src/audio_output/common.c

   1 /*****************************************************************************
   2  * common.c : audio output management of common data structures
   3  *****************************************************************************
   4  * Copyright (C) 2002-2007 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Christophe Massiot <massiot@via.ecp.fr>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 #ifdef HAVE_CONFIG_H
  25 # include "config.h"
  26 #endif
  27
  28 #include <limits.h>
  29 #include <assert.h>
  30
  31 #include <vlc_common.h>
  32 #include <vlc_aout.h>
  33 #include "aout_internal.h"
  34
  35 /*
  36  * Formats management (internal and external)
  37  */
  38
  39 /*****************************************************************************
  40  * aout_BitsPerSample : get the number of bits per sample
  41  *****************************************************************************/
  42 unsigned int aout_BitsPerSample( vlc_fourcc_t i_format )
  43 {
  44     switch( vlc_fourcc_GetCodec( AUDIO_ES, i_format ) )
  45     {
  46     case VLC_CODEC_U8:
  47     case VLC_CODEC_S8:
  48     case VLC_CODEC_ALAW:
  49     case VLC_CODEC_MULAW:
  50         return 8;
  51
  52     case VLC_CODEC_U16L:
  53     case VLC_CODEC_S16L:
  54     case VLC_CODEC_U16B:
  55     case VLC_CODEC_S16B:
  56         return 16;
  57
  58     case VLC_CODEC_U24L:
  59     case VLC_CODEC_S24L:
  60     case VLC_CODEC_U24B:
  61     case VLC_CODEC_S24B:
  62         return 24;
  63
  64     case VLC_CODEC_S24L32:
  65     case VLC_CODEC_S24B32:
  66     case VLC_CODEC_U32L:
  67     case VLC_CODEC_U32B:
  68     case VLC_CODEC_S32L:
  69     case VLC_CODEC_S32B:
  70     case VLC_CODEC_F32L:
  71     case VLC_CODEC_F32B:
  72         return 32;
  73
  74     case VLC_CODEC_F64L:
  75     case VLC_CODEC_F64B:
  76         return 64;
  77
  78     default:
  79         /* For these formats the caller has to indicate the parameters
  80          * by hand. */
  81         return 0;
  82     }
  83 }
  84
  85 /*****************************************************************************
  86  * aout_FormatPrepare : compute the number of bytes per frame & frame length
  87  *****************************************************************************/
  88 void aout_FormatPrepare( audio_sample_format_t * p_format )
  89 {
  90     p_format->i_channels = aout_FormatNbChannels( p_format );
  91     p_format->i_bitspersample = aout_BitsPerSample( p_format->i_format );
  92     if( p_format->i_bitspersample > 0 )
  93     {
  94         p_format->i_bytes_per_frame = ( p_format->i_bitspersample / 8 )
  95                                     * p_format->i_channels;
  96         p_format->i_frame_length = 1;
  97     }
  98 }
  99
 100 /*****************************************************************************
 101  * aout_FormatPrintChannels : print a channel in a human-readable form
 102  *****************************************************************************/
 103 const char * aout_FormatPrintChannels( const audio_sample_format_t * p_format )
 104 {
 105     switch ( p_format->i_physical_channels )
 106     {
 107     case AOUT_CHAN_LEFT:
 108     case AOUT_CHAN_RIGHT:
 109     case AOUT_CHAN_CENTER:
 110         if ( (p_format->i_original_channels & AOUT_CHAN_CENTER)
 111               || (p_format->i_original_channels
 112                    & (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)) )
 113             return "Mono";
 114         else if ( p_format->i_original_channels & AOUT_CHAN_LEFT )
 115             return "Left";
 116         return "Right";
 117     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT:
 118         if ( p_format->i_original_channels & AOUT_CHAN_REVERSESTEREO )
 119         {
 120             if ( p_format->i_original_channels & AOUT_CHAN_DOLBYSTEREO )
 121                 return "Dolby/Reverse";
 122             return "Stereo/Reverse";
 123         }
 124         else
 125         {
 126             if ( p_format->i_original_channels & AOUT_CHAN_DOLBYSTEREO )
 127                 return "Dolby";
 128             else if ( p_format->i_original_channels & AOUT_CHAN_DUALMONO )
 129                 return "Dual-mono";
 130             else if ( p_format->i_original_channels == AOUT_CHAN_CENTER )
 131                 return "Stereo/Mono";
 132             else if ( !(p_format->i_original_channels & AOUT_CHAN_RIGHT) )
