/src/vlc/src/audio_output/common.c

Source
/*****************************************************************************
 * common.c : audio output management of common data structures
 *****************************************************************************
 * Copyright (C) 2002-2007 VLC authors and VideoLAN
 *
 * Authors: Christophe Massiot <massiot@via.ecp.fr>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <limits.h>
#include <assert.h>

#include <vlc_common.h>
#include <vlc_aout.h>
#include "aout_internal.h"

/*
 * Formats management (internal and external)
 */

/*****************************************************************************
 * aout_BitsPerSample : get the number of bits per sample
 *****************************************************************************/
unsigned int aout_BitsPerSample( vlc_fourcc_t i_format )
{
    switch( vlc_fourcc_GetCodec( AUDIO_ES, i_format ) )
    {
    case VLC_CODEC_U8:
    case VLC_CODEC_S8:
    case VLC_CODEC_ALAW:
    case VLC_CODEC_MULAW:
        return 8;

    case VLC_CODEC_U16L:
    case VLC_CODEC_S16L:
    case VLC_CODEC_U16B:
    case VLC_CODEC_S16B:
        return 16;

    case VLC_CODEC_U24L:
    case VLC_CODEC_S24L:
    case VLC_CODEC_U24B:
    case VLC_CODEC_S24B:
        return 24;

    case VLC_CODEC_S24L32:
    case VLC_CODEC_S24B32:
    case VLC_CODEC_U32L:
    case VLC_CODEC_U32B:
    case VLC_CODEC_S32L:
    case VLC_CODEC_S32B:
    case VLC_CODEC_F32L:
    case VLC_CODEC_F32B:
        return 32;

    case VLC_CODEC_F64L:
    case VLC_CODEC_F64B:
        return 64;

    default:
        /* For these formats the caller has to indicate the parameters
         * by hand. */
        return 0;
    }
}

/*****************************************************************************
 * aout_FormatPrepare : compute the number of bytes per frame & frame length
 *****************************************************************************/
void aout_FormatPrepare( audio_sample_format_t * p_format )
{

    unsigned i_channels = aout_FormatNbChannels( p_format );
    if( i_channels > 0 )
        p_format->i_channels = i_channels;
    p_format->i_bitspersample = aout_BitsPerSample( p_format->i_format );
    if( p_format->i_bitspersample > 0 )
    {
        p_format->i_bytes_per_frame = ( p_format->i_bitspersample / 8 )
                                    * p_format->i_channels;
        p_format->i_frame_length = 1;
    }
}

/*****************************************************************************
 * aout_FormatPrintChannels : print a channel in a human-readable form
 *****************************************************************************/
const char * aout_FormatPrintChannels( const audio_sample_format_t * p_format )
{
    if (p_format->channel_type == AUDIO_CHANNEL_TYPE_AMBISONICS)
        return "Ambisonics";

    /* AUDIO_CHANNEL_TYPE_BITMAP */
    switch ( p_format->i_physical_channels )
    {
    case AOUT_CHAN_LEFT:
    case AOUT_CHAN_RIGHT:
    case AOUT_CHAN_CENTER:
        if ( (p_format->i_physical_channels & AOUT_CHAN_CENTER)
              || (p_format->i_physical_channels
                   & (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)) )
            return "Mono";
        else if ( p_format->i_physical_channels & AOUT_CHAN_LEFT )
            return "Left";
        return "Right";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT:
        if ( p_format->i_chan_mode & AOUT_CHANMODE_DOLBYSTEREO )
            return "Dolby";
        else if ( p_format->i_chan_mode & AOUT_CHANMODE_DUALMONO )
            return "Dual-mono";
        else if ( p_format->i_physical_channels == AOUT_CHAN_CENTER )
            return "Stereo/Mono";
        else if ( !(p_format->i_physical_channels & AOUT_CHAN_RIGHT) )
            return "Stereo/Left";
        else if ( !(p_format->i_physical_channels & AOUT_CHAN_LEFT) )
            return "Stereo/Right";
        return "Stereo";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER:
        return "3F";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_REARCENTER:
        return "2F1R";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
          | AOUT_CHAN_REARCENTER:
        return "3F1R";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
          | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT:
        return "2F2R";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
          | AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT:
        return "2F2M";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
          | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT:
        return "3F2R";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
          | AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT:
        return "3F2M";

    case AOUT_CHAN_CENTER | AOUT_CHAN_LFE:
        if ( (p_format->i_physical_channels & AOUT_CHAN_CENTER)
              || (p_format->i_physical_channels
                   & (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)) )
            return "Mono/LFE";
        else if ( p_format->i_physical_channels & AOUT_CHAN_LEFT )
            return "Left/LFE";
        return "Right/LFE";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_LFE:
        if ( p_format->i_chan_mode & AOUT_CHANMODE_DOLBYSTEREO )
            return "Dolby/LFE";
        else if ( p_format->i_chan_mode & AOUT_CHANMODE_DUALMONO )
            return "Dual-mono/LFE";
        else if ( p_format->i_physical_channels == AOUT_CHAN_CENTER )
            return "Mono/LFE";
        else if ( !(p_format->i_physical_channels & AOUT_CHAN_RIGHT) )
            return "Stereo/Left/LFE";
        else if ( !(p_format->i_physical_channels & AOUT_CHAN_LEFT) )
            return "Stereo/Right/LFE";
         return "Stereo/LFE";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER | AOUT_CHAN_LFE:
        return "3F/LFE";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_REARCENTER
          | AOUT_CHAN_LFE:
        return "2F1R/LFE";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
          | AOUT_CHAN_REARCENTER | AOUT_CHAN_LFE:
        return "3F1R/LFE";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
          | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_LFE:
        return "2F2R/LFE";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
          | AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_LFE:
        return "2F2M/LFE";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
          | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_LFE:
        return "3F2R/LFE";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
          | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_REARCENTER
          | AOUT_CHAN_LFE:
        return "3F3R/LFE";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
          | AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_LFE:
        return "3F2M/LFE";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
          | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_MIDDLELEFT
          | AOUT_CHAN_MIDDLERIGHT:
        return "2F2M2R";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
          | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_MIDDLELEFT
          | AOUT_CHAN_MIDDLERIGHT:
        return "3F2M2R";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
          | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_MIDDLELEFT
          | AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_LFE:
        return "3F2M2R/LFE";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
          | AOUT_CHAN_REARCENTER | AOUT_CHAN_MIDDLELEFT
          | AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_LFE:
        return "3F2M1R/LFE";
    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
          | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_REARCENTER
          | AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_LFE:
        return "3F2M3R/LFE";
    }

