stream_output.c

/*****************************************************************************
 * stream_output.c : stream output module
 *****************************************************************************
 * Copyright (C) 2002-2004 VideoLAN
 * $Id$
 *
 * Authors: Christophe Massiot <massiot@via.ecp.fr>
 *          Laurent Aimar <fenrir@via.ecp.fr>
 *          Eric Petit <titer@videolan.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/
#include <stdlib.h>                                                /* free() */
#include <stdio.h>                                              /* sprintf() */
#include <string.h>                                            /* strerror() */

#include <vlc/vlc.h>
#include <vlc/sout.h>

#include "vlc_meta.h"

#undef DEBUG_BUFFER
/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static void sout_CfgDestroy( sout_cfg_t * );

#define sout_stream_url_to_chain( p, s ) \
    _sout_stream_url_to_chain( VLC_OBJECT(p), s )
static char *_sout_stream_url_to_chain( vlc_object_t *, char * );

/*
 * Generic MRL parser
 *
 */

typedef struct
{
    char *psz_access;
    char *psz_way;
    char *psz_name;
} mrl_t;

/* mrl_Parse: parse psz_mrl and fill p_mrl */
static int  mrl_Parse( mrl_t *p_mrl, char *psz_mrl );
/* mrl_Clean: clean p_mrl  after a call to mrl_Parse */
static void mrl_Clean( mrl_t *p_mrl );

#define FREE( p ) if( p ) { free( p ); (p) = NULL; }

/*****************************************************************************
 * sout_NewInstance: creates a new stream output instance
 *****************************************************************************/
sout_instance_t *__sout_NewInstance( vlc_object_t *p_parent, char * psz_dest )
{
    sout_instance_t *p_sout;
    vlc_value_t keep;

    if( var_Get( p_parent, "sout-keep", &keep ) < 0 )
    {
        msg_Warn( p_parent, "cannot get sout-keep value" );
        keep.b_bool = VLC_FALSE;
    }
    else if( keep.b_bool )
    {
        msg_Warn( p_parent, "sout-keep true" );
        if( ( p_sout = vlc_object_find( p_parent, VLC_OBJECT_SOUT,
                                        FIND_ANYWHERE ) ) )
        {
            if( !strcmp( p_sout->psz_sout, psz_dest ) )
            {
                msg_Warn( p_parent, "sout keep : reusing sout" );
                msg_Warn( p_parent, "sout keep : you probably want to use "
                          "gather stream_out" );
                vlc_object_detach( p_sout );
                vlc_object_attach( p_sout, p_parent );
                vlc_object_release( p_sout );
                return p_sout;
            }
            else
            {
                msg_Warn( p_parent, "sout keep : destroying unusable sout" );
                sout_DeleteInstance( p_sout );
            }
        }
    }
    else if( !keep.b_bool )
    {
        while( ( p_sout = vlc_object_find( p_parent, VLC_OBJECT_SOUT,
                                           FIND_PARENT ) ) )
        {
            msg_Warn( p_parent, "sout keep : destroying old sout" );
            sout_DeleteInstance( p_sout );
        }
    }

    /* *** Allocate descriptor *** */
    p_sout = vlc_object_create( p_parent, VLC_OBJECT_SOUT );
    if( p_sout == NULL )
    {
        msg_Err( p_parent, "out of memory" );
        return NULL;
    }

    /* *** init descriptor *** */
    p_sout->psz_sout    = strdup( psz_dest );
    p_sout->p_meta      = NULL;
    p_sout->i_out_pace_nocontrol = 0;
    p_sout->p_sys       = NULL;

    vlc_mutex_init( p_sout, &p_sout->lock );
    if( psz_dest && psz_dest[0] == '#' )
    {
        p_sout->psz_chain = strdup( &psz_dest[1] );
    }
    else
    {
        p_sout->psz_chain = sout_stream_url_to_chain( p_sout, psz_dest );
        msg_Dbg( p_sout, "using sout chain=`%s'", p_sout->psz_chain );
    }
    p_sout->p_stream = NULL;