 133                 return "Stereo/Left";
 134             else if ( !(p_format->i_original_channels & AOUT_CHAN_LEFT) )
 135                 return "Stereo/Right";
 136             return "Stereo";
 137         }
 138     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER:
 139         return "3F";
 140     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_REARCENTER:
 141         return "2F1R";
 142     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
 143           | AOUT_CHAN_REARCENTER:
 144         return "3F1R";
 145     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
 146           | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT:
 147         return "2F2R";
 148     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
 149           | AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT:
 150         return "2F2M";
 151     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
 152           | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT:
 153         return "3F2R";
 154     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
 155           | AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT:
 156         return "3F2M";
 157
 158     case AOUT_CHAN_CENTER | AOUT_CHAN_LFE:
 159         if ( (p_format->i_original_channels & AOUT_CHAN_CENTER)
 160               || (p_format->i_original_channels
 161                    & (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)) )
 162             return "Mono/LFE";
 163         else if ( p_format->i_original_channels & AOUT_CHAN_LEFT )
 164             return "Left/LFE";
 165         return "Right/LFE";
 166     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_LFE:
 167         if ( p_format->i_original_channels & AOUT_CHAN_DOLBYSTEREO )
 168             return "Dolby/LFE";
 169         else if ( p_format->i_original_channels & AOUT_CHAN_DUALMONO )
 170             return "Dual-mono/LFE";
 171         else if ( p_format->i_original_channels == AOUT_CHAN_CENTER )
 172             return "Mono/LFE";
 173         else if ( !(p_format->i_original_channels & AOUT_CHAN_RIGHT) )
 174             return "Stereo/Left/LFE";
 175         else if ( !(p_format->i_original_channels & AOUT_CHAN_LEFT) )
 176             return "Stereo/Right/LFE";
 177          return "Stereo/LFE";
 178     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER | AOUT_CHAN_LFE:
 179         return "3F/LFE";
 180     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_REARCENTER
 181           | AOUT_CHAN_LFE:
 182         return "2F1R/LFE";
 183     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
 184           | AOUT_CHAN_REARCENTER | AOUT_CHAN_LFE:
 185         return "3F1R/LFE";
 186     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
 187           | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_LFE:
 188         return "2F2R/LFE";
 189     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
 190           | AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_LFE:
 191         return "2F2M/LFE";
 192     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
 193           | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_LFE:
 194         return "3F2R/LFE";
 195     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
 196           | AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_LFE:
 197         return "3F2M/LFE";
 198     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
 199           | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_MIDDLELEFT
 200           | AOUT_CHAN_MIDDLERIGHT:
 201         return "3F2M2R";
 202     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
 203           | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_MIDDLELEFT
 204           | AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_LFE:
 205         return "3F2M2R/LFE";
 206     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
 207           | AOUT_CHAN_REARCENTER | AOUT_CHAN_MIDDLELEFT
 208           | AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_LFE:
 209         return "3F2M1R/LFE";
 210     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
 211           | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_REARCENTER
 212           | AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_LFE:
 213         return "3F2M3R/LFE";
 214     }
 215
 216     return "ERROR";
 217 }
 218
 219 #undef aout_FormatPrint
 220 /**
 221  * Prints an audio sample format in a human-readable form.
