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, ENC_QUALITY_TEXT,
  83                ENC_QUALITY_LONGTEXT, false )
  84     add_integer( ENC_CFG_PREFIX "mode", 0, ENC_MODE_TEXT,
  85                  ENC_MODE_LONGTEXT, false )
  86         change_integer_list( pi_stereo_values, ppsz_stereo_descriptions );
  87     add_bool( ENC_CFG_PREFIX "vbr", false, ENC_VBR_TEXT,
  88               ENC_VBR_LONGTEXT, false )
  89     add_integer( ENC_CFG_PREFIX "psy", 3, 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     int i_frequency;
 133
 134     if( 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->fmt_out.i_codec != VLC_FOURCC('m','p','2',' ') &&
 137         !p_enc->b_force )
 138     {
 139         return VLC_EGENERIC;
 140     }
 141
 142     if( p_enc->fmt_in.audio.i_channels > 2 )
 143     {
 144         msg_Err( p_enc, "doesn't support > 2 channels" );
 145         return VLC_EGENERIC;
 146     }
 147
 148     for ( i_frequency = 0; i_frequency < 6; i_frequency++ )
 149     {
 150         if ( p_enc->fmt_out.audio.i_rate == mpa_freq_tab[i_frequency] )
 151             break;
 152     }
 153     if ( i_frequency == 6 )
 154     {
 155         msg_Err( p_enc, "MPEG audio doesn't support frequency=%d",
 156                  p_enc->fmt_out.audio.i_rate );
 157         return VLC_EGENERIC;
 158     }
 159
 160     /* Allocate the memory needed to store the decoder's structure */
 161     if( ( p_sys = (encoder_sys_t *)malloc(sizeof(encoder_sys_t)) ) == NULL )
 162         return VLC_ENOMEM;
 163     p_enc->p_sys = p_sys;
 164
 165     p_enc->pf_encode_audio = Encode;
 166     p_enc->fmt_in.i_codec = VLC_CODEC_S16N;
 167
 168     p_enc->fmt_out.i_cat = AUDIO_ES;
 169     p_enc->fmt_out.i_codec = VLC_CODEC_MPGA;
 170
 171     config_ChainParse( p_enc, ENC_CFG_PREFIX, ppsz_enc_options, p_enc->p_cfg );
 172
 173     p_sys->p_twolame = twolame_init();
 174
 175     /* Set options */
 176     twolame_set_in_samplerate( p_sys->p_twolame, p_enc->fmt_out.audio.i_rate );
 177     twolame_set_out_samplerate( p_sys->p_twolame, p_enc->fmt_out.audio.i_rate );
 178
 179     if( var_GetBool( p_enc, ENC_CFG_PREFIX "vbr" ) )
 180     {
 181         float f_quality = var_GetFloat( p_enc, ENC_CFG_PREFIX "quality" );
 182         if ( f_quality > 50.0 ) f_quality = 50.0;
 183         if ( f_quality < 0.0 ) f_quality = 0.0;
 184         twolame_set_VBR( p_sys->p_twolame, 1 );
 185         twolame_set_VBR_q( p_sys->p_twolame, f_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         switch( var_GetInteger( p_enc, ENC_CFG_PREFIX "mode" ) )
 219         {
 220         case 1:
 221             twolame_set_mode( p_sys->p_twolame, TWOLAME_DUAL_CHANNEL );
 222             break;
 223         case 2:
 224             twolame_set_mode( p_sys->p_twolame, TWOLAME_JOINT_STEREO );
 225             break;
 226         case 0:
 227         default:
 228             twolame_set_mode( p_sys->p_twolame, TWOLAME_STEREO );
 229             break;
 230         }
 231     }
 232
 233     twolame_set_psymodel( p_sys->p_twolame,
 234                           var_GetInteger( p_enc, ENC_CFG_PREFIX "psy" ) );
 235
 236     if ( twolame_init_params( p_sys->p_twolame ) )
 237     {
 238         msg_Err( p_enc, "twolame initialization failed" );
 239         return -VLC_EGENERIC;
 240     }
 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     int16_t *p_buffer = p_enc->p_sys->p_buffer
 255                          + (p_enc->p_sys->i_nb_samples
 256                              * p_enc->fmt_in.audio.i_channels);
 257
 258     memcpy( p_buffer, p_in, i_nb_samples * p_enc->fmt_in.audio.i_channels
 259                              * sizeof(int16_t) );
 260 }
 261
 262 static block_t *Encode( encoder_t *p_enc, aout_buffer_t *p_aout_buf )
 263 {
 264     encoder_sys_t *p_sys = p_enc->p_sys;
 265     int16_t *p_buffer = (int16_t *)p_aout_buf->p_buffer;
 266     int i_nb_samples = p_aout_buf->i_nb_samples;
 267     block_t *p_chain = NULL;
 268
 269     p_sys->i_pts = p_aout_buf->i_pts -
 270                 (mtime_t)1000000 * (mtime_t)p_sys->i_nb_samples /
 271                 (mtime_t)p_enc->fmt_out.audio.i_rate;
 272
 273     while ( p_sys->i_nb_samples + i_nb_samples >= MPEG_FRAME_SIZE )
 274     {
 275         int i_used;
 276         block_t *p_block;
 277
 278         Bufferize( p_enc, p_buffer, MPEG_FRAME_SIZE - p_sys->i_nb_samples );
 279         i_nb_samples -= MPEG_FRAME_SIZE - p_sys->i_nb_samples;
 280         p_buffer += (MPEG_FRAME_SIZE - p_sys->i_nb_samples) * 2;
 281
 282         i_used = twolame_encode_buffer_interleaved( p_sys->p_twolame,
 283                                p_sys->p_buffer, MPEG_FRAME_SIZE,
 284                                p_sys->p_out_buffer, MAX_CODED_FRAME_SIZE );
 285         p_sys->i_nb_samples = 0;
 286         p_block = block_New( p_enc, i_used );
 287         vlc_memcpy( p_block->p_buffer, p_sys->p_out_buffer, i_used );
 288         p_block->i_length = (mtime_t)1000000 *
 289                 (mtime_t)MPEG_FRAME_SIZE / (mtime_t)p_enc->fmt_out.audio.i_rate;
 290         p_block->i_dts = p_block->i_pts = p_sys->i_pts;
 291         p_sys->i_pts += p_block->i_length;
 292         block_ChainAppend( &p_chain, p_block );
 293     }
 294
 295     if ( i_nb_samples )
 296     {
 297         Bufferize( p_enc, p_buffer, i_nb_samples );
 298         p_sys->i_nb_samples += i_nb_samples;
 299     }
 300
 301     return p_chain;
 302 }
 303
 304 /*****************************************************************************
 305  * CloseEncoder: twolame encoder destruction
 306  *****************************************************************************/
 307 static void CloseEncoder( vlc_object_t *p_this )
 308 {
 309     encoder_t *p_enc = (encoder_t *)p_this;
 310     encoder_sys_t *p_sys = p_enc->p_sys;
 311
 312     twolame_close( &p_sys->p_twolame );
 313
 314     free( p_sys );
 315 }