vlc-0.8.4a: /home/huihoo/src/vlc/vlc-0.8.4a/src/audio

00001 /*****************************************************************************
00002  * common.c : audio output management of common data structures
00003  *****************************************************************************
00004  * Copyright (C) 2002-2005 the VideoLAN team
00005  * $Id: common.c 13671 2005-12-10 19:26:03Z hartman $
00006  *
00007  * Authors: Christophe Massiot <[email protected]>
00008  *
00009  * This program is free software; you can redistribute it and/or modify
00010  * it under the terms of the GNU General Public License as published by
00011  * the Free Software Foundation; either version 2 of the License, or
00012  * (at your option) any later version.
00013  *
00014  * This program is distributed in the hope that it will be useful,
00015  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00016  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00017  * GNU General Public License for more details.
00018  *
00019  * You should have received a copy of the GNU General Public License
00020  * along with this program; if not, write to the Free Software
00021  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
00022  *****************************************************************************/
00023 
00024 /*****************************************************************************
00025  * Preamble
00026  *****************************************************************************/
00027 #include <stdlib.h>                            /* calloc(), malloc(), free() */
00028 #include <string.h>
00029 
00030 #include <vlc/vlc.h>
00031 
00032 #include "audio_output.h"
00033 #include "aout_internal.h"
00034 
00035 
00036 /*
00037  * Instances management (internal and external)
00038  */
00039 
00040 /*****************************************************************************
00041  * aout_New: initialize aout structure
00042  *****************************************************************************/
00043 aout_instance_t * __aout_New( vlc_object_t * p_parent )
00044 {
00045     aout_instance_t * p_aout;
00046     vlc_value_t val;
00047 
00048     /* Allocate descriptor. */
00049     p_aout = vlc_object_create( p_parent, VLC_OBJECT_AOUT );
00050     if( p_aout == NULL )
00051     {
00052         return NULL;
00053     }
00054 
00055     /* Initialize members. */
00056     vlc_mutex_init( p_parent, &p_aout->input_fifos_lock );
00057     vlc_mutex_init( p_parent, &p_aout->mixer_lock );
00058     vlc_mutex_init( p_parent, &p_aout->output_fifo_lock );
00059     p_aout->i_nb_inputs = 0;
00060     p_aout->mixer.f_multiplier = 1.0;
00061     p_aout->mixer.b_error = 1;
00062     p_aout->output.b_error = 1;
00063     p_aout->output.b_starving = 1;
00064 
00065     var_Create( p_aout, "intf-change", VLC_VAR_BOOL );
00066     val.b_bool = VLC_TRUE;
00067     var_Set( p_aout, "intf-change", val );
00068 
00069     return p_aout;
00070 }
00071 
00072 /*****************************************************************************
00073  * aout_Delete: destroy aout structure
00074  *****************************************************************************/
00075 void aout_Delete( aout_instance_t * p_aout )
00076 {
00077     var_Destroy( p_aout, "intf-change" );
00078 
00079     vlc_mutex_destroy( &p_aout->input_fifos_lock );
00080     vlc_mutex_destroy( &p_aout->mixer_lock );
00081     vlc_mutex_destroy( &p_aout->output_fifo_lock );
00082 
00083     /* Free structure. */
00084     vlc_object_destroy( p_aout );
00085 }
00086 
00087 
00088 /*
00089  * Formats management (internal and external)
00090  */
00091 
00092 /*****************************************************************************
00093  * aout_FormatNbChannels : return the number of channels
00094  *****************************************************************************/
00095 unsigned int aout_FormatNbChannels( const audio_sample_format_t * p_format )
00096 {
00097     static const uint32_t pi_channels[] =
00098         { AOUT_CHAN_CENTER, AOUT_CHAN_LEFT, AOUT_CHAN_RIGHT,
00099           AOUT_CHAN_REARCENTER, AOUT_CHAN_REARLEFT, AOUT_CHAN_REARRIGHT,
00100           AOUT_CHAN_MIDDLELEFT, AOUT_CHAN_MIDDLERIGHT, AOUT_CHAN_LFE };
00101     unsigned int i_nb = 0, i;
00102 
00103     for ( i = 0; i < sizeof(pi_channels)/sizeof(uint32_t); i++ )