 222  */
 223 void aout_FormatPrint( vlc_object_t *obj, const char *psz_text,
 224                        const audio_sample_format_t *p_format )
 225 {
 226     msg_Dbg( obj, "%s '%4.4s' %d Hz %s frame=%d samples/%d bytes", psz_text,
 227              (char *)&p_format->i_format, p_format->i_rate,
 228              aout_FormatPrintChannels( p_format ),
 229              p_format->i_frame_length, p_format->i_bytes_per_frame );
 230 }
 231
 232 #undef aout_FormatsPrint
 233 /**
 234  * Prints two formats in a human-readable form
 235  */
 236 void aout_FormatsPrint( vlc_object_t *obj, const char * psz_text,
 237                         const audio_sample_format_t * p_format1,
 238                         const audio_sample_format_t * p_format2 )
 239 {
 240     msg_Dbg( obj, "%s '%4.4s'->'%4.4s' %d Hz->%d Hz %s->%s",
 241              psz_text,
 242              (char *)&p_format1->i_format, (char *)&p_format2->i_format,
 243              p_format1->i_rate, p_format2->i_rate,
 244              aout_FormatPrintChannels( p_format1 ),
 245              aout_FormatPrintChannels( p_format2 ) );
 246 }
 247
 248 /*****************************************************************************
 249  * aout_CheckChannelReorder : Check if we need to do some channel re-ordering
 250  *****************************************************************************/
 251 unsigned aout_CheckChannelReorder( const uint32_t *chans_in,
 252                                    const uint32_t *chans_out,
 253                                    uint32_t mask, uint8_t *restrict table )
 254 {
 255     static_assert(AOUT_CHAN_MAX <= (sizeof (mask) * CHAR_BIT), "Missing bits");
 256
 257     unsigned channels = 0;
 258
 259     if( chans_in == NULL )
 260         chans_in = pi_vlc_chan_order_wg4;
 261     if( chans_out == NULL )
 262         chans_out = pi_vlc_chan_order_wg4;
 263
 264     for( unsigned i = 0; chans_in[i]; i++ )
 265     {
 266         const uint32_t chan = chans_in[i];
 267         if( !(mask & chan) )
 268             continue;
 269
 270         unsigned index = 0;
 271         for( unsigned j = 0; chan != chans_out[j]; j++ )
 272             if( mask & chans_out[j] )
 273                 index++;
 274
 275         table[channels++] = index;
 276     }
 277
 278     for( unsigned i = 0; i < channels; i++ )
 279         if( table[i] != i )
 280             return channels;
 281     return 0;
 282 }
 283
 284 /**
 285  * Reorders audio samples within a block of linear audio interleaved samples.
 286  * \param ptr start address of the block of samples
 287  * \param bytes size of the block in bytes (must be a multiple of the product
 288  *              of the channels count and the sample size)
 289  * \param channels channels count (also length of the chans_table table)
 290  * \param chans_table permutation table to reorder the channels
 291  *                    (usually computed by aout_CheckChannelReorder())
 292  * \param fourcc sample format (must be a linear sample format)
 293  * \note The samples must be naturally aligned in memory.
 294  */
 295 void aout_ChannelReorder( void *ptr, size_t bytes, uint8_t channels,
 296                           const uint8_t *restrict chans_table, vlc_fourcc_t fourcc )
 297 {
 298     if( unlikely(bytes == 0) )
 299         return;
 300
 301     assert( channels != 0 );
 302
 303     /* The audio formats supported in audio output are inlined. For other
 304      * formats (used in demuxers and muxers), memcpy() is used to avoid
 305      * breaking type punning. */
 306 #define REORDER_TYPE(type) \
 307 do { \
 308     const size_t frames = (bytes / sizeof (type)) / channels; \
 309     type *buf = ptr; \
 310 \
 311     for( size_t i = 0; i < frames; i++ ) \
 312     { \
 313         type tmp[AOUT_CHAN_MAX]; \
 314 \
 315         for( size_t j = 0; j < channels; j++ ) \
 316             tmp[chans_table[j]] = buf[j]; \
 317         memcpy( buf, tmp, sizeof (type) * channels ); \
 318         buf += channels; \
 319     } \
 320 } while(0)
 321
 322     if( likely(channels <= AOUT_CHAN_MAX) )
 323     {
 324         switch( fourcc )
 325         {
 326             case VLC_CODEC_U8:   REORDER_TYPE(uint8_t); return;
 327             case VLC_CODEC_S16N: REORDER_TYPE(int16_t); return;
 328             case VLC_CODEC_FL32: REORDER_TYPE(float);   return;
 329             case VLC_CODEC_S32N: REORDER_TYPE(int32_t); return;
 330             case VLC_CODEC_FL64: REORDER_TYPE(double);  return;
 331         }
 332     }
 333
 334     unsigned size = aout_BitsPerSample( fourcc ) / 8;
 335     assert( size != 0 && size <= 8 );
 336
 337     const size_t frames = bytes / (size * channels);
 338     unsigned char *buf = ptr;
 339
 340     for( size_t i = 0; i < frames; i++ )
 341     {
 342         unsigned char tmp[256 * 8];
 343
 344         for( size_t j = 0; j < channels; j++ )
 345              memcpy( tmp + size * chans_table[j], buf + size * j, size );
 346          memcpy( buf, tmp, size * channels );
 347          buf += size * channels;
 348     }
 349 }
 350
 351 /**
 352  * Interleaves audio samples within a block of samples.
