_enc->b_force )
 139     {
 140         return VLC_EGENERIC;
 141     }
 142
 143     if( p_enc->fmt_in.audio.i_channels > 2 )
 144     {
 145         msg_Err( p_enc, "doesn't support > 2 channels" );
 146         return VLC_EGENERIC;
 147     }
 148
 149     for ( i_frequency = 0; i_frequency < 6; i_frequency++ )
 150     {
 151         if ( p_enc->fmt_out.audio.i_rate == mpa_freq_tab[i_frequency] )
 152             break;
 153     }
 154     if ( i_frequency == 6 )
 155     {
 156         msg_Err( p_enc, "MPEG audio doesn't support frequency=%d",
 157                  p_enc->fmt_out.audio.i_rate );
 158         return VLC_EGENERIC;
 159     }
 160
 161     /* Allocate the memory needed to store the decoder's structure */
 162     if( ( p_sys = (encoder_sys_t *)malloc(sizeof(encoder_sys_t)) ) == NULL )
 163         return VLC_ENOMEM;
 164     p_enc->p_sys = p_sys;
 165
 166     p_enc->pf_encode_audio = Encode;
 167     p_enc->fmt_in.i_codec = AOUT_FMT_S16_NE;
 168     p_enc->fmt_out.i_codec = VLC_FOURCC('m','p','g','a');
 169
 170     config_ChainParse( p_enc, ENC_CFG_PREFIX, ppsz_enc_options, p_enc->p_cfg );
 171
 172     p_sys->p_twolame = twolame_init();
 173
 174     /* Set options */
 175     twolame_set_in_samplerate( p_sys->p_twolame, p_enc->fmt_out.audio.i_rate );
 176     twolame_set_out_samplerate( p_sys->p_twolame, p_enc->fmt_out.audio.i_rate );
 177
 178     var_Get( p_enc, ENC_CFG_PREFIX "vbr", &val );
 179     if ( val.b_bool )
 180     {
 181         float i_quality;
 182         var_Get( p_enc, ENC_CFG_PREFIX "quality", &val );
 183         i_quality = val.i_int;
 184         if ( i_quality > 50.0 ) i_quality = 50.0;
 185         if ( i_quality < 0.0 ) i_quality = 0.0;
 186         twolame_set_VBR( p_sys->p_twolame, 1 );
 187         twolame_set_VBR_q( p_sys->p_twolame, i_quality );
 188     }
 189     else
 190     {
 191         int i;
 192         for ( i = 1; i < 14; i++ )
 193         {
 194             if ( p_enc->fmt_out.i_bitrate / 1000
 195                   <= mpa_bitrate_tab[i_frequency / 3][i] )
 196                 break;
 197         }
 198         if ( p_enc->fmt_out.i_bitrate / 1000
 199               != mpa_bitrate_tab[i_frequency / 3][i] )
 200         {
 201             msg_Warn( p_enc, "MPEG audio doesn't support bitrate=%d, using %d",
 202                       p_enc->fmt_out.i_bitrate,
 203                       mpa_bitrate_tab[i_frequency / 3][i] * 1000 );
 204             p_enc->fmt_out.i_bitrate = mpa_bitrate_tab[i_frequency / 3][i]
 205                                         * 1000;
 206         }
 207
 208         twolame_set_bitrate( p_sys->p_twolame,
 209                              p_enc->fmt_out.i_bitrate / 1000 );
 210     }
 211
 212     if ( p_enc->fmt_in.audio.i_channels == 1 )
 213     {
 214         twolame_set_num_channels( p_sys->p_twolame, 1 );
 215         twolame_set_mode( p_sys->p_twolame, TWOLAME_MONO );
 216     }
 217     else
 218     {
 219         twolame_set_num_channels( p_sys->p_twolame, 2 );
 220         var_Get( p_enc, ENC_CFG_PREFIX "mode", &val );
 221         switch ( val.i_int )
 222         {
 223         case 1:
 224             twolame_set_mode( p_sys->p_twolame, TWOLAME_DUAL_CHANNEL );
 225             break;
 226         case 2:
 227             twolame_set_mode( p_sys->p_twolame, TWOLAME_JOINT_STEREO );
 228             break;
 229         case 0:
 230         default:
 231             twolame_set_mode( p_sys->p_twolame, TWOLAME_STEREO );
 232             break;
 233         }
 234     }
 235
 236     var_Get( p_enc, ENC_CFG_PREFIX "psy", &val );
 237     twolame_set_psymodel( p_sys->p_twolame, val.i_int );
 238
 239     if ( twolame_init_params( p_sys->p_twolame ) )
 240     {
 241         msg_Err( p_enc, "twolame initialization failed" );
 242         return -VLC_EGENERIC;
 243     }
 244
 245     p_sys->i_nb_samples = 0;
 246
 247     return VLC_SUCCESS;
 248 }
 249
 250 /****************************************************************************
 251  * Encode: the whole thing
 252  ****************************************************************************
 253  * This function spits out MPEG packets.