00104     {
00105         if ( p_format->i_physical_channels & pi_channels[i] ) i_nb++;
00106     }
00107 
00108     return i_nb;
00109 }
00110 
00111 /*****************************************************************************
00112  * aout_FormatPrepare : compute the number of bytes per frame & frame length
00113  *****************************************************************************/
00114 void aout_FormatPrepare( audio_sample_format_t * p_format )
00115 {
00116     int i_result;
00117 
00118     switch ( p_format->i_format )
00119     {
00120     case VLC_FOURCC('u','8',' ',' '):
00121     case VLC_FOURCC('s','8',' ',' '):
00122         i_result = 1;
00123         break;
00124 
00125     case VLC_FOURCC('u','1','6','l'):
00126     case VLC_FOURCC('s','1','6','l'):
00127     case VLC_FOURCC('u','1','6','b'):
00128     case VLC_FOURCC('s','1','6','b'):
00129         i_result = 2;
00130         break;
00131 
00132     case VLC_FOURCC('u','2','4','l'):
00133     case VLC_FOURCC('s','2','4','l'):
00134     case VLC_FOURCC('u','2','4','b'):
00135     case VLC_FOURCC('s','2','4','b'):
00136         i_result = 3;
00137         break;
00138 
00139     case VLC_FOURCC('f','l','3','2'):
00140     case VLC_FOURCC('f','i','3','2'):
00141         i_result = 4;
00142         break;
00143 
00144     case VLC_FOURCC('s','p','d','i'):
00145     case VLC_FOURCC('s','p','d','b'): /* Big endian spdif output */
00146     case VLC_FOURCC('a','5','2',' '):
00147     case VLC_FOURCC('d','t','s',' '):
00148     case VLC_FOURCC('m','p','g','a'):
00149     case VLC_FOURCC('m','p','g','3'):
00150     default:
00151         /* For these formats the caller has to indicate the parameters
00152          * by hand. */
00153         return;
00154     }
00155 
00156     p_format->i_bytes_per_frame = i_result * aout_FormatNbChannels( p_format );
00157     p_format->i_frame_length = 1;
00158 }
00159 
00160 /*****************************************************************************
00161  * aout_FormatPrintChannels : print a channel in a human-readable form
00162  *****************************************************************************/
00163 const char * aout_FormatPrintChannels( const audio_sample_format_t * p_format )
00164 {
00165     switch ( p_format->i_physical_channels & AOUT_CHAN_PHYSMASK )
00166     {
00167     case AOUT_CHAN_CENTER:
00168         if ( (p_format->i_original_channels & AOUT_CHAN_CENTER)
00169               || (p_format->i_original_channels
00170                    & (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)) )
00171             return "Mono";
00172         else if ( p_format->i_original_channels & AOUT_CHAN_LEFT )
00173             return "Left";
00174         return "Right";
00175     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT:
00176         if ( p_format->i_original_channels & AOUT_CHAN_REVERSESTEREO )
00177         {
00178             if ( p_format->i_original_channels & AOUT_CHAN_DOLBYSTEREO )
00179                 return "Dolby/Reverse";
00180             return "Stereo/Reverse";
00181         }
00182         else
00183         {
00184             if ( p_format->i_original_channels & AOUT_CHAN_DOLBYSTEREO )
00185                 return "Dolby";
00186             else if ( p_format->i_original_channels & AOUT_CHAN_DUALMONO )
00187                 return "Dual-mono";
00188             else if ( p_format->i_original_channels == AOUT_CHAN_CENTER )
00189                 return "Stereo/Mono";
00190             else if ( !(p_format->i_original_channels & AOUT_CHAN_RIGHT) )
00191                 return "Stereo/Left";
00192             else if ( !(p_format->i_original_channels & AOUT_CHAN_LEFT) )
00193                 return "Stereo/Right";
00194             return "Stereo";
00195         }
00196     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER:
00197         return "3F";
00198     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_REARCENTER:
00199         return "2F1R";
00200     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
00201           | AOUT_CHAN_REARCENTER:
00202         return "3F1R";
00203     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
00204           | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT:
00205         return "2F2R";