    return "Unknown-chan-mask";
}

#undef aout_FormatPrint
void aout_FormatPrint( vlc_object_t *obj, const char *psz_text,
                       const audio_sample_format_t *p_format )
{
    msg_Dbg( obj, "%s '%4.4s' %d Hz %s frame=%u samples/%u bytes", psz_text,
             (char *)&p_format->i_format, p_format->i_rate,
             aout_FormatPrintChannels( p_format ),
             p_format->i_frame_length, p_format->i_bytes_per_frame );
}

#undef aout_FormatsPrint
/**
 * Prints two formats in a human-readable form
 */
void aout_FormatsPrint( vlc_object_t *obj, const char * psz_text,
                        const audio_sample_format_t * p_format1,
                        const audio_sample_format_t * p_format2 )
{
    msg_Dbg( obj, "%s '%4.4s'->'%4.4s' %u Hz->%u Hz %s->%s",
             psz_text,
             (char *)&p_format1->i_format, (char *)&p_format2->i_format,
             p_format1->i_rate, p_format2->i_rate,
             aout_FormatPrintChannels( p_format1 ),
             aout_FormatPrintChannels( p_format2 ) );
}

/*****************************************************************************
 * aout_CheckChannelReorder : Check if we need to do some channel re-ordering
 *****************************************************************************/
unsigned aout_CheckChannelReorder( const uint32_t *chans_in,
                                   const uint32_t *chans_out,
                                   uint32_t mask, uint8_t *restrict table )
{
    static_assert(AOUT_CHAN_MAX <= (sizeof (mask) * CHAR_BIT), "Missing bits");

    unsigned channels = 0;

    if( chans_in == NULL )
        chans_in = pi_vlc_chan_order_wg4;
    if( chans_out == NULL )
        chans_out = pi_vlc_chan_order_wg4;

    for( unsigned i = 0; chans_in[i]; i++ )
    {
        const uint32_t chan = chans_in[i];
        if( !(mask & chan) )
            continue;

        unsigned index = 0;
        for( unsigned j = 0; chan != chans_out[j]; j++ )
            if( mask & chans_out[j] )
                index++;

        table[channels++] = index;
    }

    for( unsigned i = 0; i < channels; i++ )
        if( table[i] != i )
            return channels;
    return 0;
}

void aout_ChannelReorder( void *ptr, size_t bytes, uint8_t channels,
                          const uint8_t *restrict chans_table, vlc_fourcc_t fourcc )
{
    if( unlikely(bytes == 0) )
        return;

    assert( channels != 0 );

    /* The audio formats supported in audio output are inlined. For other
     * formats (used in demuxers and muxers), memcpy() is used to avoid
     * breaking type punning. */
#define REORDER_TYPE(type) \
do { \
    const size_t frames = (bytes / sizeof (type)) / channels; \
    type *buf = ptr; \
\
    for( size_t i = 0; i < frames; i++ ) \
    { \
        type tmp[AOUT_CHAN_MAX]; \
\
        for( size_t j = 0; j < channels; j++ ) \
            tmp[chans_table[j]] = buf[j]; \
        memcpy( buf, tmp, sizeof (type) * channels ); \
        buf += channels; \
    } \
} while(0)

    if( likely(channels <= AOUT_CHAN_MAX) )
    {
        switch( fourcc )
        {
            case VLC_CODEC_U8:   REORDER_TYPE(uint8_t); return;
            case VLC_CODEC_S16N: REORDER_TYPE(int16_t); return;
            case VLC_CODEC_FL32: REORDER_TYPE(float);   return;
            case VLC_CODEC_S32N: REORDER_TYPE(int32_t); return;
            case VLC_CODEC_FL64: REORDER_TYPE(double);  return;
        }
    }

    unsigned size = aout_BitsPerSample( fourcc ) / 8;
    assert( size != 0 && size <= 8 );

    const size_t frames = bytes / (size * channels);
    unsigned char *buf = ptr;

    for( size_t i = 0; i < frames; i++ )
    {
        unsigned char tmp[256 * 8];

        for( size_t j = 0; j < channels; j++ )
             memcpy( tmp + size * chans_table[j], buf + size * j, size );
         memcpy( buf, tmp, size * channels );
         buf += size * channels;
    }
}

/**
 * Interleaves audio samples within a block of samples.
 * \param dst destination buffer for interleaved samples
 * \param srcv source buffers (one per plane) of uninterleaved samples
 * \param samples number of samples (per channel/per plane)
 * \param chans channels/planes count
 * \param fourcc sample format (must be a linear sample format)
 * \note The samples must be naturally aligned in memory.
 * \warning Destination and source buffers MUST NOT overlap.
 */
void aout_Interleave( void *restrict dst, const void *const *srcv,
                      unsigned samples, unsigned chans, vlc_fourcc_t fourcc )
{
#define INTERLEAVE_TYPE(type) \
do { \
    type *d = dst; \
    for( size_t i = 0; i < chans; i++ ) { \
        const type *s = srcv[i]; \
        for( size_t j = 0, k = 0; j < samples; j++, k += chans ) \
            d[k] = *(s++); \
        d++; \
    } \
} while(0)

    switch( fourcc )
    {
        case VLC_CODEC_U8:   INTERLEAVE_TYPE(uint8_t);  break;
        case VLC_CODEC_S16N: INTERLEAVE_TYPE(int16_t);  break;
        case VLC_CODEC_FL32: INTERLEAVE_TYPE(float);    break;
        case VLC_CODEC_S32N: INTERLEAVE_TYPE(int32_t);  break;
        case VLC_CODEC_FL64: INTERLEAVE_TYPE(double);   break;
        default:             vlc_assert_unreachable();
    }
#undef INTERLEAVE_TYPE
}