    /* attach it for inherit */
    vlc_object_attach( p_sout, p_parent );

    p_sout->p_stream = sout_StreamNew( p_sout, p_sout->psz_chain );

    if( p_sout->p_stream == NULL )
    {
        msg_Err( p_sout, "stream chained failed for `%s'", p_sout->psz_chain );

        FREE( p_sout->psz_sout );
        FREE( p_sout->psz_chain );

        vlc_object_detach( p_sout );
        vlc_object_destroy( p_sout );
        return NULL;
    }

    return p_sout;
}
/*****************************************************************************
 * sout_DeleteInstance: delete a previously allocated instance
 *****************************************************************************/
void sout_DeleteInstance( sout_instance_t * p_sout )
{
    /* Unlink object */
    vlc_object_detach( p_sout );

    /* remove the stream out chain */
    sout_StreamDelete( p_sout->p_stream );

    /* *** free all string *** */
    FREE( p_sout->psz_sout );
    FREE( p_sout->psz_chain );

    /* delete meta */
    if( p_sout->p_meta )
    {
        vlc_meta_Delete( p_sout->p_meta );
    }

    vlc_mutex_destroy( &p_sout->lock );

    /* *** free structure *** */
    vlc_object_destroy( p_sout );
}

/*****************************************************************************
 * Packetizer/Input
 *****************************************************************************/
sout_packetizer_input_t *sout_InputNew( sout_instance_t *p_sout,
                                        es_format_t *p_fmt )
{
    sout_packetizer_input_t *p_input;

    msg_Dbg( p_sout, "adding a new input" );

    /* *** create a packetizer input *** */
    p_input         = malloc( sizeof( sout_packetizer_input_t ) );
    p_input->p_sout = p_sout;
    p_input->p_fmt  = p_fmt;

    if( p_fmt->i_codec == VLC_FOURCC( 'n', 'u', 'l', 'l' ) )
    {
        vlc_object_release( p_sout );
        return p_input;
    }

    /* *** add it to the stream chain */
    vlc_mutex_lock( &p_sout->lock );
    p_input->id = p_sout->p_stream->pf_add( p_sout->p_stream, p_fmt );
    vlc_mutex_unlock( &p_sout->lock );

    if( p_input->id == NULL )
    {
        free( p_input );
        return NULL;
    }

    return( p_input );
}

/*****************************************************************************
 *
 *****************************************************************************/
int sout_InputDelete( sout_packetizer_input_t *p_input )
{
    sout_instance_t     *p_sout = p_input->p_sout;

    msg_Dbg( p_sout, "removing an input" );

    if( p_input->p_fmt->i_codec != VLC_FOURCC( 'n', 'u', 'l', 'l' ) )
    {
        vlc_mutex_lock( &p_sout->lock );
        p_sout->p_stream->pf_del( p_sout->p_stream, p_input->id );
        vlc_mutex_unlock( &p_sout->lock );
    }

    free( p_input );

    return( VLC_SUCCESS);
}

/*****************************************************************************
 *
 *****************************************************************************/
int sout_InputSendBuffer( sout_packetizer_input_t *p_input,
                          block_t *p_buffer )
{
    sout_instance_t     *p_sout = p_input->p_sout;
    int                 i_ret;

    if( p_input->p_fmt->i_codec == VLC_FOURCC( 'n', 'u', 'l', 'l' ) )
    {
        block_Release( p_buffer );
        return VLC_SUCCESS;
    }
    if( p_buffer->i_dts <= 0 )
    {
        msg_Warn( p_sout, "trying to send non-dated packet to stream output!");
        block_Release( p_buffer );
        return VLC_SUCCESS;
    }

    vlc_mutex_lock( &p_sout->lock );
    i_ret = p_sout->p_stream->pf_send( p_sout->p_stream,
                                       p_input->id, p_buffer );
    vlc_mutex_unlock( &p_sout->lock );

    return i_ret;
}

/*****************************************************************************
 * sout_AccessOutNew: allocate a new access out
 *****************************************************************************/
sout_access_out_t *sout_AccessOutNew( sout_instance_t *p_sout,
                                      char *psz_access, char *psz_name )
{
    sout_access_out_t *p_access;
    char              *psz_next;