00206     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
00207           | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT:
00208         return "3F2R";
00209 
00210     case AOUT_CHAN_CENTER | AOUT_CHAN_LFE:
00211         if ( (p_format->i_original_channels & AOUT_CHAN_CENTER)
00212               || (p_format->i_original_channels
00213                    & (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)) )
00214             return "Mono/LFE";
00215         else if ( p_format->i_original_channels & AOUT_CHAN_LEFT )
00216             return "Left/LFE";
00217         return "Right/LFE";
00218     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_LFE:
00219         if ( p_format->i_original_channels & AOUT_CHAN_DOLBYSTEREO )
00220             return "Dolby/LFE";
00221         else if ( p_format->i_original_channels & AOUT_CHAN_DUALMONO )
00222             return "Dual-mono/LFE";
00223         else if ( p_format->i_original_channels == AOUT_CHAN_CENTER )
00224             return "Mono/LFE";
00225         else if ( !(p_format->i_original_channels & AOUT_CHAN_RIGHT) )
00226             return "Stereo/Left/LFE";
00227         else if ( !(p_format->i_original_channels & AOUT_CHAN_LEFT) )
00228             return "Stereo/Right/LFE";
00229          return "Stereo/LFE";
00230     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER | AOUT_CHAN_LFE:
00231         return "3F/LFE";
00232     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_REARCENTER
00233           | AOUT_CHAN_LFE:
00234         return "2F1R/LFE";
00235     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
00236           | AOUT_CHAN_REARCENTER | AOUT_CHAN_LFE:
00237         return "3F1R/LFE";
00238     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
00239           | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_LFE:
00240         return "2F2R/LFE";
00241     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
00242           | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_LFE:
00243         return "3F2R/LFE";
00244     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
00245           | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_MIDDLELEFT
00246           | AOUT_CHAN_MIDDLERIGHT:
00247         return "3F2M2R";
00248     case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
00249           | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_MIDDLELEFT
00250           | AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_LFE:
00251         return "3F2M2R/LFE";
00252     }
00253 
00254     return "ERROR";
00255 }
00256 
00257 /*****************************************************************************
00258  * aout_FormatPrint : print a format in a human-readable form
00259  *****************************************************************************/
00260 void aout_FormatPrint( aout_instance_t * p_aout, const char * psz_text,
00261                        const audio_sample_format_t * p_format )
00262 {
00263     msg_Dbg( p_aout, "%s '%4.4s' %d Hz %s frame=%d samples/%d bytes", psz_text,
00264              (char *)&p_format->i_format, p_format->i_rate,
00265              aout_FormatPrintChannels( p_format ),
00266              p_format->i_frame_length, p_format->i_bytes_per_frame );
00267 }
00268 
00269 /*****************************************************************************
00270  * aout_FormatsPrint : print two formats in a human-readable form
00271  *****************************************************************************/
00272 void aout_FormatsPrint( aout_instance_t * p_aout, const char * psz_text,
00273                         const audio_sample_format_t * p_format1,
00274                         const audio_sample_format_t * p_format2 )
00275 {
00276     msg_Dbg( p_aout, "%s '%4.4s'->'%4.4s' %d Hz->%d Hz %s->%s",
00277              psz_text,
00278              (char *)&p_format1->i_format, (char *)&p_format2->i_format,
00279              p_format1->i_rate, p_format2->i_rate,
00280              aout_FormatPrintChannels( p_format1 ),
00281              aout_FormatPrintChannels( p_format2 ) );
00282 }
00283 
00284 
00285 /*
00286  * FIFO management (internal) - please understand that solving race conditions
00287  * is _your_ job, ie. in the audio output you should own the mixer lock
00288  * before calling any of these functions.