/**
 * Deinterleaves audio samples within a block of samples.
 * \param dst destination buffer for planar samples
 * \param src source buffer with interleaved samples
 * \param samples number of samples (per channel/per plane)
 * \param chans channels/planes count
 * \param fourcc sample format (must be a linear sample format)
 * \note The samples must be naturally aligned in memory.
 * \warning Destination and source buffers MUST NOT overlap.
 */
void aout_Deinterleave( void *restrict dst, const void *restrict src,
                      unsigned samples, unsigned chans, vlc_fourcc_t fourcc )
{
#define DEINTERLEAVE_TYPE(type) \
do { \
    type *d = dst; \
    const type *s = src; \
    for( size_t i = 0; i < chans; i++ ) { \
        for( size_t j = 0, k = 0; j < samples; j++, k += chans ) \
            *(d++) = s[k]; \
        s++; \
    } \
} while(0)

    switch( fourcc )
    {
        case VLC_CODEC_U8:   DEINTERLEAVE_TYPE(uint8_t);  break;
        case VLC_CODEC_S16N: DEINTERLEAVE_TYPE(int16_t);  break;
        case VLC_CODEC_FL32: DEINTERLEAVE_TYPE(float);    break;
        case VLC_CODEC_S32N: DEINTERLEAVE_TYPE(int32_t);  break;
        case VLC_CODEC_FL64: DEINTERLEAVE_TYPE(double);   break;
        default:             vlc_assert_unreachable();
    }
#undef DEINTERLEAVE_TYPE
}

/*****************************************************************************
 * aout_ChannelExtract:
 *****************************************************************************/
static inline void ExtractChannel( uint8_t *pi_dst, int i_dst_channels,
                                   const uint8_t *pi_src, int i_src_channels,
                                   int i_sample_count,
                                   const int *pi_selection, int i_bytes )
{
    for( int i = 0; i < i_sample_count; i++ )
    {
        for( int j = 0; j < i_dst_channels; j++ )
            memcpy( &pi_dst[j * i_bytes], &pi_src[pi_selection[j] * i_bytes], i_bytes );
        pi_dst += i_dst_channels * i_bytes;
        pi_src += i_src_channels * i_bytes;
    }
}

void aout_ChannelExtract( void *p_dst, int i_dst_channels,
                          const void *p_src, int i_src_channels,
                          int i_sample_count, const int *pi_selection, int i_bits_per_sample )
{
    /* It does not work in place */
    assert( p_dst != p_src );

    /* Force the compiler to inline for the specific cases so it can optimize */
    if( i_bits_per_sample == 8 )
        ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 1 );
    else  if( i_bits_per_sample == 16 )
        ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 2 );
    else  if( i_bits_per_sample == 32 )
        ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 4 );
    else  if( i_bits_per_sample == 64 )
        ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 8 );
}

bool aout_CheckChannelExtraction( int *pi_selection,
                                  uint32_t *pi_layout, int *pi_channels,
                                  const uint32_t pi_order_dst[AOUT_CHAN_MAX],
                                  const uint32_t *pi_order_src, int i_channels )
{
    static_assert(AOUT_CHAN_MAX <= (sizeof (*pi_order_dst) * CHAR_BIT),
                  "Missing bits");

    uint32_t i_layout = 0;
    int i_out = 0;
    int pi_index[AOUT_CHAN_MAX];

    /* */
    if( !pi_order_dst )
        pi_order_dst = pi_vlc_chan_order_wg4;

    /* */
    for( int i = 0; i < i_channels; i++ )
    {
        /* Ignore unknown or duplicated channels or not present in output */
        if( !pi_order_src[i] || (i_layout & pi_order_src[i]) )
            continue;

        for( int j = 0; j < AOUT_CHAN_MAX; j++ )
        {
            if( pi_order_dst[j] == pi_order_src[i] )
            {
                assert( i_out < AOUT_CHAN_MAX );
                pi_index[i_out++] = i;
                i_layout |= pi_order_src[i];
                break;
            }
        }
    }

    /* */
    for( int i = 0, j = 0; i < AOUT_CHAN_MAX; i++ )
    {
        for( int k = 0; k < i_out; k++ )
        {
            if( pi_order_dst[i] == pi_order_src[pi_index[k]] )
            {
                pi_selection[j++] = pi_index[k];
                break;
            }
        }
    }

    *pi_layout = i_layout;
    *pi_channels = i_out;

    for( int i = 0; i < i_out; i++ )
    {
        if( pi_selection[i] != i )
            return true;
    }
    return i_out != i_channels;
}

/* Return the order in which filters should be inserted */
static int FilterOrder( const char *psz_name )
{
    static const struct {
        const char psz_name[10];
        int        i_order;
    } filter[] = {
        { "equalizer",  0 },
    };
    for( unsigned i = 0; i < ARRAY_SIZE(filter); i++ )
    {
        if( !strcmp( filter[i].psz_name, psz_name ) )
            return filter[i].i_order;
    }
    return INT_MAX;
}

int aout_EnableFilter( audio_output_t *p_aout, const char *psz_name, bool b_add )
{
    if( *psz_name == '\0' )
        return VLC_EGENERIC;

    const char *psz_variable = "audio-filter";
    char *psz_list;
    psz_list = var_GetString( p_aout, psz_variable );