 353  * \param dst destination buffer for interleaved samples
 354  * \param srcv source buffers (one per plane) of uninterleaved samples
 355  * \param samples number of samples (per channel/per plane)
 356  * \param chans channels/planes count
 357  * \param fourcc sample format (must be a linear sample format)
 358  * \note The samples must be naturally aligned in memory.
 359  * \warning Destination and source buffers MUST NOT overlap.
 360  */
 361 void aout_Interleave( void *restrict dst, const void *const *srcv,
 362                       unsigned samples, unsigned chans, vlc_fourcc_t fourcc )
 363 {
 364 #define INTERLEAVE_TYPE(type) \
 365 do { \
 366     type *d = dst; \
 367     for( size_t i = 0; i < chans; i++ ) { \
 368         const type *s = srcv[i]; \
 369         for( size_t j = 0, k = 0; j < samples; j++, k += chans ) \
 370             d[k] = *(s++); \
 371         d++; \
 372     } \
 373 } while(0)
 374
 375     switch( fourcc )
 376     {
 377         case VLC_CODEC_U8:   INTERLEAVE_TYPE(uint8_t);  break;
 378         case VLC_CODEC_S16N: INTERLEAVE_TYPE(uint16_t); break;
 379         case VLC_CODEC_FL32: INTERLEAVE_TYPE(float);    break;
 380         case VLC_CODEC_S32N: INTERLEAVE_TYPE(int32_t);  break;
 381         case VLC_CODEC_FL64: INTERLEAVE_TYPE(double);   break;
 382         default:             vlc_assert_unreachable();
 383     }
 384 #undef INTERLEAVE_TYPE
 385 }
 386
 387 /**
 388  * Deinterleaves audio samples within a block of samples.
 389  * \param dst destination buffer for planar samples
 390  * \param src source buffer with interleaved samples
 391  * \param samples number of samples (per channel/per plane)
 392  * \param chans channels/planes count
 393  * \param fourcc sample format (must be a linear sample format)
 394  * \note The samples must be naturally aligned in memory.
 395  * \warning Destination and source buffers MUST NOT overlap.
 396  */
 397 void aout_Deinterleave( void *restrict dst, const void *restrict src,
 398                       unsigned samples, unsigned chans, vlc_fourcc_t fourcc )
 399 {
 400 #define DEINTERLEAVE_TYPE(type) \
 401 do { \
 402     type *d = dst; \
 403     const type *s = src; \
 404     for( size_t i = 0; i < chans; i++ ) { \
 405         for( size_t j = 0, k = 0; j < samples; j++, k += chans ) \
 406             *(d++) = s[k]; \
 407         s++; \
 408     } \
 409 } while(0)
 410
 411     switch( fourcc )
 412     {
 413         case VLC_CODEC_U8:   DEINTERLEAVE_TYPE(uint8_t);  break;
 414         case VLC_CODEC_S16N: DEINTERLEAVE_TYPE(uint16_t); break;
 415         case VLC_CODEC_FL32: DEINTERLEAVE_TYPE(float);    break;
 416         case VLC_CODEC_S32N: DEINTERLEAVE_TYPE(int32_t);  break;
 417         case VLC_CODEC_FL64: DEINTERLEAVE_TYPE(double);   break;
 418         default:             vlc_assert_unreachable();
 419     }
 420 #undef DEINTERLEAVE_TYPE
 421 }
 422
 423 /*****************************************************************************
 424  * aout_ChannelExtract:
 425  *****************************************************************************/
 426 static inline void ExtractChannel( uint8_t *pi_dst, int i_dst_channels,
 427                                    const uint8_t *pi_src, int i_src_channels,
 428                                    int i_sample_count,
 429                                    const int *pi_selection, int i_bytes )
 430 {
 431     for( int i = 0; i < i_sample_count; i++ )
 432     {
 433         for( int j = 0; j < i_dst_channels; j++ )
 434             memcpy( &pi_dst[j * i_bytes], &pi_src[pi_selection[j] * i_bytes], i_bytes );