00289  */
00290 
00291 /*****************************************************************************
00292  * aout_FifoInit : initialize the members of a FIFO
00293  *****************************************************************************/
00294 void aout_FifoInit( aout_instance_t * p_aout, aout_fifo_t * p_fifo,
00295                     uint32_t i_rate )
00296 {
00297     p_fifo->p_first = NULL;
00298     p_fifo->pp_last = &p_fifo->p_first;
00299     aout_DateInit( &p_fifo->end_date, i_rate );
00300 }
00301 
00302 /*****************************************************************************
00303  * aout_FifoPush : push a packet into the FIFO
00304  *****************************************************************************/
00305 void aout_FifoPush( aout_instance_t * p_aout, aout_fifo_t * p_fifo,
00306                     aout_buffer_t * p_buffer )
00307 {
00308     *p_fifo->pp_last = p_buffer;
00309     p_fifo->pp_last = &p_buffer->p_next;
00310     *p_fifo->pp_last = NULL;
00311     /* Enforce the continuity of the stream. */
00312     if ( aout_DateGet( &p_fifo->end_date ) )
00313     {
00314         p_buffer->start_date = aout_DateGet( &p_fifo->end_date );
00315         p_buffer->end_date = aout_DateIncrement( &p_fifo->end_date,
00316                                                  p_buffer->i_nb_samples );
00317     }
00318     else
00319     {
00320         aout_DateSet( &p_fifo->end_date, p_buffer->end_date );
00321     }
00322 }
00323 
00324 /*****************************************************************************
00325  * aout_FifoSet : set end_date and trash all buffers (because they aren't
00326  * properly dated)
00327  *****************************************************************************/
00328 void aout_FifoSet( aout_instance_t * p_aout, aout_fifo_t * p_fifo,
00329                    mtime_t date )
00330 {
00331     aout_buffer_t * p_buffer;
00332 
00333     aout_DateSet( &p_fifo->end_date, date );
00334     p_buffer = p_fifo->p_first;
00335     while ( p_buffer != NULL )
00336     {
00337         aout_buffer_t * p_next = p_buffer->p_next;
00338         aout_BufferFree( p_buffer );
00339         p_buffer = p_next;
00340     }
00341     p_fifo->p_first = NULL;
00342     p_fifo->pp_last = &p_fifo->p_first;
00343 }
00344 
00345 /*****************************************************************************
00346  * aout_FifoMoveDates : Move forwards or backwards all dates in the FIFO
00347  *****************************************************************************/
00348 void aout_FifoMoveDates( aout_instance_t * p_aout, aout_fifo_t * p_fifo,
00349                          mtime_t difference )
00350 {
00351     aout_buffer_t * p_buffer;
00352 
00353     aout_DateMove( &p_fifo->end_date, difference );
00354     p_buffer = p_fifo->p_first;
00355     while ( p_buffer != NULL )
00356     {
00357         p_buffer->start_date += difference;
00358         p_buffer->end_date += difference;
00359         p_buffer = p_buffer->p_next;
00360     }
00361 }
00362 
00363 /*****************************************************************************
00364  * aout_FifoNextStart : return the current end_date
00365  *****************************************************************************/
00366 mtime_t aout_FifoNextStart( aout_instance_t * p_aout, aout_fifo_t * p_fifo )
00367 {
00368     return aout_DateGet( &p_fifo->end_date );
00369 }
00370 
00371 /*****************************************************************************
00372  * aout_FifoFirstDate : return the playing date of the first buffer in the
00373  * FIFO
00374  *****************************************************************************/
00375 mtime_t aout_FifoFirstDate( aout_instance_t * p_aout, aout_fifo_t * p_fifo )
00376 {
00377     return p_fifo->p_first ?  p_fifo->p_first->start_date : 0;