    if( !( p_access = vlc_object_create( p_sout,
                                         sizeof( sout_access_out_t ) ) ) )
    {
        msg_Err( p_sout, "out of memory" );
        return NULL;
    }

    psz_next = sout_CfgCreate( &p_access->psz_access, &p_access->p_cfg,
                                psz_access );
    if( psz_next )
    {
        free( psz_next );
    }
    p_access->psz_name   = strdup( psz_name ? psz_name : "" );
    p_access->p_sout     = p_sout;
    p_access->p_sys = NULL;
    p_access->pf_seek    = NULL;
    p_access->pf_read    = NULL;
    p_access->pf_write   = NULL;
    p_access->p_module   = NULL;
    vlc_object_attach( p_access, p_sout );

    p_access->p_module   =
        module_Need( p_access, "sout access", p_access->psz_access, VLC_TRUE );

    if( !p_access->p_module )
    {
        free( p_access->psz_access );
        free( p_access->psz_name );
        vlc_object_detach( p_access );
        vlc_object_destroy( p_access );
        return( NULL );
    }

    return p_access;
}
/*****************************************************************************
 * sout_AccessDelete: delete an access out
 *****************************************************************************/
void sout_AccessOutDelete( sout_access_out_t *p_access )
{
    vlc_object_detach( p_access );
    if( p_access->p_module )
    {
        module_Unneed( p_access, p_access->p_module );
    }
    free( p_access->psz_access );

    sout_CfgDestroy( p_access->p_cfg );

    free( p_access->psz_name );

    vlc_object_destroy( p_access );
}

/*****************************************************************************
 * sout_AccessSeek:
 *****************************************************************************/
int sout_AccessOutSeek( sout_access_out_t *p_access, off_t i_pos )
{
    return p_access->pf_seek( p_access, i_pos );
}

/*****************************************************************************
 * sout_AccessRead:
 *****************************************************************************/
int sout_AccessOutRead( sout_access_out_t *p_access, block_t *p_buffer )
{
    return( p_access->pf_read ?
            p_access->pf_read( p_access, p_buffer ) : VLC_EGENERIC );
}

/*****************************************************************************
 * sout_AccessWrite:
 *****************************************************************************/
int sout_AccessOutWrite( sout_access_out_t *p_access, block_t *p_buffer )
{
    return p_access->pf_write( p_access, p_buffer );
}

/*****************************************************************************
 * sout_MuxNew: create a new mux
 *****************************************************************************/
sout_mux_t * sout_MuxNew( sout_instance_t *p_sout, char *psz_mux,
                          sout_access_out_t *p_access )
{
    sout_mux_t *p_mux;
    char       *psz_next;

    p_mux = vlc_object_create( p_sout, sizeof( sout_mux_t ) );
    if( p_mux == NULL )
    {
        msg_Err( p_sout, "out of memory" );
        return NULL;
    }

    p_mux->p_sout = p_sout;
    psz_next = sout_CfgCreate( &p_mux->psz_mux, &p_mux->p_cfg, psz_mux );
    if( psz_next ) free( psz_next );

    p_mux->p_access     = p_access;
    p_mux->pf_control   = NULL;
    p_mux->pf_addstream = NULL;
    p_mux->pf_delstream = NULL;
    p_mux->pf_mux       = NULL;
    p_mux->i_nb_inputs  = 0;
    p_mux->pp_inputs    = NULL;

    p_mux->p_sys        = NULL;
    p_mux->p_module     = NULL;

    p_mux->b_add_stream_any_time = VLC_FALSE;
    p_mux->b_waiting_stream = VLC_TRUE;
    p_mux->i_add_stream_start = -1;

    vlc_object_attach( p_mux, p_sout );

    p_mux->p_module =
        module_Need( p_mux, "sout mux", p_mux->psz_mux, VLC_TRUE );

    if( p_mux->p_module == NULL )
    {
        FREE( p_mux->psz_mux );

        vlc_object_detach( p_mux );
        vlc_object_destroy( p_mux );
        return NULL;
    }