 435         pi_dst += i_dst_channels * i_bytes;
 436         pi_src += i_src_channels * i_bytes;
 437     }
 438 }
 439
 440 void aout_ChannelExtract( void *p_dst, int i_dst_channels,
 441                           const void *p_src, int i_src_channels,
 442                           int i_sample_count, const int *pi_selection, int i_bits_per_sample )
 443 {
 444     /* It does not work in place */
 445     assert( p_dst != p_src );
 446
 447     /* Force the compiler to inline for the specific cases so it can optimize */
 448     if( i_bits_per_sample == 8 )
 449         ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 1 );
 450     else  if( i_bits_per_sample == 16 )
 451         ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 2 );
 452     else  if( i_bits_per_sample == 32 )
 453         ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 4 );
 454     else  if( i_bits_per_sample == 64 )
 455         ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 8 );
 456 }
 457
 458 bool aout_CheckChannelExtraction( int *pi_selection,
 459                                   uint32_t *pi_layout, int *pi_channels,
 460                                   const uint32_t pi_order_dst[AOUT_CHAN_MAX],
 461                                   const uint32_t *pi_order_src, int i_channels )
 462 {
 463     static_assert(AOUT_CHAN_MAX <= (sizeof (*pi_order_dst) * CHAR_BIT),
 464                   "Missing bits");
 465
 466     const uint32_t pi_order_dual_mono[] = { AOUT_CHAN_LEFT, AOUT_CHAN_RIGHT };
 467     uint32_t i_layout = 0;
 468     int i_out = 0;
 469     int pi_index[AOUT_CHAN_MAX];
 470
 471     /* */
 472     if( !pi_order_dst )
 473         pi_order_dst = pi_vlc_chan_order_wg4;
 474
 475     /* Detect special dual mono case */
 476     if( i_channels == 2 &&
 477         pi_order_src[0] == AOUT_CHAN_CENTER && pi_order_src[1] == AOUT_CHAN_CENTER )
 478     {
 479         i_layout |= AOUT_CHAN_DUALMONO;
 480         pi_order_src = pi_order_dual_mono;
 481     }
 482
 483     /* */
 484     for( int i = 0; i < i_channels; i++ )
 485     {
 486         /* Ignore unknown or duplicated channels or not present in output */
 487         if( !pi_order_src[i] || (i_layout & pi_order_src[i]) )
 488             continue;
 489
 490         for( int j = 0; j < AOUT_CHAN_MAX; j++ )
 491         {
 492             if( pi_order_dst[j] == pi_order_src[i] )
 493             {
 494                 assert( i_out < AOUT_CHAN_MAX );
 495                 pi_index[i_out++] = i;
 496                 i_layout |= pi_order_src[i];
 497                 break;
 498             }
 499         }
 500     }
 501
 502     /* */
 503     for( int i = 0, j = 0; i < AOUT_CHAN_MAX; i++ )
 504     {
 505         for( int k = 0; k < i_out; k++ )
 506         {
 507             if( pi_order_dst[i] == pi_order_src[pi_index[k]] )
 508             {
 509                 pi_selection[j++] = pi_index[k];
 510                 break;
 511             }
 512         }
 513     }
 514
 515     *pi_layout = i_layout;
 516     *pi_channels = i_out;
 517
 518     for( int i = 0; i < i_out; i++ )
 519     {
 520         if( pi_selection[i] != i )
 521             return true;
 522     }
 523     return i_out != i_channels;
 524 }
 525
 526 /* Return the order in which filters should be inserted */
 527 static int FilterOrder( const char *psz_name )
 528 {
 529     static const struct {
 530         const char psz_name[10];
 531         int        i_order;
 532     } filter[] = {
 533         { "equalizer",  0 },
 534     };
 535     for( unsigned i = 0; i < ARRAY_SIZE(filter); i++ )
