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->b_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->pf_encode_audio = Encode;
 165     p_enc->fmt_in.i_codec = VLC_CODEC_S16N;
 166
 167     p_enc->fmt_out.i_cat = AUDIO_ES;
 168     p_enc->fmt_out.i_codec = VLC_CODEC_MPGA;
 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     if( var_GetBool( p_enc, ENC_CFG_PREFIX "vbr" ) )
 179     {
 180         float f_quality = var_GetFloat( p_enc, ENC_CFG_PREFIX "quality" );
 181         if ( f_quality > 50.0 ) f_quality = 50.0;
 182         if ( f_quality < 0.0 ) f_quality = 0.0;
 183         twolame_set_VBR( p_sys->p_twolame, 1 );
 184         twolame_set_VBR_q( p_sys->p_twolame, f_quality );
 185     }
 186     else
 187     {
 188         int i;
 189         for ( i = 1; i < 14; i++ )
 190         {
 191             if ( p_enc->fmt_out.i_bitrate / 1000
 192                   <= mpa_bitrate_tab[i_frequency / 3][i] )
 193                 break;
 194         }
 195         if ( p_enc->fmt_out.i_bitrate / 1000
 196               != mpa_bitrate_tab[i_frequency / 3][i] )
 197         {
 198             msg_Warn( p_enc, "MPEG audio doesn't support bitrate=%d, using %d",
 199                       p_enc->fmt_out.i_bitrate,
 200                       mpa_bitrate_tab[i_frequency / 3][i] * 1000 );
 201             p_enc->fmt_out.i_bitrate = mpa_bitrate_tab[i_frequency / 3][i]
 202                                         * 1000;
 203         }
 204
 205         twolame_set_bitrate( p_sys->p_twolame,
 206                              p_enc->fmt_out.i_bitrate / 1000 );
 207     }
 208
 209     if ( p_enc->fmt_in.audio.i_channels == 1 )
 210     {
 211         twolame_set_num_channels( p_sys->p_twolame, 1 );
 212         twolame_set_mode( p_sys->p_twolame, TWOLAME_MONO );
 213     }
 214     else
 215     {
 216         twolame_set_num_channels( p_sys->p_twolame, 2 );
 217         switch( var_GetInteger( p_enc, ENC_CFG_PREFIX "mode" ) )
 218         {
 219         case 1:
 220             twolame_set_mode( p_sys->p_twolame, TWOLAME_DUAL_CHANNEL );
 221             break;
 222         case 2:
 223             twolame_set_mode( p_sys->p_twolame, TWOLAME_JOINT_STEREO );
 224             break;
 225         case 0:
 226         default:
 227             twolame_set_mode( p_sys->p_twolame, TWOLAME_STEREO );
 228             break;
 229         }
 230     }
 231
 232     twolame_set_psymodel( p_sys->p_twolame,
 233                           var_GetInteger( p_enc, ENC_CFG_PREFIX "psy" ) );
 234
 235     if ( twolame_init_params( p_sys->p_twolame ) )
 236     {
 237         msg_Err( p_enc, "twolame initialization failed" );
 238         return -VLC_EGENERIC;
 239     }
 240
 241     p_sys->i_nb_samples = 0;
 242
 243     return VLC_SUCCESS;
 244 }
 245
 246 /****************************************************************************
 247  * Encode: the whole thing
 248  ****************************************************************************
 249  * This function spits out MPEG packets.
 250  ****************************************************************************/
 251 static void Bufferize( encoder_t *p_enc, int16_t *p_in, int i_nb_samples )
 252 {
 253     int16_t *p_buffer = p_enc->p_sys->p_buffer
 254                          + (p_enc->p_sys->i_nb_samples
 255                              * p_enc->fmt_in.audio.i_channels);
 256
 257     memcpy( p_buffer, p_in, i_nb_samples * p_enc->fmt_in.audio.i_channels
 258                              * sizeof(int16_t) );
 259 }
 260
 261 static block_t *Encode( encoder_t *p_enc, block_t *p_aout_buf )
 262 {
 263     encoder_sys_t *p_sys = p_enc->p_sys;
 264
 265     /* FIXME:p_aout_buf is NULL when it's time to flush, does twolame has buffer to flush?*/
 266     if( unlikely( !p_aout_buf ) ) return NULL;
 267
 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->i_pts -
 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_Alloc( i_used );
 290         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 }