    /* *** probe mux capacity *** */
    if( p_mux->pf_control )
    {
        int b_answer = VLC_FALSE;

        if( sout_MuxControl( p_mux, MUX_CAN_ADD_STREAM_WHILE_MUXING,
                             &b_answer ) )
        {
            b_answer = VLC_FALSE;
        }

        if( b_answer )
        {
            msg_Dbg( p_sout, "muxer support adding stream at any time" );
            p_mux->b_add_stream_any_time = VLC_TRUE;
            p_mux->b_waiting_stream = VLC_FALSE;

            /* If we control the output pace then it's better to wait before
             * starting muxing (generates better streams/files). */
            if( !p_sout->i_out_pace_nocontrol )
            {
                b_answer = VLC_TRUE;
            }
            else if( sout_MuxControl( p_mux, MUX_GET_ADD_STREAM_WAIT,
                                      &b_answer ) )
            {
                b_answer = VLC_FALSE;
            }

            if( b_answer )
            {
                msg_Dbg( p_sout, "muxer prefers waiting for all ES before "
                         "starting muxing" );
                p_mux->b_waiting_stream = VLC_TRUE;
            }
        }
    }

    return p_mux;
}

/*****************************************************************************
 * sout_MuxDelete:
 *****************************************************************************/
void sout_MuxDelete( sout_mux_t *p_mux )
{
    vlc_object_detach( p_mux );
    if( p_mux->p_module )
    {
        module_Unneed( p_mux, p_mux->p_module );
    }
    free( p_mux->psz_mux );

    sout_CfgDestroy( p_mux->p_cfg );

    vlc_object_destroy( p_mux );
}

/*****************************************************************************
 * sout_MuxAddStream:
 *****************************************************************************/
sout_input_t *sout_MuxAddStream( sout_mux_t *p_mux, es_format_t *p_fmt )
{
    sout_input_t *p_input;

    if( !p_mux->b_add_stream_any_time && !p_mux->b_waiting_stream )
    {
        msg_Err( p_mux, "cannot add a new stream (unsuported while muxing "
                        "for this format)" );
        return NULL;
    }

    msg_Dbg( p_mux, "adding a new input" );

    /* create a new sout input */
    p_input = malloc( sizeof( sout_input_t ) );
    p_input->p_sout = p_mux->p_sout;
    p_input->p_fmt  = p_fmt;
    p_input->p_fifo = block_FifoNew( p_mux->p_sout );
    p_input->p_sys  = NULL;

    TAB_APPEND( p_mux->i_nb_inputs, p_mux->pp_inputs, p_input );
    if( p_mux->pf_addstream( p_mux, p_input ) < 0 )
    {
            msg_Err( p_mux, "cannot add this stream" );
            TAB_REMOVE( p_mux->i_nb_inputs, p_mux->pp_inputs, p_input );
            block_FifoRelease( p_input->p_fifo );
            free( p_input );
            return NULL;
    }

    return p_input;
}

/*****************************************************************************
 * sout_MuxDeleteStream:
 *****************************************************************************/
void sout_MuxDeleteStream( sout_mux_t *p_mux, sout_input_t *p_input )
{
    int i_index;

    if( p_mux->b_waiting_stream && p_input->p_fifo->i_depth > 0 )
    {
        /* We stop waiting, and call the muxer for taking care of the data
         * before we remove this es */
        p_mux->b_waiting_stream = VLC_FALSE;
        p_mux->pf_mux( p_mux );
    }

    TAB_FIND( p_mux->i_nb_inputs, p_mux->pp_inputs, p_input, i_index );
    if( i_index >= 0 )
    {
        if( p_mux->pf_delstream( p_mux, p_input ) < 0 )
        {
            msg_Err( p_mux, "cannot del this stream from mux" );
        }

