modules/codec/mpg123.c

   1 /*****************************************************************************
   2  * mpg123.c: MPEG-1 & 2 audio layer I, II, III + MPEG 2.5 decoder
   3  *****************************************************************************
   4  * Copyright (C) 2001-2014 VLC authors and VideoLAN
   5  *
   6  * Authors: Ludovic Fauvet <etix@videolan.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License as published by
  10  * the Free Software Foundation; either version 2.1 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this program; if not, write to the Free Software Foundation,
  20  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  21  *****************************************************************************/
  22
  23 /*****************************************************************************
  24 * Preamble
  25 *****************************************************************************/
  26
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <mpg123.h>
  32
  33 #include <vlc_common.h>
  34 #include <vlc_plugin.h>
  35 #include <vlc_aout.h>
  36 #include <vlc_block.h>
  37 #include <vlc_codec.h>
  38
  39 /*****************************************************************************
  40  * Local prototypes
  41  *****************************************************************************/
  42 static int      OpenDecoder( vlc_object_t * );
  43 static void     CloseDecoder( vlc_object_t * );
  44 static block_t *DecodeBlock( decoder_t *, block_t ** );
  45 static void     Flush( decoder_t * );
  46 static int      InitMPG123( void );
  47 static void     ExitMPG123( void );
  48
  49 static unsigned int mpg123_refcount = 0;
  50 static vlc_mutex_t mpg123_mutex = VLC_STATIC_MUTEX;
  51
  52 /*****************************************************************************
  53  * Local structures
  54  *****************************************************************************/
  55 struct decoder_sys_t
  56 {
  57     mpg123_handle * p_handle;
  58     date_t          end_date;
  59
  60     struct mpg123_frameinfo frame_info;
  61 };
  62
  63 /*****************************************************************************
  64  * Module descriptor
  65  *****************************************************************************/
  66 vlc_module_begin ()
  67     set_category( CAT_INPUT )
  68     set_subcategory( SUBCAT_INPUT_ACODEC )
  69     set_description( N_("MPEG audio decoder using mpg123") )
  70     set_capability( "decoder", 99 )
  71     set_shortname( "mpg123" )
  72     set_callbacks( OpenDecoder, CloseDecoder )
  73 vlc_module_end ()
  74
  75 /*****************************************************************************
  76  * Flush:
  77  *****************************************************************************/
  78 static void Flush( decoder_t *p_dec )
  79 {
  80     decoder_sys_t *p_sys = p_dec->p_sys;
  81
  82     date_Set( &p_sys->end_date, 0 );
  83 }
  84
  85 /****************************************************************************
  86  * DecodeBlock: the whole thing
  87  ****************************************************************************/
  88 static block_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
  89 {
  90     int i_err;
  91     decoder_sys_t *p_sys = p_dec->p_sys;
  92
  93     if( !pp_block || !*pp_block )
  94         return NULL;
  95     block_t *p_block = *pp_block;
  96
  97     if( p_block->i_buffer == 0 )
  98         return NULL;
  99
 100     if( !date_Get( &p_sys->end_date ) && p_block->i_pts <= VLC_TS_INVALID )
 101     {
 102         /* We've just started the stream, wait for the first PTS. */
 103         msg_Dbg( p_dec, "waiting for PTS" );
 104         goto error;
 105     }
 106
 107     if( p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY | BLOCK_FLAG_CORRUPTED) )
 108     {
 109         Flush( p_dec );
 110         if( p_block->i_flags & BLOCK_FLAG_CORRUPTED )
 111             goto error;
 112     }
 113
 114     /* Feed mpg123 with raw data */