    /* Split the string into an array of filters */
    int i_count = 1;
    for( char *p = psz_list; p && *p; p++ )
        i_count += *p == ':';
    i_count += b_add;

    const char **ppsz_filter = calloc( i_count, sizeof(*ppsz_filter) );
    if( !ppsz_filter )
    {
        free( psz_list );
        return VLC_ENOMEM;
    }
    bool b_present = false;
    i_count = 0;
    for( char *p = psz_list; p && *p; )
    {
        char *psz_end = strchr(p, ':');
        if( psz_end )
            *psz_end++ = '\0';
        else
            psz_end = p + strlen(p);
        if( *p )
        {
            b_present |= !strcmp( p, psz_name );
            ppsz_filter[i_count++] = p;
        }
        p = psz_end;
    }
    if( b_present == b_add )
    {
        free( ppsz_filter );
        free( psz_list );
        return VLC_EGENERIC;
    }

    if( b_add )
    {
        int i_order = FilterOrder( psz_name );
        int i;
        for( i = 0; i < i_count; i++ )
        {
            if( FilterOrder( ppsz_filter[i] ) > i_order )
                break;
        }
        if( i < i_count )
            memmove( &ppsz_filter[i+1], &ppsz_filter[i], (i_count - i) * sizeof(*ppsz_filter) );
        ppsz_filter[i] = psz_name;
        i_count++;
    }
    else
    {
        for( int i = 0; i < i_count; i++ )
        {
            if( !strcmp( ppsz_filter[i], psz_name ) )
                ppsz_filter[i] = "";
        }
    }
    size_t i_length = 0;
    for( int i = 0; i < i_count; i++ )
        i_length += 1 + strlen( ppsz_filter[i] );

    char *psz_new = malloc( i_length + 1 );

    if( unlikely( !psz_new ) )
    {
        free( ppsz_filter );
        free( psz_list );
        return VLC_ENOMEM;
    }

    *psz_new = '\0';
    for( int i = 0; i < i_count; i++ )
    {
        if( *ppsz_filter[i] == '\0' )
            continue;
        if( *psz_new )
            strcat( psz_new, ":" );
        strcat( psz_new, ppsz_filter[i] );
    }
    free( ppsz_filter );
    free( psz_list );

    var_SetString( p_aout, psz_variable, psz_new );
    free( psz_new );