        /* remove the entry */
        TAB_REMOVE( p_mux->i_nb_inputs, p_mux->pp_inputs, p_input );

        if( p_mux->i_nb_inputs == 0 )
        {
            msg_Warn( p_mux, "no more input stream for this mux" );
        }

        block_FifoRelease( p_input->p_fifo );
        free( p_input );
    }
}

/*****************************************************************************
 * sout_MuxSendBuffer:
 *****************************************************************************/
void sout_MuxSendBuffer( sout_mux_t *p_mux, sout_input_t *p_input,
                         block_t *p_buffer )
{
    block_FifoPut( p_input->p_fifo, p_buffer );

    if( p_mux->b_waiting_stream )
    {
        if( p_mux->i_add_stream_start < 0 )
        {
            p_mux->i_add_stream_start = p_buffer->i_dts;
        }

        if( p_mux->i_add_stream_start >= 0 &&
            p_mux->i_add_stream_start + I64C(1500000) < p_buffer->i_dts )
        {
            /* Wait until we have more than 1.5 seconds worth of data
             * before start muxing */
            p_mux->b_waiting_stream = VLC_FALSE;
        }
        else
        {
            return;
        }
    }
    p_mux->pf_mux( p_mux );
}

/*****************************************************************************
 *
 *****************************************************************************/
static int mrl_Parse( mrl_t *p_mrl, char *psz_mrl )
{
    char * psz_dup = strdup( psz_mrl );
    char * psz_parser = psz_dup;
    char * psz_access = "";
    char * psz_way = "";
    char * psz_name = "";

    /* *** first parse psz_dest */
    while( *psz_parser && *psz_parser != ':' )
    {
        if( *psz_parser == '{' )
        {
            while( *psz_parser && *psz_parser != '}' )
            {
                psz_parser++;
            }
            if( *psz_parser )
            {
                psz_parser++;
            }
        }
        else
        {
            psz_parser++;
        }
    }
#if defined( WIN32 ) || defined( UNDER_CE )
    if( psz_parser - psz_dup == 1 )
    {
        /* msg_Warn( p_sout, "drive letter %c: found in source string",
                          *psz_dup ) ; */
        psz_parser = "";
    }
#endif

    if( !*psz_parser )
    {
        psz_access = psz_way = "";
        psz_name = psz_dup;
    }
    else
    {
        *psz_parser++ = '\0';

        /* let's skip '//' */
        if( psz_parser[0] == '/' && psz_parser[1] == '/' )
        {
            psz_parser += 2 ;
        }

        psz_name = psz_parser ;

        /* Come back to parse the access and mux plug-ins */
        psz_parser = psz_dup;

        if( !*psz_parser )
        {
            /* No access */
            psz_access = "";
        }
        else if( *psz_parser == '/' )
        {
            /* No access */
            psz_access = "";
            psz_parser++;
        }
        else
        {
            psz_access = psz_parser;

            while( *psz_parser && *psz_parser != '/' )
            {
                if( *psz_parser == '{' )
                {
                    while( *psz_parser && *psz_parser != '}' )
                    {
                        psz_parser++;
                    }
                    if( *psz_parser )
                    {
                        psz_parser++;
                    }
                }
                else
                {
                    psz_parser++;
                }
            }

            if( *psz_parser == '/' )
            {
                *psz_parser++ = '\0';
            }
        }

        if( !*psz_parser )
        {
            /* No mux */
            psz_way = "";
        }
        else
        {
            psz_way = psz_parser;
        }
    }

    p_mrl->psz_access = strdup( psz_access );
    p_mrl->psz_way    = strdup( psz_way );
    p_mrl->psz_name   = strdup( psz_name );

    free( psz_dup );
    return( VLC_SUCCESS );
}


/* mrl_Clean: clean p_mrl  after a call to mrl_Parse */
static void mrl_Clean( mrl_t *p_mrl )
{
    FREE( p_mrl->psz_access );
    FREE( p_mrl->psz_way );
    FREE( p_mrl->psz_name );
}


/****************************************************************************
 ****************************************************************************
 **
 **
 **
 ****************************************************************************
 ****************************************************************************/

/* create a complete chain */
/* chain format:
    module{option=*:option=*}[:module{option=*:...}]
 */