 254  ****************************************************************************/
 255 static void Bufferize( encoder_t *p_enc, int16_t *p_in, int i_nb_samples )
 256 {
 257     int16_t *p_buffer = p_enc->p_sys->p_buffer
 258                          + (p_enc->p_sys->i_nb_samples
 259                              * p_enc->fmt_in.audio.i_channels);
 260
 261     memcpy( p_buffer, p_in, i_nb_samples * p_enc->fmt_in.audio.i_channels
 262                              * sizeof(int16_t) );
 263 }
 264
 265 static block_t *Encode( encoder_t *p_enc, aout_buffer_t *p_aout_buf )
 266 {
 267     encoder_sys_t *p_sys = p_enc->p_sys;
 268     int16_t *p_buffer = (int16_t *)p_aout_buf->p_buffer;
 269     int i_nb_samples = p_aout_buf->i_nb_samples;
 270     block_t *p_chain = NULL;
 271
 272     p_sys->i_pts = p_aout_buf->start_date -
 273                 (mtime_t)1000000 * (mtime_t)p_sys->i_nb_samples /
 274                 (mtime_t)p_enc->fmt_out.audio.i_rate;
 275
 276     while ( p_sys->i_nb_samples + i_nb_samples >= MPEG_FRAME_SIZE )
 277     {
 278         int i_used;
 279         block_t *p_block;
 280
 281         Bufferize( p_enc, p_buffer, MPEG_FRAME_SIZE - p_sys->i_nb_samples );
 282         i_nb_samples -= MPEG_FRAME_SIZE - p_sys->i_nb_samples;
 283         p_buffer += (MPEG_FRAME_SIZE - p_sys->i_nb_samples) * 2;
 284
 285         i_used = twolame_encode_buffer_interleaved( p_sys->p_twolame,
 286                                p_sys->p_buffer, MPEG_FRAME_SIZE,
 287                                p_sys->p_out_buffer, MAX_CODED_FRAME_SIZE );
 288         p_sys->i_nb_samples = 0;
 289         p_block = block_New( p_enc, i_used );
 290         vlc_memcpy( p_block->p_buffer, p_sys->p_out_buffer, i_used );
 291         p_block->i_length = (mtime_t)1000000 *
 292                 (mtime_t)MPEG_FRAME_SIZE / (mtime_t)p_enc->fmt_out.audio.i_rate;
 293         p_block->i_dts = p_block->i_pts = p_sys->i_pts;
 294         p_sys->i_pts += p_block->i_length;
 295         block_ChainAppend( &p_chain, p_block );
 296     }
 297
 298     if ( i_nb_samples )
 299     {
 300         Bufferize( p_enc, p_buffer, i_nb_samples );
 301         p_sys->i_nb_samples += i_nb_samples;
 302     }
 303
 304     return p_chain;
 305 }
 306
 307 /*****************************************************************************
 308  * CloseEncoder: twolame encoder destruction
 309  *****************************************************************************/
 310 static void CloseEncoder( vlc_object_t *p_this )
 311 {
 312     encoder_t *p_enc = (encoder_t *)p_this;
 313     encoder_sys_t *p_sys = p_enc->p_sys;
 314
 315     twolame_close( &p_sys->p_twolame );
 316
 317     free( p_sys );
 318 }