    return VLC_SUCCESS;
}

Coverage Report

Created: 2025-11-09 06:39

Line	Count	Source
1		/*****************************************************************************
2		* common.c : audio output management of common data structures
3		*****************************************************************************
4		* Copyright (C) 2002-2007 VLC authors and VideoLAN
5		*
6		* Authors: Christophe Massiot <massiot@via.ecp.fr>
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		#ifdef HAVE_CONFIG_H
24		# include "config.h"
25		#endif
26
27		#include <limits.h>
28		#include <assert.h>
29
30		#include <vlc_common.h>
31		#include <vlc_aout.h>
32		#include "aout_internal.h"
33
34		/*
35		* Formats management (internal and external)
36		*/
37
38		/*****************************************************************************
39		* aout_BitsPerSample : get the number of bits per sample
40		*****************************************************************************/
41		unsigned int aout_BitsPerSample( vlc_fourcc_t i_format )
42	2.22M	{
43	2.22M	switch( vlc_fourcc_GetCodec( AUDIO_ES, i_format ) )
44	2.22M	{
45	1.05M	case VLC_CODEC_U8:
46	1.05M	case VLC_CODEC_S8:
47	1.05M	case VLC_CODEC_ALAW:
48	1.05M	case VLC_CODEC_MULAW:
49	1.05M	return 8;
50
51	0	case VLC_CODEC_U16L:
52	1.14M	case VLC_CODEC_S16L:
53	1.14M	case VLC_CODEC_U16B:
54	1.15M	case VLC_CODEC_S16B:
55	1.15M	return 16;
56
57	0	case VLC_CODEC_U24L:
58	3.71k	case VLC_CODEC_S24L:
59	3.71k	case VLC_CODEC_U24B:
60	4.26k	case VLC_CODEC_S24B:
61	4.26k	return 24;
62
63	0	case VLC_CODEC_S24L32:
64	0	case VLC_CODEC_S24B32:
65	0	case VLC_CODEC_U32L:
66	0	case VLC_CODEC_U32B:
67	4.36k	case VLC_CODEC_S32L:
68	7.22k	case VLC_CODEC_S32B:
69	14.1k	case VLC_CODEC_F32L:
70	15.3k	case VLC_CODEC_F32B:
71	15.3k	return 32;
72
73	156	case VLC_CODEC_F64L:
74	278	case VLC_CODEC_F64B:
75	278	return 64;
76
77	4.52k	default:
78		/* For these formats the caller has to indicate the parameters
79		* by hand. */
80	4.52k	return 0;
81	2.22M	}
82	2.22M	}
83
84		/*****************************************************************************
85		* aout_FormatPrepare : compute the number of bytes per frame & frame length
86		*****************************************************************************/
87		void aout_FormatPrepare( audio_sample_format_t * p_format )
88	1.98M	{
89
90	1.98M	unsigned i_channels = aout_FormatNbChannels( p_format );
91	1.98M	if( i_channels > 0 )
92	1.86M	p_format->i_channels = i_channels;
93	1.98M	p_format->i_bitspersample = aout_BitsPerSample( p_format->i_format );
94	1.98M	if( p_format->i_bitspersample > 0 )
95	1.98M	{
96	1.98M	p_format->i_bytes_per_frame = ( p_format->i_bitspersample / 8 )
97	1.98M	* p_format->i_channels;
98	1.98M	p_format->i_frame_length = 1;
99	1.98M	}
100	1.98M	}
101
102		/*****************************************************************************
103		* aout_FormatPrintChannels : print a channel in a human-readable form
104		*****************************************************************************/
105		const char * aout_FormatPrintChannels( const audio_sample_format_t * p_format )
106	0	{
107	0	if (p_format->channel_type == AUDIO_CHANNEL_TYPE_AMBISONICS)
108	0	return "Ambisonics";
109
110		/* AUDIO_CHANNEL_TYPE_BITMAP */
111	0	switch ( p_format->i_physical_channels )
112	0	{
113	0	case AOUT_CHAN_LEFT:
114	0	case AOUT_CHAN_RIGHT:
115	0	case AOUT_CHAN_CENTER:
116	0	if ( (p_format->i_physical_channels & AOUT_CHAN_CENTER)
117	0	\|\| (p_format->i_physical_channels
118	0	& (AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT)) )
119	0	return "Mono";
120	0	else if ( p_format->i_physical_channels & AOUT_CHAN_LEFT )
121	0	return "Left";
122	0	return "Right";
123	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT:
124	0	if ( p_format->i_chan_mode & AOUT_CHANMODE_DOLBYSTEREO )
125	0	return "Dolby";
126	0	else if ( p_format->i_chan_mode & AOUT_CHANMODE_DUALMONO )
127	0	return "Dual-mono";
128	0	else if ( p_format->i_physical_channels == AOUT_CHAN_CENTER )
129	0	return "Stereo/Mono";
130	0	else if ( !(p_format->i_physical_channels & AOUT_CHAN_RIGHT) )
131	0	return "Stereo/Left";
132	0	else if ( !(p_format->i_physical_channels & AOUT_CHAN_LEFT) )
133	0	return "Stereo/Right";
134	0	return "Stereo";
135	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT \| AOUT_CHAN_CENTER:
136	0	return "3F";
137	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT \| AOUT_CHAN_REARCENTER:
138	0	return "2F1R";
139	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT \| AOUT_CHAN_CENTER
140	0	\| AOUT_CHAN_REARCENTER:
141	0	return "3F1R";
142	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT
143	0	\| AOUT_CHAN_REARLEFT \| AOUT_CHAN_REARRIGHT:
144	0	return "2F2R";
145	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT
146	0	\| AOUT_CHAN_MIDDLELEFT \| AOUT_CHAN_MIDDLERIGHT:
147	0	return "2F2M";
148	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT \| AOUT_CHAN_CENTER
149	0	\| AOUT_CHAN_REARLEFT \| AOUT_CHAN_REARRIGHT:
150	0	return "3F2R";
151	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT \| AOUT_CHAN_CENTER
152	0	\| AOUT_CHAN_MIDDLELEFT \| AOUT_CHAN_MIDDLERIGHT:
153	0	return "3F2M";
154
155	0	case AOUT_CHAN_CENTER \| AOUT_CHAN_LFE:
156	0	if ( (p_format->i_physical_channels & AOUT_CHAN_CENTER)
157	0	\|\| (p_format->i_physical_channels
158	0	& (AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT)) )
159	0	return "Mono/LFE";
160	0	else if ( p_format->i_physical_channels & AOUT_CHAN_LEFT )
161	0	return "Left/LFE";
162	0	return "Right/LFE";
163	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT \| AOUT_CHAN_LFE:
164	0	if ( p_format->i_chan_mode & AOUT_CHANMODE_DOLBYSTEREO )
165	0	return "Dolby/LFE";
166	0	else if ( p_format->i_chan_mode & AOUT_CHANMODE_DUALMONO )
167	0	return "Dual-mono/LFE";
168	0	else if ( p_format->i_physical_channels == AOUT_CHAN_CENTER )
169	0	return "Mono/LFE";
170	0	else if ( !(p_format->i_physical_channels & AOUT_CHAN_RIGHT) )
171	0	return "Stereo/Left/LFE";
172	0	else if ( !(p_format->i_physical_channels & AOUT_CHAN_LEFT) )
173	0	return "Stereo/Right/LFE";
174	0	return "Stereo/LFE";
175	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT \| AOUT_CHAN_CENTER \| AOUT_CHAN_LFE:
176	0	return "3F/LFE";
177	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT \| AOUT_CHAN_REARCENTER
178	0	\| AOUT_CHAN_LFE:
179	0	return "2F1R/LFE";
180	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT \| AOUT_CHAN_CENTER
181	0	\| AOUT_CHAN_REARCENTER \| AOUT_CHAN_LFE:
182	0	return "3F1R/LFE";
183	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT
184	0	\| AOUT_CHAN_REARLEFT \| AOUT_CHAN_REARRIGHT \| AOUT_CHAN_LFE:
185	0	return "2F2R/LFE";
186	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT
187	0	\| AOUT_CHAN_MIDDLELEFT \| AOUT_CHAN_MIDDLERIGHT \| AOUT_CHAN_LFE:
188	0	return "2F2M/LFE";
189	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT \| AOUT_CHAN_CENTER
190	0	\| AOUT_CHAN_REARLEFT \| AOUT_CHAN_REARRIGHT \| AOUT_CHAN_LFE:
191	0	return "3F2R/LFE";
192	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT \| AOUT_CHAN_CENTER
193	0	\| AOUT_CHAN_REARLEFT \| AOUT_CHAN_REARRIGHT \| AOUT_CHAN_REARCENTER
194	0	\| AOUT_CHAN_LFE:
195	0	return "3F3R/LFE";
196	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT \| AOUT_CHAN_CENTER
197	0	\| AOUT_CHAN_MIDDLELEFT \| AOUT_CHAN_MIDDLERIGHT \| AOUT_CHAN_LFE:
198	0	return "3F2M/LFE";
199	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT
200	0	\| AOUT_CHAN_REARLEFT \| AOUT_CHAN_REARRIGHT \| AOUT_CHAN_MIDDLELEFT
201	0	\| AOUT_CHAN_MIDDLERIGHT:
202	0	return "2F2M2R";
203	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT \| AOUT_CHAN_CENTER
204	0	\| AOUT_CHAN_REARLEFT \| AOUT_CHAN_REARRIGHT \| AOUT_CHAN_MIDDLELEFT
205	0	\| AOUT_CHAN_MIDDLERIGHT:
206	0	return "3F2M2R";
207	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT \| AOUT_CHAN_CENTER
208	0	\| AOUT_CHAN_REARLEFT \| AOUT_CHAN_REARRIGHT \| AOUT_CHAN_MIDDLELEFT
209	0	\| AOUT_CHAN_MIDDLERIGHT \| AOUT_CHAN_LFE:
210	0	return "3F2M2R/LFE";
211	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT \| AOUT_CHAN_CENTER
212	0	\| AOUT_CHAN_REARCENTER \| AOUT_CHAN_MIDDLELEFT
213	0	\| AOUT_CHAN_MIDDLERIGHT \| AOUT_CHAN_LFE:
214	0	return "3F2M1R/LFE";
215	0	case AOUT_CHAN_LEFT \| AOUT_CHAN_RIGHT \| AOUT_CHAN_CENTER
216	0	\| AOUT_CHAN_REARLEFT \| AOUT_CHAN_REARRIGHT \| AOUT_CHAN_REARCENTER
217	0	\| AOUT_CHAN_MIDDLELEFT \| AOUT_CHAN_MIDDLERIGHT \| AOUT_CHAN_LFE:
218	0	return "3F2M3R/LFE";
219	0	}
220
221	0	return "Unknown-chan-mask";
222	0	}
223
224		#undef aout_FormatPrint
225		void aout_FormatPrint( vlc_object_t obj, const char psz_text,
226		const audio_sample_format_t *p_format )
227	0	{
228	0	msg_Dbg( obj, "%s '%4.4s' %d Hz %s frame=%u samples/%u bytes", psz_text,
229	0	(char *)&p_format->i_format, p_format->i_rate,
230	0	aout_FormatPrintChannels( p_format ),
231	0	p_format->i_frame_length, p_format->i_bytes_per_frame );
232	0	}
233
234		#undef aout_FormatsPrint
235		/**
236		* Prints two formats in a human-readable form
237		*/
238		void aout_FormatsPrint( vlc_object_t obj, const char psz_text,
239		const audio_sample_format_t * p_format1,
240		const audio_sample_format_t * p_format2 )
241	0	{
242	0	msg_Dbg( obj, "%s '%4.4s'->'%4.4s' %u Hz->%u Hz %s->%s",
243	0	psz_text,
244	0	(char )&p_format1->i_format, (char )&p_format2->i_format,
245	0	p_format1->i_rate, p_format2->i_rate,
246	0	aout_FormatPrintChannels( p_format1 ),
247	0	aout_FormatPrintChannels( p_format2 ) );
248	0	}
249
250		/*****************************************************************************
251		* aout_CheckChannelReorder : Check if we need to do some channel re-ordering
252		*****************************************************************************/
253		unsigned aout_CheckChannelReorder( const uint32_t *chans_in,
254		const uint32_t *chans_out,
255		uint32_t mask, uint8_t *restrict table )
256	20.8k	{
257	20.8k	static_assert(AOUT_CHAN_MAX <= (sizeof (mask) * CHAR_BIT), "Missing bits");
258
259	20.8k	unsigned channels = 0;
260
261	20.8k	if( chans_in == NULL )
262	1	chans_in = pi_vlc_chan_order_wg4;
263	20.8k	if( chans_out == NULL )
264	20.8k	chans_out = pi_vlc_chan_order_wg4;
265
266	122k	for( unsigned i = 0; chans_in[i]; i++ )
267	101k	{
268	101k	const uint32_t chan = chans_in[i];
269	101k	if( !(mask & chan) )
270	5.09k	continue;
271
272	96.6k	unsigned index = 0;
273	383k	for( unsigned j = 0; chan != chans_out[j]; j++ )
274	286k	if( mask & chans_out[j] )
275	207k	index++;
276