00378 }
00379 
00380 /*****************************************************************************
00381  * aout_FifoPop : get the next buffer out of the FIFO
00382  *****************************************************************************/
00383 aout_buffer_t * aout_FifoPop( aout_instance_t * p_aout, aout_fifo_t * p_fifo )
00384 {
00385     aout_buffer_t * p_buffer;
00386 
00387     p_buffer = p_fifo->p_first;
00388     if ( p_buffer == NULL ) return NULL;
00389     p_fifo->p_first = p_buffer->p_next;
00390     if ( p_fifo->p_first == NULL )
00391     {
00392         p_fifo->pp_last = &p_fifo->p_first;
00393     }
00394 
00395     return p_buffer;
00396 }
00397 
00398 /*****************************************************************************
00399  * aout_FifoDestroy : destroy a FIFO and its buffers
00400  *****************************************************************************/
00401 void aout_FifoDestroy( aout_instance_t * p_aout, aout_fifo_t * p_fifo )
00402 {
00403     aout_buffer_t * p_buffer;
00404 
00405     p_buffer = p_fifo->p_first;
00406     while ( p_buffer != NULL )
00407     {
00408         aout_buffer_t * p_next = p_buffer->p_next;
00409         aout_BufferFree( p_buffer );
00410         p_buffer = p_next;
00411     }
00412 
00413     p_fifo->p_first = NULL;
00414     p_fifo->pp_last = &p_fifo->p_first;
00415 }
00416 
00417 
00418 /*
00419  * Date management (internal and external)
00420  */
00421 
00422 /*****************************************************************************
00423  * aout_DateInit : set the divider of an audio_date_t
00424  *****************************************************************************/
00425 void aout_DateInit( audio_date_t * p_date, uint32_t i_divider )
00426 {
00427     p_date->date = 0;
00428     p_date->i_divider = i_divider;
00429     p_date->i_remainder = 0;
00430 }
00431 
00432 /*****************************************************************************
00433  * aout_DateSet : set the date of an audio_date_t
00434  *****************************************************************************/
00435 void aout_DateSet( audio_date_t * p_date, mtime_t new_date )
00436 {
00437     p_date->date = new_date;
00438     p_date->i_remainder = 0;
00439 }
00440 
00441 /*****************************************************************************
00442  * aout_DateMove : move forwards or backwards the date of an audio_date_t
00443  *****************************************************************************/
00444 void aout_DateMove( audio_date_t * p_date, mtime_t difference )
00445 {
00446     p_date->date += difference;
00447 }
00448 
00449 /*****************************************************************************
00450  * aout_DateGet : get the date of an audio_date_t
00451  *****************************************************************************/
00452 mtime_t aout_DateGet( const audio_date_t * p_date )
00453 {
00454     return p_date->date;
00455 }
00456 
00457 /*****************************************************************************
00458  * aout_DateIncrement : increment the date and return the result, taking
00459  * into account rounding errors
00460  *****************************************************************************/
00461 mtime_t aout_DateIncrement( audio_date_t * p_date, uint32_t i_nb_samples )
00462 {
00463     mtime_t i_dividend = (mtime_t)i_nb_samples * 1000000;
00464     p_date->date += i_dividend / p_date->i_divider;
00465     p_date->i_remainder += (int)(i_dividend % p_date->i_divider);
00466     if ( p_date->i_remainder >= p_date->i_divider )
00467     {
00468         /* This is Bresenham algorithm. */
00469         p_date->date++;
00470         p_date->i_remainder -= p_date->i_divider;
00471     }
00472     return p_date->date;
00473 }
00474 