 115     i_err = mpg123_feed( p_sys->p_handle, p_block->p_buffer,
 116                          p_block->i_buffer );
 117
 118     if( i_err != MPG123_OK )
 119     {
 120         msg_Err( p_dec, "mpg123_feed failed: %s", mpg123_plain_strerror( i_err ) );
 121         goto error;
 122     }
 123
 124     /* Get details about the stream */
 125     i_err = mpg123_info( p_sys->p_handle, &p_sys->frame_info );
 126
 127     if( i_err == MPG123_NEED_MORE )
 128     {
 129         /* Need moar data */
 130         goto error;
 131     }
 132     else if( i_err != MPG123_OK )
 133     {
 134         msg_Err( p_dec, "mpg123_info failed: %s", mpg123_plain_strerror( i_err ) );
 135         goto error;
 136     }
 137
 138     /* Configure the output */
 139     p_block->i_nb_samples = mpg123_spf( p_sys->p_handle );
 140     p_dec->fmt_out.i_bitrate = p_sys->frame_info.bitrate * 1000;
 141
 142     switch( p_sys->frame_info.mode )
 143     {
 144         case MPG123_M_STEREO:
 145         case MPG123_M_JOINT:
 146             p_dec->fmt_out.audio.i_original_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
 147             break;
 148         case MPG123_M_DUAL:
 149             p_dec->fmt_out.audio.i_original_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
 150                                                      | AOUT_CHAN_DUALMONO;
 151             break;
 152         case MPG123_M_MONO:
 153             p_dec->fmt_out.audio.i_original_channels = AOUT_CHAN_CENTER;
 154             break;
 155         default:
 156             msg_Err( p_dec, "Unknown mode");
 157             goto error;
 158     }
 159
 160     p_dec->fmt_out.audio.i_physical_channels =
 161         p_dec->fmt_out.audio.i_original_channels & AOUT_CHAN_PHYSMASK;
 162
 163     /* Date management */
 164     if( p_dec->fmt_out.audio.i_rate != p_sys->frame_info.rate )
 165     {
 166         p_dec->fmt_out.audio.i_rate = p_sys->frame_info.rate;
 167         date_Init( &p_sys->end_date, p_dec->fmt_out.audio.i_rate, 1 );
 168         date_Set( &p_sys->end_date, 0 );
 169     }
 170
 171     if( p_block->i_pts > VLC_TS_INVALID &&
 172         p_block->i_pts != date_Get( &p_sys->end_date ) )
 173     {
 174         date_Set( &p_sys->end_date, p_block->i_pts );
 175     }
 176
 177     /* Request a new audio buffer */
 178     block_t *p_out = decoder_NewAudioBuffer( p_dec, p_block->i_nb_samples );
 179     if( unlikely( !p_out ) )
 180         goto error;
 181
 182     /* Configure the buffer */
 183     p_out->i_nb_samples = p_block->i_nb_samples;
 184     p_out->i_dts = p_out->i_pts = date_Get( &p_sys->end_date );
 185     p_out->i_length = date_Increment( &p_sys->end_date, p_block->i_nb_samples )
 186         - p_out->i_pts;
 187
 188     /* Make mpg123 write directly into the VLC output buffer */
 189     i_err = mpg123_replace_buffer( p_sys->p_handle, p_out->p_buffer, p_out->i_buffer );
 190     if( i_err != MPG123_OK )
 191     {
 192         msg_Err( p_dec, "could not replace buffer: %s", mpg123_plain_strerror( i_err ) );
 193         block_Release( p_out );
 194         goto error;
 195     }
 196
 197     *pp_block = NULL; /* avoid being fed the same packet again */
 198
 199     /* Do the actual decoding now */
 200     i_err = mpg123_decode_frame( p_sys->p_handle, NULL, NULL, NULL );
 201     if( i_err != MPG123_OK )
 202     {
 203         if( i_err == MPG123_NEED_MORE )
 204             msg_Dbg( p_dec, "mpg123_decode_frame: %s", mpg123_plain_strerror( i_err ) );
 205         else if( i_err != MPG123_NEW_FORMAT )
 206             msg_Err( p_dec, "mpg123_decode_frame error: %s", mpg123_plain_strerror( i_err ) );
 207         block_Release( p_out );
 208         goto error;
 209     }
 210
 211     block_Release( p_block );
 212     return p_out;
 213
 214 error:
 215     block_Release( p_block );
 216     return NULL;
 217 }
 218
 219 /*****************************************************************************
 220  * OpenDecoder :
 221  *****************************************************************************/