/*
 * parse module{options=str, option="str "}:
 *  return a pointer on the rest
 *  XXX: psz_chain is modified
 */
#define SKIPSPACE( p ) { while( *p && ( *p == ' ' || *p == '\t' ) ) p++; }
#define SKIPTRAILINGSPACE( p, e ) \
    { while( e > p && ( *(e-1) == ' ' || *(e-1) == '\t' ) ) e--; }

/* go accross " " and { } */
static char *_get_chain_end( char *str )
{
    char c, *p = str;

    SKIPSPACE( p );

    for( ;; )
    {
        if( !*p || *p == ',' || *p == '}' ) return p;

        if( *p != '{' && *p != '"' && *p != '\'' )
        {
            p++;
            continue;
        }

        if( *p == '{' ) c = '}';
        else c = *p;
        p++;

        for( ;; )
        {
            if( !*p ) return p;

            if( *p == c ) return ++p;
            else if( *p == '{' && c == '}' ) p = _get_chain_end( p );
            else p++;
        }
    }
}

char *sout_CfgCreate( char **ppsz_name, sout_cfg_t **pp_cfg, char *psz_chain )
{
    sout_cfg_t *p_cfg = NULL;
    char       *p = psz_chain;

    *ppsz_name = NULL;
    *pp_cfg    = NULL;

    if( !p ) return NULL;

    SKIPSPACE( p );

    while( *p && *p != '{' && *p != ':' && *p != ' ' && *p != '\t' ) p++;

    if( p == psz_chain ) return NULL;

    *ppsz_name = strndup( psz_chain, p - psz_chain );

    SKIPSPACE( p );

    if( *p == '{' )
    {
        char *psz_name;

        p++;

        for( ;; )
        {
            sout_cfg_t cfg;

            SKIPSPACE( p );

            psz_name = p;

            while( *p && *p != '=' && *p != ',' && *p != '{' && *p != '}' &&
                   *p != ' ' && *p != '\t' ) p++;

            /* fprintf( stderr, "name=%s - rest=%s\n", psz_name, p ); */
            if( p == psz_name )
            {
                fprintf( stderr, "invalid options (empty)" );
                break;
            }

            cfg.psz_name = strndup( psz_name, p - psz_name );

            SKIPSPACE( p );

            if( *p == '=' || *p == '{' )
            {
                char *end;
                vlc_bool_t b_keep_brackets = (*p == '{');

                if( *p == '=' ) p++;

                end = _get_chain_end( p );
                if( end <= p )
                {
                    cfg.psz_value = NULL;
                }
                else
                {
                    /* Skip heading and trailing spaces.
                     * This ain't necessary but will avoid simple
                     * user mistakes. */
                    SKIPSPACE( p );
                }

                if( end <= p )
                {
                    cfg.psz_value = NULL;
                }
                else
                {
                    if( *p == '\'' || *p == '"' ||
                        ( !b_keep_brackets && *p == '{' ) )
                    {
                        p++;

                        if( *(end-1) != '\'' && *(end-1) == '"' )
                            SKIPTRAILINGSPACE( p, end );

                        if( end - 1 <= p ) cfg.psz_value = NULL;
                        else cfg.psz_value = strndup( p, end -1 - p );
                    }
                    else
                    {
                        SKIPTRAILINGSPACE( p, end );
                        if( end <= p ) cfg.psz_value = NULL;
                        else cfg.psz_value = strndup( p, end - p );
                    }
                }

                p = end;
                SKIPSPACE( p );
            }
            else
            {
                cfg.psz_value = NULL;
            }

            cfg.p_next = NULL;
            if( p_cfg )
            {
                p_cfg->p_next = malloc( sizeof( sout_cfg_t ) );
                memcpy( p_cfg->p_next, &cfg, sizeof( sout_cfg_t ) );

                p_cfg = p_cfg->p_next;
            }
            else
            {
                p_cfg = malloc( sizeof( sout_cfg_t ) );
                memcpy( p_cfg, &cfg, sizeof( sout_cfg_t ) );