00475 /*****************************************************************************
00476  * aout_CheckChannelReorder : Check if we need to do some channel re-ordering
00477  *****************************************************************************/
00478 int aout_CheckChannelReorder( const uint32_t *pi_chan_order_in,
00479                               const uint32_t *pi_chan_order_out,
00480                               uint32_t i_channel_mask,
00481                               int i_channels, int *pi_chan_table )
00482 {
00483     vlc_bool_t b_chan_reorder = VLC_FALSE;
00484     int i, j, k, l;
00485 
00486     if( i_channels > AOUT_CHAN_MAX ) return VLC_FALSE;
00487 
00488     for( i = 0, j = 0; pi_chan_order_in[i]; i++ )
00489     {
00490         if( !(i_channel_mask & pi_chan_order_in[i]) ) continue;
00491 
00492         for( k = 0, l = 0; pi_chan_order_in[i] != pi_chan_order_out[k]; k++ )
00493         {
00494             if( i_channel_mask & pi_chan_order_out[k] ) l++;
00495         }
00496 
00497         pi_chan_table[j++] = l;
00498     }
00499 
00500     for( i = 0; i < i_channels; i++ )
00501     {
00502         if( pi_chan_table[i] != i ) b_chan_reorder = VLC_TRUE;
00503     }
00504 
00505     return b_chan_reorder;
00506 }
00507 
00508 /*****************************************************************************
00509  * aout_ChannelReorder :
00510  *****************************************************************************/
00511 void aout_ChannelReorder( uint8_t *p_buf, int i_buffer,
00512                           int i_channels, const int *pi_chan_table,
00513                           int i_bits_per_sample )
00514 {
00515     uint8_t p_tmp[AOUT_CHAN_MAX * 4];
00516     int i, j;
00517 
00518     if( i_bits_per_sample == 8 )
00519     {
00520         for( i = 0; i < i_buffer / i_channels; i++ )
00521         {
00522             for( j = 0; j < i_channels; j++ )
00523             {
00524                 p_tmp[pi_chan_table[j]] = p_buf[j];
00525             }
00526 
00527             memcpy( p_buf, p_tmp, i_channels );
00528             p_buf += i_channels;
00529         }
00530     }
00531     else if( i_bits_per_sample == 16 )
00532     {
00533         for( i = 0; i < i_buffer / i_channels / 2; i++ )
00534         {
00535             for( j = 0; j < i_channels; j++ )
00536             {
00537                 p_tmp[2 * pi_chan_table[j]]     = p_buf[2 * j];
00538                 p_tmp[2 * pi_chan_table[j] + 1] = p_buf[2 * j + 1];
00539             }
00540 
00541             memcpy( p_buf, p_tmp, 2 * i_channels );
00542             p_buf += 2 * i_channels;
00543         }
00544     }
00545     else if( i_bits_per_sample == 24 )
00546     {
00547         for( i = 0; i < i_buffer / i_channels / 3; i++ )
00548         {
00549             for( j = 0; j < i_channels; j++ )
00550             {
00551                 p_tmp[3 * pi_chan_table[j]]     = p_buf[3 * j];
00552                 p_tmp[3 * pi_chan_table[j] + 1] = p_buf[3 * j + 1];
00553                 p_tmp[3 * pi_chan_table[j] + 2] = p_buf[3 * j + 2];
00554             }
00555 
00556             memcpy( p_buf, p_tmp, 3 * i_channels );
00557             p_buf += 3 * i_channels;
00558         }
00559     }
00560     else if( i_bits_per_sample == 32 )
00561     {
00562         for( i = 0; i < i_buffer / i_channels / 4; i++ )
00563         {
00564             for( j = 0; j < i_channels; j++ )
00565             {
00566                 p_tmp[4 * pi_chan_table[j]]     = p_buf[4 * j];
00567                 p_tmp[4 * pi_chan_table[j] + 1] = p_buf[4 * j + 1];
00568                 p_tmp[4 * pi_chan_table[j] + 2] = p_buf[4 * j + 2];
00569                 p_tmp[4 * pi_chan_table[j] + 3] = p_buf[4 * j + 3];
00570             }
00571 
00572             memcpy( p_buf, p_tmp, 4 * i_channels );
00573             p_buf += 4 * i_channels;
00574         }
00575     }
00576 }