 222 static int OpenDecoder( vlc_object_t *p_this )
 223 {
 224     decoder_t *p_dec = (decoder_t *)p_this;
 225     decoder_sys_t *p_sys;
 226
 227     if( p_dec->fmt_in.i_codec != VLC_CODEC_MPGA &&
 228         p_dec->fmt_in.i_codec != VLC_CODEC_MP3 )
 229         return VLC_EGENERIC;
 230
 231     p_dec->fmt_out.i_cat = AUDIO_ES;
 232     p_dec->fmt_out.i_codec = VLC_CODEC_FL32;
 233
 234     /* Initialize libmpg123 */
 235     if( InitMPG123() != MPG123_OK )
 236         return VLC_EGENERIC;
 237
 238     /* Allocate the memory needed to store the module's structure */
 239     p_sys = p_dec->p_sys = malloc( sizeof(decoder_sys_t) );
 240     if( p_sys == NULL )
 241         return VLC_ENOMEM;
 242
 243     /* Create our mpg123 handle */
 244     if( ( p_sys->p_handle = mpg123_new( NULL, NULL ) ) == NULL )
 245         goto error;
 246
 247     /* Open a new bitstream */
 248     if( mpg123_open_feed( p_sys->p_handle ) != MPG123_OK )
 249     {
 250         msg_Err( p_this, "mpg123 error: can't open feed" );
 251         goto error;
 252     }
 253
 254     /* Disable resync stream after error */
 255     mpg123_param( p_sys->p_handle, MPG123_ADD_FLAGS, MPG123_NO_RESYNC, 0 );
 256
 257     /* Setup output format */
 258     mpg123_format_none( p_sys->p_handle );
 259
 260     if( MPG123_OK != mpg123_format( p_sys->p_handle,
 261                                     p_dec->fmt_in.audio.i_rate,
 262                                     MPG123_MONO | MPG123_STEREO,
 263                                     MPG123_ENC_FLOAT_32 ) )
 264     {
 265         msg_Err( p_this, "mpg123 error: %s",
 266                 mpg123_strerror( p_sys->p_handle ) );
 267         mpg123_close( p_sys->p_handle );
 268         goto error;
 269     }
 270
 271     p_dec->fmt_out.audio.i_rate = 0; /* So end_date gets initialized */
 272     p_dec->fmt_out.audio.i_format = p_dec->fmt_out.i_codec;
 273     p_dec->pf_decode_audio = DecodeBlock;
 274     p_dec->pf_flush        = Flush;
 275
 276     msg_Dbg( p_this, "%4.4s->%4.4s, bits per sample: %i",
 277              (char *)&p_dec->fmt_in.i_codec,
 278              (char *)&p_dec->fmt_out.i_codec,
 279              aout_BitsPerSample( p_dec->fmt_out.i_codec ) );
 280
 281     return VLC_SUCCESS;
 282 error:
 283     mpg123_delete( p_sys->p_handle );
 284     ExitMPG123();
 285     free( p_sys );
 286     return VLC_EGENERIC;
 287 }
 288
 289 /*****************************************************************************
 290  * CloseDecoder : deallocate data structures
 291  *****************************************************************************/
 292 static void CloseDecoder( vlc_object_t *p_this )
 293 {
 294     decoder_t *p_dec = (decoder_t *)p_this;
 295     decoder_sys_t *p_sys = p_dec->p_sys;
 296
 297     mpg123_close( p_sys->p_handle );
 298     mpg123_delete( p_sys->p_handle );
 299     ExitMPG123();
 300     free( p_sys );
 301 }
 302
 303 /*****************************************************************************
 304  * InitMPG123 : initialize the mpg123 library (reentrant)
 305  *****************************************************************************/
 306 static int InitMPG123( void )
 307 {
 308     int i_ret;
 309     vlc_mutex_lock( &mpg123_mutex );
 310     if( mpg123_refcount > 0 )
 311     {
 312         mpg123_refcount++;
 313         vlc_mutex_unlock( &mpg123_mutex );
 314         return MPG123_OK;
 315     }
 316     if( ( i_ret = mpg123_init() ) == MPG123_OK )
 317         mpg123_refcount++;
 318     vlc_mutex_unlock( &mpg123_mutex );
 319     return i_ret;
 320 }
 321
 322 /*****************************************************************************
 323  * ExitMPG123 : close down the mpg123 library (reentrant)
 324  *****************************************************************************/
 325 static void ExitMPG123( void )
 326 {
 327     vlc_mutex_lock( &mpg123_mutex );
 328     mpg123_refcount--;
 329     if( mpg123_refcount == 0 )
 330         mpg123_exit();
 331     vlc_mutex_unlock( &mpg123_mutex );
 332 }