277	96.6k	table[channels++] = index;
278	96.6k	}
279
280	90.2k	for( unsigned i = 0; i < channels; i++ )
281	75.9k	if( table[i] != i )
282	6.53k	return channels;
283	14.3k	return 0;
284	20.8k	}
285
286		void aout_ChannelReorder( void *ptr, size_t bytes, uint8_t channels,
287		const uint8_t *restrict chans_table, vlc_fourcc_t fourcc )
288	2.63k	{
289	2.63k	if( unlikely(bytes == 0) )
290	0	return;
291
292	2.63k	assert( channels != 0 );
293
294		/* The audio formats supported in audio output are inlined. For other
295		* formats (used in demuxers and muxers), memcpy() is used to avoid
296		* breaking type punning. */
297	2.63k	#define REORDER_TYPE(type) \
298	1.80k	do { \
299	1.80k	const size_t frames = (bytes / sizeof (type)) / channels; \
300	1.80k	type *buf = ptr; \
301	1.80k	\
302	317k	for( size_t i = 0; i < frames; i++ ) \
303	315k	{ \
304	315k	type tmp[AOUT_CHAN_MAX]; \
305	315k	\
306	2.87M	for( size_t j = 0; j < channels; j++ ) \
307	2.56M	tmp[chans_table[j]] = buf[j]; \
308	315k	memcpy( buf, tmp, sizeof (type) * channels ); \
309	315k	buf += channels; \
310	315k	} \
311	1.80k	} while(0)
312
313	2.63k	if( likely(channels <= AOUT_CHAN_MAX) )
314	2.63k	{
315	2.63k	switch( fourcc )
316	2.63k	{
317	607	case VLC_CODEC_U8: REORDER_TYPE(uint8_t); return;
318	301	case VLC_CODEC_S16N: REORDER_TYPE(int16_t); return;
319	406	case VLC_CODEC_FL32: REORDER_TYPE(float); return;
320	266	case VLC_CODEC_S32N: REORDER_TYPE(int32_t); return;
321	223	case VLC_CODEC_FL64: REORDER_TYPE(double); return;
322	2.63k	}
323	2.63k	}
324
325	835	unsigned size = aout_BitsPerSample( fourcc ) / 8;
326	835	assert( size != 0 && size <= 8 );
327
328	835	const size_t frames = bytes / (size * channels);
329	835	unsigned char *buf = ptr;
330
331	2.08k	for( size_t i = 0; i < frames; i++ )
332	1.24k	{
333	1.24k	unsigned char tmp[256 * 8];
334
335	7.86k	for( size_t j = 0; j < channels; j++ )
336	6.61k	memcpy( tmp + size * chans_table[j], buf + size * j, size );
337	1.24k	memcpy( buf, tmp, size * channels );
338	1.24k	buf += size * channels;
339	1.24k	}
340	835	}
341
342		/**
343		* Interleaves audio samples within a block of samples.
344		* \param dst destination buffer for interleaved samples
345		* \param srcv source buffers (one per plane) of uninterleaved samples
346		* \param samples number of samples (per channel/per plane)
347		* \param chans channels/planes count
348		* \param fourcc sample format (must be a linear sample format)
349		* \note The samples must be naturally aligned in memory.
350		* \warning Destination and source buffers MUST NOT overlap.
351		*/
352		void aout_Interleave( void restrict dst, const void const *srcv,
353		unsigned samples, unsigned chans, vlc_fourcc_t fourcc )
354	0	{
355	0	#define INTERLEAVE_TYPE(type) \
356	0	do { \
357	0	type *d = dst; \
358	0	for( size_t i = 0; i < chans; i++ ) { \
359	0	const type *s = srcv[i]; \
360	0	for( size_t j = 0, k = 0; j < samples; j++, k += chans ) \
361	0	d[k] = *(s++); \
362	0	d++; \
363	0	} \
364	0	} while(0)
365
366	0	switch( fourcc )
367	0	{
368	0	case VLC_CODEC_U8: INTERLEAVE_TYPE(uint8_t); break;
369	0	case VLC_CODEC_S16N: INTERLEAVE_TYPE(int16_t); break;
370	0	case VLC_CODEC_FL32: INTERLEAVE_TYPE(float); break;
371	0	case VLC_CODEC_S32N: INTERLEAVE_TYPE(int32_t); break;
372	0	case VLC_CODEC_FL64: INTERLEAVE_TYPE(double); break;
373	0	default: vlc_assert_unreachable();
374	0	}
375	0	#undef INTERLEAVE_TYPE
376	0	}
377
378		/**
379		* Deinterleaves audio samples within a block of samples.
380		* \param dst destination buffer for planar samples
381		* \param src source buffer with interleaved samples
382		* \param samples number of samples (per channel/per plane)
383		* \param chans channels/planes count
384		* \param fourcc sample format (must be a linear sample format)
385		* \note The samples must be naturally aligned in memory.
386		* \warning Destination and source buffers MUST NOT overlap.
387		*/
388		void aout_Deinterleave( void restrict dst, const void restrict src,
389		unsigned samples, unsigned chans, vlc_fourcc_t fourcc )
390	0	{
391	0	#define DEINTERLEAVE_TYPE(type) \
392	0	do { \
393	0	type *d = dst; \
394	0	const type *s = src; \
395	0	for( size_t i = 0; i < chans; i++ ) { \
396	0	for( size_t j = 0, k = 0; j < samples; j++, k += chans ) \
397	0	*(d++) = s[k]; \
398	0	s++; \
399	0	} \
400	0	} while(0)
401
402	0	switch( fourcc )
403	0	{
404	0	case VLC_CODEC_U8: DEINTERLEAVE_TYPE(uint8_t); break;
405	0	case VLC_CODEC_S16N: DEINTERLEAVE_TYPE(int16_t); break;
406	0	case VLC_CODEC_FL32: DEINTERLEAVE_TYPE(float); break;
407	0	case VLC_CODEC_S32N: DEINTERLEAVE_TYPE(int32_t); break;
408	0	case VLC_CODEC_FL64: DEINTERLEAVE_TYPE(double); break;
409	0	default: vlc_assert_unreachable();
410	0	}
411	0	#undef DEINTERLEAVE_TYPE
412	0	}
413
414		/*****************************************************************************
415		* aout_ChannelExtract:
416		*****************************************************************************/
417		static inline void ExtractChannel( uint8_t *pi_dst, int i_dst_channels,
418		const uint8_t *pi_src, int i_src_channels,
419		int i_sample_count,
420		const int *pi_selection, int i_bytes )
421	0	{
422	0	for( int i = 0; i < i_sample_count; i++ )
423	0	{
424	0	for( int j = 0; j < i_dst_channels; j++ )