 536     {
 537         if( !strcmp( filter[i].psz_name, psz_name ) )
 538             return filter[i].i_order;
 539     }
 540     return INT_MAX;
 541 }
 542
 543 /* This function will add or remove a module from a string list (colon
 544  * separated). It will return true if there is a modification
 545  * In case p_aout is NULL, we will use configuration instead of variable */
 546 bool aout_ChangeFilterString( vlc_object_t *p_obj, vlc_object_t *p_aout,
 547                               const char *psz_variable,
 548                               const char *psz_name, bool b_add )
 549 {
 550     if( *psz_name == '\0' )
 551         return false;
 552
 553     char *psz_list;
 554     if( p_aout )
 555     {
 556         psz_list = var_GetString( p_aout, psz_variable );
 557     }
 558     else
 559     {
 560         psz_list = var_CreateGetString( p_obj->obj.libvlc, psz_variable );
 561         var_Destroy( p_obj->obj.libvlc, psz_variable );
 562     }
 563
 564     /* Split the string into an array of filters */
 565     int i_count = 1;
 566     for( char *p = psz_list; p && *p; p++ )
 567         i_count += *p == ':';
 568     i_count += b_add;
 569
 570     const char **ppsz_filter = calloc( i_count, sizeof(*ppsz_filter) );
 571     if( !ppsz_filter )
 572     {
 573         free( psz_list );
 574         return false;
 575     }
 576     bool b_present = false;
 577     i_count = 0;
 578     for( char *p = psz_list; p && *p; )
 579     {
 580         char *psz_end = strchr(p, ':');
 581         if( psz_end )
 582             *psz_end++ = '\0';
 583         else
 584             psz_end = p + strlen(p);
 585         if( *p )
 586         {
 587             b_present |= !strcmp( p, psz_name );
 588             ppsz_filter[i_count++] = p;
 589         }
 590         p = psz_end;
 591     }
 592     if( b_present == b_add )
 593     {
 594         free( ppsz_filter );
 595         free( psz_list );
 596         return false;
 597     }
 598
 599     if( b_add )
 600     {
 601         int i_order = FilterOrder( psz_name );
 602         int i;
 603         for( i = 0; i < i_count; i++ )
 604         {
 605             if( FilterOrder( ppsz_filter[i] ) > i_order )
 606                 break;
 607         }
 608         if( i < i_count )
 609             memmove( &ppsz_filter[i+1], &ppsz_filter[i], (i_count - i) * sizeof(*ppsz_filter) );
 610         ppsz_filter[i] = psz_name;
 611         i_count++;
 612     }
 613     else
 614     {
 615         for( int i = 0; i < i_count; i++ )
 616         {
 617             if( !strcmp( ppsz_filter[i], psz_name ) )
 618                 ppsz_filter[i] = "";
 619         }
 620     }
 621     size_t i_length = 0;
 622     for( int i = 0; i < i_count; i++ )
 623         i_length += 1 + strlen( ppsz_filter[i] );
 624
 625     char *psz_new = malloc( i_length + 1 );
 626
 627     if( unlikely( !psz_new ) )
 628     {
 629         free( ppsz_filter );
 630         free( psz_list );
 631         return false;
 632     }
 633
 634     *psz_new = '\0';
 635     for( int i = 0; i < i_count; i++ )
 636     {
 637         if( *ppsz_filter[i] == '\0' )
 638             continue;
 639         if( *psz_new )
 640             strcat( psz_new, ":" );
 641         strcat( psz_new, ppsz_filter[i] );
 642     }
 643     free( ppsz_filter );
 644     free( psz_list );
 645
 646     if( p_aout )
 647         var_SetString( p_aout, psz_variable, psz_new );
 648     else
 649         config_PutPsz( p_obj, psz_variable, psz_new );
 650     free( psz_new );
 651
 652     return true;
 653 }