                *pp_cfg = p_cfg;
            }

            if( *p == ',' ) p++;

            if( *p == '}' )
            {
                p++;
                break;
            }
        }
    }

    if( *p == ':' ) return( strdup( p + 1 ) );

    return NULL;
}

static void sout_CfgDestroy( sout_cfg_t *p_cfg )
{
    while( p_cfg != NULL )
    {
        sout_cfg_t *p_next;

        p_next = p_cfg->p_next;

        FREE( p_cfg->psz_name );
        FREE( p_cfg->psz_value );
        free( p_cfg );

        p_cfg = p_next;
    }
}

void __sout_CfgParse( vlc_object_t *p_this, char *psz_prefix,
                      const char **ppsz_options, sout_cfg_t *cfg )
{
    char *psz_name;
    int  i_type;
    int  i;

    /* First, var_Create all variables */
    for( i = 0; ppsz_options[i] != NULL; i++ )
    {
        asprintf( &psz_name, "%s%s", psz_prefix,
                  *ppsz_options[i] == '*' ? &ppsz_options[i][1] : ppsz_options[i] );

        i_type = config_GetType( p_this, psz_name );

        var_Create( p_this, psz_name, i_type | VLC_VAR_DOINHERIT );
        free( psz_name );
    }

    /* Now parse options and set value */
    if( psz_prefix == NULL ) psz_prefix = "";

    while( cfg )
    {
        vlc_value_t val;
        vlc_bool_t b_yes = VLC_TRUE;
        vlc_bool_t b_once = VLC_FALSE;

        if( cfg->psz_name == NULL || *cfg->psz_name == '\0' )
        {
            cfg = cfg->p_next;
            continue;
        }
        for( i = 0; ppsz_options[i] != NULL; i++ )
        {
            if( !strcmp( ppsz_options[i], cfg->psz_name ) )
            {
                break;
            }
            if( ( !strncmp( cfg->psz_name, "no-", 3 ) &&
                  !strcmp( ppsz_options[i], cfg->psz_name + 3 ) ) ||
                ( !strncmp( cfg->psz_name, "no", 2 ) &&
                  !strcmp( ppsz_options[i], cfg->psz_name + 2 ) ) )
            {
                b_yes = VLC_FALSE;
                break;
            }

            if( *ppsz_options[i] == '*' &&
                !strcmp( &ppsz_options[i][1], cfg->psz_name ) )
            {
                b_once = VLC_TRUE;
                break;
            }

        }
        if( ppsz_options[i] == NULL )
        {
            msg_Warn( p_this, "option %s is unknown", cfg->psz_name );
            cfg = cfg->p_next;
            continue;
        }

        /* create name */
        asprintf( &psz_name, "%s%s", psz_prefix, b_once ? &ppsz_options[i][1] : ppsz_options[i] );

        /* get the type of the variable */
        i_type = config_GetType( p_this, psz_name );
        if( !i_type )
        {
            msg_Warn( p_this, "unknown option %s (value=%s)",
                      cfg->psz_name, cfg->psz_value );
            goto next;
        }
        if( i_type != VLC_VAR_BOOL && cfg->psz_value == NULL )
        {
            msg_Warn( p_this, "missing value for option %s", cfg->psz_name );
            goto next;
        }
        if( i_type != VLC_VAR_STRING && b_once )
        {
            msg_Warn( p_this, "*option_name need to be a string option" );
            goto next;
        }

        switch( i_type )
        {
            case VLC_VAR_BOOL:
                val.b_bool = b_yes;
                break;
            case VLC_VAR_INTEGER:
                val.i_int = strtol( cfg->psz_value ? cfg->psz_value : "0",
                                    NULL, 0 );
                break;
            case VLC_VAR_FLOAT:
                val.f_float = atof( cfg->psz_value ? cfg->psz_value : "0" );
                break;
            case VLC_VAR_STRING:
                val.psz_string = cfg->psz_value;
                break;
            default:
                msg_Warn( p_this, "unhandled config var type" );
                memset( &val, 0, sizeof( vlc_value_t ) );