425	0	memcpy( &pi_dst[j * i_bytes], &pi_src[pi_selection[j] * i_bytes], i_bytes );
426	0	pi_dst += i_dst_channels * i_bytes;
427	0	pi_src += i_src_channels * i_bytes;
428	0	}
429	0	}
430
431		void aout_ChannelExtract( void *p_dst, int i_dst_channels,
432		const void *p_src, int i_src_channels,
433		int i_sample_count, const int *pi_selection, int i_bits_per_sample )
434	0	{
435		/* It does not work in place */
436	0	assert( p_dst != p_src );
437
438		/* Force the compiler to inline for the specific cases so it can optimize */
439	0	if( i_bits_per_sample == 8 )
440	0	ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 1 );
441	0	else if( i_bits_per_sample == 16 )
442	0	ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 2 );
443	0	else if( i_bits_per_sample == 32 )
444	0	ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 4 );
445	0	else if( i_bits_per_sample == 64 )
446	0	ExtractChannel( p_dst, i_dst_channels, p_src, i_src_channels, i_sample_count, pi_selection, 8 );
447	0	}
448
449		bool aout_CheckChannelExtraction( int *pi_selection,
450		uint32_t pi_layout, int pi_channels,
451		const uint32_t pi_order_dst[AOUT_CHAN_MAX],
452		const uint32_t *pi_order_src, int i_channels )
453	0	{
454	0	static_assert(AOUT_CHAN_MAX <= (sizeof (pi_order_dst) CHAR_BIT),
455	0	"Missing bits");
456
457	0	uint32_t i_layout = 0;
458	0	int i_out = 0;
459	0	int pi_index[AOUT_CHAN_MAX];
460
461		/* */
462	0	if( !pi_order_dst )
463	0	pi_order_dst = pi_vlc_chan_order_wg4;
464
465		/* */
466	0	for( int i = 0; i < i_channels; i++ )
467	0	{
468		/* Ignore unknown or duplicated channels or not present in output */
469	0	if( !pi_order_src[i] \|\| (i_layout & pi_order_src[i]) )
470	0	continue;
471
472	0	for( int j = 0; j < AOUT_CHAN_MAX; j++ )
473	0	{
474	0	if( pi_order_dst[j] == pi_order_src[i] )
475	0	{
476	0	assert( i_out < AOUT_CHAN_MAX );
477	0	pi_index[i_out++] = i;
478	0	i_layout \|= pi_order_src[i];
479	0	break;
480	0	}
481	0	}
482	0	}
483
484		/* */
485	0	for( int i = 0, j = 0; i < AOUT_CHAN_MAX; i++ )
486	0	{
487	0	for( int k = 0; k < i_out; k++ )
488	0	{
489	0	if( pi_order_dst[i] == pi_order_src[pi_index[k]] )
490	0	{
491	0	pi_selection[j++] = pi_index[k];
492	0	break;
493	0	}
494	0	}
495	0	}
496
497	0	*pi_layout = i_layout;
498	0	*pi_channels = i_out;
499
500	0	for( int i = 0; i < i_out; i++ )
501	0	{
502	0	if( pi_selection[i] != i )
503	0	return true;
504	0	}
505	0	return i_out != i_channels;
506	0	}
507
508		/* Return the order in which filters should be inserted */
509		static int FilterOrder( const char *psz_name )
510	0	{
511	0	static const struct {
512	0	const char psz_name[10];
513	0	int i_order;
514	0	} filter[] = {
515	0	{ "equalizer", 0 },
516	0	};
517	0	for( unsigned i = 0; i < ARRAY_SIZE(filter); i++ )
518	0	{
519	0	if( !strcmp( filter[i].psz_name, psz_name ) )
520	0	return filter[i].i_order;
521	0	}
522	0	return INT_MAX;
523	0	}
524
525		int aout_EnableFilter( audio_output_t p_aout, const char psz_name, bool b_add )
526	0	{
527	0	if( *psz_name == '\0' )
528	0	return VLC_EGENERIC;
529
530	0	const char *psz_variable = "audio-filter";
531	0	char *psz_list;
532	0	psz_list = var_GetString( p_aout, psz_variable );
533
534		/* Split the string into an array of filters */
535	0	int i_count = 1;
536	0	for( char p = psz_list; p && p; p++ )
537	0	i_count += *p == ':';
538	0	i_count += b_add;
539
540	0	const char *ppsz_filter = calloc( i_count, sizeof(ppsz_filter) );
541	0	if( !ppsz_filter )
542	0	{
543	0	free( psz_list );
544	0	return VLC_ENOMEM;
545	0	}
546	0	bool b_present = false;
547	0	i_count = 0;
548	0	for( char p = psz_list; p && p; )
549	0	{
550	0	char *psz_end = strchr(p, ':');
551	0	if( psz_end )
552	0	*psz_end++ = '\0';
553	0	else
554	0	psz_end = p + strlen(p);
555	0	if( *p )
556	0	{
557	0	b_present \|= !strcmp( p, psz_name );
558	0	ppsz_filter[i_count++] = p;
559	0	}
560	0	p = psz_end;
561	0	}
562	0	if( b_present == b_add )
563	0	{
564	0	free( ppsz_filter );
565	0	free( psz_list );
566	0	return VLC_EGENERIC;
567	0	}
568
569	0	if( b_add )
570	0	{
571	0	int i_order = FilterOrder( psz_name );
572	0	int i;
573	0	for( i = 0; i < i_count; i++ )
574	0	{
575	0	if( FilterOrder( ppsz_filter[i] ) > i_order )
576	0	break;
577	0	}
578	0	if( i < i_count )
579	0	memmove( &ppsz_filter[i+1], &ppsz_filter[i], (i_count - i) * sizeof(*ppsz_filter) );
580	0	ppsz_filter[i] = psz_name;
581	0	i_count++;
582	0	}
583	0	else
584	0	{
585	0	for( int i = 0; i < i_count; i++ )
586	0	{
587	0	if( !strcmp( ppsz_filter[i], psz_name ) )
588	0	ppsz_filter[i] = "";
589	0	}
590	0	}
591	0	size_t i_length = 0;
592	0	for( int i = 0; i < i_count; i++ )
593	0	i_length += 1 + strlen( ppsz_filter[i] );
594
595	0	char *psz_new = malloc( i_length + 1 );
596
597	0	if( unlikely( !psz_new ) )
598	0	{
599	0	free( ppsz_filter );
600	0	free( psz_list );
601	0	return VLC_ENOMEM;
602	0	}
603
604	0	*psz_new = '\0';
605	0	for( int i = 0; i < i_count; i++ )
606	0	{
607	0	if( *ppsz_filter[i] == '\0' )
608	0	continue;
609	0	if( *psz_new )
610	0	strcat( psz_new, ":" );
611	0	strcat( psz_new, ppsz_filter[i] );
612	0	}
613	0	free( ppsz_filter );
614	0	free( psz_list );
615
616	0	var_SetString( p_aout, psz_variable, psz_new );
617	0	free( psz_new );
618
619	0	return VLC_SUCCESS;
620	0	}